The Whole PyGTK FAQ

Last changed on Thu Aug 10 11:52:51 2006 BRT

(Entries marked with ** were changed within the last 24 hours; entries marked with * were changed within the last 7 days.)

1. General information and availability

• 1.1. What is PyGTK?7
• 1.2. Where can I get PyGTK?8
• 1.3. How do I get the very latest PyGTK source code [from CVS]9
• 1.4. What is the password to change and add FAQ entries?10
• 1.5. How do I get support for PyGTK [mailing lists, IRC]?11
• 1.6. Eeek, I found a bug in PyGTK. Where do I report it?12
• 1.7. Where are the reference manuals?13
• 1.8. I need PyGTK/libglade compiled for [insert Unix OS here]!14
• 1.9. Are there any PyGTK tutorials available?15
• 1.10. I have multiple copies of python but pygtk only works with one of them!16
• 1.11. How do I extend PyGTK (or the art of wrapping)17
• 1.12. Where can I find the API documentation ?18
• 1.13. Where can I get gnome-python?19
• 1.14. How do I compile pygtk or gnome-python from CVS?20
• 1.15. How do I tell what version of PyGTK I'm running?21
• 1.16. I wrote a patch for PyGTK that fixes bug X, or implements feature Y, what do I do?22
• 1.17. How do I search Bugzilla for PyGTK bugs23
• 1.18. My programs configure says: No package 'pygtk-2.0' found24
• 1.19. Is there a PyGTK for MacOS X?25
• 1.20. Can I use PyGTK to build closed-source applications?26
• 1.21. Does PyGTK have timers?27

2. Changes from 1.2 to 1.3/2.0

• 2.1. How do I install PyGTK-2 and PyGTK-0 side by side in the same system?28
• 2.2. What are the major changes in PyGTK-2 for GTK+ 2.2?29
• 2.3. Is there a checklist of changes to migrate an application from PyGTK-0 to PyGTK-2?30
• 2.4. If I installed PyGTK-0 and PyGTK-2 in parallel (using pygtk.pth) how do I indicate which one my script should use?31
• 2.5. Which versions of PyGTK support parallel install using the pygtk.pth method?32
• 2.6. FAQ 2.4 sucks and doesn't work. Truthfuly, how do I require a specific version of PyGTK (or When do I need to use pygtk.require())?33
• 2.7. What happened to the GTK and GDK constants/symbols?34
• 2.8. For some users import libglade (or GDK) is working and for some users it's not35
• 2.9. FAQ 2.4, 2.6 and etc etc all suck. Python still doesn't find the version of pygtk I want.36
• 2.10. How do I get my 1.2 gladefiles to work with 2.0?37

3. Signal handling

• 3.1. When I connect to a signal, my handler gets called but reports "XXX takes no arguments (1 given)"38
• 3.2. How do I detect that a mouse or keyboard event has been triggered?39
• 3.3. I connected to some signals but nothing happens. Why?40
• 3.4. I've fiddled with the mask but nothing happened. Why?41
• 3.5. Which widgets are unable to receive events or be styled?42
• 3.6. I attach a callback to a signal, but I keep getting an error: "TypeError: object of type X is not callable"43
• 3.7. While my callback is executing, nothing is refreshed in the application windows!44
• 3.8. I want my callback to execute, but not the default callback (or, how to I stop GTK from doing the default action when doing X)?45
• 3.9. When creating a new signal, how do I define one of the signal arguments as Python data?46
• 3.10. How do I specify user data to a signal?47
• 3.11. How do signals and events propagate in GTK+?48
• 3.12. Why does handling expose events break drag-n-drop?49
• 3.13. How do I pass extra data to a signal handler?50
• 3.14. How to construct my own "fake" gtk.gdk.Event?51

4. Themes, fonts and styles

• 4.1. How do I change font properties on gtk.Labels and other widgets?52
• 4.2. Why don't my style changes apply only to the widget I requested it from?53
• 4.3. My user defined styles get overridden by the default theme!54
• 4.4. How do I change the background color of my application's dialog?55
• 4.5. How do I use the style object?56
• 4.6. How do I change the colour of a widget (or how do I get a GdkColor)?57
• 4.7. How do I get a Graphics Context, or GdkGC?58
• 4.8. How does the alloc() method to the GdkColormap work?59
• 4.9. How do I use pango instead of GdkFont for font handling in a GtkDrawingArea?60
• 4.10. How can I use Unicode (or other format) strings in my PyGTK application, or, why do I get a UTF-8 warning when using a string?61
• 4.11. How can I create a new pango context()62
• 4.12. How do I get antialiased fonts in GTK+?63
• 4.13. Does PyGTK support TrueType fonts?64
• 4.14. What units does pango use to define sizes and widths?65
• 4.15. Can I find out how long (wide) a string is in a certain font?66
• 4.16. How do I change the background and colour of an Editable (GtkEntry, GtkTextView and friends)?67
• 4.17. Why does FontSelection's set_font_name return False?68
• 4.18. How do I change GtkMenubar.shadow_type (or other style properties)?69
• 4.19. Can I pass strings of unicode instance to gtk or do I need to convert them to utf8?70

5. Basic Objects: GObject, GtkWidget and other critters

• 5.1. I want to understand this "data" object that is used in the set_*_data() and get_*_data() calls.71
• 5.2. How do I check if a widget is currently sensitive?72
• 5.3. Where is get_state() in PyGTK 0.6.x?73
• 5.4. How do I catch right-click, middle-click and double-click on my widget?74
• 5.5. How do I capture keypresses, and how do I perform a certain action depending on the key pressed?75
• 5.6. How do I change the cursor for a certain widget?76
• 5.7. How can I tell my program that the cursor should jump to a specific widget?77
• 5.8. What signal is triggered when I change a widget's sensitivity?78
• 5.9. How do I find out the size of a widget?79
• 5.10. How do I focus a widget? How do I focus it before its toplevel window is shown?80
• 5.11. My callback is getting a gtk.gdk.Event object, but I need an EventExpose!81
• 5.12. How do I check if a widget is mapped? And realized? And visible? [...]82
• 5.13. While calling get_property(), I get an "invalid property id" warning. Why?83
• 5.14. How can I discover what properties and signals a GObject supports?84
• 5.15. How do I access one of these properties in a GObject?85
• 5.16. What's the difference between a property and an attribute?86
• 5.17. Do I need to handle reference counting for GObjects? What about for other objects in PyGTK/gnome-python?87
• 5.18. Focusing a widget after when selecting an item from Treeview88
• 5.19. How can I listen to events from the scroll wheel on my mouse?89

6. Widget subclasses and user signals: GObject

• 6.1. What is the canonical reference on widget (and GObject) subclassing and property overriding?90
• 6.2. When subclassing a widget (or a GObject), why are the additional signals I define not usable?91
• 6.3. How do I wrap a GObject in Python?92
• 6.4. How can I draw on top of a subclassed widget?93
• 23.33. Using metaclasses in GObject subclasses.94

7. Labels: GtkLabel

• 7.1. How can I use mnemonics for my GtkLabel?95
• 7.2. Where is GtkLabel.get_text()?96
• 7.3. How do I make a GtkLabel font larger or bold?97
• 7.4. How do I left, center, right, top, bottom, middle align a GtkLabel?98
• 7.5. How do I change a Label's background color, or why doesn't my Label receive any signals?99
• 7.6. [pygtk2] How do I render a label in a button or menuitem with an underscore in its label?100
• 7.7. I set my labels to use_markup in glade-2. Why don't they markup the contents I set?101
• 7.8. How can I change the behavoir of a label without using pango markup?102

8. Images: GtkImage, GtkPixmap, GdkPixbuf

• 8.1. How do I load a pixmap from a file into my application UI?103
• 8.2. What about loading other image formats besides XPM, like JPEG or PNG?104
• 8.3. How do I convert a Numeric array to a Pixbuf object?105
• 8.4. Is there a resource leak? Why do I run out of memory using Pixbuf?106
• 8.5. How do I to display an image from data (using a drawable or Image widget)?107
• 8.6. How do I resize a gtk.Image?108
• 8.7. What if I want to add a PIL image to a drawable?109
• 8.8. Does somebody know what all these image/pixmap classes are?110
• 8.9. How do I flip an image horizontally or vertically?111
• 8.10. Is it possible to use SVG icons and images in PyGTK?112
• 8.11. How do I get a Pixbuf of a stock icon?113
• 8.12. How do I register stock icons from an image file?114
• 8.13. How can I use an image as background in a gtk.Window?115
• 8.14. How do I convert a pixbuf to a PIL Image?116
• 8.15. How can I get the data of a gtk.Image and save it in an external file?117
• 8.16. How to show data that I already own from outside, in a gtk.Image?118
• 8.17. How to make a colorful image grayscale without using PIL?119
• 8.18. How blend (composite) two images together?120
• 8.19. How can I make a stock icon the default icon?121 *

9. Buttons: GtkButtons

• 9.1. How does one group radio buttons to allow only one concurrent button to be depressed?122
• 9.2. How do I create buttons that contain a pixmap?123
• 9.3. PyGTK 0.6.x: The stock pixmap buttons in glade, but they don't show in my buttons? (pygtk0.x)124
• 9.4. Why is a handler connected to a GtkRadioButton being called twice?125
• 9.5. How do I render a stock button with a different label?126
• 9.6. How do I add tooltips to a ToolButton in a Toolbar?127
• 9.7. How do I add a stock icon to a ToggleButton?128

10. Windows: GtkWindows and GtkDialogs

• 10.1. How do I get a GdkWindow from a GtkWindow?129
• 10.2. Where are GtkDialogFlags defined?130
• 10.3. How do I get my windows to show up where I want?131
• 10.4. How do I make a dialog block the whole application, so the user is forced to answer it?132
• 10.5. I click on the close button (X) to close my gtk.Window. It disappears, but the program seems to hang!133
• 10.6. How do I avoid having my gtk.Window instance destroyed when I click on the window's close button? (or, When I redisplay my window, all my child widgets are missing and I get a bunch of Gtk-Critical errors!)134
• 10.7. How do I change the window manager's icon for a PyGTK Window?135
• 10.8. How do I get the GtkWindow's title?136
• 10.9. How do I change the buttons on a MessageDialog?137
• 10.10. How do I adjust a ScrolledWindow to adjust to a given child widget?138
• 10.11. How do GtkDialogs work?139
• 10.12. How do I make ENTER in an entry box activate the OK signal140
• 10.13. When closing the GnomeAbout box (or other GtkDialog subclasses), I get crashes and weird callback behaviour. What up with that?141
• 10.14. I created a modal dialog, but clicking on the main window covers it!142
• 10.15. How do I get the position of my window in absolute terms (IOW, relative to the root X window)143
• 10.16. How do I start up a window maximized?144
• 10.17. How do I run a dialog without running another main loop?145
• 10.18. Changing a Window's background color146
• 10.19. How do I get XID for a GtkWindow? And for the root window?147
• 10.20. How can I make my window appear in the center of the screen?148
• 10.21. How to hide a window when clicking the close button (instead of destroying it)149
• 10.22. How can I find out when my GtkWindow is minimized?150
• 10.23. How can I find out if a gtk.Window is visible?151

11. Menus: Gtk*Menu and Gtk*MenuItem GtkToolbar

• 11.1. How do I turn off tearoff menus in libglade?152
• 11.2. How do I pop up a menu with a button click?153
• 11.3. How do I find out if a GtkCheckMenuItem is selected (active)?154
• 11.4. I create a menubar with ItemFactory, but it disappears155
• 11.5. When specifying items to an ItemFactory, I pass the extra argument for the image but I can't see anything!156
• 11.6. How do I specify and save accelerators for my menu?157
• 11.7. How to i put a custom icon and custom label in a gtk.ImageMenuItem158

12. Simple Containers: GtkBoxes, GtkTable, GtkFixed, GtkAlignment

• 12.1. What are the parameters to GtkAlignment.set()159
• 12.2. How does packing work (or how do I get my widget to stay the size I want)160

13. Lists and Trees: GtkList/TreeView

• 13.1. Is there a nice tutorial on using GtkTreeView and GtkTreeModel?161
• 13.2. How do the TreeStore and ListStore sequence APIs behave? [PyGTK2]162
• 13.3. How do GtkTreePaths work? [PyGTK2]163
• 13.4. How do I define columns for a TreeView using TreeViewColumn?164
• 13.5. How do I create my own custom TreeModel.165
• 13.6. How do I put icons in a TreeView?166
• 13.7. How do I get all the selections in my TreeView.167
• 13.8. How do I delete the selected rows in a TreeView?168
• 13.9. Is there a way to mass-specify columns in ListStore?169
• 13.10. How do I make a GtkTreeView with editable cells?170
• 13.11. What signal is emitted when a user selects/clicks on a row in a GtkTreeView?171
• 13.12. How do I change the color of the alternate row shading on the TreeView widget?172
• 13.13. How do I create a lazy TreeView?173
• 13.14. How do I show different images when a TreeView item is expanded and collapsed.174
• 13.15. My TreeView/TreeModel rows represent instances (or any python object), but how can I keep track of them?175
• 13.16. My Treeview shows all my strings/text values as numbers in the columns!176
• 13.17. How do I make a popup menu appear when I right-click my TreeView?177
• 13.18. Is it possible for a TreeModel to tell a CellRendererToggle that it is in an "in between" (inconsistent) state?178
• 13.19. How do I change alignment on a specific cell renderer?179
• 13.20. How do I keep GenericTreeModel from leaking references?180
• 13.21. How do I get changes in my TreeModel to show up in my TreeView?181
• 13.22. How do I display a combo box in a Treeview?182
• 13.23. Why doesn't expand_row() display an expanded row for paths longer than one element?183
• 13.24. How do I transform the value in my model before displaying it in the TreeView?184
• 13.25. How do I delete multiple selections?185
• 13.26. How do I perform an action when the user clicks on the title column of a TreeView?186
• 13.27. How do I run a command for each TreeModel row, or how does TreeModel.foreach() work?187
• 13.28. When connecting to 'row-inserted', my model value is always None. Why?188
• 13.29. How do I use a python object to store data for all the columns in a row?189
• 13.30. How do I move rows around in a GtkTreeView?190
• 13.31. How do I change the color of a row or column of a TreeView?191
• 13.32. How do I select [or edit] a row in my TreeView?192
• 13.33. How do I handle DnD operations in a GtkTreeView?193
• 13.34. How do I work with the reorderable() property of GtkTreeview?/The reorderable() property of GtkTreeView is too limited194
• 13.35. How do I use the TreeModelFilter to process tree/store data automatically?195
• 13.36. How do I unselect a path in a TreeView?196
• 13.37. How do I avoid displaying (hide) a certain column in a TreeView?197
• 13.38. How do I display pixbufs instead of numbers for integer or boolean values in my treemodel?198
• 13.39. I defined a TreeView in glade, how do I manipulate its columns and other properties?199
• 13.40. How do I change the font of a CellRendererText?200
• 13.41. How do I show a GtkImage (even animations) in a treeview? (subclassing GtkCellRenderer)201
• 13.42. How do I show a picture (image) in a treeview background or exist any way how to set treeview (and window with treeview) as transparency ?202
• 13.43. Are there tips for improving performance when adding many rows to a Treeview?203
• 13.44. What is TreeRowReference and how to use it?204
• 13.45. How do I create a custom gtk.CellRenderer?205

14. Editables: GtkEntry, GtkCombo, GtkText, GtkSpinButton, GtkTextView

• 14.1. How do I make a GtkEntry exactly 5 characters long?206
• 14.2. What is a GtkTextIter, and how do I get one for position X (and other positions)?207
• 14.3. How do I change the cursor for a GtkEntry?208
• 14.4. Why does GtkText's insert_text generate critical messages complaining "assertion `index <= TEXT_LENGTH (text)' failed."?209
• 14.5. I want to change the text being typed into an entry or textbox, but the original text is also inserted!210
• 14.6. Why does the second parameter to insert_text (the `text' parameter) contain garbage?211
• 14.7. Why isn't GtkText.insert_defaults() generating the signal insert_text212
• 14.8. How do I get the currently selected text in a GtkCombo?213
• 14.9. How do I programatically set the max value for a GtkSpinButton?214
• 14.10. How do I scroll a TextView to display the text being inserted?215
• 14.11. How do I insert colored text into a TextView?216
• 14.12. How can I make GtkTextView to always show the last line217
• 14.13. How do I add items into GtkCombo218
• 14.14. How can get back the strings that I set using Combo.set_popdown_strings()219
• 14.15. How do I change the mouse cursor on a TextView (or how do I get the "right" GdkWindow from a TextView)?220
• 14.16. Is there a signal sent when a user hits enter in an editable?221
• 14.17. What X clipboard do TextView's context menu items use?222
• 14.18. How do I get the clipboard functions to work properly?223
• 14.19. I'm getting a Gtk-CRITICAL messsage: assertion `g_utf8_validate (text, len, NULL)' failed [using insert_*]224
• 14.20. How do I write clipboard callbacks for multiple widgets?225
• 14.21. How do I right-align text in an Entry?226
• 14.22. How do I create a mask or validator for a GtkEntry?227
• 14.23. How do I send the output of an external process to a gtk.TextView without freezing the GUI?228
• 14.24. How do I add completion support for an entry?229
• 14.25. How can I place a background image on a TextView widget?230
• 14.26. The text in the TextView is not aligned! Any ideas?231

16. GtkOptionMenu, GtkComboBox, GtkComboBoxEntry

• 16.1. Why doesn't the GtkOptionMenu work like a real listbox?232
• 16.2. Let's say I accept it as it is. How do I implement one using pygtk?233
• 16.3. If I set the OptionMenu's state to insensitive, and i call set_history() on it, and put it back to sensitive, the previously selected menuitem still looks insensitive!234
• 16.4. How do I find out which is the selected item in a GtkOptionMenu?235
• 16.5. What signal is emitted when an optionmenu's item is selected?236
• 16.6. How do I get the label of an OptionMenu's item?237
• 16.7. How do I get the text from the selected item in GtkComboBox/ComboBoxEntry238
• 16.8. How do I populate a ComboBox or ComboBoxEntry with strings?239

17. GtkNoteBook

• 17.1. How do I get a reference to the page my GtkNotebook just switched to (or, what is the deal with the second argument to GtkNotebook's switch_page handler)?240
• 17.2. How do I make one toolbar button (e.g. an Add button) call a different function for each notebook tab?241
• 17.3. How do I create a popup menu on a notebook tab and figure out which tab a click comes from242

18. GtkDrawingArea

• 18.1. How do I make a gray-scale gradient picture?243
• 18.2. When I place a DrawingArea inside a ScrolledWindow the event object in callbacks has X and Y coordinates off by a few pixels!244
• 18.3. How do I set line attributes for draw_line() and draw_lines()?245
• 18.4. How do I draw dashed or dotted lines in a GtkDrawingArea?246
• 18.5. What's the essential approach to tracking mouse events in a GtkDrawingArea?247
• 18.6. How do I get scrollbars to work with a DrawingArea?248
• 18.7. How do I make my DrawingArea have the same background used in other widgets?249
• 18.8. What basic pattern should I follow when using a DrawingArea?250
• 18.9. How to set a tiled background pixmap on gnomecanvas.Canvas? Or, how do set custom background on gnomecanvas.Canvas?251

19. Other widgets

• 19.1. Are there any HTML rendering widgets for PyGTK?252
• 19.2. What about HTML widgets for PyGTK2?253
• 19.3. GnomeIconList's get_icon_data() method doesn't work!254
• 19.4. Can I do plots or charts with PyGTK?255
• 19.5. How do I get the current color from a gnome ColorPicker?256
• 19.6. Is there a syntax highlighting widget for PyGTK?257
• 19.7. When displaying a GnomeAbout box, it doesn't display the program name or version.258
• 19.8. How do I pass extra arguments to a Gnome Applet's setup_menu() callback?259
• 19.9. In creating a Gnome Applet, how do I use class members for callbacks?260
• 19.10. How do I hide the toolbar of a gnome.ui.App() instance?261
• 19.11. Can I use OpenGL to draw in a PyGTK application?262
• 19.12. Is there support for tray notification area clients?263
• 19.13. How do I a signal a callback when a gtk.Paned widget handle is dragged?264
• 19.14. Is there a grid or spreadsheet-like widget available?265
• 19.15. How do I embed something using Plugs and Sockets?266
• 19.16. How can I use the IconView widget?267
• 19.17. How can I distribute gtkhtml2 (outside of gnomepythonextras)?268
• 19.18. Why does gtkmozembed somtimes crash in load_url()?269

20. The GTK Mainloop and Threading

• 20.1. What are the general tips for using threads with PyGTK?270
• 20.2. On Win32, the input_add() function doesn't work!271
• 20.3. How can I make Ctrl-C in the console quit my app which uses PyGTK 1.99.13 or older?272
• 20.4. I get random crashing when using lots of threads in PyGTK273
• 20.5. I want to show a splash screen and make it disappear. How?274
• 20.6. I am using a separate thread to run my code, but the application (or the UI) hangs.275
• 20.7. I set up a timeout handler using timeout_add, but the handler only runs once.276
• 20.8. How do I check if threading was compiled in my version of PyGTK277
• 20.9. I don't want to use threading. What other options do I have?278
• 20.10. When an exception is raised, it is printed out to standard error! (or how do I get exceptions to be printed to X or displayed in a window?)279
• 20.11. How can I monitor sockets or files inside the gtk mainloop (or how does gtk.input_add() work)?280
• 20.12. How do I get an action to run periodically, say, every 30 seconds?281
• 20.13. The GTK thread dies, but some windows remain open. I don't want that, what can I do?282
• 20.14. My application uses threads and GtkDialogs seem to freeze it! What can I do?283
• 20.15. I'm using threads and timeout or idle or input handlers and the app freezes. What's wrong?284
• 20.16. So how do I use gobject.io_add_watch (used to be input_add) ?285
• 20.17. Why isn't my thread running?286
• 20.18. How do I write a qt application using gobject.MainLoop?287
• 20.19. What does "Fatal Python error: GC object already tracked" mean?288

21. Win32 and PyGTK

• 21.1. How do I get PyGTK running on MS Windows?289
• 21.2. Is there a walkthrough on getting PyGTK2 and libglade2 to work on win32290
• 21.3. Does the Win32 port support threading?291
• 21.4. Where is GdkImlib for MS Windows?292
• 21.5. How can I bundle a PyGTK program in windows so my users don't need to install Python or the GTK+ libs?293
• 21.6. How do I change the Window icon of a Win32 PyGTK app?294
• 21.7. How do I make the my PyGTK app look a bit more like a `normal' Windows app?295
• 21.8. How do I compile PyGTK for win32296
• 21.9. How do I find out the GTK+ installation path on windows?297
• 21.10. DLL Errors after upgrading to PyGTK-2.0.0.win32-py2.3298
• 21.11. Is it possible to have antialiased fonts on Win32?299
• 21.12. How do themes work on win32?300
• 21.13. Can PyGTK have the native filechooser of Windows?301

22. libglade

• 22.1. How do I use PyGTK and glade together (using libglade)?302
• 22.2. How do I internationalize a PyGTK and libglade program?303
• 22.3. Why doesn't gettext work on my libglade UIs with Python <= 2.2?304
• 22.4. I'm using libglade, but what do I do with the signals and handlers I set in the glade file?305
• 22.5. I'm using Gnome and libglade, but some widgets don't work properly.306
• 22.6. When I invoke GladeXML() or glade.XML() all the widgets in my gladefile are displayed!307
• 22.7. How do I create and use a custom Glade widget?308
• 22.8. How do I retrieve the ID of a signal connection made by signal_autoconnect?309
• 22.9. My libglade files have widgets that don't show up in the GladeXML tree!310
• 22.10. When I load a glade file in GladeXML I get evil warnings about GnomeApp and a crash!311
• 22.11. How do I produce or reuse a [portion of a] widget tree in glade?312
• 22.12. How can I get a new instance of a widget defined in a glade file?313
• 22.13. Tabs in Notebook don't show up!314

23. Miscellaneous questions

• 23.1. Why does ancient PyGTK versions segfault with Python 2.2?315
• 23.2. Are there any helpful tools when developing with PyGTK?316
• 23.3. How do I find out the current X and Y position of my mouse?317
• 23.4. Are there any tips for UI designers?318
• 23.5. Why does my X selection disappear when my window dies?319
• 23.6. When compiling PyGTK, I get a bunch of weird "Could not write method ..." messages!320
• 23.7. Is there a way to get version information from pygtk?321
• 23.8. How do I beep the speaker?322
• 23.9. Is there a way to grab the keyboard from X (like XGrabKey())?323
• 23.10. When wrapping a widget into a new Python extension, I get undefined symbols on importing it!324
• 23.11. Does VTK support PyGTK?325
• 23.12. How do I create a GdkRectangle?326
• 23.13. When I create a gnome Druid, the first and last page are blank.327
• 23.14. I disable text or graphics on my GtkToolbar, or the time in my GnomeDateTime, and they still show up, or, why is show_all() considered harmful?328
• 23.15. I'm writing a C extension that uses PyGTK. How do I acess a PyGTK object's C counterparts and vice-versa?329
• 23.16. How do I change the font and colour of some GnomePrint text?330
• 23.17. Is there a way to query for the current screen size?331
• 23.18. When dragging and dropping, Netscape/Firefox/etc and gedit/native gtk apps don't behave the same. Why?332
• 23.19. What do you see as the flaws in the Minimalist Programme?333
• 23.20. How do I update a progress bar and do some work at the same time334
• 23.21. How can I package my gnome-python application using autotools?335
• 23.22. How can I extend PyGTK using gtkmm/C++ ?336
• 23.23. How do I debug a PyGTK application without an interactive session?337
• 23.24. Can GTK know the mouse position outside of GTK Application?338
• 23.25. Is widget.set_property('visible', False) the same as widget.hide() ?339
• 23.26. How do I change window properties involving atom values?340
• 23.27. How do I port a GObject/Glib based C application to PyGTK?341
• 23.28. How can I distribute gtkspell, trayicon (eg. modules that do not depend on gnome) so my application will take advantage of those but the user won't have to install gnome-python-extras?342
• 23.29. How do I configure emacs to be used with pygtk?343
• 23.30. Q_() is not available in my pygtk app. How to use Qualified translatable strings?344
• 23.31. How to get the path to the file(s)/folder(s) that was dropped (by drag 'n' drop) in my application? [using selection.data]345
• 23.32. How to get coordinates relative to X11 for a widget that has no window of it's own?346
• 23.34. How can I use gtk.binding_entry_add (and why it's better than keypress in most cases)347
• 23.35. How can you set the tab / tabbing order?348
• 23.36. How do I acquire a screenshot of the whole screen?349
• 23.37. How do I create a throbber like the one in Firefox?350
• 23.38. How can I access data returned with a gpointer?351

24. Deprecated List Widgets: GtkList, GtkCList, GtkCTree and others

• 24.1. My GtkCList rows represent instances, but how can I keep track of them?352
• 24.2. Why doesn't GtkCList's children() method return the lists rows?353
• 24.3. How do I access data that is in a GtkCList?354
• 24.4. How do I order the contents of a GtkCList according to the type of data in the columns (or, where is gtk_clist_set_compare_func)?355
• 24.5. How do I get the data out of a GtkCTree?356
• 24.6. How would I recurse through all nodes in a GtkCTree?357
• 24.7. How do I capture a right-click or double-click event on a GtkCList row?358
• 24.8. How do I find a row in a GtkCList that contains "X"?359
• 24.9. When entering data dynamically into my GtkCList or tree, it flickers like mad!360
• 24.10. How do I align a GtkCList's columns?361
• 24.11. How do I remove a row from a CList?362
• 24.12. How do I find out which row(s) are selected in the GtkCList?363
• 24.13. How do I colour the background of a GtkCList row?364
• 24.14. How do I find out what the current selection mode in the GtkCList is?365
• 24.15. How do I change the style of the white space between CList rows?366

1. General information and availability

1.1.367 What is PyGTK?

Python is an interpreted language with a very clean syntax, high-level data structures, dynamic typing, object oriented characteristics and generally acceptable performance. For more information on Python see [www.python.org]369

GTK+ is a graphical user interface toolkit, which includes user interface components (hereafter called by the usual name widgets) and a framework for handling events that are produced upon these components. For more information on GTK+ see [www.gtk.org]370

A binding is code (usually a library) that allows you to access functions that were coded in another language. In our case, GTK+ was written in C, and applications written in C can use native GTK+. For a Python program to be able to create applications using the GTK+ framework, a special library has to be used. This library is PyGTK.

Edit this entry371 / Log info372 / Last changed on Tue Oct 12 20:29:25 2004 by pachi (pachi-at-mmn-arquitectos-com)

1.2.373 Where can I get PyGTK?

That site's Downloads section has links to the proper sources for pygtk binaries and sourcecode. Anyhow, here there are some of those links:

Linux and Unix users can pick up the source code off the main site which is [ftp.gtk.org]375 .

• The latest source version released of the 2.0 branch (the "new" stable branch, based on GTK+ 2.0) is 2.0.0, which can be downloaded from [ftp.gtk.org]376

• The latest source version released of the 0.6 branch (the old stable branch based on GTK+ 1.2) is version 0.6.11, which can be downloaded from [ftp.gtk.org]377

• For coff coff Win32 PyGTK (yeah, it works on Microsoft Windows), see faq 21.1378

• For MacOS X, see FAQ 1.19379

• For gnome-python, see FAQ 1.13380

If you would like to obtain the CVS version of the current stable code, you can check it out from cvs.gnome.org, module gnome-python/pygtk and tag gtk-gnome-1-2. See the question 1.3 for more information on how to use CVS to pull pygtk.

PyGTK has a number of optional dependencies you must have installed before compiling if you want to use them. For PyGTK2:

• gtkglarea: [ftp.gnome.org]381
• libglade: [ftp.gnome.org]382

For PyGTK0.6:

• libglade: [ftp.gnome.org]383
• gtkglarea: [www.ece.ucdavis.edu]384
• imlib: [ftp.gnome.org]385
• gdk-pixbuf: [ftp.gnome.org]386

Edit this entry387 / Log info388 / Last changed on Tue Oct 12 20:13:39 2004 by pachi (pachi-at-mmn-arquitectos-com)

1.3.389 How do I get the very latest PyGTK source code [from CVS]

  :pserver:anonymous@anoncvs.gnome.org:/cvs/gnome

  cvs -d :pserver:anonymous@anoncvs.gnome.org:/cvs/gnome co -d pygtk gnome-python/pygtk

• the trunk GTK+- 2.8, and is on CVS HEAD.
• the 2.6 branch, called pygtk-2-6
• the 2.4 branch, called pygtk-2-4
• the 2.2 branch, called pygtk-2-2
• the 2.0 branch, called pygtk-2-0
• the 1.2 branch, (on which pygtk 0.x and gnome-python 1.4.x are based upon) is tagged with "gtk-gnome-1-2".

Please note that to use PyGTK you rely on recent code for GTK+ , GLib, atk, pango, Python 2.3. How recent exactly these dependencies need to be depends largely on the current target for the PyGTK development team. In general, CVS HEAD will use the latest CVS, but ask on the mailing list if problems arise.

Edit this entry391 / Log info392 / Last changed on Thu Aug 4 17:59:19 2005 by Johan Dahlin (johan-at-gnome-org)

1.4.393 What is the password to change and add FAQ entries?

We only use the password to allow a minimum of control over FAQ changes, and you are of course invited to help maintain it.

Edit this entry395 / Log info396 / Last changed on Sat Jul 20 13:40:50 2002 by Christian Reis (kiko-at-async-com-br)

1.5.397 How do I get support for PyGTK [mailing lists, IRC]?

The standard way to get some support is to join the PyGTK mailing list. You can sign up using a webform at [www.daa.com.au]399 The mailing list is searchable via Gmane: [news.gmane.org]400

We also run a channel for pygtk support on IRC. This channel is run on server irc.gnome.org and it's called #pygtk. Stop by and say hello once in a while.

If you want to check out existing bug reports for pygtk, you can use the query interface at [bugzilla.gnome.org]401 to query for bugs reported against the gnome-python module. I've added two links for easy queries here:

Open bugs (UNCONFIRMED, NEW or ASSIGNED): [bugzilla.gnome.org]402

All bugs ever reported: [bugzilla.gnome.org]403

Additional information and support is available from the Python GTK+/GNOME Wiki: [taoriver.net]404

Edit this entry405 / Log info406 / Last changed on Thu Oct 21 10:08:00 2004 by Christian Robottom Reis (kiko-at-async-com-br)

1.6.407 Eeek, I found a bug in PyGTK. Where do I report it?

a) Test against the latest CVS version of PyGTK, if you can. This helps catch errors that have already been fixed but haven't migrated into a release. Remember to test against the CVS branch you are using (0.6.x versus 1.99.x).

b) If you are unsure it's a bug, make a request discussing it on the mailing list, or present it to the IRC channel.

c) File a new bug on the pygtk product at GNOME Bugzilla [bugzilla.gnome.org]408 Remembering the bug number will help when referencing the bug through email. Bugs make remembering problems a lot easier by making sure problems are uniquely identified in a simple and focused way.

Remember, a great deal of help can be provided by a good bug report. Including a testcase will make fixing MUCH easier, and if that's impossible, listing the exact steps to reproduce will help too.

d) If you can, write some code to fix the bug and attach a patch in the unified diff format against current CVS (cvs diff -urNp will do the job) to the bug reported. After the patch has been reviewed and approved by someone on the PyGTK developer team, it can be checked in to CVS -- usually a member of the team will check it in for you if you don't have a CVS account on cvs.gnome.org. The next release will include the fix.

More information on bugzilla, the bug tracking tool GNOME uses, can be found in the Using Bugzilla section of the Bugzilla manual: [www.trilobyte.net]409

Edit this entry410 / Log info411 / Last changed on Thu Feb 12 17:46:46 2004 by Christian Reis (kiko-at-async-com-br)

1.7.412 Where are the reference manuals?

The last html version of that manual (and a tarball) is always linked in the documents section on [www.pygtk.org]414

That has been for long a recurrent question in the mailing list, which is this FAQ was originally created.

The most complete functional reference for the GTK+ and GDK libraries lives at [www.gtk.org]415 , and it covers the native C bindings. The mapping from the C API to Python is quite straightforward, and the reference is actually quite thorough.

The source code contains examples that are quite helpful (specially testgtk.py, which includes many widgets and features) in the examples/ directory. The gtk.py file itself is a worthy reference (praise to Python's readability there) and many times will solve a prototype, api or parameter question.

There are automatically generated docs for pygtk2 available at: [www.gnome.org]416 While not always up to date or complete, they give an overview of the classes involved.

pygtk2 additionally includes docstrings for many of the classes and methods available; it will probably become the definitive reference material as it is easier to be kept up to date.

Edit this entry417 / Log info418 / Last changed on Tue Oct 12 20:36:40 2004 by pachi (pachi-at-mmn-arquitectos-com)

1.8.419 I need PyGTK/libglade compiled for [insert Unix OS here]!

 cd /usr/src/pygtk-0.9.9 # we wish :-)
 ./configure
 make 
 make install

You may as well compile it yourself. Just make sure you have the python2-devel RPM installed on your system, along with the -devel rpms for gtk+, glib, and the other modules you want to be able to use. Then run the following commands:

  PYTHON=/usr/bin/python2 ./configure --prefix=/usr
  make
  make install

Edit this entry420 / Log info421 / Last changed on Thu Jan 31 19:53:53 2002 by kiko (kiko-at-async-com-br)

1.9.422 Are there any PyGTK tutorials available?

• Aug 2003 "A Beginner's Guide to using pyGTK and Glade" by Dave Aitel in the Linux Journal, available at [www.linuxjournal.com]425

• Jul 2003 "PyGTK Tutorials" by John Finlay, they are the GTK+ tutorials rewritten for PyGTK v1.x and v2.x, available at [www.moeraki.com]426

• Feb 2003 "Bonobo Tutorial for Python" an excellent tutorial by Martin Grimme, available at [www.pycage.de]427

• Nov 2002 "Developing GNOME Applications with Python(part 3)" by Hilaire Fernandes, available at [www.linuxfocus.org]428 Source code is available at [www.linuxfocus.org]429

• Jan 2002 "Developing GNOME Applications with Python(part 2)" by Hilaire Fernandes, available at [www.linuxfocus.org]430

• Aug 2001 Russ Nelson has a tutorial up at [handhelds.org]431 that takes you step-by-step to hello world, and uses an interesting class design (with __getitem__() overridden for his "View", interesting)

• Jul 2000 "GNOME Panel Applets" by Daniel Solin at OnLamp (o'reillynet member), available at [www.onlamp.com]432 (Yes those little applets that live in the gnome panel.)

• Jul 2000 "Developing GNOME Applications with Python(part 1)" by Hilaire Fernandes, available at [www.linuxfocus.org]433 Source code is available at [www.linuxfocus.org]434

• Feb 2000 "Python Gnome tutorial" (unfinished) by Daniel Kornhauser, available at [laguna.fmedic.unam.mx]435

(People looking for a GObject tutorial should take a peek at FAQ 6.1436.)

Edit this entry437 / Log info438 / Last changed on Wed Jul 21 14:33:56 2004 by Christian Robottom Reis (kiko-at-async-com-br)

1.10.439 I have multiple copies of python but pygtk only works with one of them!

If you built pygtk for one copy of python on your system (or if you are using packages from your distribution), it will probably not be available on the others.

You will probably need to build pygtk for the other python installations. To do this, set the PYTHON environment variable to the full path of the alternative python before running pygtk's configure script. For example to build pygtk for the python 2.x distributed with Red Hat 7.x, do the following:

  PYTHON=/usr/bin/python2 ./configure --prefix=/usr
  make
  make install

Edit this entry440 / Log info441 / Last changed on Wed Feb 13 12:47:48 2002 by James Henstridge (james-at-daa-com-au)

1.11.442 How do I extend PyGTK (or the art of wrapping)

Let's call the library "foo" (how original)

1) foo.defs.

• Use h2defs.py found in pygtk/codegen/ on all your _public_ headers for the library.

   h2defs.py /usr/include/foo-1.0/*.h > foo.defs

• Use atkmodule.c as a template. Replace all instances of atk with foo.
• You most probably won't use any constants (since they require additional work), so just comment out pyatk_add_constants (m, "ATK_");

3) foo.override

• You can also use atkmodule.c as a template for the override file.
• Remove the only function in there (atk_relation_new) and replace the atk headers with your own.
• Don't forget to replace the modulename too.

4) Makefile.am

  AUTOMAKE_OPTIONS=1.5

  INCLUDES = $(PYTHON_INCLUDES) $(FOO_CFLAGS)

  # foo module
  pyexec_LTLIBRARIES = foomodule.la
  foomodule_la_LDFLAGS = -module -avoid-version -export-symbols-regex initfoo
  foomodule_la_LIBADD = $(FOO_LIBS)
  foomodule_la_SOURCES = foomodule.c
  nodist_foomodule_la_SOURCES = foo.c
  foo.c: foo.defs foo.override
  CLEANFILES = foo.c
  EXTRA_DIST = foo.override

  .defs.c:
        (cd $(srcdir)\
         && $(PYTHON) codegen/codegen.py \
            --override $*.override \
            --prefix py$* $*.defs) > gen-$*.c \
        && cp gen-$*.c $*.c \
        && rm -f gen-$*.c

 ---
 Should be enough for you to get started

• Copy pygtks configure and remove unnecessary stuff. Should be trivial. Don't forget to define a FOO_LIBS and FOO_CFLAGS

  PKG_CHECK_MODULES(FOO, foo >= 1.2,,)
  AC_SUBST(FOO_CFLAGS)
  AC_SUBST(FOO_LIBS)

Eventually you'll have to wrap a few functions by hand, functions that the code generator cannot handle. Mostly functions with inout params (**) and GSList/GList parameters.

Edit this entry444 / Log info445 / Last changed on Mon Jun 28 11:34:07 2004 by Christian Reis (kiko-at-async-com-br)

1.12.446 Where can I find the API documentation ?

Edit this entry448 / Log info449 / Last changed on Fri Jul 16 11:01:06 2004 by Christian Robottom Reis (kiko-at-async-com-br)

1.13.450 Where can I get gnome-python?

Edit this entry452 / Log info453 / Last changed on Sat Dec 28 17:05:38 2002 by Christian Reis (kiko-at-async-com-br)

1.14.454 How do I compile pygtk or gnome-python from CVS?

• gnome-python/pygtk
• gnome-python/pyorbit
• gnome-python/gnome-python

You should run

 ./autogen.sh
 make
 make install

If you want to install them to a separate prefix, eg if you don't have write access to /usr/local, use --prefix as an argument to autogen.sh or configure, eg:

  ./configure --prefix /home/user/prefix

  export PYTHONPATH=/home/user/prefix/lib/python2.3/site-packages

For additional information on how to use configure, see the INSTALL file which is included in the source tarball or cvs.

