gtk.gdk.Device — an object for supporting input devices


class gtk.gdk.Device(gobject.GObject):
    def set_source(source)
def set_mode(mode)
def set_key(index, keyval, modifiers)
def set_axis_use(index, use)
def get_state(window)
def get_history(window, start, stop)
def get_axis(axes, use)

    def gtk.gdk.devices_list()
def gtk.gdk.device_get_core_pointer()


+-- gobject.GObject
  +-- gtk.gdk.Device


"axes"Reada tuple containing axes information. Each axes is described by a tuple containing: use information (one of: gtk.gdk.AXIS_IGNORE, gtk.gdk.AXIS_X, gtk.gdk.AXIS_Y, gtk.gdk.AXIS_PRESSURE, gtk.gdk.AXIS_XTILT, gtk.gdk.AXIS_YTILT, gtk.gdk.AXIS_WHEEL, gtk.gdk.AXIS_LAST), the minimum and maximum axes values.
"has_cursor"Readif TRUE the pointer follows device motion.
"keys"Reada tuple describing the mapped macro buttons. Each macro button is described by a tuple containing: a key value output when the macro button is pressed and a set of modifiers output with the key value.
"mode"Readthe mode of this device - one of: gtk.gdk.MODE_DISABLED, gtk.gdk.MODE_SCREEN, gtk.gdk.MODE_WINDOW
"name"Readthe name of this device.
"num_axes"