Edit this entry456 / Log info457 / Last changed on Tue Nov 23 13:57:28 2004 by Johan Dahlin (johan-at-gnome-org)

1.15.458 How do I tell what version of PyGTK I'm running?

 >>> gtk.pygtk_version
 (2, 2, 0)

 >>> gtk.gtk_version
 (2, 4, 0)

Edit this entry459 / Log info460 / Last changed on Sat May 22 07:50:58 2004 by Johan Dahlin (johan-at-gnome-org)

1.16.461 I wrote a patch for PyGTK that fixes bug X, or implements feature Y, what do I do?

Patches should be sent in the unified diff format (the -u flag). A good set of flags is -urNp -- look up man cvs if you're curious. It's a good idea to produce the patch against the CVS version -- see FAQ 1.3463 for information on getting pygtk from CVS.

Patches sent to the mailing list may be reviewed and checked in, but they may also be deleted without reading when the maintainers are too busy. Use bugzilla to be on the safe side and make sure your work is not wasted.

Edit this entry464 / Log info465 / Last changed on Thu Feb 12 17:48:07 2004 by Christian Reis (kiko-at-async-com-br)

1.17.466 How do I search Bugzilla for PyGTK bugs

If I am trying to do a general query, it helps to "select all" in these boxes by clicking on the first entry and then shift clicking on the last entry. You may also want to activate all the 'Status' entries to see resolved bugs, etc.

Once you have configured all these parameters, go to the Text information section, enter your search terms in the Description or Summary boxes, and click 'Submit Query'.

Edit this entry468 / Log info469 / Last changed on Tue May 25 12:26:39 2004 by Johan Dahlin (johan-at-gnome-org)

1.18.470 My programs configure says: No package 'pygtk-2.0' found

If you build pygtk on your own, from source, then you need to write the following before running the configure script:

  export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig

If you did not install it from source then it means that you forgot to install the devel/dev package. For Red Hat based distributions (Fedora, SuSe, Mandrake etc) you need to install pygtk2-devel and for debian based distributions you need to install pythonX.Y-gtk2-dev, where X.Y stands for the python version you're using.

Edit this entry471 / Log info472 / Last changed on Tue Jun 1 11:26:34 2004 by Johan Dahlin (johan-at-gnome-org)

1.19.473 Is there a PyGTK for MacOS X?

You can get the gtk libraries under OS X via darwinports from [darwinports.opendarwin.org]476

Daniel Macks and Ben Hines <bhines at alumni dot ucsd dot edu> have also put work into making packages available via Fink on the unstable tree: GNOME at [fink.sourceforge.net]477 and pygtk 2 specifically at [fink.sourceforge.net]478

Edit this entry479 / Log info480 / Last changed on Mon Nov 22 10:03:38 2004 by Michael Twomey (micktwomey-at-gmail-com)

1.20.481 Can I use PyGTK to build closed-source applications?

Edit this entry484 / Log info485 / Last changed on Fri Feb 25 11:30:55 2005 by Christian Reis (kiko-at-async-com-br)

1.21.486 Does PyGTK have timers?

See [nkour.blogspot.com]487 for a very easy example on how to use timers in PyGTK

Edit this entry488 / Log info489 / Last changed on Tue Jun 14 14:15:43 2005 by Nikos Kouremenos (kourem-at-gmail-com)

2. Changes from 1.2 to 1.3/2.0

2.1.490 How do I install PyGTK-2 and PyGTK-0 side by side in the same system?

(There are three different ways detailed to solve this problem, but I will not recommend methods 2 and 3 unless you are unable to upgrade to a version that supports method 1).

• Method 1 (the "pygtk.pth" method)

For PyGTK >= 0.6.10, gnome-python >= 1.4.3 or pygtk2 >= 1.99.13 ONLY! (See faq 2.5491)

(Note that RedHat 8.0 ships versions PRIOR to these, you will need to either upgrade the system packages, or use method 2 if you want to install PyGTK-0 and PyGTK-2 together on RH8.)

James has added to pygtk a mechanism that allows installation of both pygtk and pygtk2 to work side by side. This method should be transparent - you can install both versions and simply require one or the other for each program you need (the default being the one you install last), as per faq 2.4492. It is implemented by using a pygtk.pth file that indicates which is the default (which one `import gtk' uses) version.

Note that pygtk.pth only works if you use the *default python install path* - if you specify a --prefix to configure it will not work and you will *have to use method 2*!

• Method 2 (PYTHONPATH):

You can install the two conflicting versions to a different prefix. When configuring pygtk2, use something like:

 ./configure --prefix=/usr/local/gtk2/

 /usr/local/gtk2/lib/pythonX.Y/site-packages/

 export PYTHONPATH=/usr/local/gtk2/lib/pythonX.Y/site-packages/:$PYTHONPATH

• Method 3

You can change PyGTK-2.x's module name to something else. Thomas Leonard has released a patched version that renames the module name to gtk2, available publically at [west.dl.sourceforge.net]493 See [rox.sourceforge.net]494 for more information. To use this version, change the first line of your PyGTK-2 programs from

 import gtk

 import gtk2 as gtk

Edit this entry495 / Log info496 / Last changed on Wed Nov 6 15:54:29 2002 by Christian Reis (kiko-at-async-com-br)

2.2.497 What are the major changes in PyGTK-2 for GTK+ 2.2?

• Python 2.2 is required.
• The old, non-object-oriented C module _gtkmodule.so (accessed normally using "import _gtk" does not exist any more; this code will have to be converted to use the classes provided by the new pygtk.

• It is _strongly_ recommended that you use "import gtk" rather than "from gtk import *"
• The Gtk and Gdk prefixes on classes are gone. This can be fairly easily fixed with simple search and replace operations (gtk.GtkFoo goes to gtk.Foo, and gtk.GdkFoo goes to gtk.gdk.Foo).
• The GDK prefix for constants is gone and the GDK module is gone too. Now the constants are defined in the gtk.gdk module. For instance GDK_2BUTTON_PRESS is wrapped as gtk.gdk._2BUTTON_PRESS, and GDK_BUTTON_PRESS is gtk.gdk.BUTTON_PRESS.
• Widgets are now new style Python 2.2 classes. This probably won't affect anyone.
• Widgets that are considered "broken" (as opposed to deprecated) are not included in the binding. This list is fairly small though:

 - GtkText (replaced by GtkTextBuffer/GtkTextView)
 - GtkTree and GtkTreeItem (replaced by GtkTreeView and GtkTreeModel)

• The new pygtk fixes a number of memory and reference leaks. This may cause you some problems as objects might get freed when previously they would have stayed around (ie. leaked). However, the changes should make PyGTK a bit more predictable.
• All GObjects now have at most one wrapper for their lifetime. This gets rid of the questions about what happens to the attributes set on an object when in a signal handler.

Overall, PyGTK-2 should be a much nicer PyGTK to program with. If you are working on new code, it would be best to use PyGTK-2 instead of 0.6.x.

What's more, there is even some documentation for PyGTK-2, available at [www.gnome.org]498

Edit this entry499 / Log info500 / Last changed on Mon Jan 6 11:48:00 2003 by Florin Iucha (florin-at-iucha-net)

2.3.501 Is there a checklist of changes to migrate an application from PyGTK-0 to PyGTK-2?

• Because PyGTK now support multiple versions being installed in parallel, you need to signal which one you want to use. ie:

  import pygtk
  pygtk.require('2.0')
  import gtk

• If you used from gtk import *:

 * use import gtk instead
 * from gtk import *
 * s/mainloop/gtk.mainloop/g # and other functions calls like 'mainquit'
 * s/Gtk/gtk./g

• If you used import gtk:

 * s/Gtk//g

• Window doesn't accept a title keyword parameter to the constructor, use set_title():

 -         win = GtkWindow(title="Foo bar baz")
 +         win = gtk.Window()
 +         win.set_title("Foo bar baz")

• Label doesn't accept a label keyword parameter to the constructor: it now requires a string as an argument:

 -         label = GtkLabel(label="Foobar")
 +         label = gtk.Label("Foobar")

• GtkText should be changed to a combination of GtkTextBuffer and GtkTextView:

 -         self.text = GtkText()
 +         self.textbuffer = gtk.TextBuffer(None)
 +         self.text = gtk.TextView()
 +         self.text.set_buffer(self.textbuffer)

• TextBuffer offers insert_at_cursor, use it instead of GtkText.insert_defaults:

 -         self.text.insert_defaults( use_var )
 +         self.textbuffer.insert_at_cursor( use_var,len(use_var) )

• If you use GtkPixmap, it should be converted to gtk.Image, and use Image.set_from_pixmap() in place of GtkPixmap.set().

• Fonts can not be changed by altering the font attribute of the GdkStyle object (if you do style.font = foo it will silently be ignored). Instead, you must use something like:

  entry = gtk.Entry()
  font_desc = pango.FontDescription('monospace')
  entry.modify_font(font_desc)

• To get a GdkWindow use the "window" instance attribute (Note that the widget needs to be realized before the GdkWindow is set):

  entry = gtk.Entry()
  entry.realize()
  win = entry.window

• The GtkDrawingArea no longer offers proxy methods to its GdkDrawable's methods. In other words, you need to replace calls that looked like drawingarea.draw_point() with:

  drawingarea.window.draw_point()

• clip_rectangle(), a method associated to GdkGC, requires a tuple to be passed in (it complains about a GdkRectangle) which is converted internally by PyGTK to a GdkRectangle:

 gc.set_clip_rectangle((x, y, width, height))

• If you use a wheel mouse, listen to the new "scroll_event" signal. The old button 4/5 events are not generated anymore (jamesh says: The fact that the scroll wheel on your mouse generates button 4 and 5 events in X is an implementation detail, and was a bit of a pain for other GDK backends to implement.)

• OptionMenu wants get_children() instead of children()

 option_menu=tree.get_widget("optionmenu1")
 sometext=option_menu.get_children()[0].get()

• Function set_usize() is deprecated and should be replaced by set_size_request()

• Function GtkWindow.set_uposition() is deprecated and GtkWindow.move() should be used in its place.

Edit this entry503 / Log info504 / Last changed on Mon Aug 2 11:17:40 2004 by Christian Robottom Reis (kiko-at-async-com-br)

2.4.505 If I installed PyGTK-0 and PyGTK-2 in parallel (using pygtk.pth) how do I indicate which one my script should use?

 pygtk.require("1.2") # for pygtk-0

 pygtk.require("2.0") # for pygtk2

 # To require 2.0 
 import pygtk
 pygtk.require("2.0")
 import gtk, gtk.glade, gnome, gnome.ui

 # To require 1.2
 import pygtk
 pygtk.require("1.2")
 import gtk, libglade, gnome, gnome.ui

Edit this entry508 / Log info509 / Last changed on Thu Jan 2 16:50:53 2003 by Christian Reis (kiko-at-async-com-br)

2.5.510 Which versions of PyGTK support parallel install using the pygtk.pth method?

 - pygtk-0.6.10
 - gnome-python-1.4.3
 - pygtk2-1.99.13

Note that these versions are more recent than the version shipped in RedHat 8.0, so RH8.0 does NOT support parallel install using method 1 described in faq 2.4511.

Edit this entry512 / Log info513 / Last changed on Sun Dec 7 22:53:45 2003 by Scott Tsai (scottt958-at-yahoo-com-tw)

2.6.514 FAQ 2.4 sucks and doesn't work. Truthfuly, how do I require a specific version of PyGTK (or When do I need to use pygtk.require())?

If you installed pygtk to a non-standard directory (i.e., not in your python installation's site-packages directory), you will need to manually set pythonpath accordingly, and take care of python versions youself (checking pygtk_version, for instance). If you installed it into a standard directory, read below.

We have now a concept of a `default pygtk version'. This is the version that you get if you do a simple 'import gtk' in Python. Precisely which is the default version varies:

• If you are using a dual-install version of pygtk (faq 2.5515) it depends on the contents of a file called pygtk.pth, which is installed into the python site-packages directory. It's written there by the pygtk source tarball's `make install' target, so if you compile and install pygtk2 after pygtk0 the default will be pygtk2 and vice-versa.
• If you are using an older version of pygtk, you will need to check pygtk_version yourself, noting that you won't be able to select versions using the pygtk module.

To *make sure* you get the right version, you can use:

  import pygtk
  pygtk.require("1.2") # or 2.0 etc

 # Make sure we have version 1.2. Swap for 2.0 as necessary.

 def get_gtk():
   print """You need to get version 0.6 of PyGTK for this to work. You 
            can get source code from http://ftp.gnome.org/pub/gimp/gtk/python/v1.2/ """
   raise SystemExit

 try:
   import pygtk
   pygtk.require("1.2")
 except ImportError:
   try:
     import gtk   
   except ImportError:
     get_pygtk()
   if not hasattr(gtk, "GtkWindow"): # renamed in version 2.0
     get_pygtk()
 except AssertionError:
   get_pygtk()

  import gtk # we KNOW this is 1.2 at this point
  [...]

Edit this entry517 / Log info518 / Last changed on Thu Jan 2 16:54:39 2003 by Christian Reis (kiko-at-async-com-br)

2.7.519 What happened to the GTK and GDK constants/symbols?

So GDK_2BUTTON_PRESS is wrapped as gtk.gdk._2BUTTON_PRESS, while GDK_BUTTON_PRESS is gtk.gdk.BUTTON_PRESS (no underscore).

One exception is the keysyms constants. They are accesed through gtk.keysyms.KEY. To see the legal values of KEY just do a

import gtk print dir(gtk.keysyms)

Edit this entry520 / Log info521 / Last changed on Tue Feb 4 17:01:21 2003 by Lorenzo Gil Sanchez (loren-at-fedro-ugr-es)

2.8.522 For some users import libglade (or GDK) is working and for some users it's not

Figure out which one is working for your users, and change their script interpreter or path to use that one.

Edit this entry523 / Log info524 / Last changed on Tue Jan 7 16:56:51 2003 by Dave Aitel (dave-at-immunitysec-com)

2.9.525 FAQ 2.4, 2.6 and etc etc all suck. Python still doesn't find the version of pygtk I want.

 strace -eopen python <scriptname.py>

Don't write to the mailing list complaining, because we all know it's hard to make it work. You'll have to debug yourself. Next time complain when a solution that brings endless hassle to installers is implemented!

Edit this entry526 / Log info527 / Last changed on Thu Sep 23 02:30:49 2004 by Christian Robottom Reis (kiko-at-async-com-br)

2.10.528 How do I get my 1.2 gladefiles to work with 2.0?

There is a program included with libglade 2.0.x called libglade-convert that will do a pretty good job at converting the interface file to the new format. You should be able to edit the file in glade 1.1 after that.

Dave notes that you will probably have to redo all your dialog boxes, since they are going to be converted without some of the GTK 2 things, such as the correct active area interface and GTK 2 button images. You'll also have to redo your trees and lists to conform with GTK 2. A moderately sized project will take around 8 hours to do this to. Even if you don't "make install" libglade 2.0.x, you can use the Python file included (but renamed) in the distribution.

Edit this entry529 / Log info530 / Last changed on Mon Mar 31 14:42:08 2003 by Dave Aitel (dave-at-immunitysec-com)

3. Signal handling

3.1.531 When I connect to a signal, my handler gets called but reports "XXX takes no arguments (1 given)"

To handle a callback, your function signature, therefore, must take this into account. Often you don't even want to use any of the arguments, just trigger an action on a certain signal; an easy way to do this is using a variable argument list (*args) and ignoring them in your method:

  def on_win_delete(*args):
    print "Deleted, and who cares why"

  w = gtk.Window()
  w.connect("delete-event", on_win_delete)

Edit this entry532 / Log info533 / Last changed on Mon Nov 7 11:24:31 2005 by Johan Dahlin (johan-at-gnome-org)

3.2.534 How do I detect that a mouse or keyboard event has been triggered?

The correct way is to hook to some of the basic event signals and then act upon receiving them. The signals you want to look for are:

 - mouse motion
 - key presses
 - button presses

 def wakeup(widget, event):
     print "Event number %d woke me up" % event.type

 w = gtk.Window()

 w.add_events(gtk.gdk.KEY_PRESS_MASK |
              gtk.gdk.POINTER_MOTION_MASK |
              gtk.gdk.BUTTON_PRESS_MASK | 
              gtk.gdk.SCROLL_MASK)

 w.connect("motion-notify-event", wakeup)
 w.connect("key-press-event", wakeup)
 w.connect("button-press-event", wakeup)
 w.connect("scroll-event", wakeup)

 w.show()

 gtk.main()

Edit this entry535 / Log info536 / Last changed on Mon Nov 7 13:12:01 2005 by Johan Dahlin (johan-at-gnome-org)

3.3.537 I connected to some signals but nothing happens. Why?

The first is that some GTK+ widgets do not by nature receive events of any nature - GtkLabel comes to mind as an example. (The technical reason behind this is that they do not have their own X window, but use the one belonging to their parent widget. An X window is not the same as a GTK+ window, mind you; X windows on Unix systems are wrapped by GDK's GdkWindow, which is a lower-level creature). These widgets are listed at [www.moeraki.com]538 , and discussed further in gtkmm's tutorial: [www.gtkmm.org]539 . If you want to receive events for one of these widgets, you should add a GtkEventBox around it, and listen for events on that box.

 l = gtk.Label("I want events.")
 e = gtk.EventBox()
 e.add(l)
 e.add_events(gtk.gdk.POINTER_MOTION_MASK)
 e.connect("motion-notify-event", handle_event)

The event masks are defined in the gdk module; they are constants whose name ends in "_MASK". They map directly to X11 masks, and there is a reference to what each X11 mask is at [tronche.com]541

The functions that adjust the masks are:

 widget.set_events() 

 widget.add_events()

In the specific case of the key_press_event, the GTK+ event queue treats this signal specially to manage the widget keyboard focus.When it sees key events targetted at any subwindow within the toplevel, they are redirected to the toplevel GtkWindow. The key_press_event handler for the toplevel window checks to see if the key event corresponds to an accelerator/mnemonic (and activates the appropriate widget if so), or passes the key event on to the widget with focus. In short: if you want a global keyhandler, attach it to your application's GtkWindow(s).

Finally, understanding how the signal propagation system works is also helpful when you run into a tricky situation - you should check out FAQ 3.11542 which has more information on this.

Edit this entry543 / Log info544 / Last changed on Mon Nov 7 13:12:58 2005 by Johan Dahlin (johan-at-gnome-org)

3.4.545 I've fiddled with the mask but nothing happened. Why?

<jamesh_> yeah. A number of the masks cover multiple events and some events are selected by different masks

All event mask constants end with _MASK, and that is a good rule to remember. When doing add_events, you do NOT want (see, no _MASK!):

 widget.add_events(gtk.gdk.MOTION_NOTIFY | gtk.gdk.BUTTON_PRESS)

 widget.add_events(gtk.gdk.POINTER_MOTION_MASK | gtk.gdk.BUTTON_PRESS_MASK)

Edit this entry546 / Log info547 / Last changed on Mon Nov 7 13:13:27 2005 by Johan Dahlin (johan-at-gnome-org)

3.5.548 Which widgets are unable to receive events or be styled?

 Alignment
 AspectFrame
 Arrow
 Bin
 HBox
 VBox
 Frame
 Image
 Label
 Pixmap
 ScrolledWindow
 HSeparator
 VSeparator
 Table

Edit this entry549 / Log info550 / Last changed on Thu Feb 12 10:31:52 2004 by Christian Reis (kiko-at-async-com-br)

3.6.551 I attach a callback to a signal, but I keep getting an error: "TypeError: object of type X is not callable"

 #
 # WRONG
 button = gtk.GtkButton(label="Quit")
 button.connect("clicked", gtk.main_quit())

 # RIGHT
 button = gtk.Button(label="Quit")
 button.connect("clicked", gtk.main_quit)

Edit this entry552 / Log info553 / Last changed on Mon Nov 7 13:15:05 2005 by Johan Dahlin (johan-at-gnome-org)

3.7.554 While my callback is executing, nothing is refreshed in the application windows!

The trick here is to realize where your callback can take a while to return, or where it is dynamically changing the window contents, and add a section like this in the body of your callback handler:

 while gtk.events_pending():
   gtk.main_iteration(False)

More eloquently, in the words of the great Malcolm Tredinnick, 'this requires using what should be called "Secret Technique #1 For Making Your Application Look Responsive"(tm):

If you want to avoid freezes in your application while you are doing large amounts of work in the background, remember to call gtk.mainiteration() from time to time.'

Of course, if your callback has a single instruction that takes a long time to process, this isn't an option. There is no easy alternative to solve this problem, as far as I can see. Doug Quale remarks on how this applies even to idle_add()ed functions:

Idle functions are scheduled when gtk+ doesn't have any other work to perform, but gtk+ doesn't preempt them. Each idle function will run to completion once it's started.

Note that running a mainiteration inside an idle, io (input_add) or timeout handler is generally considered `a bad idea' because it doesn't work very well. If you really need to do so, check FAQ 20.1555.

Moreover if during the computation you want to lock the GUI (no operation can be performed) without making all the widget insensitive you can use the other secret tecnique called "Yeti"... [1]

 import gtk
 from time import sleep

 def response(widget, response_id):
     if response_id != gtk.RESPONSE_APPLY:
         gtk.main_quit()
     else:
         i=0
         n=1000

         progress = dialog.get_data("progress")
         progress.set_text("Calculating....")
         progress.grab_add()

         while i < n:
             sleep(0.005)
             progress.set_fraction(i/(n - 1.0))
             i += 1

             while gtk.events_pending():
                 gtk.main_iteration_do(False)

         progress.set_fraction(0.0)
         progress.set_text("")
         progress.grab_remove()

 dialog = gtk.Dialog("Modal Trick", None, 0, (gtk.STOCK_EXECUTE,  gtk.RESPONSE_APPLY, 
                         gtk.STOCK_CLOSE, gtk.RESPONSE_CLOSE))

 dialog.connect("response", response)
 dialog.connect("destroy", gtk.main_quit)

 box = dialog.get_child()

 widget = gtk.CheckButton("Check me!")
 box.pack_start(widget, False, False, 0)

 widget = gtk.Entry()
 box.pack_start(widget, False, False, 0)

 adj = gtk.Adjustment(0.0, 0.0, 100.0, 1.0, 10.0, 0.0)
 widget = gtk.HScale(adj)
 box.pack_start(widget, False, False, 0)

 widget = gtk.ProgressBar()
 box.pack_start(widget, False, False, 0)

 dialog.set_data("progress", widget)

 dialog.show_all()
 gtk.main()

[1] [mail.gnome.org]556

Edit this entry557 / Log info558 / Last changed on Sat May 6 11:16:01 2006 by Gian Mario Tagliaretti (g-tagliaretti-at-parafernalia-org)

3.8.559 I want my callback to execute, but not the default callback (or, how to I stop GTK from doing the default action when doing X)?

The process to disable a default action is:

• Find out what signal is being emitted and handled by the default handler. Many times you already know the signal since you may be hooking to it already, and observing the default action happen after yours.
• call widget.emit_stop_by_name("signal_name") (to stop the signal emission in the current widget)
• return True (to make sure that the signal won't propagate into parent handlers that may be the actual culprits for the default action)

An example of this usage was reported by Graham Ashton. He had customized a keypress handler for a window, but every time the user triggered the Alt-arrow combination he was handling, the focus moved around between the widgets in the interface (as is the default behaviour).

The solution was simply calling window.emit_stop_by_name("key_press_event") and returning True.

Edit this entry560 / Log info561 / Last changed on Mon Nov 7 13:15:30 2005 by Johan Dahlin (johan-at-gnome-org)

3.9.562 When creating a new signal, how do I define one of the signal arguments as Python data?

When you add your signal using gobject.signal_new(), use gobject.TYPE_PYOBJECT as the type for the argument being passed in:

    gobject.signal_new("signal", ClassName,
                       gobject.SIGNAL_RUN_LAST,
                       gobject.TYPE_NONE,
                       (gobject.TYPE_PYOBJECT,))

    mydict = {}
    mydict["foo"] = "bar"
    class_instance.emit("signal", mydict)

    def signal_cb(instance, mydict):
        print mydict["foo"]

    class_instance.connect("signal", signal_cb)

Edit this entry563 / Log info564 / Last changed on Wed Nov 6 16:12:30 2002 by Christian Reis (kiko-at-async-com-br)

3.10.565 How do I specify user data to a signal?

 widget.connect("my_signal", handler, userdata [, ...])

Edit this entry566 / Log info567 / Last changed on Wed Nov 6 16:10:43 2002 by Christian Reis (kiko-at-async-com-br)

3.11.568 How do signals and events propagate in GTK+?

A single signal emission will only call handlers attached to the object it was emitted on. The propagation of events up the heirachy is acheived by emitting the signal a number of times.

For events such as the button presses and motion events, the event is delivered first to the widget the event occurred in. It will emit the appropriate event signal. If the event signal returns false (indicating that the event hasn't been handled), then a signal will be emitted on the parent. This continues all the way up to the toplevel if no one handles the event.

Keyboard events are handled differently. When your window receives a keyboard event, it is first dispatched to the toplevel window, which will check if it matches any keyboard shortcuts. If the key press doesn't match a shortcut, then the event is dispatched to the child widget that currently has focus.

Edit this entry570 / Log info571 / Last changed on Wed Nov 13 07:40:34 2002 by Christian Reis (kiko-at-async-com-br)

3.12.572 Why does handling expose events break drag-n-drop?

  queue_draw_area(x_beg, y_beg, x_end, y_end) 

Edit this entry573 / Log info574 / Last changed on Mon Aug 30 17:38:57 2004 by Christian Robottom Reis (kiko-at-async-com-br)

3.13.575 How do I pass extra data to a signal handler?

Suppose you have a dialog with an entry widget. If you want the dialog response handler to do something with the entry value, you could connect to the response signal like this

     dialog.connect('response', on_dialog_response, entry)

     def on_dialog_response(widget, response, entry):
         if response == gtk.RESPONSE.ACCEPT:
             print 'Accepting', entry.get_text()

    # probably wrong!
    dialog.connect('response', on_dialog_response, entry.get_text())

Edit this entry576 / Log info577 / Last changed on Mon Aug 30 20:35:12 2004 by Doug Quale (quale1-at-charter-net)

3.14.578 How to construct my own "fake" gtk.gdk.Event?

 event = gtk.gdk.Event(gtk.gdk.KEY_PRESS)
 event.keyval = gtk.keysyms.Return
 event.state = gtk.gdk.CONTROL_MASK
 event.time = 0 # assign current time

 widget_that_should_accept_signal.emit('key_press_event', event)

Edit this entry579 / Log info580 / Last changed on Tue Mar 14 21:09:13 2006 by Nikos Kouremenos (kourem-at-gmail-com)

4. Themes, fonts and styles

4.1.581 How do I change font properties on gtk.Labels and other widgets?

 label = gtk.Label("MyLabel")
 label.modify_font(pango.FontDescription("sans 48"))

Note that, some widgets are only containers for others, like gtk.Button. For those you'd have to get the child widget. For a gtk.Button do this:

  if button.get_use_stock():
     label = button.child.get_children()[1]
  elif isinstance(button.child, gtk.Label):
     label = button.child
  else:
     raise ValueError("button does not have a label")

Edit this entry582 / Log info583 / Last changed on Thu Sep 1 14:46:30 2005 by Johan Dahlin (johan-at-gnome-org)

4.2.584 Why don't my style changes apply only to the widget I requested it from?

get_style() returns an object what aways have the current style of widget. If you want to save an static style, use get_style().copy() instead:

 style = widget.get_style().copy()

Edit this entry585 / Log info586 / Last changed on Thu Dec 16 13:13:23 2004 by Johan Dahlin (johan-at-gnome-org)

4.3.587 My user defined styles get overridden by the default theme!

I have succesfully changed the bg colour of some buttons in my program by the use of styles. But..

As soon as my beautiful greenish colour has been painted onto the buttons, my default pixmap theme paints it over with it's gradient grey.

How do I stop this?!

I know I can stop it by choosing a different engine (like notif), but I want to use the default engine... See the prob?

XXX: NEEDS ANSWER

Edit this entry588 / Log info589 / Last changed on Thu Jan 31 21:22:29 2002 by kiko (kiko-at-async-com-br)

4.4.590 How do I change the background color of my application's dialog?

Edit this entry591 / Log info592 / Last changed on Sat Feb 9 14:47:25 2002 by kiko (kiko-at-async-com-br)

4.5.593 How do I use the style object?

The style is shared between widgets of the same type (XXX: is this true?). To change the style of only one widget in your application, the style object offers a copy() method, which returns a new copy of the GdkStyle, which can me changed and set_style() back to the desired widget.

All attributes of a style can be get and set independently by direct access. The most important attributes of style are the colours (see faq 4.6594):

• fg
• bg
• light
• dark
• mid
• text
• base
• black
• white

And the font and bg_pixmap attributes.

Edit this entry595 / Log info596 / Last changed on Thu Sep 12 00:14:50 2002 by Christian Reis (kiko-at-async-com-br)

4.6.597 How do I change the colour of a widget (or how do I get a GdkColor)?

There is some confusion about GdkColor and how it is created. There are both the GdkColor() class and colour_alloc() that seem to do the right thing, but they are both duds (as far as I can tell).

The right way of creating a colour is getting the colormap from the widget and using it to allocate a new colour using the GtkColorMap's alloc method:

 e = gtk.GtkEntry()
 map = e.get_colormap()
 colour = map.alloc_color("red") # light red

 colour = map.alloc_color("#FF9999") # light red

The next step is understanding how to manipulate GtkStyle's colour attributes, which are actually dictionaries: each attribute maps a number of different gtk constants that indicate states:

• gtk.STATE_NORMAL, the normal state of the widget.
• gtk.STATE_ACTIVE, a clicked button or checkbutton, etc.
• gtk.STATE_INSENSITIVE, when the widget is insensitive (set_sensitive(0))
• gtk.STATE_PRELIGHT, when onmouseovered
• gtk.STATE_SELECTED, when part of the widget is selected (text in a GtkEntry, or a selected radiobutton)

So, to change the default border of our entry above to red:

 style = e.get_style().copy()
 style.bg[gtk.STATE_NORMAL] = colour
 e.set_style(style)

Edit this entry600 / Log info601 / Last changed on Sat Feb 4 04:41:20 2006 by John Pye (john-pye-at-student-unsw-edu-au)

4.7.602 How do I get a Graphics Context, or GdkGC?

 gdkwin = widget.window
 gc = gdkwin.new_gc()

Edit this entry604 / Log info605 / Last changed on Mon Dec 5 20:43:16 2005 by László Monda (mondalaci-at-gmail-com)

4.8.606 How does the alloc() method to the GdkColormap work?

 cmap = widget.get_colormap()
 color = cmap.alloc_color("#FFCCAA")
 color = cmap.alloc_color("red")
 color = cmap.alloc_color(0, 0, 65535)

Complete reference documentation on GdkColormap is available at [www.moeraki.com]607

Edit this entry608 / Log info609 / Last changed on Thu Dec 16 13:04:16 2004 by Johan Dahlin (johan-at-gnome-org)

4.9.610 How do I use pango instead of GdkFont for font handling in a GtkDrawingArea?

 import pango

 # create a font description
 font_desc = pango.FontDescription('Serif 12')

 # create a layout for your drawing area
 layout = darea.create_pango_layout('hello pango!')

 # tell the layout which font description to use
 layout.set_font_description(font_desc)

 # draw the text with the draw_layout method
 darea.window.draw_layout(gc, x, y, layout)

 # get the pixel size of a layout
 text_width, text_height = layout.get_pixel_size()

Edit this entry611 / Log info612 / Last changed on Tue Jun 24 11:57:22 2003 by Christian Reis (kiko-at-async-com-br)

4.10.613 How can I use Unicode (or other format) strings in my PyGTK application, or, why do I get a UTF-8 warning when using a string?

 WARNING **: Invalid UTF8 string passed to pango_layout_set_text()

  unistr = unicode("your iso 8859-15 text", "iso8859-15")
  utfstr = unistr.encode("utf-8")

Edit this entry614 / Log info615 / Last changed on Thu Jan 26 18:45:40 2006 by Patrick K. O'Brien (pobrien-at-orbtech-com)

4.11.616 How can I create a new pango context()

A: widget.create_pango_context() should give you a new one.

Note that pango.Context() doesn't work: PangoContext is really an abstract interface. There are currently context implementations for core X fonts (already removed from the HEAD branch), Xft, Win32 and freetype. Widget.create_pango_context() will create a context appropriate for use with that widget, so you don't need to worry about these details.

Edit this entry617 / Log info618 / Last changed on Wed Sep 17 12:32:43 2003 by Christian Reis (kiko-at-async-com-br)

4.12.619 How do I get antialiased fonts in GTK+?

 export GDK_USE_XFT=1 

Note that the Xft backend is much better at producing scaled versions of the fonts. The reason is that the core X font system, when you use scalable fonts, will render the entire set of glyphs as bitmaps at the requested size when you open the font (which isn't fast or a good use of memory -- it quite large for big point sizes or fonts with large coverage, such as with Asian fonts).

Edit this entry620 / Log info621 / Last changed on Wed Sep 17 13:03:57 2003 by Christian Reis (kiko-at-async-com-br)

4.13.622 Does PyGTK support TrueType fonts?

Note that the way the font is rendered is handled by the rendering backend; see FAQ 4.12623 for more information.

Edit this entry624 / Log info625 / Last changed on Wed Sep 17 12:58:53 2003 by Christian Reis (kiko-at-async-com-br)

4.14.626 What units does pango use to define sizes and widths?

Edit this entry627 / Log info628 / Last changed on Sat Oct 25 15:34:18 2003 by Christian Reis (kiko-at-async-com-br)

4.15.629 Can I find out how long (wide) a string is in a certain font?

   context = widget.get_pango_context()
   metrics = context.get_metrics('font name, 12')
   width = pango.PIXELS(metrics.get_approximate_char_width() * n_chars)

For a monospaced font, this should be quite accurate. You can then use widget.set_size_request() if you would like to set that width as the minimum width for the widget/view.

In PyGTK-0.6, you can ask the font directly how long a given string is going to be, as well as how high. Retrieve the font object from the style, and then query it with the string in question:

  font = widget.get_style().font

  h = font.height(my_string)
  w = font.width(my_string)

  widget.set_usize(w*2, h*2)

Edit this entry631 / Log info632 / Last changed on Sat Oct 25 15:36:22 2003 by Christian Reis (kiko-at-async-com-br)

4.16.633 How do I change the background and colour of an Editable (GtkEntry, GtkTextView and friends)?

  widget.modify_fg(state, color)
  widget.modify_bg(state, color)
  widget.modify_base(state, color)
  widget.modify_text(state, color)

    import gtk

    window = gtk.Window(gtk.WINDOW_TOPLEVEL)
    window.connect("destroy", gtk.mainquit)

    label = gtk.Label("one, two, testing...")
    eb = gtk.EventBox()
    eb.add(label)
    eb.modify_bg(gtk.STATE_NORMAL, gtk.gdk.color_parse("blue"))
    window.add(eb)

    window.show_all()
    gtk.main()

Edit this entry635 / Log info636 / Last changed on Mon Nov 7 13:19:02 2005 by Johan Dahlin (johan-at-gnome-org)

4.17.637 Why does FontSelection's set_font_name return False?

  >>> w = gtk.Window()
  >>> f = gtk.FontSelection()
  >>> f.get_font_name()
  'Sans 10'
  >>> f.set_font_name('Sans 12')
  False
  >>> w.add(f)
  >>> f.set_font_name('Sans 12')
  True

Edit this entry638 / Log info639 / Last changed on Mon Nov 7 13:19:16 2005 by Johan Dahlin (johan-at-gnome-org)

4.18.640 How do I change GtkMenubar.shadow_type (or other style properties)?

    style "menubar-style" { 
        GtkMenuBar::shadow_type = etched-in 
    }

    class "GtkMenuBar" style "menubar-style"

  none, in, out, etched-in, etched-out

Which can be passed on to gtk.rc_parse_string (or put in a file and then passed to gtk.rc_parse).

Edit this entry642 / Log info643 / Last changed on Sun Oct 31 12:30:00 2004 by Christian Robottom Reis (kiko-at-async-com-br)

4.19.644 Can I pass strings of unicode instance to gtk or do I need to convert them to utf8?

    label.set_text(u'abc')

Edit this entry645 / Log info646 / Last changed on Mon Nov 7 13:19:35 2005 by Johan Dahlin (johan-at-gnome-org)

5. Basic Objects: GObject, GtkWidget and other critters

5.1.647 I want to understand this "data" object that is used in the set_*_data() and get_*_data() calls.

For example, you can attach to a GtkLabel the instance it represents and a list of of versions using the following code:

 l = gtk.Label()
 l.set_data("object-name", some_object)

 >>> some_object = l.get_data("object-name")

Edit this entry648 / Log info649 / Last changed on Mon Nov 7 13:19:46 2005 by Johan Dahlin (johan-at-gnome-org)

5.2.650 How do I check if a widget is currently sensitive?

  if widget.get_property('sensitive') == 0:
    print "I'm insensitive!"

Edit this entry651 / Log info652 / Last changed on Tue Nov 16 15:02:49 2004 by Johan Dahlin (johan-at-gnome-org)

5.3.653 Where is get_state() in PyGTK 0.6.x?

And therefore no way to wrap it in pygtk. There are actually a number of state constants defined in gtk:

 gtk.STATE_ACTIVE
 gtk.STATE_NORMAL
 gtk.STATE_SELECTED
 gtk.STATE_INSENSITIVE
 gtk.STATE_PRELIGHT     

Edit this entry654 / Log info655 / Last changed on Tue May 25 12:29:53 2004 by Johan Dahlin (johan-at-gnome-org)

5.4.656 How do I catch right-click, middle-click and double-click on my widget?

 window.add_events(gtk.gdk.BUTTON_PRESS_MASK)

 def button_clicked(widget, event):
     # which button was clicked?
     if event.button == 1:
         print "left click"
     elif event.button == 2:
         print "middle click"
     elif event.button == 3:
         print "right click"

     # was it a multiple click?
     if event.type == gtk.gdk.BUTTON_PRESS:
         print "single click"
     elif event.type == gtk.gdk._2BUTTON_PRESS:
         print "double click"
     elif event.type == gtk.gdk._3BUTTON_PRESS:
         print "triple click. ouch, you hurt your user."

Edit this entry659 / Log info660 / Last changed on Mon Nov 7 13:20:48 2005 by Johan Dahlin (johan-at-gnome-org)

5.5.661 How do I capture keypresses, and how do I perform a certain action depending on the key pressed?

 def on_key_press_event(widget, event):
   keyname = gtk.gdk.keyval_name(event.keyval)
   print "Key %s (%d) was pressed" % (keyname, event.keyval)

 w = gtk.Window()
 w.connect('key_press_event', on_key_press_event)

Which will print out the key pressed for that window. To use a specific handler for each key pressed, you can set something up like this:

  def on_key_press(self, widget, event):
    keyname = gtk.gdk.keyval_name(event.keyval)
    func = getattr(self, 'keypress_' + keyname, None)
    if func:
      return func()

  def keypress_A(self):
    print "A was pressed!"

  def keypress_B(self):
    print "B was pressed!"

 def on_key_press(widget, event):
   keyname = gtk.gdk.keyval_name(event.keyval)
   print "Key %s (%d) was pressed" % (keyname, event.keyval)
   if event.state & gtk.gdk.CONTROL_MASK:
     print "Control was being held down"
   if event.state & gtk.gdk.MOD1_MASK:
     print "Alt was being held down"
   if event.state & gtk.gdk.SHIFT_MASK:
     print "Shift was being held down"

 w = gtk.Window()
 w.connect('key_press_event', on_key_press)

Edit this entry662 / Log info663 / Last changed on Tue Nov 16 15:09:08 2004 by Johan Dahlin (johan-at-gnome-org)

5.6.664 How do I change the cursor for a certain widget?

• You need to create a gtk.gdk.Cursor object first. It's constructor takes a gtk.gdk constant from the list at the end of this faq entry.
• To apply the cursor to a widget, you need to to use gdk.Window's (gdk, _not_ gtk) set_cursor() method (which requires the widget to have an associated X window, as per faq 3.3665).
• To change it back to the default cursor, call set_cursor(None).

To change it for a button,

 def realize_cb(widget):
   b.window.set_cursor(watch)

 b = gtk.Button()
 watch = gtk.gdk.Cursor(gtk.gdk.WATCH)
 b.connect("realize", realize_cb)

 b.window.set_cursor(None)

 pix_data = """/* XPM */
 static char * invisible_xpm[] = {
 "1 1 1 1",
 "       c None",
 " "};"""
 color = gtk.gdk.Color()
 pix = gtk.gdk.pixmap_create_from_data(None, pix_data, 1, 1, 1, color, color)
 invisible = gtk.gdk.Cursor(pix, pix, color, color, 0, 0)

 b.window.set_cursor(invisible)

 boat = gtk.gdk.Cursor(gtk.gdk.BOAT)

 b = gtk.EventBox()
 l = gtk.Label()
 b.add(l)
 b.window.set_cursor(boat)

To change the cursor for all the widgets, you'd need to recurse into all child widgets and set_cursor() on their gdk.Windows. However, there seems to be a workaround that can be implemented using some gdk.Window functions. For details, read: [www.daa.com.au]666 (yes, that patch was checked in and those functions are available)

It is also worth noticing that some widgets are composed of multiple X windows. gtk.Entry is an example -- see FAQ 14.3667 (you can use the gdk.Window's children() method to get its child windows). Another example is TextView, described in FAQ 14.15668.

The constants for icons defined in gtk.gdk are:

 X_CURSOR            ARROW                BASED_ARROW_DOWN
 BASED_ARROW_UP      BOAT                 BOGOSITY
 BOTTOM_LEFT_CORNER  BOTTOM_RIGHT_CORNER  BOTTOM_SIDE
 BOTTOM_TEE          BOX_SPIRAL           CENTER_PTR
 CIRCLE              CLOCK                COFFEE_MUG
 CROSS               CROSS_REVERSE        CROSSHAIR
 DIAMOND_CROSS       DOT                  DOTBOX
 DOUBLE_ARROW        DRAFT_LARGE          DRAFT_SMALL
 DRAPED_BOX          EXCHANGE             FLEUR
 GOBBLER             GUMBY                HAND1
 HAND2               HEART                ICON
 IRON_CROSS          LEFT_PTR             LEFT_SIDE
 LEFT_TEE            LEFTBUTTON           LL_ANGLE
 LR_ANGLE            MAN                  MIDDLEBUTTON
 MOUSE               PENCIL               PIRATE
 PLUS                QUESTION_ARROW       RIGHT_PTR
 RIGHT_SIDE          RIGHT_TEE            RIGHTBUTTON
 RTL_LOGO            SAILBOAT             SB_DOWN_ARROW
 SB_H_DOUBLE_ARROW   SB_LEFT_ARROW        SB_RIGHT_ARROW
 SB_UP_ARROW         SB_V_DOUBLE_ARROW    SHUTTLE
 SIZING              SPIDER               SPRAYCAN
 STAR                TARGET               TCROSS
 TOP_LEFT_ARROW      TOP_LEFT_CORNER      TOP_RIGHT_CORNER
 TOP_SIDE            TOP_TEE              TREK
 UL_ANGLE            UMBRELLA             UR_ANGLE
 WATCH               XTERM                CURSOR_IS_PIXMAP

 ## This Will Not Work ##
 watch = gtk.gdk.Cursor(gtk.gdk.WATCH)
 gtk_window.set_cursor(watch)
 time.sleep(10)             # your time consuming operation here
 gtk_window.set_cursor()

 def idle_cb(gtk_window):
    time.sleep(10)             # your time consuming operation here
    gtk_window.set_cursor()

 watch = gtk.gdk.Cursor(gtk.gdk.WATCH)
 gobject.idle_add(idle_cb, gtk_window)

Edit this entry669 / Log info670 / Last changed on Thu May 4 21:13:44 2006 by blaize (blaize-at-itee-uq-edu-au)

5.7.671 How can I tell my program that the cursor should jump to a specific widget?

 entry = gtk.Entry()
 [...]
 entry.grab_focus()

Edit this entry672 / Log info673 / Last changed on Tue Nov 16 15:10:51 2004 by Johan Dahlin (johan-at-gnome-org)

5.8.674 What signal is triggered when I change a widget's sensitivity?

Edit this entry675 / Log info676 / Last changed on Thu Sep 19 22:04:09 2002 by Christian Reis (kiko-at-async-com-br)

5.9.677 How do I find out the size of a widget?

  >>> win = gtk.Window()
  >>> win.realize() # or win.show()
  >>> rect = win.allocation

  >>> rect.width, rect.height, rect.x and rect.y

  >>> t = tuple(rect)

To find out how high or wide a widget is (or would be) based on a string size and a font, see FAQ 5.16678

Edit this entry679 / Log info680 / Last changed on Sat Feb 26 22:20:28 2005 by Nikos Kouremenos (kourem-at-gmail-com)

5.10.681 How do I focus a widget? How do I focus it before its toplevel window is shown?

 e = gtk.Entry()
 e.show()
 e.grab_focus()
 w = gtk.Window()
 w.add(e) # oh-oh, added after grab_focus()
 w.show()

 e = gtk.Entry()
 w = gtk.Window()
 w.add(e)
 e.grab_focus() # called after add
 w.show_all() # no need for e.show() in this case

Edit this entry682 / Log info683 / Last changed on Tue Nov 16 15:13:24 2004 by Johan Dahlin (johan-at-gnome-org)

5.11.684 My callback is getting a gtk.gdk.Event object, but I need an EventExpose!

 event.area.x

Edit this entry685 / Log info686 / Last changed on Tue May 25 12:28:41 2004 by Johan Dahlin (johan-at-gnome-org)

5.12.687 How do I check if a widget is mapped? And realized? And visible? [...]

In PyGTK the method is called flags(), and it doesn't take arguments, so you must perform the binary AND yourself:

 # To check if `widget' is mapped:
 if widget.flags() & gtk.MAPPED:
    print "MAPPED!"

 # gtk.Object
 DESTROYED
 FLOATING
 CONNECTED
 CONSTRUCTED

 # gtk.Widget
 TOPLEVEL
 NO_WINDOW
 REALIZED
 MAPPED
 VISIBLE
 SENSITIVE
 PARENT_SENSITIVE
 CAN_FOCUS
 HAS_FOCUS
 CAN_DEFAULT
 HAS_DEFAULT
 HAS_GRAB
 RC_STYLE
 COMPOSITE_CHILD
 BASIC
 APP_PAINTABLE
 RECEIVES_DEFAULT

Edit this entry688 / Log info689 / Last changed on Tue Nov 16 15:15:53 2004 by Johan Dahlin (johan-at-gnome-org)

5.13.690 While calling get_property(), I get an "invalid property id" warning. Why?

  (:2640): Gtk-WARNING **: ../../gtk/gtkcontainer.c:874: invalid property
           id 3 for "child" of type `GParamObject' in `GtkButton'

The GtkContainer "child" property looks more like a convenience. Setting the property adds the widget to the container. However, GtkContainer can have multiple children, so it isn't clear what should be returned when reading it.

Edit this entry691 / Log info692 / Last changed on Fri Sep 19 19:49:33 2003 by Christian Reis (kiko-at-async-com-br)

5.14.693 How can I discover what properties and signals a GObject supports?

There are several methods to find out what properties and signals are supported in a GObject. First of all, you have the two introspection methods, so for properties use this:

  >>> gobject.list_properties(obj)

  >>> gobject.signal_list_names(obj)

  >>> help(obj)

If the type is in gobject, atk, pango, gdk or gtk, the reference manual is preferred, check it out here:

[www.pygtk.org]694

Edit this entry695 / Log info696 / Last changed on Tue Nov 16 15:33:31 2004 by Johan Dahlin (johan-at-gnome-org)

5.15.697 How do I access one of these properties in a GObject?

  >>> w = gtk.Window()
  >>> w.set_title('My Window')
  >>> w.show_all()
  >>> print w.get_property('modal')
  False
  >>> print w.get_property('title')
  'My Window'

Edit this entry698 / Log info699 / Last changed on Tue Nov 16 15:26:39 2004 by Johan Dahlin (johan-at-gnome-org)

5.16.700 What's the difference between a property and an attribute?

A property is a GObject property and can be read and write with the GObject.get_property (propname) and GObject.set_property (propname, value) methods.

An attribute is a mapping to the C struct of the GObject and can be read from and (sometimes) written to directly. For example:

 adj = gtk.Adjustment(value=0, lower=0, upper=100, step_incr=1, page_incr=10, page_size=10)
 adj.value = 4.0

Edit this entry701 / Log info702 / Last changed on Wed Dec 8 09:02:25 2004 by Gustavo Carneiro (gjc-at-inescporto-pt)

5.17.703 Do I need to handle reference counting for GObjects? What about for other objects in PyGTK/gnome-python?

• There is a reference cycle between the python wrapper and its underlying C object; this means that the object will not be automatically deallocated when there are no more user references, and you will need the garbage collector to kick in (which may take a few cycles). This occasionally causes the odd problem, such as with pixbufs described in FAQ 8.4704

Note that while gnome-vfs objects are not based on GObject, and implement their own reference counting, it's the same from the point of view of Python code: nothing needs to be done. A significant difference in gnome-vfs objects is that they do not allow the programmer to add new attributes or subclass them. Also, they don't have reference cycles, so they are deallocated without help from the garbage collector.

Bonobo objects are GObject based, but they require manual reference counting. There are well defined rules for ownership semantics in remote calls: [developer.gnome.org]705 . However, for in-process bonobo API calls, there are no rules, and you have to be very careful with the ownership of the references obtained on a per API function basis. Unfortunately the API itself is underdocumented, so...

Edit this entry706 / Log info707 / Last changed on Thu Nov 18 13:13:02 2004 by Gustavo Carneiro (gjc-at-inescporto-pt)

5.18.708 Focusing a widget after when selecting an item from Treeview

The solution is to add a timeout. This is how we do it:

    # Connect Treeview with cursor-changed signal
    treeview.connect("cursor-changed", self.timeoutFocus, focusme)

    # The callback function: 
    # focusme is the widget that will be focused
    def timeoutFocus(self,widget, focusme):
       gobject.timeout_add(10, lambda: focusme.grab_focus())

Edit this entry709 / Log info710 / Last changed on Mon Nov 7 13:21:52 2005 by Johan Dahlin (johan-at-gnome-org)

5.19.711 How can I listen to events from the scroll wheel on my mouse?

  gtk.gdk.SCROLL_UP, 
  gtk.gdk.SCROLL_DOWN, 
  gtk.gdk.SCROLL_LEFT, 
  gtk.gdk.SCROLL_RIGHT

  def on_button_scroll_event(button, event):
    if event.direction == gtk.gdk.SCROLL_UP:
       print "You scrolled up"

  b = gtk.Button()
  b.connect('scroll-event', on_button_scroll_event)

Edit this entry712 / Log info713 / Last changed on Wed Feb 15 17:19:14 2006 by Johan Dahlin (johan-at-gnome-org)

6. Widget subclasses and user signals: GObject

6.1.714 What is the canonical reference on widget (and GObject) subclassing and property overriding?

Edit this entry716 / Log info717 / Last changed on Tue Jun 29 09:54:29 2004 by Christian Reis (kiko-at-async-com-br)

6.2.718 When subclassing a widget (or a GObject), why are the additional signals I define not usable?

  gtk.DrawingArea.__init__(self)

If you get a "signal XXX cannot be used for action emissions" message, it's also likely that you missed adding gobject.SIGNAL_ACTIONS to the signal flags in the signal definition.

Read more about GObject subclassing in Lorenzo's tutorial at [www.sicem.biz]719

Edit this entry720 / Log info721 / Last changed on Tue Dec 6 11:29:57 2005 by Fabian Sturm (f-at-rtfs-org)

6.3.722 How do I wrap a GObject in Python?

It takes you throught the steps of generating the wrapper, customizing and compiling it, and then using it from Python. See also FAQ 1.11724 for a walkthrough of the process.

Edit this entry725 / Log info726 / Last changed on Sat Mar 29 02:19:46 2003 by Christian Reis (kiko-at-async-com-br)

6.4.727 How can I draw on top of a subclassed widget?

First, subclass the type properly and make sure the constructor is chained to properly:

 class MyButton(gtk.Button):
    def __init__(self):
      gtk.Button.__init__(self)

    def do_expose_event(self, event):

     retval = gtk.Button.do_expose_event(self, event)

    self.window.draw_ ....()

    return retval

 gobject.type_register(MyButton)

Edit this entry728 / Log info729 / Last changed on Mon May 23 14:31:08 2005 by Johan Dahlin (johan-at-gnome-org)

23.33.730 Using metaclasses in GObject subclasses.

   TypeError: Error when calling the metaclass bases
       metaclass conflict: the metaclass of a derived class must be a  (non-strict) subclass of the metaclasses of all its bases

 class Foo:
     __metaclass__ = MetaFoo

 # This will throw an error
 class Bar(Foo, gtk.Object):
     pass

 # This will not throw an error
 class GMetaFoo(MetaFoo, gobject.GObjectMeta):
     pass

 class Bar(Foo, gtk.Object):
     __metaclass__ = GMetaFoo

Edit this entry731 / Log info732 / Last changed on Mon Nov 7 13:22:21 2005 by Johan Dahlin (johan-at-gnome-org)

7. Labels: GtkLabel

7.1.733 How can I use mnemonics for my GtkLabel?

 label = gtk.Label('_Change the above color') 
 label.set_property("use-underline", gtk.TRUE)

Edit this entry734 / Log info735 / Last changed on Tue May 25 12:30:49 2004 by Johan Dahlin (johan-at-gnome-org)

7.2.736 Where is GtkLabel.get_text()?

 l = gtk.GtkLabel("foobar")
 print l.get() # prints "foobar"

 >>> l = gtk.Label("foobar")
 >>> print l.get_text()
 foobar
 >>> 

 >>> print l.get()
 foobar

Edit this entry737 / Log info738 / Last changed on Fri Dec 31 13:50:22 2004 by Gian Mario Tagliaretti (g-tagliaretti-at-parafernalia-org)

7.3.739 How do I make a GtkLabel font larger or bold?

 bold =  "-adobe-helvetica-bold-r-normal-*-*-120-*-*-p-*-iso8859-1"
 big  =  "-adobe-helvetica-medium-r-normal-*-*-180-*-*-p-*-iso8859-1"

 s = label.get_style().copy()
 font = gtk.load_font(bold) # or big if you want big.
 s.font = font
 label.set_style(s)

 label.set_use_markup(gtk.TRUE)
 # weights
 label.set_markup('normal text, <b>bold text</b>, <i>italic text</i>')
 # size; 38000 = 38pt (use pt size * 1000)
 label.set_markup('<span size="38000">big text</span>, normal text')

 label = gtk.Label("<b>N</b>ame")
 label.set_use_markup(True)

Edit this entry741 / Log info742 / Last changed on Thu Feb 19 13:30:37 2004 by Christian Reis (kiko-at-async-com-br)

7.4.743 How do I left, center, right, top, bottom, middle align a GtkLabel?

Use the label's set_alignment feature, which already does everything for you:

 l = gtk.Label("Text goes here")
 l.set_alignment(xalign=1, yalign=0.5) 

Edit this entry744 / Log info745 / Last changed on Mon Nov 7 13:23:20 2005 by Johan Dahlin (johan-at-gnome-org)

7.5.746 How do I change a Label's background color, or why doesn't my Label receive any signals?

This also happens to other windowless widgets.

If you want to provide such features to a label (or windowless widgets) you need to add the label to a gtk.EventBox in order to assign it a window and thus have some more properties (such as background) and the ability to catch its own signals.

You can even nest gtk.EventBoxes, with some border width, to get colored frames.

See FAQ 4.16749 for an example

Edit this entry750 / Log info751 / Last changed on Thu Mar 4 21:43:29 2004 by Rafael Villar Burke (pachi-at-mmn-arquitectos-com)

7.6.752 [pygtk2] How do I render a label in a button or menuitem with an underscore in its label?

 gtk.Button("_New order")

 gtk.Button("Foo__bar")

 button = gtk.Button("Foo_bar")
 button.set_use_underline(0)

(The question remains of why would you want to do such a thing.)

Edit this entry754 / Log info755 / Last changed on Thu Mar 25 13:27:10 2004 by Christian Reis (kiko-at-async-com-br)

7.7.756 I set my labels to use_markup in glade-2. Why don't they markup the contents I set?

• always use set_markup() if you want the content you are setting to be parsed as markup -- do NOT use set_text() (it will happily ignore the markup and you will be left in a confused state where will you wander into this FAQ).
• The glade use_markup setting is actually the 'use-markup' gtk.Label GObject property. "use-markup" only controls how to interpret the text given in the 'label' property. label.set_text("foo") is roughly equivalent to:

 label.set_property("use-markup", False)
 label.set_property("label", "foo")

 label.set_property("use-markup", True)
 label.set_property("label", "<i>bar</i>")

Edit this entry757 / Log info758 / Last changed on Thu Nov 18 09:08:32 2004 by Gustavo Carneiro (gjc-at-inescporto-pt)

7.8.759 How can I change the behavoir of a label without using pango markup?

here is a little example:

 import gtk
 import pango
 w = gtk.Window()
 w.connect("destroy", lambda w: gtk.main_quit())
 l = gtk.Label("some VERY_BOLD ITALIC text")
 k = gtk.Label("some normal text")
 PLIST = pango.AttrList()
 BOLD = pango.AttrWeight(pango.WEIGHT_HEAVY, 0, -1)
 ITALIC = pango.AttrStyle(pango.STYLE_ITALIC, 0, -1)
 PLIST.insert(BOLD)
 PLIST.insert(ITALIC)
 l.set_property("attributes", PLIST)
 v = gtk.VBox()
 v.pack_start(l)
 v.pack_start(k)
 w.add(v)
 w.show_all()
 gtk.main()

Edit this entry760 / Log info761 / Last changed on Mon May 9 15:49:01 2005 by Gian Mario Tagliaretti (g-tagliaretti-at-parafernalia-org)

8. Images: GtkImage, GtkPixmap, GdkPixbuf

8.1.762 How do I load a pixmap from a file into my application UI?

 from gtk import *
 w=GtkWindow()
 pix, mask=create_pixmap_from_xpm(w, None, "logo.xpm")
 mypixmap=GtkPixmap(pix,mask)
 w.add(mypixmap) 
 w.connect("destroy", mainquit)
 w.show_all()
 mainloop()

 pix, mask=create_pixmap_from_xpm(w, None, "logo2.xpm")
 mypixmap.set(pix, mask)

Edit this entry763 / Log info764 / Last changed on Sat Jun 12 11:15:42 2004 by Christian Reis (kiko-at-async-com-br)

8.2.765 What about loading other image formats besides XPM, like JPEG or PNG?

 w = gtk.Window()
 image = gtk.Image()
 image.set_from_file(filename)
 w.add(image)
 w.show_all()

 import gtk
 import gdkpixbuf

 w=gtk.GtkWindow()

 img=gdkpixbuf.new_from_file("images/logo.gif")
 gdkpix, mask = img.render_pixmap_and_mask() # Create a GdkPixmap object
 gtkpix = gtk.GtkPixmap(gdkpix, mask)
 w.add(gtkpix)
 w.show_all()
 gtk.mainloop()

 pixbuf = gtk.gdk.pixbuf_new_from_file(imagefilename)
 image = gtk.Image()
 image.set_from_pixbuf(pixbuf) 

Edit this entry766 / Log info767 / Last changed on Thu Jul 24 11:11:53 2003 by Christian Reis (kiko-at-async-com-br)

8.3.768 How do I convert a Numeric array to a Pixbuf object?

Assuming that you have a (n,m,3) or (n,m,4) shape 'b' type array of RGB or RGBA values called 'data', you would do this:

 w,h = data.shape[:2]
 hasalpha = data.shape[3] == 4
 p = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB, hasalpha, 8, w, h)
 p.pixel_array[:] = data # see below

Note however that modifying the pixel data of some GdkPixbufs will cause a segfault (ones that are backed by a const string, such as the stock icons). Pixbufs you create yourself are safe to modify.

(There was a bug which could cause crashes; see [bugzilla.gnome.org]769 for details -- it was fixed in CVS HEAD in Aug 2003)

(Tim Evans)

Edit this entry770 / Log info771 / Last changed on Wed Dec 15 12:07:31 2004 by Steve Chaplin (stevech1097-at-yahoo-com-au)

8.4.772 Is there a resource leak? Why do I run out of memory using Pixbuf?

For example, I had some code that looked like this:

  for image_path in images:
     pb = gtk.gdk.pixbuf_new_from_file(image_path)
     pb = pb.scale_simple(thumb_width, thumb_height, gtk.gdk.INTERP_BILINEAR)
     thumb_list_model.set_value(thumb_list_model.append(None), 0, pb)

  import gc

  for image_path in images:
     pb = gtk.gdk.pixbuf_new_from_file(image_path)
     pb = pb.scale_simple(thumb_width, thumb_height, gtk.gdk.INTERP_BILINEAR)
     thumb_list_model.set_value(thumb_list_model.append(None), 0, pb)
     del pb
     gc.collect()

Edit this entry773 / Log info774 / Last changed on Tue May 11 07:24:51 2004 by Steve Chaplin (stevech1097-at-yahoo-com-au)

8.5.775 How do I to display an image from data (using a drawable or Image widget)?

The first example uses any gdk.Drawable's draw_rgb_image() method:

  # 0,0 are the coordinates for the top left corner; this 
  # renders an image flush at this corner.
  drawable.draw_rgb_image(gc, 0, 0, width, height, gtk.gdk.RGB_DITHER_NONE, imagedata)         

(Ionutz Borcoman)

The next example creates a pixbuf from an Image using the gtk.gdk.pixbuf_new_from_data method. image can be any PIL Image object using RGB or RGBA mode.

 image = Image.open('foo.png')
 IS_RGBA = image.mode=='RGBA'
 gtk.gdk.pixbuf_new_from_data(
            image.tostring(), # data
            gtk.gdk.COLORSPACE_RGB, # color mode
            IS_RGBA, # has alpha
            8, # bits
            image.size[0], # width
            image.size[1], # height
            (IS_RGBA and 4 or 3) * image.size[0] # rowstride
            ) 

(Tom Hinkle)

The next example uses Numeric (which allows for further image manipulation), and will will work with RGB and RGBA images:

  import Numeric, gtk

  data = Numeric.fromstring(imagedata, 'b')
  data.shape = (height, width, -1)
  p = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB, i.mode == 'RGBA', 8, w, h)
  p.pixel_array[:] = data

  im = gtk.Image()
  im.set_from_pixbuf(p)

Edit this entry777 / Log info778 / Last changed on Sat Jun 25 15:21:21 2005 by Tom Hinkle (Thomas_Hinkle-at-alumni-brown-edu)

8.6.779 How do I resize a gtk.Image?

  im =gtk.Image()
  pixbuf = gtk.gdk.pixbuf_new_from_file("my.jpg")
  scaled_buf = pixbuf.scale_simple(150,150,gtk.gdk.INTERP_BILINEAR)
  im.set_from_pixbuf(scaled_buf)
  im.show()

Edit this entry780 / Log info781 / Last changed on Wed Jan 21 09:20:45 2004 by Christian Reis (kiko-at-async-com-br)

8.7.782 What if I want to add a PIL image to a drawable?

  import PIL.Image, Numeric, gtk

  i = PIL.Image.open('foo.png')
  w, h = i.size
  imagestr = i.tostring()

  im = gtk.Image()
  pixmap = gtk.gdk.Pixmap(self.im.window, width, height, depth)

  gc = self.im.style.fg_gc[gtk.STATE_NORMAL]
  # 0,0 are the coordinates for the top left corner; this 
  # renders an image with no border.
  pixmap.draw_rgb_image(gc, x, y, w, h, gtk.gdk.RGB_DITHER_NONE, buff)        

  im.set_from_pixmap(pixmap, None)

Edit this entry785 / Log info786 / Last changed on Mon May 30 14:04:17 2005 by Christian Reis (kiko-at-async-com-br)

8.8.787 Does somebody know what all these image/pixmap classes are?

• GdkPixbuf: a client-side object that holds an image. The pixbuf is merely a holder for image data, which allows you to manipulate it, but has no facilities for rendering (being a client-side object, this is quite obvious).

• GdkPixmap: a X server object that contains an image. Can not be rendered in itself, even though the image is stored on the server. Manipulating a GdkPixmap is slower than a pixbuf mainly because of the communication roundtrip with the server.

• GdkDrawable: any X server object you can draw to, i.e. a GdkWindow or a GdkPixmap. A reference of the Drawable API is at [www.pygtk.org]788

• GtkImage: a GTK widget that renders an image based on a Pixmap or Pixbuf. The GtkImage differs from a regular Drawable in the sense that it implements an expose-event handler that takes care of redrawing its contents (based on its pixbuf or pixmap) when necessary. When using a Drawable (such as the DrawingArea) it is necessary to handle expose-events yourself.

Edit this entry789 / Log info790 / Last changed on Mon Jun 14 16:19:01 2004 by Christian Reis (kiko-at-async-com-br)

8.9.791 How do I flip an image horizontally or vertically?

David Hugh-Jones submitted an [unoptimized] example function that flips a pixbuf:

  def flip_pixbuf(pb):
    bps = pb.get_bits_per_sample()
    rs = pb.get_rowstride()
    pix = pb.get_pixels()

    newpix = ""
    x = rs
    pixstride = pb.get_n_channels() * bps/8 

    while x <= len(pix):
        newrow = ""
        y = pixstride
        row = pix[x - rs: x]

        while y <= len(row):
            sample = row[y - pixstride: y]
            newrow = sample + newrow
            y += pixstride

        newpix += newrow
        x += rs

    return gtk.gdk.pixbuf_new_from_data(newpix,
                                        pb.get_colorspace(),
                                        pb.get_has_alpha(), 
                                        bps,
                                        pb.get_width(),
                                        pb.get_height(), 
                                        rs)

Edit this entry792 / Log info793 / Last changed on Thu Jul 1 10:09:14 2004 by Christian Reis (kiko-at-async-com-br)

8.10.794 Is it possible to use SVG icons and images in PyGTK?

  w = gtk.Window()
  pixbuf = gtk.gdk.pixbuf_new_from_file('my_imagefile.svg')
  w.set_icon(pixbuf)

(Dennis Craven)

You can also do:

  img = gtk.Image()
  img.set_from_file('my_imagefile.svg')

Edit this entry795 / Log info796 / Last changed on Fri Apr 1 11:28:17 2005 by Nikos Kouremenos (kourem-at-gmail-com)

8.11.797 How do I get a Pixbuf of a stock icon?

    pixbuf = dialog.render_icon(gtk.STOCK_FIND, gtk.ICON_SIZE_MENU)
    dialog.set_icon(pixbuf)

Edit this entry798 / Log info799 / Last changed on Fri Nov 19 11:29:01 2004 by Christian Robottom Reis (kiko-at-async-com-br)

8.12.800 How do I register stock icons from an image file?

  factory = gtk.IconFactory()
  pixbuf = gtk.gdk.pixbuf_new_from_file(filename)
  iconset = gtk.IconSet(pixbuf)
  factory.add('my-image', iconset)
  factory.add_default()

  def register_iconsets(icon_info):
      iconfactory = gtk.IconFactory()
      stock_ids = gtk.stock_list_ids()
      for stock_id, file in icon_info:
          # only load image files when our stock_id is not present
          if stock_id not in stock_ids:
              pixbuf = gtk.gdk.pixbuf_new_from_file(file)
              iconset = gtk.IconSet(pixbuf)
              iconfactory.add(stock_id, iconset)
      iconfactory.add_default()

  register_iconsets([('gnome-stock-mic', 'gnome-stock-mic.png'),
                     ('gnome-stock-midi', 'stock_midi.png')])

Edit this entry801 / Log info802 / Last changed on Mon Feb 14 06:59:24 2005 by Gabriel Munoz (munozga-at-gmail-com)

8.13.803 How can I use an image as background in a gtk.Window?

iconsdir = './icons'
imagename = 'image.png'

win = gtk.Window()
path = os.path.join(iconsdir, imagename)
pixbuf = gtk.gdk.pixbuf_new_from_file(path)
pixmap, mask = pixbuf.render_pixmap_and_mask()
width, height = pixmap.get_size()
del pixbuf
win.set_app_paintable(gtk.TRUE)
win.resize(width, height)
win.realize()

win.shape_combine_mask(mask, 0, 0)  # make it transparent
win.window.set_back_pixmap(pixmap, gtk.FALSE)
del pixmap

Edit this entry804 / Log info805 / Last changed on Thu Mar 3 20:55:34 2005 by Nikos Kouremenos (kourem-at-gmail-com)

8.14.806 How do I convert a pixbuf to a PIL Image?

  import gtk
  import Image

  def pixbuf2Image(pb):
    assert(pb.get_colorspace() == gtk.gdk.COLORSPACE_RGB)
    dimensions = pb.get_width(), pb.get_height()
    stride = pb.get_rowstride()
    pixels = pb.get_pixels()
    mode = pb.get_has_alpha() and "RGBA" or "RGB"
    return Image.frombuffer(mode, dimensions, pixels,
                            "raw", mode, stride, 1)

  pb = gtk.gdk.pixbuf_new_from_file("foo.jpg")
  im = pixbuf2Image(pb)
  im.save("welldone.jpg", "JPEG", quality=80)

Edit this entry807 / Log info808 / Last changed on Mon May 30 15:37:20 2005 by Danny Milosavljevic (danny_milo-at-yahoo-com)

8.15.809 How can I get the data of a gtk.Image and save it in an external file?

    pixbuf = img.get_pixbuf()
    pixbuf.save(filename, "jpeg", {"quality":"100"})

Edit this entry810 / Log info811 / Last changed on Tue Jun 7 13:13:53 2005 by Nikos Kouremenos (kourem-at-gmail-com)

8.16.812 How to show data that I already own from outside, in a gtk.Image?

Some example code:

    import urlib
    f = urllib.urlopen(url_to_image)
    data = f.read()
    pbl = gtk.gdk.PixbufLoader()
    pbl.write(data)
    pbuf = pbl.get_pixbuf()
    pbl.close()
    img.set_from_pixbuf(pbuf)

Edit this entry814 / Log info815 / Last changed on Thu Jun 30 16:04:02 2005 by Johannes Spielmann (johannes-spielmann-at-shezi-de)

8.17.816 How to make a colorful image grayscale without using PIL?

 import gtk

 pixbuf = gtk.gdk.pixbuf_new_from_file('image.png')
 pixbuf2 = pixbuf.copy()
 pixbuf.saturate_and_pixelate(pixbuf2, 0.0, False)

 pixbuf2.save('image_grayscale.png', 'png')

Edit this entry817 / Log info818 / Last changed on Thu Jan 12 20:04:43 2006 by Nikos Kouremenos (kourem-at-gmail-com)

8.18.819 How blend (composite) two images together?

Obligatory example:

 pixbuf = gtk.gdk.pixbuf_new_from_file("foo.png")
 pixbuf2 = gtk.gdk.pixbuf_new_from_file("bar.png")
 pixbuf.composite(pixbuf2, 0, 0, pixbuf.props.width, pixbuf.props.height, 0, 0, 1.0, 1.0, gtk.gdk.INTERP_HYPER, 127)

 ## now pixbuf2 contains the result of the compositing operation
 pixbuf2.save("zbr.png", 'png')

  python foo.py foo.py:7: GtkWarning?: gdk_pixbuf_composite: assertion `dest_x >= 0 && dest_x + dest_width <= dest->width' failed

 import cairo

 s1 = cairo.ImageSurface.create_from_png('foo.png')
 s2 = cairo.ImageSurface.create_from_png('bar.png')

 ctx = cairo.Context(s1)
 ctx.set_source_surface(s2, 0, 0)
 ctx.paint()

 s1.write_to_png('result.png')

Edit this entry820 / Log info821 / Last changed on Sun Jan 29 14:58:56 2006 by Nikos Kouremenos (kourem-at-gmail-com)

8.19.822 How can I make a stock icon the default icon? *

     def __init__(self):
         self.window=gtk.Window(gtk.WINDOW_TOPLEVEL)
         icon=self.window.render_icon(gtk.STOCK_FIND, 
                                      gtk.ICON_SIZE_DIALOG)
         gtk.window_set_default_icon(icon)

[1] [www.pygtk.org]823

Edit this entry824 / Log info825 / Last changed on Thu Aug 10 11:52:51 2006 by Thomas Guettler (guettli+pygtkfaq-at-thomas-guettler-de)

9. Buttons: GtkButtons

9.1.826 How does one group radio buttons to allow only one concurrent button to be depressed?

 w = gtk.Window()
 v = gtk.VBox()
 b1 = gtk.RadioButton(label="Cows")
 b2 = gtk.RadioButton(label="Dogs", group=b1)
 b3 = gtk.RadioButton(label="Mountains", group=b1)
 v.add(b1)
 v.add(b2)
 v.add(b3)
 w.add(v)
 w.show_all()

Edit this entry827 / Log info828 / Last changed on Sat Jan 1 11:54:15 2005 by Gian Mario Tagliaretti (g-tagliaretti-at-parafernalia-org)

9.2.829 How do I create buttons that contain a pixmap?

 w = gtk.GtkWindow()
 button = gtk.GtkButton()
 label = gtk.GtkLabel('foobar')
 pix,mask = gtk.create_pixmap_from_xpm(w,None,'icon.xpm')
 pixmap = gtk.GtkPixmap(pix,mask)
 box = gtk.GtkHBox()
 button.add(box)
 box.add(pixmap)
 box.add(label)

 (( \o/ foobar ))

Edit this entry830 / Log info831 / Last changed on Thu Jul 11 10:53:20 2002 by Christian Reis (kiko-at-async-com-br)

9.3.832 PyGTK 0.6.x: The stock pixmap buttons in glade, but they don't show in my buttons? (pygtk0.x)

Edit this entry833 / Log info834 / Last changed on Tue May 25 12:33:12 2004 by Johan Dahlin (johan-at-gnome-org)

9.4.835 Why is a handler connected to a GtkRadioButton being called twice?

In practical terms, this means that if there is a currently selected item (item A) in a radiobutton group and you select another one (item B), a signal clicked will be generated for item A and for item B.

Inside the handler, you can use radiobutton.active to check its state: if it is TRUE, it's been selected, and vice-versa.

Edit this entry836 / Log info837 / Last changed on Fri Sep 20 14:55:09 2002 by Christian Reis (kiko-at-async-com-br)

9.5.838 How do I render a stock button with a different label?

  gtk.stock_add([(gtk.STOCK_SAVE_AS, "Rename", 0, 0, "")])

Alternatively, if you don't want to override the default stock object, you can get the label child of the stock button and set the text directly. Thanks to Christian Reis for the suggestion!

  button = gtk.Button(stock=gtk.STOCK_CANCEL)
  button.show()

  alignment = button.get_children()[0]
  hbox = alignment.get_children()[0]
  image, label = hbox.get_children()
  label.set_text('Hide')

  items = [('pg-create', '_Create', 0, 0, None),
           ('pg-alter', '_Alter', 0, 0, None),
           ('pg-drop', '_Drop', 0, 0, None),]

  # We're too lazy to make our own icons, 
  # so we use regular stock icons.
  aliases = [('pg-create', gtk.STOCK_NEW),
             ('pg-alter', gtk.STOCK_PROPERTIES),
             ('pg-drop', gtk.STOCK_DELETE),]

  gtk.stock_add(items)
  factory = gtk.IconFactory()
  factory.add_default()
  style= window.get_style()
  for new_stock, alias in aliases:
      icon_set = style.lookup_icon_set(alias)
      factory.add(new_stock, icon_set)

  # Create the relabeled buttons
  b_create = gtk.Button(stock='pg-create')
  b_alter = gtk.Button(stock='pg-alter')  
  b_drop = gtk.Button(stock='pg-drop')  

Edit this entry840 / Log info841 / Last changed on Mon Aug 30 15:09:10 2004 by Christian Robottom Reis (kiko-at-async-com-br)

9.6.842 How do I add tooltips to a ToolButton in a Toolbar?

  tooltips = gtk.Tooltips()
  [...]

  toolbar = gtk.Toolbar()
  toolbar.set_tooltips(True)
  [...]

  toolbutton = gtk.ToolButton()
  toolbutton.set_tooltip(tooltips, "hi")

Edit this entry843 / Log info844 / Last changed on Sun May 15 18:19:06 2005 by Christian Reis (kiko-at-async-com-br)

9.7.845 How do I add a stock icon to a ToggleButton?

  img = gtk.image_new_from_stock(gtk.STOCK_MEDIA_RECORD,  gtk.ICON_SIZE_BUTTON)

  self.recButton = gtk.ToggleButton("")

  self.recButton.set_property("image", img)

Edit this entry846 / Log info847 / Last changed on Thu Mar 9 19:18:56 2006 by Christian Reis (kiko-at-async-com-br)

10. Windows: GtkWindows and GtkDialogs

10.1.848 How do I get a GdkWindow from a GtkWindow?

• PyGTK-0.6.x: Use the get_window() method of GtkWindow:

 >>> w = gtk.GtkWindow()
 >>> w.realize()
 >>> w.get_window()
 <GdkWindow at 838ec70>

• PyGTK2: Use the window attribute of GtkWindow:

 w = gtk.Window()
 w.realize()
 w.window

Edit this entry849 / Log info850 / Last changed on Mon Feb 3 23:14:51 2003 by Christian Reis (kiko-at-async-com-br)

10.2.851 Where are GtkDialogFlags defined?

Matt Wilson said They are:

 gtk.DIALOG_MODAL	          If set, the dialog grabs all keyboard events
 gtk.DIALOG_DESTROY_WITH_PARENT	  If set, the dialog is destroyed when its parent is.
 gtk.DIALOG_NO_SEPARATOR	  If set, there is no separator bar above the buttons.

Edit this entry852 / Log info853 / Last changed on Sat Jan 1 12:32:20 2005 by Gian Mario Tagliaretti (g-tagliaretti-at-parafernalia-org)

10.3.854 How do I get my windows to show up where I want?

 The window manager is responsible for placing the window on the screen
 when mapped if it isn't given an exact position.  For dialog boxes, 
 make sure you're passing in the parent window when creating the dialog
 box.  Then GTK will set up the correct hints that would make window
 managers treat the dialog window as a child of its parent.  How the
 window manager decides to treat the placement is configurable in some
 window managers...

 w = gtk.Window()
 # ...
 d = gtk.Dialog()
 d.set_position(gtk.WIN_POS_CENTER_ON_PARENT)
 d.set_transient_for(w)

(Note that some X11 servers such as Xming appear not to honour these placement settings.)

To do this with a dialog defined in a glade file, you'll need to do something like:

 d = glade_tree.get_widget(dialog_name)
 d.set_position(gtk.WIN_POS_CENTER_ON_PARENT)
 d.set_transient_for(parent_window)

You can also save and restore the window position and size. Save the position with:

    (x, y) = w.get_position()
    (w, h) = w.get_size()

    w = gtk.GtkWindow()
    w.move(x, y)
    w.set_size_request(w, h)

Edit this entry856 / Log info857 / Last changed on Fri Feb 24 02:37:05 2006 by John Pye (john-pye-at-student-unsw-edu-au)

10.4.858 How do I make a dialog block the whole application, so the user is forced to answer it?

Having said that, there are times where a modal dialog is either necessary or an easy solution. Any window of the application can be set as modal; this will force it to be dismissed before the normal flow of the application is restored. FIXME: window.hide() removes modality?

To make a dialog modal, simply use:

 import gtk
 w = gtk.GtkWindow()
 w.set_modal(gtk.TRUE)

 w = gtk.Dialog()
 ret = w.run()
 w.hide()
 return gtk.TRUE

 def on dialog_w_okbutton_clicked(*args):
     w.response(response_id)

Edit this entry860 / Log info861 / Last changed on Wed Apr 6 07:15:27 2005 by Floris Bruynooghe (fb102-at-soton-ac-uk)

10.5.862 I click on the close button (X) to close my gtk.Window. It disappears, but the program seems to hang!

 win = gtk.Window()
 win.connect("delete-event", gtk.main_quit) # no parenthesis; you pass functions to connect

Edit this entry863 / Log info864 / Last changed on Sat Apr 29 10:36:06 2006 by Tiago Cogumbreiro (cogumbreiro-at-users-sf-net)

10.6.865 How do I avoid having my gtk.Window instance destroyed when I click on the window's close button? (or, When I redisplay my window, all my child widgets are missing and I get a bunch of Gtk-Critical errors!)

You can avoid the window's destruction by attaching a callback handler to the 'delete-event' handler in the GtkWindow and having it return 'True':

 win = gtk.Window()

 def on_delete_event(widget, event):
   print "Delete was called but I won't die!"
   return True

 win.connect("delete-event",on_delete_event)

The 'return True' part indicates that the default handler is _not_ to be called, and therefore the window will not be destroyed.

The actual process of event propagation is not simple to grasp and is better described at [www.gtk.org]867 .

It is important to note that you should not attach to 'destroy-event', as it cannot be overridden (it occurs server-side, and no client callback is triggered). Your window will always be destroyed, and your handler will not be called at all.

For gtk.Dialog its easier: just test the response id from running the dialogue against gtk.RESPONSE_DELETE_EVENT. It will match in time to be able to prevent the widget be destroyed, and there is no need to connect a signal.

For the specific case of GnomeAbout, see FAQ 10.13868.

Edit this entry869 / Log info870 / Last changed on Sat Apr 29 10:36:47 2006 by Tiago Cogumbreiro (cogumbreiro-at-users-sf-net)

10.7.871 How do I change the window manager's icon for a PyGTK Window?

here an example:

 w = gtk.Window()
 icon = w.render_icon(gtk.STOCK_DIALOG_INFO, gtk.ICON_SIZE_BUTTON)
 w.set_icon(icon)
 w.show()
 gtk.main()

Edit this entry872 / Log info873 / Last changed on Sun Jan 2 11:16:21 2005 by Gian Mario Tagliaretti (g-tagliaretti-at-parafernalia-org)

10.8.874 How do I get the GtkWindow's title?

 >>> w = gtk.GtkWindow()
 >>> w.set_title("foo")
 >>> print w['title']
 foo

 >>> w = gtk.Window()
 >>> w.set_title('foo')
 >>> print w.title
 foo

Edit this entry875 / Log info876 / Last changed on Sat Mar 15 17:20:04 2003 by Christian Reis (kiko-at-async-com-br)

10.9.877 How do I change the buttons on a MessageDialog?

  gtk.MessageDialog(parent, options, type, buttons, message)

 message = gtk.MessageDialog(None, gtk.DIALOG_MODAL, gtk.MESSAGE_INFO, gtk.BUTTONS_NONE, "message here")
 message.add_button(gtk.STOCK_QUIT, gtk.RESPONSE_CLOSE)
 resp = message.run()
 if resp == gtk.RESPONSE_CLOSE:
    message.destroy()

Edit this entry879 / Log info880 / Last changed on Sun Jan 2 11:39:56 2005 by Gian Mario Tagliaretti (g-tagliaretti-at-parafernalia-org)

10.10.881 How do I adjust a ScrolledWindow to adjust to a given child widget?

 def focus_in(widget, event, adj):
   alloc = widget.get_allocation()        
   if alloc.y < adj.value or alloc.y > adj.value + adj.page_size:
     adj.set_value(min(alloc.y, adj.upper-adj.page_size))

 scrolled_window = gtk.ScrolledWindow()
 adj = scrolled_window.get_vadjustment()
 # ... create child widget
 child.connect('focus_in_event', focus_in, adj)

Edit this entry882 / Log info883 / Last changed on Wed Apr 9 13:01:32 2003 by Christian Reis (kiko-at-async-com-br)

10.11.884 How do GtkDialogs work?

 dialog = gtk.Dialog('Window Title',
                     parent_window,  # the window that spawned this dialog
                     gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT,                       
                     ("Play Now", 77, gtk.STOCK_CLOSE, gtk.RESPONSE_CLOSE))
 dialog.vbox.pack_start(gtk.Label('Do you want to play a game?'))
 dialog.show_all()
 result = dialog.run()
 if result == 77:
    play_the_game()
 elif result == gtk.RESPONSE_CLOSE:
    user_just_closed_dialog()
 dia.destroy()

The upper part of a Dialog has a gtk.VBox where you can pack your own widgets, e.g. the Label shown above, or a scrolledwindow containing a gtk.TreeStore (which could display a list or a tree). The buttons live in dia.action_area, a gtk.HBox where you can also manually put your own buttons or whatever.

MODAL_DIALOG means you app is locked until a response is made. DIALOG_DESTROY_WITH_PARENT tells the window manager to lose/open/destroy this dialog with your app window -- you usually want this.

Canned response values are:

 GTK_RESPONSE_NONE
 GTK_RESPONSE_REJECT
 GTK_RESPONSE_ACCEPT
 GTK_RESPONSE_DELETE_EVENT
 GTK_RESPONSE_OK
 GTK_RESPONSE_CANCEL
 GTK_RESPONSE_CLOSE
 GTK_RESPONSE_YES
 GTK_RESPONSE_NO
 GTK_RESPONSE_APPLY
 GTK_RESPONSE_HELP

Many canned "stock" button icons are available from ADD to ZOOM_OUT; if you have the gtk source installed, you can use the gtk-demo program which offers a nice "Stock Item and Icon Browse" window.

There is a tutorial page relevant at [www.pygtk.org]885 and a reference page for GtkDialog at [www.pygtk.org]886

For PyGTK2, there is a good example in the examples/pygtk-demo/demos/ subdirectory in your tarball.

Edit this entry887 / Log info888 / Last changed on Tue Oct 5 16:48:38 2004 by Christian Robottom Reis (kiko-at-async-com-br)

10.12.889 How do I make ENTER in an entry box activate the OK signal

  dlg = gtk.Dialog('Marker Label')
  dlg.show()

  entry = gtk.Entry()
  entry.show()
  entry.set_activates_default(gtk.TRUE)
  dlg.vbox.pack_start(entry)

  dlg.add_button(gtk.STOCK_CANCEL, gtk.RESPONSE_CANCEL)
  dlg.add_button(gtk.STOCK_OK, gtk.RESPONSE_OK)
  dlg.set_default_response(gtk.RESPONSE_OK)
  response = dlg.run()

  if response == gtk.RESPONSE_OK:
      label = entry.get_text()
      print label
  dlg.destroy()

Edit this entry890 / Log info891 / Last changed on Thu Jun 12 16:26:58 2003 by John Hunter (jdhunter-at-ace-bsd-uchicago-edu)

10.13.892 When closing the GnomeAbout box (or other GtkDialog subclasses), I get crashes and weird callback behaviour. What up with that?

Jon Willeke took the time to point out that in the case of GnomeAbout, to avoid having a window be destroyed when you close it, you need to also connect to the "response" handler. Malcolm Tredinnick offered a more detailed explanation of how this works:

A GtkDialog box has two main signals it implements: 'close' and 'response'. It also inherits the 'delete-event' signal from the GtkWidget class which also has a role to play here.

The 'response' signal is emitted pretty much whenever any action happens that causes the dialog box to finish running. The response signal emission will contain a "response ID" which can be user-defined or any one of the gtk.RESPONSE_* constants in pyGTK. The standard values correspond to things like one of the standard buttons being pushed or the window being destroyed. You can act differently based on the response ID.

The 'delete' signal is emitted whenever the corresponding GtkWidget is deleted in a "strange" (for want of a better word) way. The main case here is when the user closes the window via the window manager (Alt-F4, or clicking on the 'X' button in a typical window manager, for example). In that case, you also get a 'response' signal, so generally you just ignore the 'delete' signal (return gtk.TRUE as has been mentioned elsewhere).

For your standard GtkDialog widget, the only way the 'close' signal is emitted is when the Escape key is pressed. Widgets deriving from GtkDialog may have other buttons that are hooked up to emit 'close', but by default it is only bound to the Escape key (try it and see for the About dialog -- you can close it with Escape and it emits the predicted signal).

Colin Fox posted a summary of the signals he had to connect and the methods he needed to define to make things work as expected:

  def __init__(self, *args):
      # ...
      self.connect("response", on_aboutbox_response)
      self.connect("close", on_aboutbox_close)
      self.connect("delete_event", on_aboutbox_close)

  def on_aboutbox_response(self, dialog, response, *args):
      # system-defined GtkDialog responses are always negative, in which    
      # case we want to hide it
      if response < 0:
        dialog.hide()
        dialog.emit_stop_by_name('response')

  def on_aboutbox_close(self, widget, event=None):
      self.aboutbox.hide()
      return gtk.TRUE

It remains to be seen why you have to emit_stop_by_name() in the response handler -- it might be a GTK+ bug, but nobody alive seems to know the answer.

Edit this entry894 / Log info895 / Last changed on Tue Jan 13 12:40:32 2004 by Christian Reis (kiko-at-async-com-br)

10.14.896 I created a modal dialog, but clicking on the main window covers it!

  dialog.set_transient_for(main_window)

Edit this entry898 / Log info899 / Last changed on Tue Sep 2 14:19:06 2003 by Christian Reis (kiko-at-async-com-br)

10.15.900 How do I get the position of my window in absolute terms (IOW, relative to the root X window)

The get_position() method returns the position of the window relative to its parent window.

Edit this entry901 / Log info902 / Last changed on Fri Sep 19 20:42:18 2003 by Christian Reis (kiko-at-async-com-br)

10.16.903 How do I start up a window maximized?

  win = gtk.Window()
  win.maximize()
  win.show()
  gtk.main()

Edit this entry904 / Log info905 / Last changed on Thu Sep 2 11:13:30 2004 by Christian Robottom Reis (kiko-at-async-com-br)

10.17.906 How do I run a dialog without running another main loop?

However, in some cases (for example when integrating with twisted) you do not want to use a nested mainloop, but rather reuse the current one.

So, here is a non blocking version version of GtkDialog.run that reuses the current mainloop:

 def dialog_response_cb(dialog, response_id):
   dialog.destroy()

   if response_id == gtk.RESPONSE_OK:
     print 'OK clicked'

 def dialog_run(dialog):
   if not dialog.modal:
     dialog.set_modal(True)
   dialog.connect('response', dialog_response_cb)
   dialog.show()

Edit this entry907 / Log info908 / Last changed on Wed Feb 23 13:49:48 2005 by Johan Dahlin (johan-at-gnome-org)

10.18.909 Changing a Window's background color

   import pygtk
   pygtk.require('2.0')
   import gtk

   class FirstWin:
       def __init__(self):
           self.win = gtk.Window(gtk.WINDOW_TOPLEVEL)
           color = gtk.gdk.color_parse('#234fdb')
           self.win.modify_bg(gtk.STATE_NORMAL, color)
           #  To change the color again, just modify it again
           self.win.show()

       def main(self):
           gtk.main()

   if __name__ == "__main__":
       first = FirstWin()
       first.main()

Edit this entry910 / Log info911 / Last changed on Wed Apr 20 03:59:57 2005 by Charles Hixson (charleshixsn-at-earthlink-net)

10.19.912 How do I get XID for a GtkWindow? And for the root window?

  >>> win = gtk.Window()
  >>> print win.window
  None

  >>> win.realize()

  >>> print win.window.xid
  58720259L

  >>> root = gtk.gdk.screen_get_default().get_root_window()
  >>> print root.xid
  72L

Edit this entry913 / Log info914 / Last changed on Mon May 16 12:41:49 2005 by Johan Dahlin (johan-at-gnome-org)

10.20.915 How can I make my window appear in the center of the screen?

   window.set_position(gtk.WIN_POS_CENTER)

Edit this entry917 / Log info918 / Last changed on Sat Jul 9 22:54:39 2005 by Johan Dahlin (johan-at-gnome-org)

10.21.919 How to hide a window when clicking the close button (instead of destroying it)

  def hide_window(window, event):
    window.hide()
    return True

  window.connect('delete-event', hide_window)

Edit this entry920 / Log info921 / Last changed on Fri Sep 2 20:18:07 2005 by Raphael Slinckx (raphael-at-slinckx-net)

10.22.922 How can I find out when my GtkWindow is minimized?

Connect to the window-state-event signal of the window and check if the window was iconified:

 def window_state_event_cb(window, event):
   if event.changed_mask & gtk.gdk.WINDOW_STATE_ICONIFIED:
      if event.new_window_state & gtk.gdk.WINDOW_STATE_ICONIFIED:
         print 'Window was minimized!'
      else:
         print 'Window was unminimized!'

 window = gtk.Window()
 window.connect('window-state-event', window_state_event_cb)

 gtk.gdk.WINDOW_STATE_WITHDRAWN
 gtk.gdk.WINDOW_STATE_ICONIFIED
 gtk.gdk.WINDOW_STATE_MAXIMIZED 
 gtk.gdk.WINDOW_STATE_STICKY

Edit this entry923 / Log info924 / Last changed on Fri Jan 6 12:46:08 2006 by Johan Dahlin (johan-at-gnome-org)

10.23.925 How can I find out if a gtk.Window is visible?

 self.window = gtk.Window()
 self.window.show()
 self.window.get_property("visible")

Edit this entry926 / Log info927 / Last changed on Fri Jan 27 09:00:59 2006 by Marc (m4rccd-at-yahoo-com)

11. Menus: Gtk*Menu and Gtk*MenuItem GtkToolbar

11.1.928 How do I turn off tearoff menus in libglade?

 [UI_GnomeApp]
 Menubar_detachable=false
 Menus_have_tearoff=false

Johan has suggested I turn off Gnome support in the glade files. That doesn't work either.

I currently think this is a problem with libglade itself. Pure PyGTK apps don't have tearoff menus by default (see testgtk.py for an example).

Edit this entry929 / Log info930 / Last changed on Thu Jan 31 20:16:31 2002 by kiko (kiko-at-async-com-br)

11.2.931 How do I pop up a menu with a button click?

 def popup(widget, event):
   popup_menu.popup(None, None, None, event.button, event.time)

You are also advised to call popup_menu.attach_to_widget() or at least .set_screen() so your application does not suffer in multiple screens environments.

Callling attach_to_widget() also means that your menu will be destroyed when widget that is being attached to, is destroyed. Popdown that happens by GTK does NOT destroy the menu, so if you want this behaviour, connect to 'deactivate' signal and in callback do widget.destroy()

Don't ask me what the None's are supposed to be. The API dox say:

 GtkWidget *parent_menu_shell,
 GtkWidget *parent_menu_item,
 GtkMenuPositionFunc func,
 gpointer data, 
 guint button,
 guint32 activate_time

 def popup(self, pms, pmi, func, button, time)

Edit this entry932 / Log info933 / Last changed on Fri Apr 7 09:44:20 2006 by Nikos Kouremenos (kourem-at-gmail-com)

11.3.934 How do I find out if a GtkCheckMenuItem is selected (active)?

 m = menu.get_menu()
 items = m.children()
 # assuming all items are checkitems
 for i in items:
  if i.active:
    print "Item %i is active"

Edit this entry935 / Log info936 / Last changed on Thu Jul 11 13:20:57 2002 by Christian Reis (kiko-at-async-com-br)

11.4.937 I create a menubar with ItemFactory, but it disappears

e.g.

   self.item_factory = gtk.ItemFactory(gtk.MenuBar, "<main>", accel_group)

Storing a reference to the ItemFactory where I could retrieve it later prevents the garbage collector from tidying it up. A global variable would work too, but of course "global vars are bad".

Edit this entry938 / Log info939 / Last changed on Mon Jan 5 23:06:31 2004 by David Moore (djm-at-linuxsoftware-co-nz)

11.5.940 When specifying items to an ItemFactory, I pass the extra argument for the image but I can't see anything!

For example, using a stock image, assuming popup_stop is the callback function:

 factory = gtk.ItemFactory(gtk.Menu, '<foo_popup'>)
 items = (("/_Stop", None, popup_stop, 0, "<StockItem>",  gtk.STOCK_CANCEL),)
 factory.create_items(items)

Edit this entry941 / Log info942 / Last changed on Thu Feb 19 12:47:05 2004 by Christian Reis (kiko-at-async-com-br)

11.6.943 How do I specify and save accelerators for my menu?

You can save the specified accelerators using gtk.accel_map_save(filename) and gtk.accel_map_load(filename). The stored file uses the accelpaths to associate the stored entry with the menu entry, so be sure to set language independent accelpaths for the menus and menu entries (and include some text prefix to make the windows distinguishable since accel_map_* functions work in app global scope).

XXX: providing a default set of accelerators for an application

Edit this entry944 / Log info945 / Last changed on Mon Nov 29 17:16:35 2004 by Danny Milosavljevic (danny_milo-at-yahoo-com)

11.7.946 How to i put a custom icon and custom label in a gtk.ImageMenuItem

 item = gtk.ImageMenuItem('Foo')
 img = gtk.Image()
 img.set_from_file('data/myimage.png')
 item.set_image(img)

 item = gtk.ImageMenuItem('Foo')
 img = gtk.image_new_from_stock(gtk.STOCK_REFRESH, gtk.ICON_SIZE_MENU)
 item.set_image(img)

Edit this entry947 / Log info948 / Last changed on Sun Oct 9 15:46:51 2005 by Nikos Kouremenos (kourem-at-gmail-com)

12. Simple Containers: GtkBoxes, GtkTable, GtkFixed, GtkAlignment

12.1.949 What are the parameters to GtkAlignment.set()

 align.set(xalign, yalign, xscale, yscale)

• xalign: the horizontal alignment of the child widget, from 0 (left) to 1 (right).
• yalign: the vertical alignment of the child widget, from 0 (top) to 1 (bottom).
• xscale: the amount that the child widget expands horizontally to fill up unused space, from 0 to 1. A value of 0 indicates that the child widget should never expand. A value of 1 indicates that the child widget will expand to fill all of the space allocated for the GtkAlignment.
• yscale: the amount that the child widget expands vertically to fill up unused space, from 0 to 1. The values are similar to xscale.

If you pack a GtkAlignment into a container, be careful to set the scale attributes to 1 or the alignment will not expand to take up the whole space in the parent widget (instead, an empty space will be left in the outer container, and get_allocation() will return bogus values for the GtkAlignment).

Edit this entry950 / Log info951 / Last changed on Sat Oct 12 02:20:53 2002 by Christian Reis (kiko-at-async-com-br)

12.2.952 How does packing work (or how do I get my widget to stay the size I want)

This is often confusing, and a good idea would be to play around a bit with gazpacho or glade to get a feeling for the box model. Essentially, the idea is based on a few key concepts:

• if you have a container a single child, this child will take up all its space minus its border:

                                        Border
    .----------------------------------/---.
    | Window                          H    |
    | .----------------------------------. |
    | | Entry                            | |   
    | '----------------------------------' |
    |                                      |
    '--------------------------------------

• if you have a container (say a V/HBox) with two (or more) children, they will fight[*] to determine who takes up more space:

    .---------------------------------------------------------.
    | Window                                                  |
    | .--------------------. .------------------------------. |
    | | Entry1             | | Entry2                       | |
    | | packed w/ expand=0 | | packed w/ expand=1           | |
    | '--------------------' '------------------------------' |
    |                                                         |
    '---------------------------------------------------------'

• the default and requested sizes of the widgets, which normally depends on things like their contents (for labels, in particular).

• the expand and fill arguments supplied to add() or pack_start/end():
  • Expand means "I will fight for space"
  • No expand means "I don't care for space"
  • Fill means "If I got more space, I will occupy it with my content"
  • No fill means "If I got more space, leave it blank because I don't care for it"

This is important to understand when assembling your interfaces, and is the most peculiar thing about GTK+ programming to a newbie; although the packing-based widget geometry is more complex to understand initially than MS-style fixed layouts, it is infinitely superior, because GTK+ windows actually resize properly.

Spend some time experimenting with the "packing" tab in gazpacho/glade and some composite interfaces: it will teach you a lot in very short time.

[*] A cute analogy; in reality fill, expansion, requested sizes, widget expansion semantics, container packing semantics, electron spins and lunar cycles are computed to determine how much space each widget wins.

Edit this entry953 / Log info954 / Last changed on Thu Jul 22 21:15:49 2004 by Christian Robottom Reis (kiko-at-async-com-br)

13. Lists and Trees: GtkList/TreeView

13.1.955 Is there a nice tutorial on using GtkTreeView and GtkTreeModel?

Lars Wirzenius wrote a very nice guide using Python for all his examples, and it's definitely worth checking out: [liw.iki.fi]957

Edit this entry958 / Log info959 / Last changed on Sun Nov 28 20:24:06 2004 by pachi (pachi-at-mmn-arquitectos-com)

13.2.960 How do the TreeStore and ListStore sequence APIs behave? [PyGTK2]

    liststore = gtk.ListStore(str, str, int)   # create list store  
    treestore = gtk.TreeStore(int, str, str)   # and a tree store
    ...   # fill in some rows
    row = liststore[42]   # get the row object for the 42nd row in the list
    print row[2]   # print 3rd column in row
    print liststore[42][2]   # or the two operations can be combined

    # print first column of first child of the second top level node
    print treestore[1,0][0]

    # assignment works too
    liststore[42][2] = 42 

    # you can also assign to the entire row in one go
    treestore[1,0] = (5, 'foo', 'bar')

    # or delete rows
    del liststore[42]

    * next: next sibling row object
    * parent: parent row object
    * model: the GtkTreeModel for this row
    * path: the tree path of this row.
    * iter: a GtkTreeIter pointing at this row.

    for row in liststore:
        print row[0]

Extra optional argument on append/prepend/insert methods: I added an additional optional argument to the insert, insert_before, insert_after, prepend and append methods. If passed, the additional argument is interpreted as a sequence of values of the columns in the new row. For instance:

    liststore.append(('foo', 'bar', 42))

Edit this entry961 / Log info962 / Last changed on Wed Apr 9 18:21:05 2003 by Christian Reis (kiko-at-async-com-br)

13.3.963 How do GtkTreePaths work? [PyGTK2]

• strings: these get parsed by gtk_tree_path_new_from_string(). The syntax is like "1:2:3:4".
• tuples of integers: as described above.
• integers: treated as a path of length one. Useful for GtkListStores, as made apparent in FAQ 13.2964.

By accepting integers as length-one tree paths, the user can just pass in integers for GtkListStore methods, and think of them as row numbers. They don't even need to think about paths.

Edit this entry965 / Log info966 / Last changed on Mon Sep 29 12:23:10 2003 by Christian Reis (kiko-at-async-com-br)

13.4.967 How do I define columns for a TreeView using TreeViewColumn?

Then, you add a column to your tree view. You can instantiate a TreeViewColumn manually:

 col = gtk.TreeViewColumn(title, renderer, property1=column1, ...)
 treeview.insert_column(col, position)
 # note that treeview.append_column() exists too

 gtk.TreeView.insert_column_with_attributes(position, title, renderer,
                                            property1=column1, ....)

• position: the column position (index) in the treeview, usually -1, meaning the last position (append);

• title: the text string to appear in the column header;

• renderer: the gtk.CellRenderer subclass created in the first step

• property1=column1, ....: a series of key=value pairs, connecting cell renderer properties to tree model column numbers (starting from zero); use of symbolic constants instead of column numbers is advised.

  For CellRendererText, the most common cell renderer, the most important properties are 'text' (indicating from which treemodel column the data should come), 'markup' (the same as text, but indicating that pango markup should be parsed from the data), and 'visible' (indicating if the column should be displayed by default or not).

Notice that the order and number of columns in a tree view is unrelated to the columns in a tree model. It is not unusual to store extra application data in a hidden column in the tree model. It is only the property=column parameters that truly make the connection between the tree model and the tree view.

And now a simple example:

 COLUMN_NAME = 2              # the third model column holds 'name';
                              # column numbers start at zero, mind you
 renderer = gtk.CellRendererText()
 treeview.insert_column_with_attributes(-1, 'Name', renderer,
                                        text=COLUMN_NAME)

(Answer contributed by Gustavo Carneiro)

Edit this entry969 / Log info970 / Last changed on Sun Oct 26 12:37:49 2003 by Christian Reis (kiko-at-async-com-br)

13.5.971 How do I create my own custom TreeModel.

Some other examples making use of GenericTreeModel:

• Michele Campeot's filesystem viewer: [www.micampe.it]973

• NamespaceModel from Arjan Molena's gaphor (in gaphor/ui/namespace.py): [gaphor.sourceforge.net]974

• The GTK TreeModel is very similar to the TreeModel class from Java Swing: [java.sun.com]975

Edit this entry976 / Log info977 / Last changed on Mon Dec 30 12:53:11 2002 by Dave Cook (dave-at-davidcook-org)

13.6.978 How do I put icons in a TreeView?

 (COL_PIXBUF, COL_STRING) = range(2)
 model = gtk.ListStore(gtk.gdk.Pixbuf, str)
 treeview = gtk.TreeView(model)
 model.append([gtk.gdk.Pixbuf('icon.png'), 'This is a string'])

 renderer = gtk.CellRendererPixbuf()
 column = gtk.TreeViewColumn('Icon', cell, pixbuf=COL_PIXBUF)
 treeview.append_column(column)

 renderer = gtk.CellRendererText()
 column = gtk.TreeViewColumn('Text', cell, text=COL_STRING)
 treeview.append_column(column)

Advanced usage, if you want to be able to sgiw the icon and the string in the same column, you'd have to replace the last 6 lines in the above example with the following code:

  column = gtk.TreeViewColumn()
  column.set_title('Icons & Text')
  treeview.append_column(column)

  rendererer = gtk.CellRendererPixbuf()
  column.pack_start(renderer, expand=False)
  column.add_attribute(renderer, 'pixbuf', COL_PIXBUF)

  renderer = gtk.CellRendererText()
  column.pack_start(renderer, expand=True)
  column.add_attribute(renderer, 'text', COL_STRING)

Edit this entry979 / Log info980 / Last changed on Wed Jul 6 09:52:40 2005 by Johan Dahlin (johan-at-gnome-org)

13.7.981 How do I get all the selections in my TreeView.

 selected = []
 selection = treeview.get_selection()
 selection.selected_foreach(lambda model, path, iter, 
                            sel=selected: sel.append(path))

 selection = treeview.get_selection()
 model, selected = selection.get_selected_rows()

Edit this entry983 / Log info984 / Last changed on Thu Nov 18 12:40:20 2004 by Chris Lambacher (lambacck-at-computer-org)

13.8.985 How do I delete the selected rows in a TreeView?

   selection = self.list_view.get_selection() 
   model, iter, = selection.get_selected()
   if iter:
      path = model.get_path(iter)
      model.remove(iter)
      # now that we removed the selection, play nice with 
      # the user and select the next item
      selection.select_path(path)

      # well, if there was no selection that meant the user
      # removed the last entry, so we try to select the 
      # last item
      if not selection.path_is_selected(path):
         row = path[0]-1
         # test case for empty lists
         if row >= 0:
            selection.select_path((row,))

Edit this entry987 / Log info988 / Last changed on Sun May 15 19:04:46 2005 by Christian Reis (kiko-at-async-com-br)

13.9.989 Is there a way to mass-specify columns in ListStore?

 # 4 columns, 1-3 string, 4 int.
 columns = [gobject.TYPE_STRING]*3 + [gobject.TYPE_INT]
 gtk.ListStore(*columns)

Edit this entry990 / Log info991 / Last changed on Wed Nov 6 15:22:59 2002 by Christian Reis (kiko-at-async-com-br)

13.10.992 How do I make a GtkTreeView with editable cells?

1) Set the "editable" property to True for all the cells in a column:

 renderer = gtk.CellRendererText()
 renderer.connect('edited', cell_edited_callback)
 renderer.set_property('editable', True)
 treeview.insert_column_with_attributes(-1, 'Editable String', renderer, text=0)

2) Set the "editable" property to True for individual cells:

The first thing you have to do is include a column of type boolean. It will specify if a row is editable or not.

 model = gtk.TreeStore(str, int, bool)

 iter = model.append()
 model.set_value(iter, 0, 'foo')
 model.set_value(iter, 1, 34)
 model.set_value(iter, 2, True)

 treeView = gtk.TreeView(model)

 renderer = gtk.CellRendererText()
 column = gtk.TreeViewColumn('column 1', renderer, text=0, editable=2)
 treeView.append_column(column)

 renderer = gtk.CellRendererText()
 column = gtk.TreeViewColumn('column 2', renderer, text=1, editable=2)
 treeView.append_column(column)

The process is similar for ToggleButtons, but the property names are different and you need to set up a callback for the toggle signal to make the changes persistent. So let's create a simple model:

 model = gtk.ListStore(bool, bool)
 model.append(row=(True, True))
 model.append(row=(False, False))

 treeview = gtk.TreeView(model)
 renderer = gtk.CellRendererToggle()
 renderer.connect('toggled', toggled_callback, model)
 column = gtk.TreeViewColumn('test', renderer, active=0, activatable=1)
 treeview.append_column(column)

 def toggled_callback(cell, path, model=None):
     iter = model.get_iter(path)
     model.set_value(iter, 0, not cell.get_active())

• Note that the toggled_callback changes the model value for column 0. The path argument is actually the row number in the model. In a multi-column view, add a fourth argument to the renderer.connect call to pass the column to the callback. For example, if the ToggleButton is in column 2:

    renderer.connect('toggled', toggled_callback, model, 1)

 def toggled_callback(cell, path, model=None, col_num=0):

Edit this entry993 / Log info994 / Last changed on Wed Apr 6 19:41:55 2005 by Johan Dahlin (johan-at-gnome-org)

13.11.995 What signal is emitted when a user selects/clicks on a row in a GtkTreeView?

 def on_selection_changed(selection, ...): 
     model, paths = selection.get_selected_rows()
     if paths:
        # do the thing!

 self.treeView = gtk.TreeView(mymodel)
 selection = self.treeView.get_selection()
 selection.connect('changed', on_selection_changed)

(Lorenzo Gil Sanchez, David Cook)

Edit this entry997 / Log info998 / Last changed on Tue Jun 21 19:37:06 2005 by Christian Reis (kiko-at-async-com-br)

13.12.999 How do I change the color of the alternate row shading on the TreeView widget?

The gtkrc directives would look something like this:

    style "mystyle" {
        GtkTreeView::even_row_color = "xxxx"
        GtkTreeView::odd_row_color = "yyyy"
    }

Edit this entry1000 / Log info1001 / Last changed on Fri Apr 25 01:10:18 2003 by Christian Reis (kiko-at-async-com-br)

13.13.1002 How do I create a lazy TreeView?

An easy way to do this is to append a "blank" child row to each row that you know will have children. Schematically:

 if hasChildren(iter):
     store.append(iter)

Then in the "row-expanded" handler, check for a NULL value in a column you are sure will never be NULL for actual data:

 def on_row_expanded(view, iter, path):
     store = view.get_model()
     child = store.iter_children(iter)
     if store.get_value(child, 0) is None:
         # append actual rows at iter

Edit this entry1003 / Log info1004 / Last changed on Thu Jun 12 12:11:44 2003 by Dave Cook (dave-at-davidcook-org)

13.14.1005 How do I show different images when a TreeView item is expanded and collapsed.

  class silly_list(gtk.TreeView):
    def __init__(self):
        gtk.TreeView.__init__(self)
        self.init_model()
        self.init_view_columns()

    def init_model(self):       
        store = gtk.TreeStore(gtk.gdk.Pixbuf, gtk.gdk.Pixbuf, str)
        # Fill the model with some silly sample data.             
        add_pixbuf = self.get_icon_pixbuf(gtk.STOCK_ADD)
        remove_pixbuf = self.get_icon_pixbuf(gtk.STOCK_REMOVE)
        for p in xrange(10):
            parent = store.append(None, (add_pixbuf, remove_pixbuf,
                                         'Parent %s' % p))
            for c in xrange(5):
                store.append(parent, (None, None, 'Child %s' % c))
        self.set_model(store)

    def get_icon_pixbuf(self, stock):
        return self.render_icon(stock,
                                size=gtk.ICON_SIZE_MENU,
                                detail=None)

    def init_view_columns(self):            
        col = gtk.TreeViewColumn()
        col.set_title('Silly Example')
        render_pixbuf = gtk.CellRendererPixbuf()
        col.pack_start(render_pixbuf, expand=False)
        col.add_attribute(render_pixbuf, 'pixbuf-expander-closed', 0)
        col.add_attribute(render_pixbuf, 'pixbuf-expander-open', 1)
        render_text = gtk.CellRendererText()
        col.pack_start(render_text, expand=True)
        col.add_attribute(render_text, 'text', 2)
        self.append_column(col)

    def __init__(self):
       # same as above
       self.connect('row-expanded', self.on_row_expanded)
       self.connect('row-collapsed', self.on_row_collapsed)

    def set_row_icon(self, treeiter, stock):
        store = self.get_model()
        store.set(treeiter, 0, self.get_icon_pixbuf(stock))

    def on_row_expanded(self, treeiter, path):
        self.set_row_icon(treeiter, gtk.STOCK_REMOVE)
    on_row_expanded = staticmethod(on_row_expanded)

    def on_row_collapsed(self, treeiter, path):
        self.set_row_icon(treeiter, gtk.STOCK_ADD)
    on_row_collapsed = staticmethod(on_row_collapsed)

Edit this entry1007 / Log info1008 / Last changed on Mon Sep 29 12:21:36 2003 by Christian Reis (kiko-at-async-com-br)

13.15.1009 My TreeView/TreeModel rows represent instances (or any python object), but how can I keep track of them?

For Example:

 model = gtk.ListStore(gobject.TYPE_STRING, gobject.TYPE_PYOBJECT)

Now you can set the reference to the instance for a row like this:

 COLUMN_TEXT = 0
 COLUMN_OBJECT = 1

 # the iter is pointing to the row which you want to set
 model.set(iter, COLUMN_TEXT, unicode("Hey", 'iso-8859-1'),   COLUMN_OBJECT, theObject)

Later on if you want to get the Reference to the Instance again:

 COLUMN_TEXT = 0
 COLUMN_OBJECT = 1

 # the iter is pointing to the row which you want to get
 object = model.get_value(iter, COLUMN_OBJECT)

Edit this entry1010 / Log info1011 / Last changed on Wed Feb 11 12:53:43 2004 by Christian Reis (kiko-at-async-com-br)

13.16.1012 My Treeview shows all my strings/text values as numbers in the columns!

Edit this entry1013 / Log info1014 / Last changed on Mon Sep 29 11:36:27 2003 by Christian Reis (kiko-at-async-com-br)

13.17.1015 How do I make a popup menu appear when I right-click my TreeView?

  def on_treeview_button_press_event(self, treeview, event):
    if event.button == 3:
        x = int(event.x)
        y = int(event.y)
        time = event.time
        pthinfo = treeview.get_path_at_pos(x, y)
        if pthinfo is not None:
            path, col, cellx, celly = pthinfo
            treeview.grab_focus()
            treeview.set_cursor( path, col, 0)
            self.popup.popup( None, None, None, event.button, time)
        return 1

Edit this entry1016 / Log info1017 / Last changed on Sat Dec 31 15:30:08 2005 by Gustavo Carneiro (gjc-at-inescporto-pt)

13.18.1018 Is it possible for a TreeModel to tell a CellRendererToggle that it is in an "in between" (inconsistent) state?

The C documentation lists all the CellRendererToggle's properties: [developer.gnome.org]1019

Edit this entry1020 / Log info1021 / Last changed on Mon Sep 29 11:51:45 2003 by Christian Reis (kiko-at-async-com-br)

13.19.1022 How do I change alignment on a specific cell renderer?

 renderer.set_property('xalign', 1.0)

Another thing to note is that renderers use the normal GTK packing mechanism. If you want one renderer to expand and take up any extra space (or `compete' for it if more than one cell has expand=TRUE), pack it with expand=TRUE, and vice-versa.

Edit this entry1023 / Log info1024 / Last changed on Mon Jan 13 13:59:04 2003 by Christian Reis (kiko-at-async-com-br)

13.20.1025 How do I keep GenericTreeModel from leaking references?

If you turn off "leak_references" and don't keep careful track of your nodes, you get a good old-fashioned segfault.

One easy way to "ensure that objects which are used as iterators are not destroyed before the iterator is destroyed" is to have your model keep a dictionary or list of tree nodes so that a reference stays around until you explicitly delete it. (See FAQ 13.151026 for another method of keeping track of node references.)

 class MyTreeModel(GenericTreeModel):
      def __init__(self, ...)
 	 GenericTreeModel.__init__(self)
 	 self.set_property("leak_references", 0)
          ...
         self.nodemap = {} # a mapping from paths to nodes
          ...

      def on_get_iter(self, path):
 	 ...
         node = self.nodemap.setdefault(path, MyNodeClass(path, ...))
         return node

Edit this entry1027 / Log info1028 / Last changed on Mon Dec 30 21:20:02 2002 by Dave Cook (dave-at-davidcook-org)

13.21.1029 How do I get changes in my TreeModel to show up in my TreeView?

• row_changed() emits the "row-changed" signal. Call this when there are changes in the content of a row (node) in your model.

• row_deleted() emits the "row-deleted" signal. Call this when a row is deleted.

• row_has_child_toggled() emits the "row-has-child-toggled" signal. Call this after adding children to a childless row or removing all the children of a row.

• row_inserted() emits the "row-inserted" signal. Call this when a new row is inserted or appended to the model.

You can also emit the signals directly with the gtk.Object emit() method. See the TreeModel API reference for more info on these functions and signals: [developer.gnome.org]1030

Edit this entry1031 / Log info1032 / Last changed on Tue Dec 16 15:24:51 2003 by Christian Reis (kiko-at-async-com-br)

13.22.1033 How do I display a combo box in a Treeview?

If you want to do it the old way:

Lorenzo Gil Sanchez writes: Currently, you can only do that with C. With Python you can create a custom CellRenderer to render the cells in the way you want. What you can not do in Python is a CellRender with edit capabilities, like a combo box. If you want a CellRenderer to support edition it must implement the CellEditable interface. There is no way to make a Python class to implement a GLib interface with the current PyGTK bindings.

Having said that, Lorenzo did provide a hacked version of a Treeview with Combos; check it out at [www.mail-archive.com]1035

Edit this entry1036 / Log info1037 / Last changed on Sat Sep 3 14:23:49 2005 by Kees Cook (kees-at-outflux-net)

13.23.1038 Why doesn't expand_row() display an expanded row for paths longer than one element?

  for i in range(len(path))
    treeview.expand_row(path[:i+1], gtk.FALSE)

Edit this entry1039 / Log info1040 / Last changed on Fri Oct 17 02:40:08 2003 by Doug Quale (quale1-at-charter-net)

13.24.1041 How do I transform the value in my model before displaying it in the TreeView?

Here's a quick and dirty example:

  def render_filesize(column, cell, model, iter):
      origstr = cell.get_property('text')
      sizestr = origstr + 'B' # Add a "B" for bytes after value
      cell.set_property('text', sizestr)

  model = gtk.ListStore(str, int)
  view = gtk.TreeView(model)

  column = gtk.TreeViewColumn('File', gtk.CellRendererText(), text=0)
  view.append_column(column)

  size_renderer = gtk.CellRendererText()
  size_renderer.set_property('xalign', 1.0)
  size_column = gtk.TreeViewColumn('Size', size_renderer, text=1)
  size_column.set_cell_data_func(size_renderer, render_filesize)
  view.append_column(size_column)

Edit this entry1042 / Log info1043 / Last changed on Fri Oct 17 01:32:13 2003 by Doug Quale (quale1-at-charter-net)

13.25.1044 How do I delete multiple selections?

  # list that stores all the iterators of the selected rows
  selectList = []
  # function to get iterator of selected row
  def GetSelectedIter(model,path,iter,rowList):
    selectIter = model.get_iter(path)
    rowList.append(selectIter)

  # get reference to each row 
  selection = watchvar_treeview.get_selection()
  selection.selected_foreach(GetSelectedIter,selectList)
  # actual removal of rows
  for iter in selectList:
    watchvar_treestore.remove(iter)

    selection = treeview.get_selection()
    model, selected = selection.get_selected_rows()
    iters = [model.get_iter(path) for path in selected]
    for iter in iters:
         model.remove(iter)

Edit this entry1045 / Log info1046 / Last changed on Wed Dec 22 14:09:44 2004 by Chris Lambacher (lambacck-at-computer-org)

13.26.1047 How do I perform an action when the user clicks on the title column of a TreeView?

The callback will receive as an argument the clicked column instance, and you can either attach data to the TreeViewColumn or pass user data in when you connect the signal (for example a key or column number). You'll usually do this when adding the columns to the TreeView.

(David Cook)

Edit this entry1049 / Log info1050 / Last changed on Mon Nov 17 12:17:39 2003 by Christian Reis (kiko-at-async-com-br)

13.27.1051 How do I run a command for each TreeModel row, or how does TreeModel.foreach() work?

  def foreach_handler(model, path, iter, user_data):
    # get value from current row, column 1
    val1 = model.get_value(iter, 1)
    print "value is: %s" % val1
    # set user_data ("my value") as value of current row, column 2
    model.set_value(iter, 2, user_data)

  treemodel.foreach(foreach_handler, "my value")

Edit this entry1052 / Log info1053 / Last changed on Wed Sep 8 04:08:13 2004 by Doug Quale (quale1-at-charter-net)

13.28.1054 When connecting to 'row-inserted', my model value is always None. Why?

This gotcha seems to be almost certain to trip up everyone at some point. When the 'row-inserted' signal is emitted, the model frequently (always?) contains unitialized (empty) rows. The reason for this is kind of odd, but it's a logical consequence of the gtk+ C API.

If you look at the C API, there's no way to add an initialized row to a TreeModel in one step. The available functions like ListStore.append() and ListStore.insert() add new uninitialized rows to the model and you must subsequently use ListStore.set() to set the column values in the row. This seems harmless, but gtk+ emits the 'row-inserted' signal as soon as the empty row is added and confusion and befuddlement ensues in the signal handlers.

Because of this, the 'row-inserted' signal isn't very useful. Most of the time when you might think you want 'row-inserted' you actually want 'row-changed' instead. This will catch the ListStore.set() which almost inevitably follows an insert. Try changing your handler to be called on 'row-changed' instead of 'row-inserted' to see if that works better. Or you can leave the handler as it is and add a new 'row-changed' handler to set the correct row values when they are set in the model.

Edit this entry1055 / Log info1056 / Last changed on Wed Nov 19 11:00:35 2003 by Christian Reis (kiko-at-async-com-br)

13.29.1057 How do I use a python object to store data for all the columns in a row?

   def dict_cell_data_func(column, cell, model, iter, col_key):
     text = model.get_value(iter, col_key[0])[col_key[1]]
     cell.set_property("text", text)

   model = gtk.ListStore(object)
   tree_view = gtk.TreeView(model)
   renderer = gtk.CellRendererText()
   column = gtk.TreeViewColumn("Foo", renderer)
   column.set_cell_data_func(renderer, dict_cell_data_func, (0, 'foo'))
   tree_view.append_column(column)

   obj = {'foo': 'foo text'}
   model.append([obj])

Edit this entry1058 / Log info1059 / Last changed on Fri Jan 30 21:09:22 2004 by Jeff Bowden (jlb-at-houseofdistraction-com)

13.30.1060 How do I move rows around in a GtkTreeView?

Remember to send in model as the second argument to the connect handler, like this:

 button.connect("clicked", button_clicked_cb, model)

 def button_clicked_cb(button, model):
   selection = model.get_selection()
   model, selected = selection.get_selected()
   assert not selected is None
   path = model.get_path(selected)
   row = path[0]
   assert row > 0
   this = model[row][0]
   prev = model[row-1][0]
   model[row-1][0] = this
   model[row][0] = prev
   selection.select_path(row-1)

This handler takes a model, which should be specified as the optional "user_data" argument while connect()ing. You may of course obtain the model reference through other means, such as via an instance variable.

In case you have an iter and need to obtain a corresponding path to it, just use the model's get_path() method, which takes an iter. From this path you can obtain the row id. (There is no iter_prev() method corresponding to the model's iter_next()).

(Doug Quale)

Edit this entry1062 / Log info1063 / Last changed on Tue Jan 27 12:52:12 2004 by Johan Dahlin (johan-at-gnome-org)

13.31.1064 How do I change the color of a row or column of a TreeView?

 renderer = gtk.CellRendererText()
 renderer.set_property("foreground", "red")
 # ... and use renderer in TreeViewColumn 

 model = gtk.ListStore(str, str, str, str)
 model.append(("Henrik","Ibsen","green","#23abff"))
 model.append(("Samuel","Beckett","orange","OldLace"))
 model.append(("Thomas","Mann","yellow","peach puff"))
 treeview = gtk.TreeView(model)
 renderer = gtk.CellRendererText()
 treeview.append_column(gtk.TreeViewColumn("First Name", renderer, 
                        text=0, foreground=2, background=3))
 treeview.append_column(gtk.TreeViewColumn("Last Name", renderer,
                        text=1, foreground=3, background=2))

(Walter Anger)

Edit this entry1065 / Log info1066 / Last changed on Mon Mar 8 18:27:27 2004 by Christian Reis (kiko-at-async-com-br)

13.32.1067 How do I select [or edit] a row in my TreeView?

 # assuming treeview is instantiated
 sel = treeview.get_selection()
 sel.select_path(path)

 treeview.set_cursor(path, focus_column, start_editing=True)

Note that the scroll_to_cell() call may come in handy given that the cell you want to edit may not be on-screen. Dave Aitel points out that it may be necessary to place scroll_to_cell in an idle handler after your set_cursor call or it won't work (at least in Redhat9).

Edit this entry1069 / Log info1070 / Last changed on Sun Mar 5 00:30:50 2006 by Phillip Calvin (phillipc-at-toasterlogic-com)

13.33.1071 How do I handle DnD operations in a GtkTreeView?

• Dragging of external objects into the GtkTreeView / Dragging rows out of a GtkTreeView to an external app.
• Manipulating the rows within a GtkTreeView

Furthermore, there are two ways to enable DnD for a GtkTreeView:

• The drag_dest_set()/drag_source_set() functions inherited from GtkWidget
• The enable_model_drag_dest()/enable_model_drag_source() functions specific to GtkTreeView.

Note that these functions behave differently:

• The functions inherited from GtkWidget cannot be used when one wants to use the reorderable() property of a GtkTreeView (One could still implement one's own reordering mechanism on this basis though). On the other hand they allow for external items to be dropped into the blank area of an empty treeview.
• The second set of functions, specific to GtkTreeView, allow the use of the reorderable() property. They do not enable DnD on the blank area of a GtkTreeView though. External objects can only be dropped into an already filled GtkTreeView.
• If you want to set the drag icon yourself, you cannot use the second set of functions; otherwise your custom icon will be overridden. You should use the drag_source_set_icon_pixbuf from the drag-begin handler.

Using the functions together yields the possibility of dropping external objects onto the column titles but not into the blank area. reorderable() can be used. FAQ 13.341072 includes code examples of these approaches.

Edit this entry1073 / Log info1074 / Last changed on Fri Apr 9 13:21:22 2004 by Christian Reis (kiko-at-async-com-br)

13.34.1075 How do I work with the reorderable() property of GtkTreeview?/The reorderable() property of GtkTreeView is too limited

For example, when a reparenting of rows via DnD is needed, reorderable() won't do. For these cases Walter Anger created an example that covers a reorderable GtkTreeView exaustively (more discussion on the topic can be found in the mailing list thread starting at: [www.daa.com.au]1076 ) This example is also useful for a better insight into DnD in GtkTreeViews.

Such a custom made implementation of reorderable() consists of four parts:

Proper setup of the GtkTreeView with the appropriate DnD functions:

 treeview.enable_model_drag_source(gtk.gdk.BUTTON1_MASK,
				 [("example", 0, 0)], gtk.gdk.ACTION_COPY)
 treeview.enable_model_drag_dest([("example", 0, 0)],
 				gtk.gdk.ACTION_COPY)
 treeview.connect("drag_data_received", on_dragdata_received_cb)

 def on_dragdata_received_cb(treeview, drag_context, x, y,
 						    selection, info, eventtime):
         model, iter_to_copy = treeview.get_selection().get_selected()
         temp = treeview.get_dest_row_at_pos(x, y)
         if temp != None:
             path, pos = temp
         else:
             path, pos = (len(model)-1,), gtk.TREE_VIEW_DROP_AFTER
         target_iter = model.get_iter(path)
         if check_row_path(model, iter_to_copy, target_iter):
             iter_copy(model, iter_to_copy, target_iter, pos)
             drag_context.finish(gtk.TRUE, gtk.TRUE, eventtime)
             treeview.expand_all()
         else:
             drag_context.finish(gtk.FALSE, gtk.FALSE, eventtime) 

A checking function for ancestry and equality of the row:

 def check_row_path(model, iter_to_copy, target_iter):
         path_of_iter_to_copy = model.get_path(iter_to_copy)
         path_of_target_iter = model.get_path(target_iter)
         if path_of_target_iter[0:len(path_of_iter_to_copy)] ==
 	    path_of_iter_to_copy:
             return False
         else:
             return True

 def iter_copy(model, iter_to_copy, target_iter, pos):

   	[...retrieve data of the selected row...]

         if (pos == gtk.TREE_VIEW_DROP_INTO_OR_BEFORE) or (pos ==
 	     gtk.TREE_VIEW_DROP_INTO_OR_AFTER):
             new_iter = model.prepend(target_iter, None)
         elif pos == gtk.TREE_VIEW_DROP_BEFORE:
             new_iter = model.insert_before(None, target_iter)
         elif pos == gtk.TREE_VIEW_DROP_AFTER:
             new_iter = model.insert_after(None, target_iter)

 	[...copy over the values of the old row into the new one ...]

         for n in range(model.iter_n_children(iter_to_copy)): 
             next_iter_to_copy = model.iter_nth_child(iter_to_copy, n)
             iter_copy(model, next_iter_to_copy, new_iter,
 		 gtk.TREE_VIEW_DROP_INTO_OR_BEFORE)

 	[...remove old row...]

If you're moving the data instead of copying it, change the .iter_nth_child(iter_to_copy, n) in the last part to be .iter_nth_child(iter_to_copy, 0). As you move items, next siblings all move down.

Edit this entry1077 / Log info1078 / Last changed on Thu Aug 5 23:43:27 2004 by Paul Dickson (dickson-at-permanentmail-com)

13.35.1079 How do I use the TreeModelFilter to process tree/store data automatically?

 import gtk

 # A "business object" class.  Instances will be nodes of our TreeStore.
 class Person(object):
     def __init__(self, lastname='', firstname=''):
         self.lastname = lastname
 	 self.firstname = firstname

 # Create some person objects
 people = [['Ellison', 'Larry'], ['Gates', 'Bill'], ['McNealy', 'Scott']]
 nodes = [Person(*names) for names in people]

 # Put the objects in a store.
 store = gtk.ListStore(object) # A store with only Python objects.
 for node in nodes: store.append([node])

 # Here we use a ModelFilter to synthesize values on the fly using the 
 # modify_func callback.  These values can be used for interactive 
 # searches and ComboBoxes, whereas the original store of Python objects would 
 # not be understood as valid strings by gtk.  The original TreeModel is 
 # a "child" of the ModelFiter.

 # obtain a ModelFilter from our store
 filtered = store.filter_new()

 # The modify func is where the values in the ModelFilter are computed from
 # the the objects in the child model.
 def modify_func(model, iter, col, attrs):
     # Convert the filter iter to the corresponding child model iter.
     child_model_iter = model.convert_iter_to_child_iter(iter)
     child_model = model.get_model()
     obj = child_model.get_value(child_model_iter, 0)
     return getattr(obj, attrs[col])

 # Set the modify func, passing in the "virtual" column types.  The
 # last parameter is user data to specify the attributes/properties of the 
 # business objects that we want to display.
 filtered.set_modify_func([str]*2, modify_func, ['lastname', 'firstname'])

 # Callback for printing out nodes.
 def print_node(model, path, iter):
     print [model.get_value(iter, i) for i in range(model.get_n_columns())]

 # Print out the contents of the ModelFilter.
 filtered.foreach(print_node)

 # Modify the original objects directly.
 people = [['van Rossum', 'Guido'], ['Torvalds', 'Linus'], ['Henstridge', 'James']]
 for node, names in zip(nodes, people):
     node.lastname, node.firstname = names

 # Does the ModelFilter track our changes?    
 filtered.foreach(print_node)

Edit this entry1081 / Log info1082 / Last changed on Mon Jul 5 21:31:47 2004 by Daverz (dave-at-davidcook-org)

13.36.1083 How do I unselect a path in a TreeView?

However, the gtk.TreeView class functions don't directly let you do more complex selection work, such as unselecting everything in a TreeView, or unselecting anything at all for that matter.

However, a TreeSelection object lets you do that just those sorts of things. You can get the TreeSelection object associated with any Treeview with the TreeView's get_selection() member function.

Every Treeview has one gtk.TreeSelection object associated with it. This object is associated with the TreeView, not its underlying model. (So if a particular model has multiple views, each view will have a separate selection object associated with it.)

As an example, to unselect the path of the current cursor:

  path, focus_column = treeview.get_cursor()

  treeview.get_selection().unselect_path(path)

Edit this entry1084 / Log info1085 / Last changed on Mon Jul 19 06:56:55 2004 by Mark Shewmaker (mark-at-primefactor-com)

13.37.1086 How do I avoid displaying (hide) a certain column in a TreeView?

(the great John Finlay)

Edit this entry1088 / Log info1089 / Last changed on Wed Jul 21 14:31:09 2004 by Christian Robottom Reis (kiko-at-async-com-br)

13.38.1090 How do I display pixbufs instead of numbers for integer or boolean values in my treemodel?

The cell data function is straightforward. We set the 'pixbuf' cell property to the pixbuf to display or None for a blank column. Replace MODEL_COLUMN_NUMBER with the model column number that provides the value and MY_PIXBUF with the pixbuf you want to display:

    def cell_data_func(tree_column, cell, model, tree_iter):
        if model.get_value(tree_iter, MODEL_COLUMN_NUMBER):
            pixbuf = MY_PIXBUF
        else:
            pixbuf = None
        cell.set_property('pixbuf', pixbuf)

    cell = gtk.CellRendererPixbuf()
    treeview.insert_column_with_data_func(-1, 'title xxx', cell,
         cell_data_func)

    def cell_data_func(tree_column, cell, model, tree_iter):
        if model.get_value(tree_iter, MODEL_COLUMN_NUMBER):
            stock_id = 'gtk-yes'
        else:
            stock_id = 'gtk-no'
        cell.set_property('stock-id', stock_id)

Edit this entry1091 / Log info1092 / Last changed on Fri Aug 20 20:42:51 2004 by Doug Quale (quale1-at-charter-net)

13.39.1093 I defined a TreeView in glade, how do I manipulate its columns and other properties?

Note that you get hold of your glade-defined treeview using get_widget("treeview1") as you would for any other widget in the glade widget tree. From there on you can use treeview API to add columns, set its model, and manipulate its configuration. An example follows:

  glade = gtk.glade.XML("stuff.glade")
  treeview1 = glade.get_widget("treeview1")

  # add columns:
  C_DATA_COLUMN_NUMBER_IN_MODEL = 0
  cell0 = gtk.CellRendererText()
  col0 = gtk.TreeViewColumn("title", cell0,    
                            text=C_DATA_COLUMN_NUMBER_IN_MODEL)
  treeview1.append_column(col0)

  # set model (i.e. the data it contains)
  store = gtk.TreeStore(gobject.TYPE_STRING)
  treeview1.set_model(store)

  # set reorderable
  treeview1.set_reorderable(True)

  # to add a row see FAQ 13.21094

Edit this entry1095 / Log info1096 / Last changed on Thu Sep 23 00:42:46 2004 by Christian Robottom Reis (kiko-at-async-com-br)

13.40.1097 How do I change the font of a CellRendererText?

  model = gtk.ListStore(str, str)
  tv = gtk.TreeView(model)

  cell = gtk.CellRendererText()
  font = pango.FontDescription('courier bold 12')
  cell.set_property('font-desc', font)
  col = gtk.TreeViewColumn('This column in courier-bold-12!', cell, text=0)
  tv.append_column(col)

  cell = gtk.CellRendererText()
  col = gtk.TreeViewColumn('default font', cell, text=1)
  tv.append_column(col)

  model.append(('cell with changed font', 'cell with default font'))

  model = gtk.ListStore(str, str)
  tv = gtk.TreeView(model)

  cell = gtk.CellRendererText()
  col = gtk.TreeViewColumn('header', cell, text=0, font=1)
  tv.append_column(col)

  model.append(('This text in arial bold 12', 'arial bold 12'))
  model.append(('And this in courier 14', 'courier 14'))
  model.append(('And yet this in mono 12', 'mono 12'))

(John Finlay, examples by Guilherme Salgado)

Edit this entry1100 / Log info1101 / Last changed on Fri Nov 19 01:28:19 2004 by Christian Robottom Reis (kiko-at-async-com-br)

13.41.1102 How do I show a GtkImage (even animations) in a treeview? (subclassing GtkCellRenderer)

 class CellRendererImage(gtk.GenericCellRenderer):

   __gproperties__ = {
      "image": (gobject.TYPE_OBJECT, "Image",
      "Image", gobject.PARAM_READWRITE),
   }

   def __init__(self):
      self.__gobject_init__()
      self.image = None

   def do_set_property(self, pspec, value):
      setattr(self, pspec.name, value)

   def do_get_property(self, pspec):
      return getattr(self, pspec.name)

   def func(self, model, path, iter, (image, tree)):
      if model.get_value(iter, 0) == image:
         self.redraw = 1
         cell_area = tree.get_cell_area(path, tree.get_column(0))
         tree.queue_draw_area(cell_area.x, cell_area.y, cell_area.width, \

            cell_area.height)

   def animation_timeout(self, tree, image):
      if image.get_storage_type() == gtk.IMAGE_ANIMATION:
         self.redraw = 0
         image.get_data('iter').advance()
         model = tree.get_model()
         model.foreach(self.func, (image, tree))
         if self.redraw:
            gobject.timeout_add(image.get_data('iter').get_delay_time(), \
               self.animation_timeout, tree, image)
         else:
            image.set_data('iter', None)

   def on_render(self, window, widget, background_area,cell_area, \
      expose_area, flags):
      if not self.image:
         return
      pix_rect = gtk.gdk.Rectangle()
      pix_rect.x, pix_rect.y, pix_rect.width, pix_rect.height = \
         self.on_get_size(widget, cell_area)

      pix_rect.x += cell_area.x
      pix_rect.y += cell_area.y
      pix_rect.width  -= 2 * self.get_property("xpad")
      pix_rect.height -= 2 * self.get_property("ypad")

      draw_rect = cell_area.intersect(pix_rect)
      draw_rect = expose_area.intersect(draw_rect)

      if self.image.get_storage_type() == gtk.IMAGE_ANIMATION:

         if not self.image.get_data('iter'):
            animation = self.image.get_animation()
            self.image.set_data('iter', animation.get_iter())
            gobject.timeout_add(self.image.get_data('iter').get_delay_time(), \
               self.animation_timeout, widget, self.image)

         pix = self.image.get_data('iter').get_pixbuf()
      elif self.image.get_storage_type() == gtk.IMAGE_PIXBUF:
         pix = self.image.get_pixbuf()
      else:
         return
      window.draw_pixbuf(widget.style.black_gc, pix, \
         draw_rect.x-pix_rect.x, draw_rect.y-pix_rect.y, draw_rect.x, \
         draw_rect.y+2, draw_rect.width, draw_rect.height, \
         gtk.gdk.RGB_DITHER_NONE, 0, 0)

   def on_get_size(self, widget, cell_area):
      if not self.image:
         return 0, 0, 0, 0
      if self.image.get_storage_type() == gtk.IMAGE_ANIMATION:
         animation = self.image.get_animation()
         pix = animation.get_iter().get_pixbuf()
      elif self.image.get_storage_type() == gtk.IMAGE_PIXBUF:
         pix = self.image.get_pixbuf()
      else:
         return 0, 0, 0, 0
      pixbuf_width  = pix.get_width()
      pixbuf_height = pix.get_height()
      calc_width  = self.get_property("xpad") * 2 + pixbuf_width
      calc_height = self.get_property("ypad") * 2 + pixbuf_height
      x_offset = 0
      y_offset = 0
      if cell_area and pixbuf_width > 0 and pixbuf_height > 0:
         x_offset = self.get_property("xalign") * (cell_area.width - \
            calc_width -  self.get_property("xpad"))
         y_offset = self.get_property("yalign") * (cell_area.height - \
            calc_height -  self.get_property("ypad"))
      return x_offset, y_offset, calc_width, calc_height

 gobject.type_register(CellRendererImage)

 col = gtk.TreeViewColumn()
 cell = CellRendererImage()
 col.pack_start(cell, False)
 col.add_attribute(cell, 'image', 0)

Edit this entry1103 / Log info1104 / Last changed on Wed May 4 07:36:11 2005 by Nikos Kouremenos (kourem-at-gmail-com)

13.42.1105 How do I show a picture (image) in a treeview background or exist any way how to set treeview (and window with treeview) as transparency ?

Edit this entry1106 / Log info1107 / Last changed on Wed May 4 07:33:15 2005 by Nikos Kouremenos (kourem-at-gmail-com)

13.43.1108 Are there tips for improving performance when adding many rows to a Treeview?

• Call treeview.freeze_child_notify(), then append your values and finally call treeview.thaw_child_notify(). This will disable refreshing while you append your elements, thus notably speeding things up.

• If sort_column_id has been set, note what the Treeview tutorial says:

  Once a sort column ID has been set on a TreeModel implementing the TreeSortable interface it cannot be returned to the original unsorted state. You can change the sort function or use a default sort function but you cannot set the TreeModel to have no sort function.

• Given sorting can slow down addition dramatically, there are a few workarounds for this problem. First, set an alternative sort function to be used for the duration of the insert:

  model.set_default_sort_func(lambda *args: -1) 
  model.set_sort_column_id(-1, gtk.SORT_ASCENDING)

• You can also detach the model from the view while doing the insertion:

  view.set_model(None)
  # load data into the model
  view.set_model(model)

• Alternatively, you can just start with a new model, prefill it before attaching it to the view, and enabling sorting at the end of this process.

• John Gill, author of Easygrid ([www.earthenware-services.org]1109 ) says: "I've found the liststore ok up to about 10-20K rows, after that I start to run into problems. With easygrid I'm able to browse tables with 500K rows with no performance problems."

• The Ruby/Gtk TreeView tutorial informs us "...you should not keep around a lot of tree row references if you have so many rows, because with each insertion (or removal) every single tree row reference will check whether its path needs to be updated or not." For ListStore and TreeStore you may be able to use iters instead of TreeRowReferences, as, according to the pygtk manual "...some models guarantee that an treeiter is valid for as long as the node it refers to is valid (most notably the gtk.TreeStore and gtk.ListStore)."

• For a large model, it may be more efficient to simply dump the model rows out,

 rows = [r for r in model]

 rows.sort(key=your_sort_key_callable)

Edit this entry1111 / Log info1112 / Last changed on Mon Jun 12 22:00:19 2006 by Daverz (dave-at-davidcook-org)

13.44.1113 What is TreeRowReference and how to use it?

Everytime you need the path you do tree_row_ref.get_path() and you get the current path

and to create a new tree_row_ref that you can use follow:

 iter = model.append(None, 'LSD')
 path = self.tree.get_path(iter)
 tree_row_ref = gtk.TreeRowReference(tree_model, path)

Edit this entry1115 / Log info1116 / Last changed on Fri Jul 22 16:11:28 2005 by Nikos Kouremenos (kourem-at-gmail-com)

13.45.1117 How do I create a custom gtk.CellRenderer?

The following example shows a CellRenderer for a custom object.

 class CellRendererCustom(gtk.GenericCellRenderer):
        __gproperties__ = {
                "custom": (gobject.TYPE_OBJECT, "Custom",
                "Custom", gobject.PARAM_READWRITE),
        }

        def __init__(self):
                self.__gobject_init__()
                self.custom = None

        def do_set_property(self, pspec, value):
                setattr(self, pspec.name, value)

        def do_get_property(self, pspec):
                return getattr(self, pspec.name)

        def on_render(self, window, widget, background_area, cell_area, expose_area, flags):
                self.custom.draw(window, widget, cell_area.x, cell_area.y)

        def on_get_size(self, widget, cell_area=None):
                return (0, 0, self.custom.get_width(), self.custom.get_height())

 gobject.type_register(CellRendererCustom)

Edit this entry1118 / Log info1119 / Last changed on Thu Apr 13 10:03:17 2006 by Christoph Leuzinger (leuzi-at-trash-net)

14. Editables: GtkEntry, GtkCombo, GtkText, GtkSpinButton, GtkTextView

14.1.1120 How do I make a GtkEntry exactly 5 characters long?

a) just call

  entry.set_width_chars(5)

b) On older gtk+ only, according to Jamesh; first get a reference to the font used by the entry:

    font = entry.get_style().font

 width = font.width('55555')

 entry.set_usize(width, -1)

Note that this must be done at runtime if the size is to adapt to a font selected through themes.

c) On older gtk+ only, measure and set a fixed size in pixels using glade or set_usize. argh.

Edit this entry1121 / Log info1122 / Last changed on Fri May 19 22:13:23 2006 by Danny Milosavljevic (danny-milo-at-gmx-net)

14.2.1123 What is a GtkTextIter, and how do I get one for position X (and other positions)?

Text iters represent a position in the text buffer. You can create them with a GtkTextBuffer object as follows.

To get an iter for the current line:

  line_iter = text_buffer.get_iter_at_line_offset(linenum, charoffset)

  offset_iter = text_buffer.get_iter_at_offset(charoffset)

  start_iter = text_buffer.get_start_iter()
  end_iter = text_buffer.get_end_iter()

  start_iter, end_iter = text_buffer.get_bounds()

  iter_here = text_buffer.get_iter_at_mark(text_buffer.get_insert())

  iter.backward_char()
  iter.forward_char()

  iter.forward_word_end()
  iter.backward_word_start()

  iter.forward_line()
  iter.backward_line()

Edit this entry1125 / Log info1126 / Last changed on Tue Jan 27 12:48:40 2004 by Johan Dahlin (johan-at-gnome-org)

14.3.1127 How do I change the cursor for a GtkEntry?

 watch = gtk.cursor_new(GDK.WATCH)
 gdkwin = entry.get_window()
 gdkwin.set_cursor(watch)
 # the gdkwin has a child window, which is for the editable area 
 gdkwin.children[0].set_cursor(watch)

Edit this entry1129 / Log info1130 / Last changed on Thu Jul 11 12:39:02 2002 by Christian Reis (kiko-at-async-com-br)

14.4.1131 Why does GtkText's insert_text generate critical messages complaining "assertion `index <= TEXT_LENGTH (text)' failed."?

The workaround is to use insert_defaults(), which works and doesn't generate warnings. It has one nasty side-effect: see faq 14.71132

For the original message explaining this, see [www.mail-archive.com]1133

insert_text has been fixed (in the same patch that added the position argument to GtkEditable.insert_text()) in version 0.6.10 and should be used if that version is available.

Edit this entry1134 / Log info1135 / Last changed on Mon Sep 23 17:43:09 2002 by Christian Reis (kiko-at-async-com-br)

14.5.1136 I want to change the text being typed into an entry or textbox, but the original text is also inserted!

The general solution to this is to use two functions, one as a "proxy" callback that calls emit_stop_by_name() and idle_add()s the real function. It could work something like this:

 def insert_cb(widget, text, length, *args):
    # if you don't do this, garbage comes in with text
    text = text[:length]
    pos = widget.get_position()
    # stop default emission
    widget.emit_stop_by_name("insert_text")
    gtk.idle_add(insert, widget, text, pos)

 def insert(widget, text, pos):
    # the next three lines set up the text. this is done because we
    # can't use insert_text(): it always inserts at position zero.
    orig_text = widget.get_text()
    text = string.replace(text, " ", "<SPACE>")
    new_text = orig_text[:pos] + text + orig_text[pos:]
    # avoid recursive calls triggered by set_text
    widget.signal_handler_block(insert_sig)
    # replace the text with some new text
    widget.set_text(new_text)
    widget.signal_handler_unblock(insert_sig)
    # set the correct position in the widget
    widget.set_position(pos + len(text))

 entry = gtk.GtkEntry()
 signal = entry.connect("insert_text", insert_cb)

• We need to do some funky stuff when using set_text() in insert() regarding the position of the text being inserted. This is because insert_text() doesn't provide a position argument in pygtk-0.x
• Signals need to be blocked inside insert() or we end up with a recursive call, with text being inserted triggering the callback.
• There could be nicer solutions, but this one works.
• This originally comes from Ricardo Lenzi's code that was contributed to Kiwi, and is used in the Kiwi Entry wrapper.

Edit this entry1137 / Log info1138 / Last changed on Mon Jul 22 11:57:42 2002 by Christian Reis (kiko-at-async-com-br)

14.6.1139 Why does the second parameter to insert_text (the `text' parameter) contain garbage?

 def on_insert_text(widget, text, len, *args):
   pass

 text = text[:len]

Edit this entry1140 / Log info1141 / Last changed on Tue Jul 23 01:12:46 2002 by Christian Reis (kiko-at-async-com-br)

14.7.1142 Why isn't GtkText.insert_defaults() generating the signal insert_text

  text.connect("insert_text", self._insert_text)
  text.connect("changed", self._insert_text)
  text.insert_defaults("GTK+ is broken") # generates no signals :-(
  self.changed()                         # triggers changed()

Edit this entry1143 / Log info1144 / Last changed on Mon Sep 23 17:17:38 2002 by Christian Reis (kiko-at-async-com-br)

14.8.1145 How do I get the currently selected text in a GtkCombo?

 text = combo.child.get_text()

Edit this entry1146 / Log info1147 / Last changed on Sun Jul 17 19:08:33 2005 by Phillip Calvin (phillipc-at-toasterlogic-com)

14.9.1148 How do I programatically set the max value for a GtkSpinButton?

 # Sets the upper limit from 99...
 adj = GtkAdjustment(1, 1, 99, 1, 1, 1)
 sb = GtkSpinButton(adj, 1, 0)
 # ... to 5
 my_adj = sb.get_adjustment()
 my_adj.upper = 5
 my_adj.set_all(my_adj.value, my_adj.lower, my_adj.upper,
                my_adj.step_increment, my_adj.page_increment, 
                my_adj.page_size)
 # isn't that the darndest API I've seen

Edit this entry1149 / Log info1150 / Last changed on Thu Mar 20 20:07:16 2003 by Christian Reis (kiko-at-async-com-br)

14.10.1151 How do I scroll a TextView to display the text being inserted?

Gustavo Carneiro and Mikoyan wrote in to suggest using the textbuffer's scroll_to_mark() method, which scrolls to a certain point in the buffer. You can use the get_insert() method to return the current insert position right after inserting if you want to make sure you scroll to the end of the text.

  end_iter = text_buffer.get_end_iter()
  text_buffer.insert(end_iter, text)
  text_view.scroll_to_mark(text_buffer.get_insert(), 0)

  text_view.scroll_mark_onscreen(text_buffer.get_insert())

Edit this entry1152 / Log info1153 / Last changed on Tue Jan 27 12:45:07 2004 by Johan Dahlin (johan-at-gnome-org)

14.11.1154 How do I insert colored text into a TextView?

 tag_table = text_buffer.get_tag_table()

 warn_tag = gtk.TextTag("warning")
 warn_tag.set_property("foreground", "blue")
 tag_table.add(warn_tag)

 sob, eob = text_buffer.get_bounds()
 text_buffer.insert_with_tags_by_name(eob, "This is a warning", "warning")

Edit this entry1155 / Log info1156 / Last changed on Tue Jan 27 12:44:22 2004 by Johan Dahlin (johan-at-gnome-org)

14.12.1157 How can I make GtkTextView to always show the last line

The way that I did it for a scrolling text window is to set a mark at the end of the buffer like this:

 mark = text_buffer.create_mark("end", text_buffer.get_end_iter(), False)

 text_view.scroll_to_mark(mark, 0.05, True, 0.0, 1.0)

Edit this entry1158 / Log info1159 / Last changed on Tue Jan 27 12:42:36 2004 by Johan Dahlin (johan-at-gnome-org)

14.13.1160 How do I add items into GtkCombo

Just add one item like this

 listitem = gtk.ListItem("String 1")
 combo.list.append_items([Listitem])
 listitem.show()

 listitem_a = gtk.ListItem("String 2")
 listitem_b = gtk.ListItem("String 3")
 combo.list.append_items([listitem_a, listitem_b])
 listitem_a.show()
 listitem_b.show()

Edit this entry1161 / Log info1162 / Last changed on Tue Jan 27 12:42:01 2004 by Johan Dahlin (johan-at-gnome-org)

14.14.1163 How can get back the strings that I set using Combo.set_popdown_strings()

However, you have a much simpler alternative: just store the strings yourself, locally.

    def set_combo_strings(self, s):
        self.strings = s
        self.combo.set_popdown_strings(s)

Edit this entry1164 / Log info1165 / Last changed on Wed Dec 3 22:20:07 2003 by Christian Reis (kiko-at-async-com-br)

14.15.1166 How do I change the mouse cursor on a TextView (or how do I get the "right" GdkWindow from a TextView)?

 child_win = v.get_window(gtk.TEXT_WINDOW_TEXT)
 child_win.set_cursor(gtk.gdk.Cursor(gtk.gdk.HAND2))

Edit this entry1169 / Log info1170 / Last changed on Wed Dec 10 18:48:32 2003 by Christian Reis (kiko-at-async-com-br)

14.16.1171 Is there a signal sent when a user hits enter in an editable?

Edit this entry1172 / Log info1173 / Last changed on Sun Feb 8 17:34:22 2004 by Christian Reis (kiko-at-async-com-br)

14.17.1174 What X clipboard do TextView's context menu items use?

Edit this entry1176 / Log info1177 / Last changed on Mon Jun 14 16:37:35 2004 by Christian Reis (kiko-at-async-com-br)

14.18.1178 How do I get the clipboard functions to work properly?

 display = gtk.gdk.display_manager_get().get_default_display()

 clipboard = gtk.Clipboard(display, "CLIPBOARD")

 def on_cut_activate(self, obj):
 	textbuffer.cut_clipboard(clipboard, textview.get_editable())

 def on_copy_activate(self, obj):
 	textbuffer.copy_clipboard(clipboard)

 def on_paste_activate(self, obj):
 	textbuffer.paste_clipboard(clipboard, None, textview.get_editable())

Note: the functions used in the callbacks are available as of PyGTK 2.4

Edit this entry1179 / Log info1180 / Last changed on Tue Jun 22 15:26:35 2004 by Christian Reis (kiko-at-async-com-br)

14.19.1181 I'm getting a Gtk-CRITICAL messsage: assertion `g_utf8_validate (text, len, NULL)' failed [using insert_*]

Try using unicode objects instead of strings if you're getting these problems -- python will automatically convert to utf-8 for you.

(Gustavo Carneiro)

Edit this entry1182 / Log info1183 / Last changed on Thu Jul 1 10:00:23 2004 by Christian Reis (kiko-at-async-com-br)

14.20.1184 How do I write clipboard callbacks for multiple widgets?

  clipboard = gtk.Clipboard(gtk.gdk.display_get_default(), 'CLIPBOARD')
  clipPrimary = gtk.Clipboard(gtk.gdk.display_get_default(), 'PRIMARY')

  def on_copy_activate(self, *extra):
      # If the PRIMARY selection has a listed owner, then it belongs to our app
      if clipPrimary.get_owner():
          selectionText = clipPrimary.wait_for_text()
          if selectionText:
              clipboard.set_text(selectionText, -1)

  def on_cut_activate(self, *extra):
      owner = clipPrimary.get_owner()
      if owner:
          # If the widget which owns Primary selection is an Editable, we can
          # use the editable's clipboard functions to do our operations.
          # Otherwise just perform a copy.
          if isinstance(owner, gtk.Editable):
              owner.cut_clipboard()
          else:
              selectionText = clipSelect.wait_for_text()
              if selectionText:
                  clipboard.set_text(selectionText, -1)

  def on_paste_activate(self, *extra):
      # Get the widget with the focus
      entry = appWindow.focus_widget
      if isinstance(entry, gtk.Editable):
          entry.paste_clipboard()

Edit this entry1185 / Log info1186 / Last changed on Sat Oct 16 11:49:49 2004 by Toshio Kuratomi (toshio-at-tiki-lounge-com)

14.21.1187 How do I right-align text in an Entry?

  entry.set_property('xalign', 1)

  [        23.22 ]

Edit this entry1188 / Log info1189 / Last changed on Thu Nov 18 13:10:25 2004 by Christian Robottom Reis (kiko-at-async-com-br)

14.22.1190 How do I create a mask or validator for a GtkEntry?

In short, there is no feature currently implemented that makes this easy. You can hack your own mask support by catching the insert and delete_text signals and doing the appropriate manipulation, but it is far from trivial to write; FAQ 14.51192 includes a basic recipe. There is a bug filed at [bugzilla.gnome.org]1193 that discusses implementation of something like this (validation and masks) at the C level.

See the thread at [www.daa.com.au]1194 for more details.

Edit this entry1195 / Log info1196 / Last changed on Sat Jun 24 00:56:35 2006 by Daniel Popowich (dpopowich-at-astro-umass-edu)

14.23.1197 How do I send the output of an external process to a gtk.TextView without freezing the GUI?

This example shows how to do it the "threaded way", as it seems quite straightforward and portable through platforms without additional tweaking.

• -------------------------------------

 #!/usr/bin/env python
 """Show a shell command's output in a gtk.TextView without freezing the UI"""

 import os, threading, locale

 import pygtk
 pygtk.require('2.0')
 import gtk

 encoding = locale.getpreferredencoding()
 utf8conv = lambda x : unicode(x, encoding).encode('utf8')

 def on_button_clicked(button, buffer, command):
     thr = threading.Thread(target= read_output, args=(buffer, command))
     thr.start()

 def read_output(buffer, command):
     stdin, stdouterr = os.popen4(command)
     for line in stdouterr.readlines():
          buffer.insert(buffer.get_end_iter(), utf8conv(line))

 sw = gtk.ScrolledWindow()
 sw.set_policy(gtk.POLICY_AUTOMATIC, gtk.POLICY_AUTOMATIC)
 textview = gtk.TextView()
 textbuffer = textview.get_buffer()
 sw.add(textview)
 win = gtk.Window()
 win.resize(300,500)
 win.connect('delete-event', gtk.main_quit)
 button = gtk.Button(u"Press me!")
 command = 'dir -R %s' % os.getcwd()
 button.connect("clicked", on_button_clicked, textbuffer, command)
 vbox = gtk.VBox()
 vbox.pack_start(button, gtk.FALSE)
 vbox.pack_start(sw)
 win.add(vbox)
 win.show_all()

 gtk.main()

• ---------------------------------------------

This recipe doesn't circumvent the behaviour of applications using <stdio.h> that don't throw their output till the process has finished. The stdio library seems to be using block buffering instead of line buffering whenever the output goes to anything other than a terminal.

The flow of data seems to be something like this:

shell process output --(stdio buffer)*--> | --(python "shell interpreter" buffer)**--> python output

That way, even when popen or other python process handling functions are told not to use buffered output the resulting output seems to be buffered anyway. The problem is that buffering is only disabled on the python side (in the buffer tagged with **), but not on the application side (buffer tagged with *), so the the overall result is buffered output.

If a terminal like result is desired we can take different approaches:

• use a real terminal if we need its full capabilities (there are some of these with python bindings which are also derived from gtk.Widget so they can be used in a pygtk app. One example of these is vte).
• create a fake terminal so stdio doesn't buffer the subprocess' output using a module like pexpect.
• maybe a different solution could be based on the following example: [cvs.gnome.org]1198 and it basically wraps a textview with a file interface.

Edit this entry1199 / Log info1200 / Last changed on Thu Jul 13 14:54:06 2006 by Christian Reis (kiko-at-async-com-br)

14.24.1201 How do I add completion support for an entry?

 import gtk

 COL_TEXT = 0

 class CompletedEntry(gtk.Entry):
     def __init__(self):
         gtk.Entry.__init__(self)
         completion = gtk.EntryCompletion()
         completion.set_match_func(self.match_func)
         completion.connect("match-selected",
                             self.on_completion_match)
         completion.set_model(gtk.ListStore(str))
         completion.set_text_column(COL_TEXT)
         self.set_completion(completion)

     def match_func(self, completion, key, iter):
         model = completion.get_model()
         return model[iter][COL_TEXT].startswith(self.get_text())

     def on_completion_match(self, completion, model, iter):
         self.set_text(model[iter][COL_TEXT])
         self.set_position(-1)

     def add_words(self, words):
         model = self.get_completion().get_model()
         for word in words:
             model.append([word])

 if __name__ == "__main__":
     win = gtk.Window()
     win.connect('delete-event', gtk.main_quit)

     entry = CompletedEntry()
     entry.add_words(['abc', 'def', 'ghi', 'jkl', 'mno',
                      'pqr', 'stu', 'vwx', 'yz'])
     win.add(entry)
     win.show_all()

     gtk.main()

Edit this entry1202 / Log info1203 / Last changed on Mon Jul 11 15:13:40 2005 by Johan Dahlin (johan-at-gnome-org)

14.25.1204 How can I place a background image on a TextView widget?

 tv = gtk.TextView()
 tv.show()
 tv_win = tv.get_window(gtk.TEXT_WINDOW_TEXT)
 tv_win.set_back_pixmap(yourPixmap, gtk.FALSE)

Edit this entry1205 / Log info1206 / Last changed on Wed Jun 1 14:37:44 2005 by Matt Bradshaw (matt-bradshaw-at-gmail-com)

14.26.1207 The text in the TextView is not aligned! Any ideas?

You will have to use TextTags which is not as easy as set_text() but not as very hard either. Then you do something like:

   tag = gtk.TextBuffer.create_tag('aligned')
   tag.set_property("font", "Courier")
   tag.set_property("foreground", "red")
   tag.set_property("size-points", 12)
   tag.set_property("weight", 400)

TextBuffer.insert_with_tags(your_text, 'aligned')

Edit this entry1208 / Log info1209 / Last changed on Mon Jun 27 11:13:36 2005 by Nikos Kouremenos (kourem-at-gmail-com)

16. GtkOptionMenu, GtkComboBox, GtkComboBoxEntry

16.1.1210 Why doesn't the GtkOptionMenu work like a real listbox?

GtkOptionMenu will be deprecated in GTK+ 2.4 in favor of the new GtkComboBox.

Edit this entry1211 / Log info1212 / Last changed on Thu Nov 6 14:25:26 2003 by Steve Chaplin (stevech1097-at-yahoo-com-au)

16.2.1213 Let's say I accept it as it is. How do I implement one using pygtk?

 def on_optionmenu_activate(widget, data):
     print data                      # print the data for the 
                                     # current selection
 options = ["cat", "dog", "mouse"]   # our options
 menu = gtk.Menu()                   # create a menu
 for str in options:                 # fill our menu with the options
    menu_item = gtk.MenuItem(str)
    menu_item.connect("activate",    # attach "str" to widget
                      on_optionmenu_activate, str) 
    menu_item.show()                 # don't forget this here
    menu.append(menu_item)
 option_menu = gtk.OptionMenu()      # create the optionmenu
 option_menu.set_menu(menu)          # add the menu into the optionmenu

Edit this entry1214 / Log info1215 / Last changed on Tue Jan 27 12:40:10 2004 by Johan Dahlin (johan-at-gnome-org)

16.3.1216 If I set the OptionMenu's state to insensitive, and i call set_history() on it, and put it back to sensitive, the previously selected menuitem still looks insensitive!

  menu = optionmenu.get_menu()
  for item in menu.get_children():
     item.set_state(gtk.STATE_PRELIGHT)
     item.set_state(gtk.STATE_NORMAL)

Edit this entry1219 / Log info1220 / Last changed on Tue Jan 27 12:39:20 2004 by Johan Dahlin (johan-at-gnome-org)

16.4.1221 How do I find out which is the selected item in a GtkOptionMenu?

• The OptionMenu is a container that holds a label, and that responds to clicks by presenting a menu. It is NOT a menu!
• The OptionMenu's `menu' property gives access to its menu - it may be None when there is no menu associated (in that case, you can create a new GtkMenu and use optionmenu.set_menu(menu)). The menu is a regular menu and contains GtkMenuItems.
• The selected GtkMenuItem contains no label - its label is reparented to the GtkOptionMenu itself. The label (or nothing) will be the only child the optionmenu has.

To get the text of the selected menuitem you can take advantage of this last point and use:

  selected_text = optionmenu.children()[0].get()

  menu = optionmenu.get_menu()
  items = menu.children()
  selected_item = menu.get_active()
  index = children.index(item)

(FAQ suggested by Padraig Brady, thanks)

Edit this entry1222 / Log info1223 / Last changed on Thu Dec 19 08:31:47 2002 by Christian Reis (kiko-at-async-com-br)

16.5.1224 What signal is emitted when an optionmenu's item is selected?

  def optionmenu_changed(self, item, *args):
    print "it changed: %s was selected", item

  for item in optionmenu.get_menu().children();
    item.connect("activate", optionmenu_changed)

In PyGTK2, the `changed' signal is emitted (along with the item's `activate' signal, I suspect), so you don't need this hack.

Edit this entry1226 / Log info1227 / Last changed on Thu Dec 19 08:39:07 2002 by Christian Reis (kiko-at-async-com-br)

16.6.1228 How do I get the label of an OptionMenu's item?

• The label is normally the only child widget in a GtkMenuItem. In other words, if you have an item, calling get_children() will normally return a list containing only a single label - unless it is the selected item.

 menu = optionmenu.get_menu()
 for item in menu.get_children():
   chilren = item.get_children()
   if children:
     label = item.get_children()[0]

• HOWEVER, in the case of the *currently selected item*, this doesn't hold true. The label is *TEMPORARILY REPARENTED* to the GtkOptionMenu (has anybody noticed it actually inherit from GtkButton and as such is a normal GtkBin?) itself, and the GtkMenuItem will have *NO CHILDREN*. In other words, if you want to get hold of the label of the menuitem currently selected, use:

 label = optionmenu.get_children()[0] # notice - NOT item.get_children()

Edit this entry1229 / Log info1230 / Last changed on Tue Jan 27 12:35:09 2004 by Johan Dahlin (johan-at-gnome-org)

16.7.1231 How do I get the text from the selected item in GtkComboBox/ComboBoxEntry

  def on_combo_box_changed(widget):
     model = widget.get_model()
     iter = widget.get_active_iter()
     print model.get_value(iter, 0)

  combo.connect("changed", on_combo_box_changed)

For a ComboBoxEntry, the text can be retrieved using:

  combo_box_entry.child.get_text()

  def on_combo_box_entry_changed(widget):
     model = widget.get_model()
     iter = widget.get_active_iter()
     if iter:
         print model.get_value(iter, 0)

Edit this entry1232 / Log info1233 / Last changed on Sat Jul 10 13:00:49 2004 by John Finlay (finlay-at-moeraki-com)

16.8.1234 How do I populate a ComboBox or ComboBoxEntry with strings?

  store = gtk.ListStore(gobject.TYPE_STRING)
  store.append (["testing1"])
  store.append (["testing2"])
  store.append (["testing3"])
  store.append (["testing4"])

  combo = tree.get_widget("comboboxentry1")
  combo.set_model(store)
  combo.set_text_column(0)

  combo = tree.get_widget("combobox1")
  combo.set_model(store)
  cell = gtk.CellRendererText()
  combo.pack_start(cell, True)
  combo.add_attribute(cell, 'text',0)

  def set_model_from_list (cb, items):
    """Setup a ComboBox or ComboBoxEntry based on a list of strings."""           
    model = gtk.ListStore(str)
    for i in items:
        model.append([i])
    cb.set_model(model)
    if type(cb) == gtk.ComboBoxEntry:
        cb.set_text_column(0)
    elif type(cb) == gtk.ComboBox:
        cell = gtk.CellRendererText()
        cb.pack_start(cell, True)
        cb.add_attribute(cell, 'text', 0)

[www.pygtk.org]1235 [www.pygtk.org]1236

(John Finlay, Thomas Hinkle)

Edit this entry1237 / Log info1238 / Last changed on Mon Nov 29 21:46:17 2004 by Christian Robottom Reis (kiko-at-async-com-br)

17. GtkNoteBook

17.1.1239 How do I get a reference to the page my GtkNotebook just switched to (or, what is the deal with the second argument to GtkNotebook's switch_page handler)?

  newpage isn't a GtkObject (if it was, it would have been wrapped in a 
  class already).  For 2.0, it is an opaque struct, so useless to C 
  programmers as well.  Use the pagenum argument and methods of the 
  GtkNotebook to get info about the page.

    pagenum = widget.current_page()

  def handler(widget, dummy, pagenum):
    page_widget = widget.get_nth_page(pagenum)
    print "Page number switched to: %s" % pagenum
    print "Widget attached to page %s: %s" % ( pagenum, page_widget )

  notebook.connect("switch_page", handler)

Edit this entry1240 / Log info1241 / Last changed on Thu Mar 31 00:45:46 2005 by Kathryn Patterson (kathryn-patterson-at-gmail-com)

17.2.1242 How do I make one toolbar button (e.g. an Add button) call a different function for each notebook tab?

 def on_add_activate(self, widget, *args):
        #context yourApp.on_add_activate {
        # create a dictionary where the key is the name of the main
        # widget of the notebook tab and the value is the name 
        # of the function that should be called for that specific tab
        addItem = {'CustomerTab':AddCustomerWindow,
                    'InventoryTab':AddInventoryWindow,
                    'VendorTab':AddVendorWindow,
                    'ReportTab':AddReportWindow}
        # for readability purposes, create a variable that points to  
        # the notebook
        notebook = self.MainNotebook
        # tabChild points to the main widget in the current tab
        tabChild = notebook.get_nth_page(notebook.get_current_page())
        # tabName is the name of tabChild
        tabName = tabChild.get_name()
        # now you can use tabName to reference the dictionary and call
        # the appropriate function  
        additem[tabName]()  
        return gtk.TRUE
        #context yourApp.on_add_activate }

Edit this entry1243 / Log info1244 / Last changed on Fri Apr 8 19:07:40 2005 by Kathryn Patterson (kathryn-patterson-at-gmail-com)

17.3.1245 How do I create a popup menu on a notebook tab and figure out which tab a click comes from

For an easy way to create popup menus, and figuring out which tab a click comes from, put your tab labels into event boxes:

 tab_label_box = gtk.EventBox()
 tab_label = gtk.Label("Some label here")
 tab_label_box.add(tab_label)
 tab_label_box.connect('event', on_tab_click, your_page_widget)
 notebook.append_page(your_page_widget, tab_label_box)

 def on_tab_click(self, widget, event, child):
    if event.type == gtk.gdk.BUTTON_PRESS:
        n = notebook.page_num(child)
        # this will automagically switch to whatever page you click on
        notebook.set_current_page(n)
        if event.button == 3:
             menu = create_a_menu() # I still use the ItemFactory
             menu.popup(None, None, None, event.button, event.time)

Edit this entry1246 / Log info1247 / Last changed on Tue Jun 28 12:20:21 2005 by Gian Mario Tagliaretti (g-tagliaretti-at-parafernalia-org)

18. GtkDrawingArea

18.1.1248 How do I make a gray-scale gradient picture?

John Finlay provided this code example (hacked for brevity):

 #!/usr/bin/env python

 from gtk import *

 WIDTH=300
 HEIGHT=300

 def pix_init(d_area, width, height):
    d_area.realize()
    win = d_area.get_window()
    pixmap = create_pixmap(win, width, height, -1)
    context = win.new_gc()
    cmap = d_area.get_colormap()
    for x in range(WIDTH):
        color = cmap.alloc(x*200, x*200, x*200)
        context.foreground = color
        for y in range(HEIGHT):
            draw_point(pixmap, context, x, y)
    d_area.connect("expose-event", pix_expose, pixmap)

 def pix_expose(da, event, pixmap):
    x, y, width, height = da.get_allocation()
    da.draw_pixmap(da.get_style().fg_gc[0], pixmap, 0, 0, 0, 0, -1, -1)

 def main():
    top = GtkWindow(WINDOW_TOPLEVEL)
    da = GtkDrawingArea()
    da.size(WIDTH, HEIGHT)
    top.add(da)
    pix_init(da, WIDTH, HEIGHT)
    top.show_all()
    mainloop()

 if __name__ =="__main__":
    main()

Edit this entry1249 / Log info1250 / Last changed on Thu Jan 31 21:06:18 2002 by kiko (kiko-at-async-com-br)

18.2.1251 When I place a DrawingArea inside a ScrolledWindow the event object in callbacks has X and Y coordinates off by a few pixels!

a) Connecting to GtkDrawingArea's button_press_event doesn't get called on button presses (when inside a GtkScrolledWindow).

b) If you work around this connecting the signal to the GtkScrolledWindow instead, the X and Y coordinates are off by a few pixels (3 and 4, horizontal and vertically, respectively for the default pointer).

To get this working it's matter of setting the event mask correctly on GtkDrawingArea (faq 3.31252) and not attaching to GtkScrolledWindow's button_press_event signal.

 drawingarea.add_events(GDK.BUTTON_PRESS_MASK)

Edit this entry1253 / Log info1254 / Last changed on Mon Jan 12 21:42:50 2004 by Christian Reis (kiko-at-async-com-br)

18.3.1255 How do I set line attributes for draw_line() and draw_lines()?

All drawing operations in X take a GC (which stands for graphics context), which holds some settings used for doing the drawing. If you are going to change the settings of a GC, it is probably best to create your own (you don't really want to cause all your widgets to draw with double dashed lines).

This can be done with the drawable.new_gc() method. You can then use the gc.set_line_attributes() method to set the line width, line style, cap style and join style:

 gc.set_line_attributes(3, 
                        gdk.LINE_DOUBLE_DASH, 
                        gdk.CAP_BUTT, 
                        gdk.JOIN_MITER)

Edit this entry1256 / Log info1257 / Last changed on Tue Jan 27 12:30:41 2004 by Johan Dahlin (johan-at-gnome-org)

18.4.1258 How do I draw dashed or dotted lines in a GtkDrawingArea?

 LINE_SOLID
 LINE_ON_OFF_DASH
 LINE_DOUBLE_DASH

 line_style = GDK.LINE_ON_OFF_DASH
 gc.line_style(line_style)

"To define a dash pattern (taking notice that the line_style must be set to LINE_ON_OFF_DASH or LINE_DOUBLE_DASH), use the following GC method:

 gc.set_dashes(offset, dash_list)

John Hunter shows us how dots can be done in practice:

 self._spacing = 2
 gc.line_style = GDK.LINE_ON_OFF_DASH
 gc.cap_style =  GDK.CAP_BUTT
 gc.join_style = GDK.JOIN_ROUND
 gc.set_dashes(0,[1,self._spacing])
 widget.draw_lines(gc, zip(x, y) )

Edit this entry1260 / Log info1261 / Last changed on Wed Nov 6 14:48:31 2002 by Christian Reis (kiko-at-async-com-br)

18.5.1262 What's the essential approach to tracking mouse events in a GtkDrawingArea?

• register to listen for click or motion events
• handle them

 drawing_area.connect('motion-notify-event', motion_notify_event_cb)
 drawing_area.connect('button-press-event', button_press_event_cb)  

 drawing_area.set_events(gdk.BUTTON_PRESS_MASK | gdk.POINTER_MOTION_MASK)

 def button_press_event_cb(widget, event):
    if event.button == 1:
      ... do something, when the first button is pressed ...
    elif event.button == 3:
      ... do something, when the third buttin is pressed ...
    return True

For mouse motion, you simply need to define something like this:

 def motion_notify_event_cb(self, widget, event):
   print "Mouse moved to", event.x, event.y
   return True

Edit this entry1263 / Log info1264 / Last changed on Tue Jan 27 12:29:42 2004 by Johan Dahlin (johan-at-gnome-org)

18.6.1265 How do I get scrollbars to work with a DrawingArea?

Small example:

 sw = gtk.ScrolledWindow()
 sw.set_policy(gtk.POLICY_ALWAYS, gtk.POLICY_ALWAYS)
 viewport = gtk.ViewPort()
 drawing_area = gtk.DrawingArea()

 sw.add(viewport)
 viewport.add(drawing_area)

Edit this entry1266 / Log info1267 / Last changed on Tue Jan 27 12:24:42 2004 by Johan Dahlin (johan-at-gnome-org)

18.7.1268 How do I make my DrawingArea have the same background used in other widgets?

We just need to add this line to our redraw function:

  drawing_area.style.apply_default_background(drawing_area.window, True, gtk.STATE_NORMAL, None, 0, 0, w, h)

Edit this entry1269 / Log info1270 / Last changed on Tue Jan 27 10:49:32 2004 by Johan Dahlin (johan-at-gnome-org)

18.8.1271 What basic pattern should I follow when using a DrawingArea?

The key to this pattern is the 'expose-event' signal. The handler you connect to it has the following signature:

  def expose_event_cb(widget, event):
     # ...

Note that you should call widget.queue_draw() whenever you want to repaint your widget (i.e., when you want to redraw it with something different from what's currently displayed on it).

Here's some example code to start off from:

    class MyWidget(gtk.DrawingArea):
        def __init__(self):
            gtk.DrawingArea.__init__(self)
            self.gc = None  # initialized in realize-event handler
            self.width  = 0 # updated in size-allocate handler
            self.height = 0 # idem
            self.connect('size-allocate', self.on_size_allocate)
            self.connect('expose-event',  self.on_expose_event)
            self.connect('realize',       self.on_realize)

        def on_realize(self, widget):
            self.gc = widget.window.new_gc()
            self.gc.set_line_attributes(3, gtk.gdk.LINE_ON_OFF_DASH,
                                        gtk.gdk.CAP_ROUND, gtk.gdk.JOIN_ROUND)

        def on_size_allocate(self, widget, allocation):
            self.width = allocation.width
            self.height = allocation.height

        def on_expose_event(self, widget, event):
            # This is where the drawing takes place

            widget.window.draw_rectangle(self.gc, False,
                                         1, 1, self.width - 2, self.height - 2)
            widget.window.draw_line(self.gc,
                                    0, 0, self.width - 1, self.height - 1)
            widget.window.draw_line(self.gc,
                                    self.width - 1, 0, 0, self.height - 1)

    win = gtk.Window()
    win.add(MyWidget())
    win.show_all()
    win.connect("destroy", lambda w: gtk.main_quit())
    gtk.main()

Edit this entry1272 / Log info1273 / Last changed on Fri Feb 27 22:46:14 2004 by Christian Reis (kiko-at-async-com-br)

18.9.1274 How to set a tiled background pixmap on gnomecanvas.Canvas? Or, how do set custom background on gnomecanvas.Canvas?

 import gtk
 from gtk import gdk
 import gnomecanvas as canvas

 def drawbk(acv, dw, x, y, ww, hh, pb):
     gc = dw.new_gc()
     pw = pb.get_width()
     ph = pb.get_height()
     offset_x = x % pw
     offset_y = y % ph
     dw_y = -offset_y
     while dw_y < hh:
         dw_x = -offset_x
         while dw_x < ww:
             dw.draw_pixbuf(gc, pb, 0, 0, dw_x, dw_y)
             dw_x += pw
         dw_y += ph

 # window 
 win = gtk.Window()
 win.resize(100, 200)
 win.connect('destroy', gtk.main_quit)
 win.realize()

 # load a graphic
 pb = gdk.pixbuf_new_from_file('baize.png')
 w, h = pb.get_width(), pb.get_height()

 cv = canvas.Canvas()
 cv.connect_after('draw-background', drawbk, pb)

 win.add(cv)
 win.show_all()
 gtk.main()

Edit this entry1275 / Log info1276 / Last changed on Fri Jun 10 16:58:41 2005 by Gustavo J. A. M. Carneiro (gjc-at-inescporto-pt)

19. Other widgets

19.1.1277 Are there any HTML rendering widgets for PyGTK?

Edit this entry1278 / Log info1279 / Last changed on Thu Jan 31 21:32:07 2002 by kiko (kiko-at-async-com-br)

19.2.1280 What about HTML widgets for PyGTK2?

gtkhtml2 uses pango for i18n text rendering, etc. [gtkhtml2.codefactory.se]1281 . The HTML rendering still needs work.

Note that Evolution uses libgtkhtml3, which is yet unwrapped.

Gustavo Carneiro did a XHTML-IM (XHTML-1.0 subset) renderer on top of gtk.TextView. It can be found at: [www.gnome.org]1282

Edit this entry1283 / Log info1284 / Last changed on Fri Sep 30 20:03:33 2005 by Gustavo Carneiro (gjc-at-inescporto-pt)

19.3.1285 GnomeIconList's get_icon_data() method doesn't work!

 l = gnome.GnomeIconList() 
 l.append('some-icon.png', 'some text')
 l.get_icon_data(0)

If you didn't set the data associated with the icon, then the results can be unpredictable (ie. get_icon_data() will return whatever you set with set_icon_data()).

Basically, don't get() the data unless you have set() it. This could result of a basic lack of understanding of what the object data attribute is. See question 5.1

Edit this entry1286 / Log info1287 / Last changed on Tue Feb 5 14:54:21 2002 by kiko (kiko-at-async-com-br)

19.4.1288 Can I do plots or charts with PyGTK?

John Hunter's Matplotlib: [matplotlib.sourceforge.net]1289

matplotlib is a pure python 2D plotting library with a Matlab® syntax which produces publication quality figures using in a variety of hardcopy formats (PNG, JPG, TIFF, PS) and interactive GUI environments (WX, GTK) across platforms. matplotlib can be used in python scripts, interactively from the python shell (ala matlab or mathematica), in web application servers generating dynamic charts, or embedded in GTK or WX applications.

Jonathan Merritt's PyStripchart [jstripchart.sourceforge.net]1290

PyStripchart is a set of widgets for displaying sampled information in an interactive "strip chart" form. The website contains code and screenshots.

Edit this entry1291 / Log info1292 / Last changed on Wed Jan 14 12:56:28 2004 by John Hunter (jdhunter-at-ace-bsd-uchicago-edu)

19.5.1293 How do I get the current color from a gnome ColorPicker?

 color_picker.get_property("red")
 color_picker.get_property("green")
 color_picker.get_property("blue")

Edit this entry1294 / Log info1295 / Last changed on Sat Jul 26 16:49:50 2003 by Christian Reis (kiko-at-async-com-br)

19.6.1296 Is there a syntax highlighting widget for PyGTK?

Edit this entry1298 / Log info1299 / Last changed on Wed Aug 20 18:48:35 2003 by Christian Reis (kiko-at-async-com-br)

19.7.1300 When displaying a GnomeAbout box, it doesn't display the program name or version.

  aboutbox.set_property('name','Demo Program')
  aboutbox.set_property('version','0.1')

(Malcolm Tredinnick, Colin Fox)

Edit this entry1301 / Log info1302 / Last changed on Mon Sep 1 13:13:24 2003 by Christian Reis (kiko-at-async-com-br)

19.8.1303 How do I pass extra arguments to a Gnome Applet's setup_menu() callback?

Edit this entry1304 / Log info1305 / Last changed on Mon Oct 6 11:38:18 2003 by Martin Gadbois (martin-gadbois-at-colubris-com)

19.9.1306 In creating a Gnome Applet, how do I use class members for callbacks?

 class MyApplet:
   def __init__(self,applet):
     verbs = [ ( "Properies", self.properties), ("About",self.about) ]
     applet.setup_menu("xml here",verbs,None)
   def properties(self):
     pass # and display properties
   def about(self):
     pass # and display about box.

Edit this entry1307 / Log info1308 / Last changed on Mon Oct 6 14:54:50 2003 by Martin Gadbois (martin-gadbois-at-colubris-com)

19.10.1309 How do I hide the toolbar of a gnome.ui.App() instance?

Here is a snippet from some test code that might put you on the right track. The variable my_app is a reference to the gnome.ui.App instance.

    # Hide toolbar.  We need to get the bonobo dock item to show/hide
    # instead of simply hiding the toolbar itself or we will leave
    # blank dock space when we hide.
    # The default toolbar name for a gnome.ui.App seems to be 'Toolbar'.
    bonobo_toolbar = my_app.get_dock_item_by_name('Toolbar')            
    if bonobo_toolbar:
        bonobo_toolbar.hide()

(Doug Quale)

Edit this entry1310 / Log info1311 / Last changed on Wed Jan 21 09:12:32 2004 by Christian Reis (kiko-at-async-com-br)

19.11.1312 Can I use OpenGL to draw in a PyGTK application?

• [gtkglext.sourceforge.net]1313 is actively supported and mature, includes a set of Python bindings, works on win32 (with installers) and so on. From the web page

  As opposed to Jane Loff's GtkGLArea , it provides not an OpenGL
  widget, but an additional GtkWidget API which enables the standard
  (and custom) GTK+ widgets to render 3D scene using OpenGL.

• The other alternative GtkGlArea, is currently a bit dusty. There are plans for Xavier to pick it up for maintenence, but right now it's not included in the standard pygtk distribution (as it once was).

Edit this entry1314 / Log info1315 / Last changed on Thu Mar 25 14:33:03 2004 by Christian Reis (kiko-at-async-com-br)

19.12.1316 Is there support for tray notification area clients?

These wrap the libegg trayicon components (viewable at [cvs.gnome.org]1318 ).

For Microsoft Windows you can look at [aspn.activestate.com]1319

A common problem with libbegg is that Image widgets do not receive events -- to solve this, place them inside an EventBox.

Edit this entry1320 / Log info1321 / Last changed on Mon Jul 18 01:51:59 2005 by Phillip Calvin (phillipc-at-toasterlogic-com)

19.13.1322 How do I a signal a callback when a gtk.Paned widget handle is dragged?

John Finlay suggests a good solution: Connect to the 'notify' signal and watch for changes in the 'position' property of the paned window. The 'notify' signal will be emitted when any property of a GObject changes.

    def on_pane_notify(pane, gparamspec):
        # A widget property has changed.  Ignore unless it is 'position'.
        if gparamspec.name == 'position':
            print 'pane position is now', pane.get_property('position')

    pane = gtk.HPaned()
    pane.connect('notify', on_pane_notify)

Edit this entry1323 / Log info1324 / Last changed on Tue Aug 24 02:42:26 2004 by Doug Quale (quale1-at-charter-net)

19.14.1325 Is there a grid or spreadsheet-like widget available?

It is currently in alpha state. There is also a GtkSheet widget which was included in GtkExtras, but no python wrapper currently exists for it, and the project itself is no longer active.

Edit this entry1327 / Log info1328 / Last changed on Tue May 17 17:13:49 2005 by Christian Reis (kiko-at-async-com-br)

19.15.1329 How do I embed something using Plugs and Sockets?

We'll use as an example embedding an xterm.

• Grab the socket.py example script from [www.pygtk.org]1330

• Start the xterm

• Execute "xwininfo". The mouse cursor will change to a crosshair. Select the xterm. The window information is displayed, e.g.

 xwininfo: Window id: 0x1a0000e "xterm"

  Absolute upper-left X:  5
  Absolute upper-left Y:  649
  Relative upper-left X:  5
  Relative upper-left Y:  21
  Width: 484
  Height: 316
  Depth: 24
  Visual Class: TrueColor
  Border width: 0
  Class: InputOutput
  Colormap: 0x20 (installed)
  Bit Gravity State: NorthWestGravity
  Window Gravity State: NorthWestGravity
  Backing Store State: NotUseful
  Save Under State: no
  Map State: IsViewable
  Override Redirect State: no
  Corners:  +5+649  -791+649  -791-59  +5-59
  -geometry 80x24+0-54

• Now call socket.py with the given window id. A hex number on the command line would be misinterpreted by socket.py, so you need to convert the hex number beforehand, e.g. by calling long(windowid) in the python shell.

  >>> long(0x1a0000e)
  27262990L

• Now on the command line, issue

  $ python socket.py 27262990

• Finished! The xterm is now reparented. You will notice that you can't type anything in the embedded xterm window; this is possibly a compatibility issue, and embedding other windows (like gnuplot) may have different results.

For another example, take a look at the example in the pygtk tutorial: [www.pygtk.org]1331

(N. Volbers, Maciej Katafiasz)

Edit this entry1332 / Log info1333 / Last changed on Tue May 24 14:39:47 2005 by Christian Reis (kiko-at-async-com-br)

19.16.1334 How can I use the IconView widget?

    import pygtk
    pygtk.require('2.0')
    import gtk

    class PreferencesMgr(gtk.Dialog):
        def __init__(self):
            gtk.Dialog.__init__(self, 'Preferences', None,
                       gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT,
                       (gtk.STOCK_OK, gtk.RESPONSE_OK,
                        gtk.STOCK_CANCEL, gtk.RESPONSE_CANCEL))
            self.current_frame = None
            self.create_gui()

        def create_gui(self):

            model = gtk.ListStore(str, gtk.gdk.Pixbuf)

            pixbuf = gtk.gdk.pixbuf_new_from_file('images/prefs_general.png')        
            model.append(['General', pixbuf])

            pixbuf = gtk.gdk.pixbuf_new_from_file('images/prefs_security.png')
            model.append(['Security', pixbuf])

            self.icon_view = gtk.IconView(model)
            self.icon_view.set_text_column(0)
            self.icon_view.set_pixbuf_column(1)
            self.icon_view.set_orientation(gtk.ORIENTATION_VERTICAL)
            self.icon_view.set_selection_mode(gtk.SELECTION_SINGLE)
            self.icon_view.connect('selection-changed', self.on_select, model)
            self.icon_view.set_columns(1)
            self.icon_view.set_item_width(-1)
            self.icon_view.set_size_request(72, -1)

            self.content_box = gtk.HBox(False)
            self.content_box.pack_start(self.icon_view, fill=True, expand=False)
            self.icon_view.select_path((0,)) # select a category, will create frame
            self.show_all()
            self.vbox.pack_start(self.content_box)        
            self.resize(640, 480)
            self.show_all()

        def on_select(self, icon_view, model=None):
            selected = icon_view.get_selected_items()
            if len(selected) == 0: return
            i = selected[0][0]
            category = model[i][0]
            if self.current_frame is not None:
                self.content_box.remove(self.current_frame)
                self.current_frame.destroy()
                self.current_frame = None
            if category == 'General':
                self.current_frame = self.create_general_frame()
            elif category == 'Security':
                self.current_frame = self.create_security_frame()    
            self.content_box.pack_end(self.current_frame, fill=True, expand=True)
            self.show_all()

        def create_general_frame(self):
            frame = gtk.Frame('General')        
            return frame        

        def create_security_frame(self):
            frame = gtk.Frame('Security')        
            return frame        

    if __name__ == '__main__':
        p = PreferencesMgr()
        p.run()
        p.destroy()

Edit this entry1335 / Log info1336 / Last changed on Sun Jun 12 20:26:19 2005 by Nikos Kouremenos (kourem-at-gmail-com)

19.17.1337 How can I distribute gtkhtml2 (outside of gnomepythonextras)?

	PYTHONVER = `python -c 'import sys; print sys.version[:3]'`
	CFLAGS = `pkg-config --cflags gtk+-2.0 pygtk-2.0 libgtkhtml-2.0` -fPIC -I/usr/include/python$(PYTHONVER) -I.
	LDFLAGS = `pkg-config --libs gtk+-2.0 pygtk-2.0 libgtkhtml-2.0`

	all: gtkhtml2.so

	# Build the shared objects
	gtkhtml2.so: gtkhtml2.o gtkhtml2module.o
		$(CC) $(LDFLAGS) -shared $^ -o $@

	# The path to the GTK+ python types
	DEFS=`pkg-config --variable=defsdir pygtk-2.0`

	# Generate the C wrapper from the defs and our override file
	gtkhtml2.c: gtkhtml2.defs gtkhtml2.override
		pygtk-codegen-2.0 --prefix pygtkhtml2 \
		--register $(DEFS)/gdk-types.defs \
		--register $(DEFS)/gtk-types.defs \
		--override gtkhtml2.override \
		gtkhtml2.defs > $@

	# A rule to clean the generated files
	clean:
		rm -f gtkhtml2.so *.o gtkhtml2.c *~  

	.PHONY: clean

Edit this entry1338 / Log info1339 / Last changed on Tue Aug 30 09:23:17 2005 by Nikos Kouremenos (kourem-at-gmail-com)

19.18.1340 Why does gtkmozembed somtimes crash in load_url()?

  gtkmozembed.set_profile_path("/tmp", "foobar")
  gtkmozembed.MozEmbed().load_url("http://art.gnome.org")

Edit this entry1342 / Log info1343 / Last changed on Thu Oct 20 18:34:21 2005 by Björn Lindqvist (bjourne-at-gmail-com)

20. The GTK Mainloop and Threading

20.1.1344 What are the general tips for using threads with PyGTK?

 import gobject
 gobject.threads_init()

 ...

 gtk.main()

Signal callbacks will be done in the main thread. They will also need to do threads_enter/threads_leave I believe.

A way to avoid using threads_enter/threads_leave is to call the function from the main thread, a simple way of sending a request to the server is to use gobject.idle_add:

  gobject.idle_add(...)

  gobject.idle_add(entry.set_text, 'new text')

Edit this entry1345 / Log info1346 / Last changed on Thu Mar 23 16:46:53 2006 by Johan Dahlin (johan-at-gnome-org)

20.2.1347 On Win32, the input_add() function doesn't work!

In PyGTK 2.6 it's called gobject.io_add_watch()

Edit this entry1348 / Log info1349 / Last changed on Fri Jun 3 09:42:42 2005 by Nikos Kouremenos (kourem-at-gmail-com)

20.3.1350 How can I make Ctrl-C in the console quit my app which uses PyGTK 1.99.13 or older?

 while True:
   gtk.main_iteration()

See the thread [www.daa.com.au]1352 for more information, and GNOME bug 72333: [bugzilla.gnome.org]1353

If you are only interested in Ctrl-c finishing your application and you don't need special cleanup handlers, the following will perhaps work for you:

 import signal
 signal.signal(signal.SIGINT, signal.SIG_DFL)

Edit this entry1354 / Log info1355 / Last changed on Thu Mar 23 16:53:14 2006 by Johan Dahlin (johan-at-gnome-org)

20.4.1356 I get random crashing when using lots of threads in PyGTK

• Andrew Schmeder wrote:

  I am writing a pygtk-1.2 app. I have lots of interaction with GnomeCanvas and lots of threading. For example, it is common to have a thread running which moves, creates or destroys a widget on the canvas.

  In the process of doing this I encountered a number of non-deterministic, intermittent, severe crashes related to threading problems. Even after extensive locking they would not go away.

  1) While moving an object from a thread GnomeUI-ERROR **: file gnome-canvas.c: line 3812 (gnome_canvas_request_redraw_uta): assertion failed: (canvas->redraw_area != NULL) aborting...

  2) While creating an object from a thread Xlib: unexpected async reply (sequence 0x10b9)! (plus various other sequence numbers)

• JamesH says:

  Were you making use of the gtk.threads_enter() and gtk.threads_leave() calls to protect GTK calls outside of the main thread/signal handlers?

  If not, that would explain the problems you ran into. GTK is not completely thread safe, so in some cases you need to acquire the GDK thread lock. Note that you can assume the GDK thread lock is acquired within signal handlers, but it isn't within idle, timeout and IO handlers.

• Rob Brown-Bayliss says:

  Try upgrading the libpthread packages on your machine.

  I have had a problem with random threads crashing on pygtk 2, my app was interacting with another and all sorts of weird crap was going on, but, only some times, it might run for one minute, or 5 days, but eventually it would crash while starting a new thread. This crash would even lock gdb.

  Finally used a small C prog to simulate what I was doing and still got the crashes. Turns out to be a semi known problem with the pthread library (some refs on google to same problem with oracle and pthread)

  I upgraded and have gone from my app guaranteed crash once a day to crash free for 30 days, every time the crash was either init'ing a new thread or a thread communicating with the main app.

  I note that the new Redhat beta for 8.1 lists as a feature a new posix threading lib.

• Kiko says:

  Stay away from Redhat betas :-)

Edit this entry1357 / Log info1358 / Last changed on Wed Jan 22 23:45:47 2003 by Christian Reis (kiko-at-async-com-br)

20.5.1359 I want to show a splash screen and make it disappear. How?

 def setup_app(*args):
   main = gtk.Window()
   # [...] set main up

 splash = gtk.Window() 
 # [...] set splash up
 splash.show()
 # ensure it is rendered immediately
 while gtk.events_pending():
   gtk.main_iteration()

 gobject.timeout_add(5000, splash.hide) # 5*1000 miliseconds
 gobject.idle_add(setup_app)
 gtk.mainloop()

Edit this entry1360 / Log info1361 / Last changed on Tue Nov 8 15:45:19 2005 by Johan Dahlin (johan-at-gnome-org)

20.6.1362 I am using a separate thread to run my code, but the application (or the UI) hangs.

Now there are two approaches for threads in PyGTK:

1. Allow only the main thread to touch the GUI (gtk) part, while letting other threads do background work. For this to work, first call

  gobject.threads_init()

 import threading
 import time
 import gobject
 import gtk

 gobject.threads_init()

 class MyThread(threading.Thread):
     def __init__(self, label):
         super(MyThread, self).__init__()
         self.label = label
         self.quit = False

     def update_label(self, counter):
         self.label.set_text("Counter: %i" % counter)
         return False

     def run(self):
         counter = 0
         while not self.quit:
             counter += 1
             gobject.idle_add(self.update_label, counter)
             time.sleep(0.1)

 w = gtk.Window()
 l = gtk.Label()
 w.add(l)
 w.show_all()
 w.connect("destroy", lambda _: gtk.main_quit())
 t = MyThread(l)
 t.start()

 gtk.main()
 t.quit = True

Anyway, to make this work, start by calling:

 gtk.gdk.threads_init()

Then you have to wrap your main loop with gtk.threads_enter()/gtk.threads_leave(), like this:

 gtk.threads_enter()
 gtk.main()
 gtk.threads_leave()

  ...
  gtk.threads_enter()
  try:
      myentry.set_text("foo")
  finally:
      gtk.threads_leave()
  ...

Cedric Gustin posted a short example of threaded code at [www.daa.com.au]1364 -- it's a good building block for a more complex threaded application.

Finally, if you are writing a C extension module, remember that you need to protect calls that potentially lock the thread with Py_BEGIN_ALLOW_THREADS and Py_END_ALLOW_THREADS.

Edit this entry1365 / Log info1366 / Last changed on Mon Aug 29 14:48:07 2005 by Gustavo Carneiro (gjc-at-inescporto-pt)

20.7.1367 I set up a timeout handler using timeout_add, but the handler only runs once.

 def on_timeout(self, *args):
   print "Ping", args 

 gobject.timeout_add(1000, on_timeout)

 def on_timeout(self, *args):
   print "Ping", args 
   return True

Edit this entry1368 / Log info1369 / Last changed on Mon Apr 4 14:31:37 2005 by Nikos Kouremenos (kourem-at-gmail-com)

20.8.1370 How do I check if threading was compiled in my version of PyGTK

In PyGTK-0, use ldd to list the dependencies of _gtkmodule.so -- if it lists pthread, it was compiled with threading.

Edit this entry1371 / Log info1372 / Last changed on Sat Jun 12 15:49:05 2004 by Christian Reis (kiko-at-async-com-br)

20.9.1373 I don't want to use threading. What other options do I have?

• James Henstridge's post at [www.daa.com.au]1374
• David Mertz' Charming Python article `Implementing "weightless threads" with Python generators': [www-106.ibm.com]1375

Advantages:

• Guaranteed to work regardless of underlying thread support
• Much simpler to code and debug, no need for locks, semaphores etc.
• Allows extremely efficient scheduling. Thread creation/deletion overhead is minimal.

Disadvantages:

• Potentially long running or blocking operations (file.read etc) need to be handled specially.

For capturing the output of another process, or other file-based I/O, Danny Milosavljevic proposes using non-blocking I/O. This works like so:

• start the process via popen2.Popen4 (or use any other stuff that uses file descriptors, like pipes, ptys, whatever)
• set the file descriptor to non blocking mode (via fcntl F_SETFL O_NONBLOCK)
• use gtk.input_add to add a handler to be called a) on data or b) on process termination (gtk.gdk.INPUT_READ | gtk.gdk.INPUT_EXCEPTION)
• This handler
  • read()s what it can
  • when reaching EOF that means the process terminated, and you can check the Popen4 object for the exit code
  • when exception IOError with errno EAGAIN is fired, that means currently there is no (more) data available
  • other IOErrors are fatal.

He has an example module available under the LGPL at [cvs.sourceforge.net]1376

Edit this entry1377 / Log info1378 / Last changed on Sat Jul 10 11:56:26 2004 by Danny Milosavljevic (danny_milo-at-yahoo-com)

20.10.1379 When an exception is raised, it is printed out to standard error! (or how do I get exceptions to be printed to X or displayed in a window?)

There are two approaches here, both useful in different situations.

• The first is assigning your own file to sys.stderr, which allows you to store a log of exceptions:

  logfile = os.path.expanduser("~/.myapp.log")
  sys.stderr = open(logfile, 'a')

  def log(self, s):
      now = time.strftime("%Y-%m-%d %H:%M")
      sys.stderr.write("%s: %s\n" % (now, s))

• The second approach is to have exceptions displayed in a dialog. Gustavo Carneiro has written "a sys.excepthook function that displays a nice dialog for uncaught exceptions. To use, just import the module, that's all. The license is whatever you want.". You might want to extend on his module to add something like a talkback function "Oops. Something bad happened. Should I send a report back to the developer?".

  Grab Gustavo's code from [www.daa.com.au]1380 .

Edit this entry1381 / Log info1382 / Last changed on Tue Nov 8 15:46:38 2005 by Johan Dahlin (johan-at-gnome-org)

20.11.1383 How can I monitor sockets or files inside the gtk mainloop (or how does gtk.input_add() work)?

 id = gtk.input_add(file_object, condition, function)

condition is one of the following (use gtk.gdk for PyGTK-2):

• gtk.INPUT_READ : the file descriptor has become available for reading, or the listening socket has a new connection
• gtk.INPUT_WRITE : the file descriptor has become available for writing.
• gtk.INPUT_EXCEPTION : an exception was raised on the file descriptor.

Note, some versions of pyGTK require you to use:

 import GDK
 GDK.INPUT_READ

Example call:

 id = gtk.input_add(self.server, gtk.INPUT_READ, self.GetIO)

 gtk.input_remove(id)

The callable function should return gtk.TRUE if it wants to continue getting called in the future.

John Nelson writes to say: It may be worth noting that if your application has separate mainloop threads (i.e. you run the pygtk mainloop from more than one thread), there seems to be evidence that gtk "may" use a seperate thread to notify your program when the desired condition becomes true. Thus, if you do any gtk (gdk, really) work in the handler, you may need to call gtk.threads_enter() and gtk.threads_leave() when done.

While I can't confirm this is true, if you are seeing this symptom, give it a try and email me to update the FAQ if you do.

Another important note is that in GTK version 2, you will get back a fd in your handler if the object you pass in has a fileno() method (like a socket does). In GTK version 1, you will get a socket back if you pass a socket in. E.G.:

 ...
 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)

 listenhost=""
 listenport=port
 s.bind((listenhost, listenport))
 s.listen(5)
 #GDK->gtk.gdk in GTK V 2.0
 id=gtk.input_add(s, GDK.INPUT_READ, handleNewConnection)

 ...

 def handleNewConnection(self,source,condition):
     #source is a socket in GTK v 1 and a fd in version 2
     ...
     return gtk.TRUE

Edit this entry1384 / Log info1385 / Last changed on Fri Jan 30 19:07:19 2004 by Christian Reis (kiko-at-async-com-br)

20.12.1386 How do I get an action to run periodically, say, every 30 seconds?

Edit this entry1388 / Log info1389 / Last changed on Tue Nov 8 15:49:02 2005 by Johan Dahlin (johan-at-gnome-org)

20.13.1390 The GTK thread dies, but some windows remain open. I don't want that, what can I do?

You can use the gtk.window_list_toplevels() function that will get all top level windows in the application. And you can destory those windows. If you want to close only some windows, then you must keep track of them or somehow choose which ones to destroy.

Note that closing all windows won't release all memory allocated by GTK. AFAIK, there is no function to clean up everything. GTK is designed to run for the lifetime of the process, so it is not a high priority to add functions to clean up internal hash tables and other data structures because they are usually needed until the process terminates. If you need a hard guarantee that everything will be freed, you may want to start a separate process.

Information provided by John Ehresman

Edit this entry1391 / Log info1392 / Last changed on Thu Mar 3 22:47:56 2005 by Nikos Kouremenos (kourem-at-gmail-com)

20.14.1393 My application uses threads and GtkDialogs seem to freeze it! What can I do?

Edit this entry1394 / Log info1395 / Last changed on Thu Mar 3 23:18:45 2005 by Nikos Kouremenos (kourem-at-gmail-com)

20.15.1396 I'm using threads and timeout or idle or input handlers and the app freezes. What's wrong?

An example to illustrate better the proposed solution follows:

    def run(self, called_by_timeout=False):
        if called_by_timeout:
           # if it was called outside of GDK global lock (eg. here a timeout) make sure we threas_enter
           gtk.gdk.threads_enter()

        ...code-here...

        if called_by_timeout:
           gtk.gdk.threads_leave()

info provided by Víctor M. Hernández Rocamora

Edit this entry1398 / Log info1399 / Last changed on Tue Mar 15 09:49:32 2005 by Nikos Kouremenos (kourem-at-gmail-com)

20.16.1400 So how do I use gobject.io_add_watch (used to be input_add) ?

	import socket
	import gobject
	import gtk

	def handle_data(source, condition):
		data = source.recv(1024)
		if len(data) > 0:
			return True # run again
		else:
			return False # stop looping (or else gtk+ goes CPU 100%)

	sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
	sock.settimeout(15)
	sock.connect(('pygtk.org', 80))
	sock.send('GET /index.html HTTP/1.1\nHost: pygtk.org\n\n')

	gobject.io_add_watch(sock, gobject.IO_IN, handle_data)

	w = gtk.Window()
	w.add(gtk.Button('abc'))
	w.show_all()
	gtk.main()

Please keep in mind that io_add_watch() works for sockets on all platforms, but if you want to watch files you have to use GNU/Linux or other Unices

Advanced Usage:

as you can see once you get EOF gtk+ forces you to give up on reading more possible stuff there. That is not sane for all usages but it's what it's done. I sat down and tried to workaround this. I ended up with something I hope you will find useful:

	import socket
	import gobject
	import gtk
	import signal

	def get_file():
		sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
		sock.settimeout(15)
		sock.connect(('pygtk.org', 80))
		sock.send('GET /index.html HTTP/1.1\nHost: pygtk.org\n\n')
		return sock

	def handle_data(source, condition):
		data = source.recv(12)
		print len(data)
		if len(data) > 0:
			return True #run forever
		else:
			print 'closed'
			print 'so get new data...'
			sock = get_file()
			gobject.io_add_watch(sock, gobject.IO_IN, handle_data)
			return False # stop looping

	sock = get_file()
	gobject.io_add_watch(sock, gobject.IO_IN, handle_data)

	w = gtk.Window()
	w.set_border_width(15)
	msg = '''\
	Play with resizing the window...

	RESULT:
	It will only block on sock.connect()
	which is normal because to use the socket you have to connect
	here we wait for maximum 15 seconds and then we timeout'''
	w.add(gtk.Label(msg))
	w.show_all()
	signal.signal(signal.SIGINT, signal.SIG_DFL) # ^C exits the application
	gtk.main()

Edit this entry1401 / Log info1402 / Last changed on Mon Jun 27 18:10:38 2005 by Nikos Kouremenos (kourem-at-gmail-com)

20.17.1403 Why isn't my thread running?

Edit this entry1404 / Log info1405 / Last changed on Wed Jul 13 02:58:25 2005 by Phillip Calvin (phillipc-at-toasterlogic-com)

20.18.1406 How do I write a qt application using gobject.MainLoop?

GStreamer-0.10 uses asynchronous calls to control its pipelines, and these calls have async replies. You can get these replies by either polling the pipeline's bus, or by running a gobject.MainLoop. Problems arise when you are writing a qt application that has its own main loop, and your application doesn't necessarily have multi-threaded requirements (besides those already implemented by gstreamer). The following class will run the gobject.MainLoop whenever the QApplication is idle by using QTimer.start(0), and gobject.MainLoop.MainContext.pending/iteration.

The exception in the constructor protects the singleton-nature of gobject.MainLoop for this application. Now you can just make your async calls from within the main qt thread. Fire away!

 import sys
 import time
 import gobject
 from PyQt4.QtCore import QObject, QTimer, SIGNAL, QThread, QEventLoop
 from PyQt4.QtGui import QApplication

 gobject.threads_init()

 class GObjectLoop:
     """ Manages a gobject.MainLoop. """

     _instance = None

     def __init__(self):
         if not QGObjectLoop._instance is None:
             raise RuntimeError('there can only be one QGObjectLoop')
         else:
             QGObjectLoop._instance = self
         self.gmainloop = gobject.MainLoop()
         # this is horribly inefficient!
         self.gcontext = self.gmainloop.get_context()
         self.idletimer = QTimer(QApplication.instance())
         QObject.connect(self.idletimer, SIGNAL('timeout()'),
                         self.on_idle)
         self.idletimer.start(0)

     def __del__(self):
         self.gmainloop.quit()

     def on_idle(self):
         while self.gcontext.pending():
             self.gcontext.iteration()

 # this prevents a seg fault, not sure why.
 import atexit
 def _atexit():
     GObjectLoop._instance = None
 atexit.register(_atexit)

Edit this entry1408 / Log info1409 / Last changed on Sun Apr 30 21:00:34 2006 by Christian Reis (kiko-at-async-com-br)

20.19.1410 What does "Fatal Python error: GC object already tracked" mean?

Edit this entry1411 / Log info1412 / Last changed on Sun Apr 30 21:00:58 2006 by Christian Reis (kiko-at-async-com-br)

21. Win32 and PyGTK

21.1.1413 How do I get PyGTK running on MS Windows?

Cédric Gustin maintains the primary windows pygtk site containing win32 ports: [www.pcpm.ucl.ac.be]1414

The site includes installers of PyGTK-0.6.x and the 2.x line for Python 2.2. If you require Python 2.1, the older 0.6.9 version is available here: [www.pcpm.ucl.ac.be]1415

Note that, to run pygtk2, you will need a number of prerequisite DLLs. FAQ 21.21416 describes the steps to get pygtk running, including getting the dependencies installed and configured.

There are some older versions of pygtk still available:

• Alexandre Fayolle has made a Windows installer for PyGTK and Python 1.5, 2.0 and 2.1 that is available from [ftp.logilab.org]1417 . Alexandre's installers are also based on source code changes by Hans Breuer, as described below.
• Hans Breuer keeps a source code patch and Python 2.0 binaries at his GTK+ ports page at [hans.breuer.org]1418 [There are all sorts of Win32 ports and goodies on that page, so check it out if you are chained to Windows]. On that same page you can also find a port of libglade for Win32 that you can use, additionally.
• There is an even older, outdated set of bindings for Windows by Kevin Butler at [www.geocities.com]1419 Don't use these; the link is provided for the code-curious.

Edit this entry1420 / Log info1421 / Last changed on Wed Jun 16 10:44:25 2004 by Christian Reis (kiko-at-async-com-br)

21.2.1422 Is there a walkthrough on getting PyGTK2 and libglade2 to work on win32

• python
• GTK runtime
• libglade
• PyGTK

Here is how to do it:

1. If you don't have it, get Python for Windows from [www.python.org]1423

2. There is more than one way to install GTK runtime for win32. (2a) is the easiest (2b) gives a recipe that uses a simple installer. (2c) is more complicated but lets you choose which bits of GTK you want.

2a. The gladewin32 project [gladewin32.sourceforge.net]1424 offers a Gtk+/Win32 Development Environment (runtime, devel, docs, glade, etc.) Installer. This includes both GTK and glade libraries, plus a win32 version of the glade editor too. It installs in C:/GTK by default (we refer to this folder as %gtkdir% in a step further down).

If you use this installer, it includes libglade, and you can skip to step 4.

2b. From [www2.arnes.si]1425 get the GTK+ 2 for Windows runtime environment. Unzip it and run the setup program. It should install the libraries in C:\Program Files\Common Files\GTK\2.0\ (from now on called %gtkdir%).

Note this does not include libglade. Go to step 3.

2c. From [www.gimp.org]1426 get the recommended versions of the following packages:

• libintl
• glib
• gtk+
• atk
• pango
• The page lists libiconv, but the version recommended doesn't seem to uncompress its directory structure correctly (so Grzegorz Hankiewicz says at least), so I recommend you download libiconv from the GnuWin32 project at [sourceforge.net]1427

Unpack the packages downloaded in a common directory, e.g. C:\Program Files\Common Files\GTK\2.0\ (from now on called %gtkdir%)

Note this does not include libglade. Go to step 3.

3. From [gladewin32.sourceforge.net]1428 download libglade-bin. Unzip and copy the contents of the bin directory to %gtkdir%/bin. While you're there, you can grab the Glade for Win32 Binary Installer [gladewin32.sourceforge.net]1429 which confusingly does not include libglade!

4. There are two possibilities for this step, which involves making the installed libraries visible to other programs. *Note that this requires modifying PATH and NOT PYTHONPATH*

4a. The simplest way to enable GTK+ for your system is to add %gtkdir%\lib and %gtkdir%\bin to your PATH.

If you are using Windows 2000/XP, you can edit the path in Start - Control Panels - System - Advanced - Environment Variables.

If you are using a DOS-based Windows version (W95,W98,ME), add the following line to your C:\AUTOEXEC.BAT file:

  set PATH="%PATH%;%gtkdir%\lib;%gtkdir%\bin" 

4b. If you don't want to alter the system path, but can change the scripts you will run that require gtk2, add these lines to them (before the pygtk import):

 # Make Windows actually find the stuff installed
 gtkdir = 'C:/Program Files/Common Files/GTK/2.0'
 import os
 os.environ['PATH'] += ";%s/lib;%s/bin" % (gtkdir, gtkdir)

6. Download and install the PyGTK package from [www.mapr.ucl.ac.be]1430

7. You can test everything is working by starting a Python interpreter and issuing:

  # ensure we're using the right version
  import pygtk
  pygtk.require ('2.0')

  import gtk
  import gtk.glade

8. Don't get an error message.

9. You're done.

* Note that on WinXP with the default Luna theme, GTK+-2.2.4.1 has a bug where radio buttons do not activate when clicked. GTK+-2.2.4 works fine.

(Lars Bensmann, John Platte, John Hunter)

Edit this entry1431 / Log info1432 / Last changed on Sat Feb 19 06:15:58 2005 by matthew arnison (maffew-at-cat-org-au)

21.3.1433 Does the Win32 port support threading?

The current (and unlikely to change) status of threads on win32 is that you basically can't perform gui operations from a subthread, even with gdk_threads_enter/leave (and any GTK or GDK call should be considered a "gui operation"). Essentially, the X11 and win32 gui/threading models are different, and making gtk work the same on both would be very hard. There is a proposal to solve this problem more fundamentally at [bugzilla.gnome.org]1434

This isn't entirely bad news, though. Threads on win32 /do/ work in most situations.

If you need to use signals in a threaded win32 application, you need to make sure that the signal sent to your widget is done from the main thread instead of the subthread. The easiest way to do this is using gobject.idle_add via a wrapperfunction:

  def do_gui_operation(function, *args, **kw):
      def idle_func():
          gtk.threads_enter()
          try:
              function(*args, **kw)
              return False
          finally:
              gtk.threads_leave()
      gobject.idle_add(idle_func)

  gtk.threads_enter()
  do_gtk_stuff(arg1, arg2)
  gtk.threads_leave()

  do_gui_operation(do_gtk_stuff, arg1, arg2)

Note also some advice from Alexandre Fayolle, Win32 PyGTK extraordinaire, on older versions of PyGTK:

A trick to get threads to work properly that was sent to the list some time ago (I don't remember who I should credit for it, but it works very well) is to add a timeout function that does a very short sleep, for instance 1e-3 seconds, using timeout_add(...), for instance:

 from gtk import *
 import time
 import sys
 def sleeper():
    time.sleep(.001)
    return 1 # don't forget this otherwise the timeout will be removed

 if __name__== '__main__':
    # do other inits here
    if sys.platform == 'win32':
        timeout_add(400,sleeper)
    mainloop()

If you want pseudothreads that do not suffer from such problems see: [aspn.activestate.com]1435 [www.gnome.org]1436

Edit this entry1437 / Log info1438 / Last changed on Sun May 15 18:59:06 2005 by Nikos Kouremenos (kourem-at-gmail-com)

21.4.1439 Where is GdkImlib for MS Windows?

See [groups.yahoo.com]1440 . The native port of gdkimlib has been "abandoned" by the author of gtk+ on win32. I guess the only solution is to compile gtk+-1.2, gdkimlib and pygtk for X11 using cygwin and its port of XFree 4.2.

(Cedric Gustin)

If you plan to work with pygtk and gnome 2.0, you should switch to gdk-pixbuf, which actually works under windows : [developer.gnome.org]1441

(Runar Petursson)

Edit this entry1442 / Log info1443 / Last changed on Thu Aug 7 21:36:33 2003 by Christian Reis (kiko-at-async-com-br)

21.5.1444 How can I bundle a PyGTK program in windows so my users don't need to install Python or the GTK+ libs?

Michal Pasternak recommends giving cxFreeze a try: [starship.python.net]1446 . It works in a different way than py2exe and McMillan Installer; it's faster building the package, and it doesn't automatically include all the DLLs.

The gtk+-2.x runtime environment is available here, and also as a nice installer: [gladewin32.sourceforge.net]1447

Other alternatives may include Gordon McMillan's installer which used to be available at [www.mcmillan-inc.com]1448 ([web.archive.org]1449 waybackmachine copy) - he had an overview of the other options as well in the right-hand column of that page.

[www.anti-particle.com]1450 describes one example using GTK+ 2.4, py2exe (0.5.x) and Inno Setup, and here's another one, courtesy of Jamey Cribbs:

Ok, here are some very rough notes on creating a self-executing installer of your pygtk app for Windows. I'm sure there are better ways to do this, but this works for me.

1.) Install py2exe and Inno Setup.

2.) Add os.environ['PATH'] += ";gtk/lib;gtk/bin" to top of your script.

3.) Create an executable of your app using py2exe. This is going to take a lot of trial and error, because, although the exe will probably work on your original machine, when you move it to a "clean" machine, you invariably will be missing a module that py2exe did not automatically include. Not to worry! Py2exe give you various ways to manually include missing modules. It's going to take some tweaking, but you will get there. Here is an example of the command line that I use for my app:

python setup.py py2exe --force --excludes gtk, gobject,pango --packages pyPgSQL --icon fred6.ico

(Note I think this command example is a bit stale. E.g. --force does not seem to work with versions downloaded in Oct 2004. Also the --excludes and other options can be included in the setup.py script. I suggest checking the mailing list archives.)

The reason we exclude gtk is that gtk needs some extra files, which gtk searches for relative to the path of the gtk DLLs. So it is safer to just copy the whole gtk tree intact, as is done below. This means the extra files can be found, e.g. those in gtk/etc and gtk/lib; and helps with debugging by avoiding multiple copies of the same DLL in the installation.

Here's what my setup.py script looks like:

  from distutils.core import setup
  import py2exe
  import glob

  setup(name="fredgui", scripts=["fredgui.pyw"],
   data_files=[(".",glob.glob("*.bmp")),(".",glob.glob("*.gif")),
               (".",glob.glob("*.png")),(".",glob.glob("*.jpg")),
               (".",glob.glob("*.ico")),(".",glob.glob("*.xpm")),
               (".",glob.glob("../../jgcmodules/*.py"))],)

5.) Now, we turn to Inno Setup. There's a copy of my Inno script at [www.async.com.br]1451 .

6.) I compile the script and it creates a setup.exe. Copy this to a "clean" machine and run it. It should install the app, create desktop icon, start menu icons, etc. Try to run the app. If it doesn't work, chances are that you are missing a module that didn't get included in either py2exe or Inno setup. One cheezy way to debug it is to initially create the executable in py2exe as a console app (using the --console flag in py2exe). This means that, even though the app is a gui, it will still open a dos box when it runs on the target machine. This will alllow you to see the error message that gets generated when it bombs out on the clean machine.

7). Don't give up. It will probably take several tries, but eventually you will end up with a working executable on the clean machine!

Note: The above instructions are an EXTREMELY cheesy way to accomplish the task of creating a self-installing pygtk app. I'm sure that there are many more efficient ways of doing this. Also, my knowledge of py2exe and Inno setup is VERY limited, so I'm sure that there are things that could be done much better using these tools.

I hope these notes have been helpful (and that I didn't forget any steps!).

Note: If your app crashes on non-English Windows, but works OK on English Windows, it may be due to corrupted locale files (*.mo in the gtk runtime tree).

Final note: If you are using Python 2.2.3 or later, and you're getting a UnicodeError when running your script, see Michal's Pasternak's explanation at [pasternak.w.lub.pl]1452

Edit this entry1453 / Log info1454 / Last changed on Wed Mar 1 06:49:14 2006 by Filip Van Raemdonck (mechanix-at-debian-org)

21.6.1455 How do I change the Window icon of a Win32 PyGTK app?

Edit this entry1457 / Log info1458 / Last changed on Sun Jan 2 11:19:59 2005 by Gian Mario Tagliaretti (g-tagliaretti-at-parafernalia-org)

21.7.1459 How do I make the my PyGTK app look a bit more like a `normal' Windows app?

It is based on the Redmond95 theme but changed significantly. Note that Raleigh is also pretty close to windows (except for subtle colors and the optionmenu).

John K Luebs offered this great explanation on what sort of differences exist, and workarounds if you don't want to use Wimp:

One important difference is the size of the fonts. The reason the default font looks so big is because Windows has a default res of 96 dpi. When GTK was first released, most people were running with monitors that were actually around 75dpi (I bet you that even today this is still the case) and therefore most people were running their X server at 75 dpi. When you run the default GTK font size (can't remember if its 10 or 12 points) at 96 it looks ridiculously big.

This does not require a change of theme. You simply need to edit your gtkrc file or parse a new one when your program starts. The "default" font on Windows 2000 systems is Tahoma 8.You can edit the gtkrc-2.0 file in your GTK runtime tree. You can also use the gtk.rc_parse function to parse a specific rc file when your application starts.

As for the resource file syntax, I think you do best to read the Resource Files chapter in section II of the GTK 2.0 API reference. What you might want is something like this in one of the rc files:

 style "win32-font"
 {
   font_name = "tahoma 8"
 }
 class "*" style "win32-font"

Edit this entry1461 / Log info1462 / Last changed on Thu Apr 17 12:11:23 2003 by Christian Reis (kiko-at-async-com-br)

21.8.1463 How do I compile PyGTK for win32

One potential roadbump is that for WindowsME/mingw/python2.2/pygtk2, the compiler flag -mms-bitfields needs to be set to successfully import pygtk. You can do this by editing setup.py and calling

  for module in ext_modules:
      module.extra_compile_args.append('-mms-bitfields')

Edit this entry1465 / Log info1466 / Last changed on Mon Mar 21 12:41:07 2005 by Christian Reis (kiko-at-async-com-br)

21.9.1467 How do I find out the GTK+ installation path on windows?

 import sys

 if sys.platform.startswith("win"):
     # Fetchs gtk2 path from registry
     import _winreg
     import msvcrt
     try:
         k = _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, "Software\\GTK\\2.0")
     except EnvironmentError:
         print "You must install the Gtk+ 2.2 Runtime Environment to run this program"
         while not msvcrt.kbhit():
             pass
         sys.exit(1)
     else:    
         gtkdir = _winreg.QueryValueEx(k, "Path")
         import os
         os.environ['PATH'] += ";%s/lib;%s/bin" % (gtkdir[0], gtkdir[0])
         import pygtk
         pygtk.require ('2.0')
 import gtk

Edit this entry1468 / Log info1469 / Last changed on Fri Jun 27 16:27:28 2003 by Luca 'Ziabice' Gambetta (ziabice-at-ziabice-net)

21.10.1470 DLL Errors after upgrading to PyGTK-2.0.0.win32-py2.3

The dll could be any of several GTK related DLLs. Such as iconv.dll, libgdk-win32-2.0-0.dll etc.. Charles Lepple was exactly right when he pointed me to the winnt/system32 directory. Glade 1.1.2 had installed a bunch of dll's in that location that were getting picked up by Python and the system, before the new GTK+ runtime 2.2.4 dlls. Python wasn't happy about it. On another system, I found a PATH with d:\tcl\bin in it, and the iconv.dll was there as well. After removing the entry from the path, and removing the dlls from the system32 dir I rebooted. Now the app loads perfectly. I haven't tried reinstalling Glade yet... However I think if I leave the GTK 2.2.4 in the PATH, and remove any rouge dlls after the install, everything should be fine.

Edit this entry1471 / Log info1472 / Last changed on Mon Sep 15 23:53:12 2003 by Steven Bell (sfbell-at-mindspring-com)

21.11.1473 Is it possible to have antialiased fonts on Win32?

On versions other than WinXP, you can enable font smoothing on Windows by following these steps:

• Right-click on the desktop, select Properties to get the Display Properties dialog.
• Choose the Effects tab.
• Look for an option that mentions font smoothing, or smooth edges and enable it.

And on Windows XP:

• Right-click on the desktop, select Properties to get the Display Properties dialog.
• Choose the Appearance tab and click on the Effects button.
• Enable "Use the following method to smooth edges of screen fonts".
• From the combo box, choose "Standard" to get the same font smoothing that older versions of Window use, or "ClearType" to get smoothing of all fonts.
• There is a web page for configuring ClearType (IE only): [www.microsoft.com]1474

Note that GTK and Pango do not use Xft on Windows, so the GDK_USE_XFT flag doesn't have any meaning there.

(James and Tim Evans)

Edit this entry1475 / Log info1476 / Last changed on Mon May 31 20:36:31 2004 by Christian Reis (kiko-at-async-com-br)

21.12.1477 How do themes work on win32?

• The standard location for themes is <GTK Folder>/share/themes. You can drop any theme you want in there.

• Theme engines go into <GTK Folder>/lib/gtk-2.0/2.2.0/engines. The only one included in the standard package is libwimp.dll. Themes bluecurve, cleanice, galaxy, industrial, thincream, thinice, xfce, pixbuf have been successfully built and used - it should be quite straightforward if you have the GTK Dev package installed (Tyler used Visual C++ 6, Fabien used MinGW).

A patch was submitted to sourceforge to request the inclusion of the precompiled engines and associated themes in the main distro a while ago; check the patches page on [sourceforge.net]1478 .

The tricky bit is how to tell GTK on Windows which theme to use. There are at least 3 ways to do this (though I have only tested 2):

• Rename the theme folder in share/themes to 'Default'. This will then be the one used on the next execution of your GTK app.
• Copy the gtkrc from the theme directory you want into <GTK Folder>/etc/gtk-2.0. (I also tried putting a shortcut in there instead, to no effect - would have been nice though).
• (From the source) Put a .gtk-2.0rc (not sure of exact name at the moment) in your 'HOME' folder. The issue here is that every version of Windows gives you a different 'HOME' location. On my XP box, it is <SYSTEM DRIVE>/Documents and Settings/<USERNAME>.

With the second choice there is less room for error since you do not have to rename folders: you simply copy one file into a different location. To get back to the original settings you just delete that gtkrc from the etc/gtk-2.0 folder.

If you don't want to tweak with rc files, there also a GUI program by Alex Shaduri to preview and select the theme and font to be used by all GTK apps. It's called "gtk2_prefs" and you will find it at [members.lycos.co.uk]1479 (version 0.2.0 was current as of this writing).

Note that all themes mostly work with some off-by-one glitch drawing seen on the right of some borders.

(Tyler Wilson, Fabien Coutant)

Edit this entry1480 / Log info1481 / Last changed on Thu Mar 18 18:14:55 2004 by Fabien COUTANT (no-email -at- world-com)

21.13.1482 Can PyGTK have the native filechooser of Windows?

The following is directly copied from C:\Python24\Lib\site-packages\win32\Demos\GetSaveFileName.py (so you need to install the 'win32all' package).

  import win32gui, win32con, os

  filter='Python Scripts\0*.py;*.pyw;*.pys\0Text files\0*.txt\0'
  customfilter='Other file types\0*.*\0'

  fname, customfilter, flags=win32gui.GetSaveFileNameW(
    InitialDir=os.environ['temp'],
    Flags=win32con.OFN_ALLOWMULTISELECT|win32con.OFN_EXPLORER,
    File='somefilename', DefExt='py',
    Title='GetSaveFileNameW',
    Filter=filter,
    CustomFilter=customfilter,
    FilterIndex=1)

  print 'save file names:', repr(fname)
  print 'filter used:', repr(customfilter)
  print 'Flags:', flags
  for k,v in win32con.__dict__.items():
    if k.startswith('OFN_') and flags & v:
        print '\t'+k

  fname, customfilter, flags=win32gui.GetOpenFileNameW(
    InitialDir=os.environ['temp'],
    Flags=win32con.OFN_ALLOWMULTISELECT|win32con.OFN_EXPLORER,
    File='somefilename', DefExt='py',
    Title='GetOpenFileNameW',
    Filter=filter,
    CustomFilter=customfilter,
    FilterIndex=0)

  print 'open file names:', repr(fname)
  print 'filter used:', repr(customfilter)
  print 'Flags:', flags
  for k,v in win32con.__dict__.items():
    if k.startswith('OFN_') and flags & v:
        print '\t'+k

Edit this entry1483 / Log info1484 / Last changed on Thu Mar 9 02:35:26 2006 by John Pye (john-pye-at-student-unsw-edu-au)

22. libglade

22.1.1485 How do I use PyGTK and glade together (using libglade)?

Basically, the steps involved are:

1. Create your interface with glade, and save the XML file (say, foo.glade).

2. Implement the relevant code using gtk.glade:

  import gtk.glade
  # instantiate XML object
  tree = gtk.glade.XML("foo.glade")
  # get references to individual widgets
  w1 = tree.get_widget("window1")
  e1 = tree.get_widget("entry1")

It's important to understand that by creating an XML instance you are in fact *generating the UI*, and all widgets will be created in this step. To deal with visibility issues, see FAQ 22.61487.

The most important method in the XML instance is get_widget(), which returns widgets defined in your glade file by name. Glade assigns names by default, and the pattern is usually <widgetname><number>; in the example above we are using the default widget names for a GtkWindow and a GtkEntry. You are advised to change these names to something that makes sense for your application to avoid going insane performing code maintenance.

If you'd like to deal with signals defined in the gladefile, take a look at FAQ 22.41488.

Keep in mind that gtk.glade automatically caches XML trees. So don't try any complex tricks to reuse XML trees if you have to create the same UI multiple times. The correct thing to do is simply to instantiate the XML multiple times with the same parameters.

Edit this entry1489 / Log info1490 / Last changed on Sat Feb 4 02:06:56 2006 by Steve Chaplin (stevech1097-at-yahoo-com-au)

22.2.1491 How do I internationalize a PyGTK and libglade program?

1.1 Prepare your application

• Use _('') at all places where you handle user-visible strings. Please avoid non-ASCII letters.

 print _('Hello World!')
 s = _('%s: %u / %u\n') % (id, x, y)

• You will have to choose a non-ambiguous name for your application (or library), let's say "myapp". Furthermore the translated message-files will have to be stored somewhere, the default is often "/usr/share/locale". When working with a not installed application its though much easier to have them lying in a local subdirectory, let's choose "locale".

 APP = 'myapp'
 DIR = 'locale'

• Use the gettext module, which provides the well known basic gettext API, but has some new features. It's easy to use this module for internationalization of your application:

 import locale
 import gettext
 locale.setlocale(locale.LC_ALL, '')
 gettext.bindtextdomain(APP, DIR)
 gettext.textdomain(APP)

Please note that the command line tools used in this example requires gettext installed. See* [www.gnu.org]1492 for more information

• Extract the strings to translate from the source files, repeat this after changing the strings in your code. If using intltool you should combine the messages.pot that xgettext produces with the pot-file that intltool generates.

 xgettext -k_ -kN_ -o messages.pot *.py

• Whenever someone wants to start a new translation, you have to create a file for it. This is easily done by "msginit", for example the following line will create and setup a de_DE (eg German spoken in Germany) translation file "de.po".

 LANG=de_DE msginit

• Translation is done by editing such *.po files, have a look at them and the gettext documentation about this.

• Now imagine "de.po" already contains a full translation but the code changes. You will then have to merge the existing translation with new and changed translation strings:

 msgmerge -U de.po messages.pot

• The *.po files contain human readable entrys, they have to be prepared for usage by the real application:

 mkdir -p locale/de/LC_MESSAGES/
 msgfmt de.po -o locale/de/LC_MESSAGES/myapp.mo

 # start without any translation
 LANG=de_DE python myapp.py

2.1 Extracting strings

• Use intltool to extract translatable strings directly from the glade files:

 intltool-extract --type=gettext/glade foo.glade

• Alternatively, to extract strings within Glade: go to the "LibGlade Options" page in your projects options and enable "Save Translatable Strings". Choose a nice filename like "glade-msg.c". Yes - ".c"! Glade will create a C pseudo source file with all the messages in it whenever you save your project. (Please don't compile this file or use it somehow or other without knowing what you do...)

Include *.c as an argument to xgettext if you chose to have glade generate .c file instead of using intltool. In case of intltool-extract add *.glade.h instead of the .c file

2.2 Using the right domain

• Change your code so that when you instantiate gtk.glade.XML(), you include a parameter specifying the textdomain:

 widgets = gtk.glade.XML(glade_file, widget_name, APP)

Edit this entry1493 / Log info1494 / Last changed on Thu Jan 19 16:34:35 2006 by Johan Dahlin (johan-at-gnome-org)

22.3.1495 Why doesn't gettext work on my libglade UIs with Python <= 2.2?

This was actually a problem with Python. Python2.0 to 2.2 included a pure-python gettext.py module, which provides the same basic gettext API, but has some new features. The problem with a pure python implementation is that it never calls glibc textdomain() and bindtextdomain(). Since libglade is implemented in C, the internationalization happens outside the scope of the python interpreter. Without *textdomain(), libglade never knows that C gettext support is to be activated for the UI you are instantiating.

There are a few workarounds:

• One is to use Martin's C gettext module intl.so, which can be downloaded from [www.informatik.hu-berlin.de]1497 If you import intl and call the *textdomain() functions, things should work fine.

• You may try upgrading to Python 2.2.2 - its "locale" module now has the required functions. [This is currently not much tested - reports are welcome.]

• If you are using a not too old PyGTK version, it contains gtk.glade.bindtextdomain() and gtk.glade.textdomain(), so this will do:

 gtk.glade.bindtextdomain(APP, DIR)
 gtk.glade.textdomain(APP)

• Last - and perhaps least - a dirty trick if your Python installation contains the "dl" module:

 import dl
 l = dl.open('/lib/libc.so.6')
 l.call('bindtextdomain', APP, DIR)
 # if you want unicode strings:
 l.call('bind_textdomain_codeset', APP, 'UTF-8');

Edit this entry1498 / Log info1499 / Last changed on Wed May 25 10:09:56 2005 by Christian Reis (kiko-at-async-com-br)

22.4.1500 I'm using libglade, but what do I do with the signals and handlers I set in the glade file?

 class MyWindow:

    def __init__(self):
	# Load the glade file
        wtree = glade.XML('foo.glade')
	# Connect the glade signals handlers to the python callbacks
	wtree.signal_autoconnect(self)

    # define a callback (method)
    def a_name_of_a_signal_handler(self, *args):
        ....

Often, you will also want to reference the widgets that you construct. This snippet of code, to be placed at the end of __init__, will make add each widget as an attribute of your object:

        for w in wtree.get_widget_prefix(''):
            name = w.get_name()
            # make sure we don't clobber existing attributes
            assert not hasattr(self, name)
            setattr(self, name, w)

Instead of passing signal_autoconnect an object, you can pass it a dict filled with methods, like

 dict[glade_method name] = python_method_reference

 gladetree.signal_autoconnect(dict)

There are a number of base classes that wrap this process, as well. One is included with Kiwi: [www.async.com.br]1501 and another, with Mitch Chapman's GladeBase: [ftp.ssc.com]1502 (article at [www.linuxjournal.com]1503 )

Jonathan Bartlett also contributed this class to the list:

 import new, types

 class GladeWidget:
    #This method loads the XML file and autoconnects the signals
    def initialize(self, glade_file, widget_name):

        #initialize variables
        self.widgets = GladeXML(glade_file, widget_name)
        callbacks = {}

        #find and store methods as bound callbacks
        class_methods = self.__class__.__dict__
        for method_name in class_methods.keys():
            method = class_methods[method_name]
            if type(method) == types.FunctionType:
                callbacks[method_name] = new.instancemethod(
                                         method, self, self.__class__)
        self.widgets.signal_autoconnect(callbacks)

Here's an example where arguments other than the widget are passed to the signal handler (note the tuple for handling clicks to the ok button):

 wTree2 = libglade.GladeXML("somefile.glade","proxy1")
 proxywidget = wTree2.get_widget("proxy1")
 id=1
 dic= {"on_cancel_clicked": proxywidget.destroy,
       "gtk_widget_destroy": proxywidget.destroy,
       "on_ok_clicked": ( handle_ok_clicked, wTree2,id)}
 wTree2.signal_autoconnect (dic)

 def handle_ok_clicked(self,widget,name,wTree2,widgetid):

Edit this entry1505 / Log info1506 / Last changed on Mon Jun 13 12:02:39 2005 by Nikos Kouremenos (kourem-at-gmail-com)

22.5.1507 I'm using Gnome and libglade, but some widgets don't work properly.

When using Gnome and libglade, you MUST import gnome.ui before doing any GladeXML parsing. Failing to do that means gnome will never be initialized and libglade will just Do Bad Things<tm>

Edit this entry1508 / Log info1509 / Last changed on Fri Jan 10 12:14:11 2003 by Christian Reis (kiko-at-async-com-br)

22.6.1510 When I invoke GladeXML() or glade.XML() all the widgets in my gladefile are displayed!

Normally, you want to make all *top-level* widgets in your gladefile non-visible. The child widgets should be visible - this way, you only need to show/hide the toplevel to show the whole window, which is what you usually want.

Edit this entry1511 / Log info1512 / Last changed on Thu Jul 24 19:03:11 2003 by Christian Reis (kiko-at-async-com-br)

22.7.1513 How do I create and use a custom Glade widget?

        import gtk
        import gtk.glade

        def create_source_cd_dropdown():
            return gtk.Label("source")

        gtk.glade.set_custom_widget_callbacks(locals())
        glade = gtk.glade.XML("cd-copier.glade")
        window = glade.get_widget("window")
        window.show_all()
        gtk.main()

The above method is deprecated in recent versions of pygtk.

The new API uses the method gtk.glade.set_custom_handler, which allows you to treat widget creation more dynamically if you wish.The set_custom_handler API works as follows:

    def my_handler (glade, function_name, widget_name, str1, str2, int1 , int2):
        # create your widget based on our arguments...
        return a_custom_widget

    gtk.glade.set_custom_handler(my_handler)

IMPORTANT: The call to gtk.glade.set_custom_handler() (as well gtk.glade.set_custom_widget_callbacks()) must come before the load of any Glade widget (by calling gtk.glade.XML()). The reason is that Glade needs to call the handlers when processing the XML file. The handlers are used to construct widgets, which happens at construction-time.

 class MyGladeApp:

     def __init__ (self):
         gtk.glade.set_custom_handler(self.get_custom_handler)
         self.glade = gtk.glade.XML('/path/to/gladefile.glade')
     ...

     def get_custom_handler(self, glade, function_name, widget_name,
			str1, str2, int1, int2):
	"""
	Generic handler for creating custom widgets, used to
	enable custom widgets.

	The custom widgets have a creation function specified in design time.
	Those creation functions are always called with str1,str2,int1,int2 as
	arguments, that are values specified in design time.

	This handler assumes that we have a method for every custom widget
        creation function specified in glade.

        If a custom widget has create_foo as creation function, then the
	method named create_foo is called with str1,str2,int1,int2 as arguments.
	"""
	handler = getattr(self, function_name)
	return handler(str1, str2, int1, int2)

Edit this entry1514 / Log info1515 / Last changed on Tue Dec 6 11:22:30 2005 by Fabian Sturm (f-at-rtfs-org)

22.8.1516 How do I retrieve the ID of a signal connection made by signal_autoconnect?

Edit this entry1517 / Log info1518 / Last changed on Wed Sep 17 12:30:43 2003 by Christian Reis (kiko-at-async-com-br)

22.9.1519 My libglade files have widgets that don't show up in the GladeXML tree!

Do you have repeated widget names? That is usually the cause of these problems. Try doing a grep for "<name>" in the glade file, and look for duplicates.

Edit this entry1520 / Log info1521 / Last changed on Thu Apr 25 12:47:06 2002 by Christian Reis (kiko-at-async-com-br)

22.10.1522 When I load a glade file in GladeXML I get evil warnings about GnomeApp and a crash!

 GnomeUI-CRITICAL **: file gnome-app.c: 
    line 208 (gnome_app_new): assertion `appname != NULL' failed.
 Gtk-WARNING **: invalid cast from (NULL) pointer to `GnomeApp'

• unclick the "Enable Gnome support" button in the glade "Project Options" dialog.
• don't use any gnome widgets - I mean NONE

 *NOTE* STOCK ICONS ARE GNOME-ONLY IN GTK+ 1.2!
 YOUR BUTTONS SHOULD NOT USE THEM IF YOU DON'T WANT TO REQUIRE GNOME!

 import gnome.ui    
 gnome.init("programname", "version")

Edit this entry1523 / Log info1524 / Last changed on Sun Nov 3 15:21:24 2002 by Christian Reis (kiko-at-async-com-br)

22.11.1525 How do I produce or reuse a [portion of a] widget tree in glade?

The example below creates 10 identical dialogs:

  for i in range(10):
      xml = gtk.glade.XML("foo.glade", "my-window")
      win = xml.get_widget("my-window")
      win.show()

  xml = gtk.glade.XML("foo.glade", "my-vbox")
  vbox = xml.get_widget("my-vbox")
  win = gtk.Window()
  win.add(vbox)
  win.show()

NB: The only thing to watch out for is keyboard accelerators, which need to be attached to the main window. This, at least in PyGTK 0.6, was a non-trivial task.

Edit this entry1527 / Log info1528 / Last changed on Sun Jun 5 13:40:15 2005 by Joel Rosdahl (joel-at-rosdahl-net)

22.12.1529 How can I get a new instance of a widget defined in a glade file?

  PyGladeXMLObject = gtk.glade.XML(fname, root, domain)

root points to the widget from which the PyGladeXML object will start to be built. Thus, if you have a widget with an id such as "label6" and you need a new copy of it you would create a new PyGladeXML object using the glade file as fname and the widget's id as the root parameter.

This is better shown with an example:

 >>> import pygtk
 >>> pygtk.require('2.0')
 >>> import gtk
 >>> gladeXML = gtk.glade.XML("mygladefile.glade") # first 
 >>> print gladeXML
 <gtk.glade.XML object (PyGladeXML) at 0xd8d990>
 >>> label6a = gtk.glade.XML.get_widget(gladeXML, "label6")
 >>> print label6a
 <gtk.Label object (GtkLabel) at 0xf5b030>
 >>> label6b = gtk.glade.XML.get_widget(gladeXML, "label6")
 >>> print label6b
 <gtk.Label object (GtkLabel) at 0xf5b030>
 >>> gladeXML2 = gtk.glade.XML("mygladefile.glade", "label6")
 >>> print gladeXML2
 <gtk.glade.XML object (PyGladeXML) at 0xef22b0>
 >>> newlabel6 = gtk.glade.XML.get_widget(gladeXML2, "label6")
 >>> print newlabel6
 <gtk.Label object (GtkLabel) at 0xf5a7d8>

Edit this entry1530 / Log info1531 / Last changed on Sun Jun 5 13:39:55 2005 by Joel Rosdahl (joel-at-rosdahl-net)

22.13.1532 Tabs in Notebook don't show up!

you might have got this message:

(gtk_notebook_set_tab_label): assertion `GTK_IS_WIDGET (child)' failed

Edit this entry1533 / Log info1534 / Last changed on Tue Dec 21 13:01:58 2004 by Nikos Kouremenos (kourem-at-gmailDOTcom)

23. Miscellaneous questions

23.1.1535 Why does ancient PyGTK versions segfault with Python 2.2?

The fix is to do a search and replace s/PyMem_DEL/PyObject_DEL/ in the pygtk sources.

Thanks go to Dave Wallace for tracking this down.

Edit this entry1536 / Log info1537 / Last changed on Sat Jun 4 10:27:42 2005 by Johan Dahlin (johan-at-gnome-org)

23.2.1538 Are there any helpful tools when developing with PyGTK?

• There is a _very_ useful pygtk-test script that was created by Brian McErlean and hacked upon by Johan Dahlin. It is available at ASPN: [aspn.activestate.com]1539 (That page states I did the changes. The way I remember it, Johan did all the work) It allows you to run a session interactively and still see the widgets render and have signals behave normally (as you would when debugging Tk).

• Jon Anderson has written a version of the console that runs inside a gtk Widget, with color-coding and completion. It should run with PyGTK2: [sinai.sourceforge.net]1540

• Skip Montanaro gives us a dirpat method for interactive use that allows me to filter symbols based upon regular expressions:

    def dirpat(o, pat):
        """like dir, but only return strings matching re pat"""
        import re
        names = dir(o)
        pat = re.compile(pat)
        return [x for x in names if pat.search(x) is not None]

• MVC and Observer patterns were implemented in an MVC Framework, written by Roberto Cavada and available at [sourceforge.net]1541

• A complete object-oriented framework build upon PyGTK, called Kiwi, exists. It is quite stable, containing base classes and widget wrappers with enhanced functionality, and has full reference documentation and a tutorial. It's available at [www.async.com.br]1542

• Another is Mitch Chapman's GladeBase: [ftp.ssc.com]1543 (article at [www.linuxjournal.com]1544 )

• Basile Starynkevitch has written a GUI application server in Python called Guis. Guis communicates with a client application through textual communication channels; input requests (from application to guis) are Python code, and output replies (or events) are arbitrary lines of text from Guis to the client application. There is a possibility to trace the exchanges between application & guis (in a graphical window). See [www.starynkevitch.net]1545 for more information.

• Marco Sousa reminded us that there are a number of cool Python interactive tools at [www.idyll.org]1546 -- as discussed in [www.onlamp.com]1547 , which describes the LazyPython and pythonstartup.py tools that , among other things, provide autocompletion , like bash:

 >>> import gtk
 >>> gtk.DI <Press TAB !>
 gtk.DIALOG_DESTROY_WITH_PARENT  gtk.DIR_LEFT
 gtk.DIALOG_MODAL                gtk.DIR_RIGHT
 gtk.DIALOG_NO_SEPARATOR         gtk.DIR_TAB_BACKWARD
 [...]

Edit this entry1548 / Log info1549 / Last changed on Wed Jan 18 19:13:27 2006 by Johan Dahlin (johan-at-gnome-org)

23.3.1550 How do I find out the current X and Y position of my mouse?

 def on_w_motion(event):
  print "Mouse position: X:%s Y:%s" % (event.x, event.y)

 w = gtk.Window()
 e = gtk.EventBox()
 w.add(e)
 e.connect("motion_notify_event",on_w_motion)
 w.show_all()
 gtk.main()

Edit this entry1551 / Log info1552 / Last changed on Sat Jun 4 10:28:35 2005 by Johan Dahlin (johan-at-gnome-org)

23.4.1553 Are there any tips for UI designers?

[www.asktog.com]1554 is a real nice reference site by Bruce Tognazzini. His column on Fitts' law is particularly interesting: [www.asktog.com]1555

[www.useit.com]1556 is Jakon Nielsen's site. Nielsen is the usability guru, but he has been concentrating on the web and appliances lately, so you might not see much conventional computer UI advice.

You should spend some time reading the HCI guidelines for the relevant projects. Reading other UI specs is interesting because you get a feeling of what research led to what.

• Gnome HI Guidelines: [developer.gnome.org]1557 and mpt's rehash of them: [geocities.com]1558 and rationale at [mail.gnome.org]1559

• MacOS HI Guidelines: [developer.apple.com]1560 and [mactech.com]1561 (review os MacOS8)

• Mozilla UI Specs: [mozilla.org]1562 and [www.mozilla.org]1563

Books I can recommend are:

• The design of Everyday Things, by Donald Norman, a general design book that lays out why design is important, and why we all ignore it.
• XXX: add more - tog's book is good, UI bloopers, etc.

Edit this entry1564 / Log info1565 / Last changed on Tue Feb 5 14:23:44 2002 by kiko (kiko-at-async-com-br)

23.5.1566 Why does my X selection disappear when my window dies?

X selection handling is an asynchronous operation. When a user "copies" some text to the clipboard, the text doesn't necessarily get copied anywhere. Instead, the application claims the CLIPBOARD selection. When another app wants to paste the contents of the clipboard, they request the contents of the CLIPBOARD selection in a particular format (eg. UTF8 text, html, an image, etc), which sends a message to the first app. The first app then sends the data back in the requested format. This has the benefit that no data is sent over the wire until it is requested, and content type negotiation can be performed.

As you can see, this model breaks down when the selection owner window gets destroyed. There are some tools to work around this problem such as xclipboard. The downside to xclipboard is that every time the CLIPBOARD selection is claimed, the data gets requested by xclipboard, and xclipboard will only store the data in one format.

Edit this entry1567 / Log info1568 / Last changed on Tue May 28 00:57:02 2002 by Christian Reis (kiko-at-async-com-br)

23.6.1569 When compiling PyGTK, I get a bunch of weird "Could not write method ..." messages!

 Could not write method GtkTextIter.forward_find_char: No ArgType 
       for GtkTextCharPredicate
 Could not write method GtkTextIter.backward_find_char: No ArgType 
       for GtkTextCharPredicate
 Could not write method GtkAccelGroup.connect: No ArgType for 
       GClosure*
 Could not write method GtkAccelGroup.connect_by_path: No ArgType 
       for GClosure*
 [...]

Edit this entry1570 / Log info1571 / Last changed on Sat Jun 4 10:29:10 2005 by Johan Dahlin (johan-at-gnome-org)

23.7.1572 Is there a way to get version information from pygtk?

Use gtk.pygtk_version which is a tuple with three items, (major, minor, micro):

  if gtk.pygtk_version >= (1,99,12):
      ...

  if gtk.gtk_version >= (2,0,5):
      ...

Edit this entry1573 / Log info1574 / Last changed on Sun Aug 25 10:11:08 2002 by Christian Reis (kiko-at-async-com-br)

23.8.1575 How do I beep the speaker?

 gtk.gdk.beep()

Edit this entry1576 / Log info1577 / Last changed on Wed Dec 15 14:46:53 2004 by Xavier Spriet (xavier-at-wuug-org)

23.9.1578 Is there a way to grab the keyboard from X (like XGrabKey())?

 gdk_win = window.window
 gdk_win.keyboard_grab(1, 0) # owner_events and time, respectively
                             # XXX: is this the way?

Russ Nelson originally asked this, and Markus Schaber offered this tip.

Edit this entry1579 / Log info1580 / Last changed on Sat Jun 4 10:30:18 2005 by Johan Dahlin (johan-at-gnome-org)

23.10.1581 When wrapping a widget into a new Python extension, I get undefined symbols on importing it!

 I import gtksourceview, kablam, here is what I get:

  /usr/lib/python2.2/site-packages/gtksourceviewmodule.so: 
     undefined symbol: gtk_source_buffer_get_tag_end

Edit this entry1582 / Log info1583 / Last changed on Sat Apr 10 18:04:41 2004 by Johan Dahlin (johan-at-gnome-org)

23.11.1584 Does VTK support PyGTK?

Edit this entry1587 / Log info1588 / Last changed on Sun May 15 18:21:03 2005 by Christian Reis (kiko-at-async-com-br)

23.12.1589 How do I create a GdkRectangle?

Instead of providing the widget as a Python class, PyGTK allows one to use a tuple wherever a GdkRectangle is expected. You can simply pass in a sequence of 4 integers of the form (x, y,width, height), and it will be interpreted as a rectangle.

Edit this entry1591 / Log info1592 / Last changed on Tue May 25 12:36:18 2004 by Johan Dahlin (johan-at-gnome-org)

23.13.1593 When I create a gnome Druid, the first and last page are blank.

The first and last pages need to have their show() method called, I just did this:

 wtree = glade.XML("glade_file.glade")
 start_page = wtree.get_widget("start_page")
 start_page.show()
 finish_page = wtree.get_widget("finish_page")
 finish_page.show()

Edit this entry1594 / Log info1595 / Last changed on Sat Jun 4 10:32:47 2005 by Johan Dahlin (johan-at-gnome-org)

23.14.1596 I disable text or graphics on my GtkToolbar, or the time in my GnomeDateTime, and they still show up, or, why is show_all() considered harmful?

If you use show_all() to display them (either calling show_all() on them or on one of their parent containers) then the subwidget that was originally hidden will be shown again.

Moral of the story: avoid using show_all() when possible; it may produce unexpected results.

Edit this entry1597 / Log info1598 / Last changed on Mon Sep 29 11:33:47 2003 by Christian Reis (kiko-at-async-com-br)

23.15.1599 I'm writing a C extension that uses PyGTK. How do I acess a PyGTK object's C counterparts and vice-versa?

• Make your foomodule.c look like this:

  #include <pygobject.h>           
  #include <pygtk.h>    
  /* global variable declared at top of file */
  static PyTypeObject *PyGObject_Type=NULL;    
  /* ... */                                
  void initfoo(void)
  {                 
      PyObject *module;
      Py_InitModule("foo", foo_functions);

      init_pygobject();
      init_pygtk();
      module = PyImport_ImportModule("gobject");
      if (module) {
          PyGObject_Type =
           (PyTypeObject*)PyObject_GetAttrString(module, "GObject");
          Py_DECREF(module);
      }
  }    

• To create a python gtk widget from a C gtk widget:

  pygobject_new((GObject*) widget);             
  /* If a python wrapper for 'widget' already exists, it will
    incref and return that, otherwise it will create a new
    python wrapper object. */

• To get a pointer to the underlying C widget from a Python widget that

  was passed as an argument, do something like this:

  PyGObject *py_widget;                         
  GtkWidget *widget;   

  if (!PyArg_ParseTuple(args, "O!", PyGObject_Type, &py_widget))
      return NULL;
  widget = GTK_WIDGET(py_widget->obj);

Edit this entry1600 / Log info1601 / Last changed on Thu Feb 19 12:53:29 2004 by Christian Reis (kiko-at-async-com-br)

23.16.1602 How do I change the font and colour of some GnomePrint text?

  gnomeprint.font_find_closest_from_weight_slant(family(string),
                                                 weight(enum), 
                                                 italic(gboolean), 
                                                 size(float))

You can't change the color of a gnomeprint.Font. You should change the color of your gnomeprint.Context instead, with

  gnomeprint.Context.setrgbcolor(r,g,b).  

Edit this entry1604 / Log info1605 / Last changed on Tue Dec 16 00:27:16 2003 by Christian Reis (kiko-at-async-com-br)

23.17.1606 Is there a way to query for the current screen size?

Edit this entry1607 / Log info1608 / Last changed on Mon Mar 8 18:17:10 2004 by Christian Reis (kiko-at-async-com-br)

23.18.1609 When dragging and dropping, Netscape/Firefox/etc and gedit/native gtk apps don't behave the same. Why?

 text/_moz_htmlcontext
 text/_moz_htmlinfo
 text/html
 text/unicode
 text/plain

 GTK_TEXT_BUFFER_CONTENTS
 UTF8_STRING
 COMPOUND_TEXT
 TEXT
 STRING

 tree.enable_model_drag_dest([('text/plain',0,0),
                              ('TEXT', 0, 1),
                              ('STRING', 0, 2),
                              ('COMPOUND_TEXT', 0, 3),
                              ('UTF8_STRING', 0, 4)],
                               gtk.gdk.ACTION_DEFAULT |
                               gtk.gdk.ACTION_COPY |
                               gtk.gdk.ACTION_MOVE)

 def gettargets(wid, context, x, y, time):
   for t in context.targets:
       print t
   return True

 w = gtk.Window()
 w.set_size_request(100, 100)
 w.drag_dest_set(0, [], 0)
 w.connect('drag_motion', gettargets)
 w.show_all()

 gtk.main()

Edit this entry1610 / Log info1611 / Last changed on Mon Jun 14 16:50:47 2004 by Christian Reis (kiko-at-async-com-br)

23.19.1612 What do you see as the flaws in the Minimalist Programme?

(Joe Geldart)

Edit this entry1613 / Log info1614 / Last changed on Tue Jul 13 18:28:00 2004 by Christian Robottom Reis (kiko-at-async-com-br)

23.20.1615 How do I update a progress bar and do some work at the same time

    while work_left:
        ...do something...
        progressbar.set_fraction(...)

The simplest solution consists on temporarily giving control back to gtk every time the progress is changed:

    while work_left:
        ...do something...
        progressbar.set_fraction(...)
        while gtk.events_pending():
            gtk.main_iteration()

Another solution consists on using gtk idle functions, which are called by the gtk main loop whenever it has nothing to do. Therefore, gtk is in control, and the idle function has to do a bit of work. It should return True if there's more work to be done, otherwise False.

The best solution (it has no drawbacks) was pointed out by James Henstridge. It is taking advantage of python's generators as idle functions, to make python automatically preserve the state for us. It goes like this:

    def my_task(data):
        ...some work...
        while heavy_work_needed:
            ...do heavy work here...
            progress_label.set_text(data) # here we update parts of UI
            # there's more work, return True
            yield True
        # no more work, return False
        yield False

   def on_start_my_task_button_click(data):
        task = my_task()
        gobject.idle_add(task.next, data)

More on generators:

Generators are objects that are defined as functions, and when called produce iterators that return values defined by the body of the function, specifically yield statements.

The neat thing about generators are not the iterators themselves but the fact that a function's state is completely frozen and restored between one call to the iterator's next() and the following one. This is just the right thing we need to turn our functions into pseudo-threads, without actually incurring the wrath of the gods of software. More: [www.gnome.org]1616

Edit this entry1617 / Log info1618 / Last changed on Thu Jun 22 09:44:37 2006 by Johan Dahlin (johan-at-gnome-org)

23.21.1619 How can I package my gnome-python application using autotools?

[bandsaw.sourceforge.net]1620

I found the GNOME Blog autotools files provided a good starting point.

The one thing I didn't find online was up to date information on setting up autogen.sh for use with GNOME. I was targetting GNOME 2.6 and ended up following largely out of date documentation. The correct approach is to checkout the latest version of gnome-common from the GNOME CVS server (don't use the 2.4.0 version that is packaged with many distributions; it is far too old to provide the right tools) and modify an existing autogen.sh to suit your needs. Band Saw's should be fine (for GNOME 2.6 at least).

Edit this entry1621 / Log info1622 / Last changed on Thu Sep 9 19:54:51 2004 by Graham Ashton (ashtong-at-users-sourceforge-net)

23.22.1623 How can I extend PyGTK using gtkmm/C++ ?

• Looking at the gtkmm-documentation you'll discover that *before* creating any gtk-objects you have to instantiate an object of type Gtk::Main. You can simple do this by typing:

   int argc = 0;
   char **argv = NULL;
   Gtk::Main kit(argc, argv)

• Create a public function in your custom gtkmm-widget like

   public PyObject* get_pyobject()
   {
     return pygobject_new((GObject*)gobj());
   }

• Finally: If you want to add your custom widget to a pygtk container do something like this:

   hbox = gtk.HBox()
   widget = MyCustomWidget()
   widget.thisown = 0
   hbox.pack_start(widget.get_pyobject())

In case you still want to have Python delete the object at the end you have the option to instantiate it using the global or object's self namescope. Normally this shouldn't be necessary because gtk takes care of the widgets memory management.

Edit this entry1625 / Log info1626 / Last changed on Mon Dec 6 06:42:01 2004 by Alexander Lehmann (lehmanna-at-in-tum-de)

23.23.1627 How do I debug a PyGTK application without an interactive session?

1. Install Xnest;

2. Add a test user to your system;

3. Run a nested window GDM session (in System Tools);

4. Login as the test user;

5. In your own user session:

• open a shell
• change DISPLAY to the test user nested session display (eg. :20)
• run: gdb python
• inside gdb: run /foo/bar/myapplet.py

6. In the test user nested session, trigger the error.

7. View the python backtrace in your shell, or trigger an interrupt in gdb to capture a stack trace.

Edit this entry1628 / Log info1629 / Last changed on Tue Mar 22 04:21:45 2005 by Christian Reis (kiko-at-async-com-br)

23.24.1630 Can GTK know the mouse position outside of GTK Application?

  gdkwindow.get_pointer() 

  rootwin = widget.get_screen().get_root_window()
  x, y, mods = rootwin.get_pointer()

(James Henstridge)

Edit this entry1631 / Log info1632 / Last changed on Tue Apr 19 16:06:43 2005 by Christian Reis (kiko-at-async-com-br)

23.25.1633 Is widget.set_property('visible', False) the same as widget.hide() ?

set_property('visible', True) is also the same as widget.show()

Edit this entry1634 / Log info1635 / Last changed on Tue May 3 13:12:03 2005 by Nikos Kouremenos (kourem-at-gmail-com)

23.26.1636 How do I change window properties involving atom values?

An example follows:

 desktop_type = gtk.gdk.atom_intern("_NET_WM_WINDOW_TYPE_DESKTOP", False)
 win = gtk.Window()
 win.show()
 win.realize()
 win.window.property_change(gtk.gdk.atom_intern("_NET_WM_WINDOW_TYPE", False),
                            gtk.gdk.atom_intern("ATOM", False), 32,
                            gtk.gdk.PROP_MODE_REPLACE,
                            [desktop_type])

(Gustavo Carneiro)

Edit this entry1637 / Log info1638 / Last changed on Mon May 9 19:09:49 2005 by Christian Reis (kiko-at-async-com-br)

23.27.1639 How do I port a GObject/Glib based C application to PyGTK?

  gtk_init(&argc, &argv);

  import gtk

  GtkWidget *button;
  button = gtk_button_new();

  button = gtk.Button()

  gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(button));

  window.add(button)

  g_signal_connect(G_OBJECT(button), "clicked",
                   G_CALLBACK(button_clicked_cb), NULL);

  object.connect("clicked", button_clicked_cb)

• g_message is usually replaced by a print statement
• A GMutex can be replaced by a threading.Lock

Edit this entry1640 / Log info1641 / Last changed on Mon Jun 6 14:55:07 2005 by Christian Reis (kiko-at-async-com-br)

23.28.1642 How can I distribute gtkspell, trayicon (eg. modules that do not depend on gnome) so my application will take advantage of those but the user won't have to install gnome-python-extras?

	# Set the C flags to include the GTK+ and Python libraries
	PYTHONVER = `python -c 'import sys; print sys.version[:3]'`
	CFLAGS = `pkg-config --cflags gtk+-2.0 pygtk-2.0` -fPIC -I/usr/include/python$(PYTHONVER) -I.
	LDFLAGS = `pkg-config --libs gtk+-2.0 pygtk-2.0`

	all: trayicon.so gtkspell.so

	# Build the shared objects
	trayicon.so: trayicon.o eggtrayicon.o trayiconmodule.o
		$(CC) $(LDFLAGS) -shared $^ -o $@

	gtkspell.so:
		$(CC) $(CFLAGS) $(LDFLAGS) `pkg-config --libs --cflags gtkspell-2.0` -shared gtkspellmodule.c $^ -o $@

	# The path to the GTK+ python types
	DEFS=`pkg-config --variable=defsdir pygtk-2.0`

	# Generate the C wrapper from the defs and our override file
	trayicon.c: trayicon.defs trayicon.override
		pygtk-codegen-2.0 --prefix trayicon \
		--register $(DEFS)/gdk-types.defs \
		--register $(DEFS)/gtk-types.defs \
		--override trayicon.override \
		trayicon.defs > $@

	# A rule to clean the generated files
	clean:
		rm -f trayicon.so *.o trayicon.c gtkspell.so *~  

	.PHONY: clean

Edit this entry1643 / Log info1644 / Last changed on Fri Jun 17 09:26:27 2005 by Nikos Kouremenos (kourem-at-gmail-com)

23.29.1645 How do I configure emacs to be used with pygtk?

To turn on Abbrev mode, type:

  M-x abbrev-mode

  M-x write-abbrev-file [RET] ~/.pygtk-abbrevs [RET]

  M-x read-abbrev-file [RET] ~/.pygtk-abbrevs [RET]

This abbrevs keybinding configuration seems to be quite useful too for some people:

  ;; code completion
  (global-set-key (quote [S-iso-lefttab]) (quote dabbrev-expand))
  (global-set-key (quote [S-tab]) (quote dabbrev-expand))
  (global-set-key (quote [f9]) (quote dabbrev-completion))

Edit this entry1646 / Log info1647 / Last changed on Wed Jun 22 09:38:39 2005 by pachi (pachi-at-mmn-arquitectos-com)

23.30.1648 Q_() is not available in my pygtk app. How to use Qualified translatable strings?

has:

 G_CONST_RETURN gchar *
 g_strip_context  (const gchar *msgid, 
		  const gchar *msgval)
 {
  if (msgval == msgid)
    {
      const char *c = strchr (msgid, '|');
      if (c != NULL)
	return c + 1;
    }

  return msgval;
 }

now this is done in python this way (apart from the | check which I did not implement):

 def Q_(s):
   s = _(s)
   if s[0] == '?':
       s = s[s.find(':')+1:] # remove ?abc: part
   return s

in your code you do:

 menu.name = Q_('?vcard:Unknown')
 special.name = Q_('?os:Unknown') 

 #: vcard.py:123 
 msgid "?vcard:Unknown" 
 msgstr "" 

 #: vcard.py:126
 msgid "?os:Unknown" 
 msgstr ""

this helps them so then now the context but moreover the know that gender (masculine, feminine, neutral)

thanks to piman, nkour

Edit this entry1649 / Log info1650 / Last changed on Fri Aug 12 15:39:43 2005 by Nikos Kouremenos (kourem-at-gmail-com)

23.31.1651 How to get the path to the file(s)/folder(s) that was dropped (by drag 'n' drop) in my application? [using selection.data]

 widget.connect('drag_data_received', on_drag_data_received)

 def on_drag_data_received(widget, context, x, y, selection, target_type, timestamp):
	uri = selection.data.strip()
	uri_splitted = uri.split() # we may have more than one file dropped
	for uri in uri_splitted:
		path = get_file_path_from_dnd_dropped_uri(uri)
		if os.path.isfile(path): # is it file?
			data = file(path).read()
			print data

 def get_file_path_from_dnd_dropped_uri(uri):
	path = urllib.url2pathname(uri) # escape special chars
	path = path.strip('\r\n\x00') # remove \r\n and NULL

	# get the path to file
	if path.startswith('file:\\\\\\'): # windows
		path = path[8:] # 8 is len('file:///')
	elif path.startswith('file://'): # nautilus, rox
		path = path[7:] # 7 is len('file://')
	elif path.startswith('file:'): # xffm
		path = path[5:] # 5 is len('file:')
	return path

 import gtk
 import urllib
 import os

 TARGET_TYPE_URI_LIST = 80
 dnd_list = [ ( 'text/uri-list', 0, TARGET_TYPE_URI_LIST ) ]

 def get_file_path_from_dnd_dropped_uri(uri):
	path = urllib.url2pathname(uri) # escape special chars
	path = path.strip('\r\n\x00') # remove \r\n and NULL

	# get the path to file
	if path.startswith('file:\\\\\\'): # windows
		path = path[8:] # 8 is len('file:///')
	elif path.startswith('file://'): # nautilus, rox
		path = path[7:] # 7 is len('file://')
	elif path.startswith('file:'): # xffm
		path = path[5:] # 5 is len('file:')
	return path

 def on_drag_data_received(widget, context, x, y, selection, target_type, timestamp):
	if target_type == TARGET_TYPE_URI_LIST:
		uri = selection.data.strip()
		print 'uri', uri
		uri_splitted = uri.split() # we may have more than one file dropped
		for uri in uri_splitted:
			path = get_file_path_from_dnd_dropped_uri(uri)
			print 'path to open', path
			if os.path.isfile(path): # is it file?
				data = file(path).read()
				#print data

 w = gtk.Window()
 w.connect('drag_data_received', on_drag_data_received)
 w.drag_dest_set( gtk.DEST_DEFAULT_MOTION |
			gtk.DEST_DEFAULT_HIGHLIGHT | gtk.DEST_DEFAULT_DROP,
				dnd_list, gtk.gdk.ACTION_COPY)

 w.show_all()
 gtk.main()

Edit this entry1652 / Log info1653 / Last changed on Wed Aug 17 13:51:39 2005 by Nikos Kouremenos (kourem-at-gmail-com)

23.32.1654 How to get coordinates relative to X11 for a widget that has no window of it's own?

 # here I get the coordinates of the button relative to
 # window (self.window)
 button_x, button_y = self.actions_button.allocation.x, self.actions_button.allocation.y

 # now convert them to X11-relative
 window_x, window_y = self.window.window.get_origin()
 x = window_x + button_x
 y = window_y + button_y

Something more advanced but hopefully useful:

 menu.popup(None, None, self.position_actions_menu, 1, 0)
 menu.show_all()

 def position_actions_menu(self, menu):
	# here I get the coordinates of the button relative to
	# window (self.window)
	button_x, button_y = self.actions_button.allocation.x, self.actions_button.allocation.y

	# now convert them to X11-relative
	window_x, window_y = self.window.window.get_origin()
	x = window_x + button_x
	y = window_y + button_y

	# now move the menu below the button
	y += self.actions_button.allocation.height

	push_in = True # push_in is True so all menu is always inside screen
	return (x, y, push_in)

Edit this entry1655 / Log info1656 / Last changed on Tue Sep 20 15:29:35 2005 by Nikos Kouremenos (kourem-at-gmail-com)

23.34.1657 How can I use gtk.binding_entry_add (and why it's better than keypress in most cases)

It's because normal signals like 'key_press_event' are first catched by your application and then by the IM/GTK (and they are catched only if you do not return True). So you have to use bindings which are superior in most cases (NOTE: Bindings on a combination will never call your Callback if for the same combination a GTK default action exists). Those bindings need a signal-name, so you have to subclass so you can add those bindings only for that class:

	import gtk
	import gobject

	class MyTextView(gtk.TextView):
	    __gsignals__ = dict(
	        mykeypress = (gobject.SIGNAL_RUN_LAST | gobject.SIGNAL_ACTION,
	                  None, # return value
	                  (str,)) # arguments
	        )
	if gobject.pygtk_version < (2, 8):
	    gobject.type_register(MyTextView)

	gtk.binding_entry_add_signal(MyTextView, gtk.keysyms.Return, 0, 'mykeypress', str, 'return')
	gtk.binding_entry_add_signal(MyTextView, gtk.keysyms.Home, gtk.gdk.CONTROL_MASK, 'mykeypress', str, 'ctrl+home')

	def activate_cb(tv, what):
	    print 'You pressed', what

	tv = MyTextView()
	tv.connect('mykeypress', activate_cb)
	w = gtk.Window()
	w.add(tv)
	w.set_default_size(400, 300)
	w.show_all()
	w.connect('destroy', lambda w: gtk.main_quit())
	gtk.main()

Thanks to Gustavo and Muntyan

Edit this entry1659 / Log info1660 / Last changed on Thu Nov 3 16:11:24 2005 by Nikos Kouremenos (kourem-at-gmail-com)

23.35.1661 How can you set the tab / tabbing order?

Note: you can set the order, for direct children.

An example is here: [calmar.ws]1662

once the tab/tabbing order reaches the focus of the table2 (packed into the main table), the tab-chain of table2's children is active.

Edit this entry1663 / Log info1664 / Last changed on Tue Feb 14 12:07:04 2006 by calmar (mac-at-calmar-ws)

23.36.1665 How do I acquire a screenshot of the whole screen?

 # Either "png" or "jpeg"
 format = "jpeg"

 width = gtk.gdk.screen_width()
 height = gtk.gdk.screen_height()
 screenshot = gtk.gdk.Pixbuf.get_from_drawable(
              gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB, True, 8, width, height),
              gtk.gdk.get_default_root_window(),
              gtk.gdk.colormap_get_system(),
              0, 0, 0, 0, width, height)

 # Pixbuf's have a save method 
 # Note that png doesnt support the quality argument. 
 screenshot.save("screenshot." + format, format,  {"quality": "20"})

 del screenshot
 gc.collect()

Edit this entry1667 / Log info1668 / Last changed on Sat Apr 22 01:08:54 2006 by Marc (m4rccd-at-yahoo-com)

23.37.1669 How do I create a throbber like the one in Firefox?

 hbox = gtk.HBox(expand=False)
 hbox.pack_start(menubar)
 self.throbber = gtk.Image()
 self.throbber.set_from_file('image_path/Throbber.png')
 hbox.pack_start(self.throbber, expand=False)

 self.animation = gtk.gdk.PixbufAnimation('image_path/Throbber.gif')

 pixbuf = self.throbber.get_pixbuf() # save the Image contents so we can set it back later
 self.throbber.set_from_animation(self.animation)
 ...
 # then later to stop the animation just put the old contents back
 self.throbber.set_from_pixbuf(pixbuf)

 gobject.threads_init() # called somewhere at the top of your file

 def someActionCallback(self, *args):
     pixbuf = self.throbber.get_pixbuf()
     self.throbber.set_from_animation(self.animation)
     # make sure the throbbing starts now
     while gtk.events_pending():
         gtk.main_iteration()
     def call():
         try:
             # hard working code goes here
         finally: # make sure the throbbing stops whatever else happens
             gobject.idle_add(self.throbber.set_from_pixbuf, pixbuf)
     # start the hard work in a thread
     threading.Thread(target=call).start()

Edit this entry1670 / Log info1671 / Last changed on Sun May 28 08:30:50 2006 by Daverz (dave-at-davidcook-org)

23.38.1672 How can I access data returned with a gpointer?

Have a look at the following example, using the gtkmozembed widget. This function is the callback for the 'open_uri' widget signal. The second argument 'uri' should be a string, but all you'll get is a gpointer. The gpointer is converted to string to get the pointer value in [13:-1] characters as an hex number, which may be converted to an integer. Using ctypes this integer is typecasted to a pointer to c style string (c_char_p), which is converted to a python string by the value method.

 def mozilla_open_uri(widget, uri, *args):
     p=int(str(uri)[13:-1],16)
     url=ctypes.cast(p,ctypes.c_char_p).value
     print(url)
     return False

Edit this entry1673 / Log info1674 / Last changed on Tue May 30 18:16:02 2006 by Miguel Angel Alvarez (maacruz-at-gmail-com)

24. Deprecated List Widgets: GtkList, GtkCList, GtkCTree and others

24.1.1675 My GtkCList rows represent instances, but how can I keep track of them?

Each row in a CList can have a data object attached to it by using the set_row_data() method. This method takes an object reference and attaches it to a row. Any object reference can be attached:

 class Foo: 
   pass
 f = Foo()
 clist = GtkCList(cols=2)
 row = clist.append(["foobar","noogie"])
 clist.set_row_data(row, f) # attaches a reference to f to row

 instance = clist.get_row_data(row)

Edit this entry1676 / Log info1677 / Last changed on Sun Aug 25 08:52:19 2002 by Christian Reis (kiko-at-async-com-br)

24.2.1678 Why doesn't GtkCList's children() method return the lists rows?

  c = gtk.GtkCList()
  c.append(["foo"])
  print c.children()

  the children() call is to return child _widgets_.  The rows of the clist 
  are not children of the CList.

Edit this entry1679 / Log info1680 / Last changed on Tue Jan 22 13:27:59 2002 by kiko (kiko-at-async-com-br)

24.3.1681 How do I access data that is in a GtkCList?

  c = gtk.GtkCList(cols=2)
  c.append(["foo","bar"])
  c.append(["snark","boojum"])

  >>> c.get_text(0,0)
  'foo'
  >>> c.get_text(0,1)
  'bar'

  ret = []
  for row in range(0, c.rows):
    tmp = []
    for col in range(0, c.cols):
      tmp.append(c.get_text(row,col))
    ret.append(tmp)

Edit this entry1682 / Log info1683 / Last changed on Tue Jan 22 13:40:21 2002 by kiko (kiko-at-async-com-br)

24.4.1684 How do I order the contents of a GtkCList according to the type of data in the columns (or, where is gtk_clist_set_compare_func)?

• The first solution involves manually sorting the items in the clist according to your own sort function. Then it's a matter of clearing the clist and adding back the values that you've rearranged.

  The Kiwi source code includes a complete CList mod, which adds arrows and does direct/reverse sorting. Browse the code to see what it's like. The following is a simplification of the algorithm I use in Kiwi to do this:

 # pop_all_rows removes and returns a list of rows, each of these being 
 # a list of columns. e.g. for a clist with 2 rows and 2 columns, it  ]
 # would produce: [ [ 'foo', 'bar' ] , [ 'baz', 'noogie'] ] 
 # See the Kiwi source code for an implementation.
 rows = clist.pop_all_rows()
 # use other funcs for other types
 func = int
 rows.sort( lambda x, y, column=column, func=func:    
            cmp(func(x[column]), func(y[column]) )
 clist.freeze()
 for r in rows:
   clist.append(r)
 clist.thaw()

• The second solution was offered by Don Allingham. It takes advantage of the built in sort capabilitiy of the gtk_clist. This produces a much faster sort, since it uses the builtin C sorting routines. Since the default method is to sort by ascii order, build a new column that contains the sort order, and set that as the sort column. You can turn off the visibility of the column, so that the sort information does not show.

  This prevents the need to remove and re-add all the data. To sort again,just call the .sort() method of the clist, or turn on autosorting with clist.set_auto_sort(1)

  This approach is used in GRAMPS (a genealogy program: [gramps.sourceforge.net]1685 ), and the sorts are quite fast, even for clists with 1000s of entries.

 values = [3,4,5,1,49,456,342,345]

 # turn off column 1's visibility, so that only column 0 shows
 clist.set_column_visibility(1,0)

 # set the sort column to column 1
 clist.set_sort_column(1)

 # add the values, converting the integer to a string, and creating
 # a 8 character string that is left padded with zeros. This turns '1'
 # into '00000001' and 49345 into '00049345', allowing ascii to sort
 # by numerical value.

 for value in values:
   clist.append([str(value),"%08d" % value])

 clist.sort()

Edit this entry1686 / Log info1687 / Last changed on Sat Jul 13 13:15:42 2002 by Christian Reis (kiko-at-async-com-br)

24.5.1688 How do I get the data out of a GtkCTree?

  >>> ctree = gtk.GtkCTree(2, 0)
  >>> node = ctree.insert_node(None, None, ['foo', 'bar'])
  ...
  >>> ctree.node_get_text(node, 1)
  'bar'

  >>> ctree.get_node_info(node)
  ('foo', 5, None, None, None, None, 1, 0)

Edit this entry1689 / Log info1690 / Last changed on Tue Jan 29 12:21:04 2002 by James Henstridge (james-at-daa-com-au)

24.6.1691 How would I recurse through all nodes in a GtkCTree?

  >>> def recurse(node):
  ...     # do something with node
  ...     for child_node in node.children:
  ...         recurse(child_node)
  ... 
  >>> for node in ctree.base_nodes():
  ...     recurse(node)
  ...

Edit this entry1692 / Log info1693 / Last changed on Sat Jun 15 16:13:47 2002 by Christian Reis (kiko-at-async-com-br)

24.7.1694 How do I capture a right-click or double-click event on a GtkCList row?

However, for right-clicks, the row you right-click on may not have been previously selected. This means the row will have to be selected first, and then right-clicked, which is bad usability (left-click then right-click). To avoid this, you can use something like this to select the row automatically on right-click:

 def button_clicked(list, event):
  # Check for right click
  if event.button == 3:
   sel=list.get_selection_info(event.x,event.y)
   list.select_row(sel[0], sel[1])
   print "Click."
   print list.selection

Note that if you are trying to spawn a new window when double-clicking, *if that window is modal* your application may get stuck in a pointer-focus bug. I don't know of a good workaround beyond making the window non-modal (and then changing using idle_add to make it modal again -- it sucks but it works).

Edit this entry1697 / Log info1698 / Last changed on Wed Aug 6 22:17:58 2003 by Christian Reis (kiko-at-async-com-br)

24.8.1699 How do I find a row in a GtkCList that contains "X"?

  row = clist.find_row_from_text(text)
  print "Row that contains %s: %s" % (text, row)

  row = clist.find_row_from_data(obj)

Edit this entry1700 / Log info1701 / Last changed on Mon Feb 4 10:25:46 2002 by kiko (kiko-at-async-com-br)

24.9.1702 When entering data dynamically into my GtkCList or tree, it flickers like mad!

 c = gtk.GtkCList
 # ...
 c.freeze() # avoid flickering
 for f in ...:
  c.insert_row(row_data)
 c.thaw()

Edit this entry1703 / Log info1704 / Last changed on Thu Jun 6 15:20:14 2002 by Christian Reis (kiko-at-async-com-br)

24.10.1705 How do I align a GtkCList's columns?

 c = gtk.GtkCList(cols=2)
 c.set_column_justification(0, GTK.JUSTIFY_RIGHT)
 c.set_column_justification(1, GTK.JUSTIFY_CENTER)

 GTK.JUSTIFY_LEFT
 GTK.JUSTIFY_RIGHT
 GTK.JUSTIFY_CENTER

Edit this entry1706 / Log info1707 / Last changed on Thu Aug 22 16:24:59 2002 by Christian Reis (kiko-at-async-com-br)

24.11.1708 How do I remove a row from a CList?

 clist.remove(2) # remove row 2

Edit this entry1709 / Log info1710 / Last changed on Thu Aug 22 16:43:34 2002 by Christian Reis (kiko-at-async-com-br)

24.12.1711 How do I find out which row(s) are selected in the GtkCList?

 row = clist.selection[0]
 print "Row %d is selected" % row

 for row in clist.selection:
   print "Row %d is selected" % row

Edit this entry1712 / Log info1713 / Last changed on Sun Aug 25 09:06:56 2002 by Christian Reis (kiko-at-async-com-br)

24.13.1714 How do I colour the background of a GtkCList row?

 map = clist.get_colormap()
 color = map.alloc("red")
 clist.set_background(row,color)

 map = clist.get_colormap()
 color = map.alloc(0xffff, 0x0000, 0x0000)
 clist.set_background(row,color)

Edit this entry1715 / Log info1716 / Last changed on Sun Aug 25 10:06:56 2002 by Christian Reis (kiko-at-async-com-br)

24.14.1717 How do I find out what the current selection mode in the GtkCList is?

 print clist['selection_mode']

Edit this entry1718 / Log info1719 / Last changed on Tue Oct 8 22:26:35 2002 by Christian Reis (kiko-at-async-com-br)

24.15.1720 How do I change the style of the white space between CList rows?

Edit this entry1722 / Log info1723 / Last changed on Wed Aug 13 21:18:06 2003 by Christian Reis (kiko-at-async-com-br)

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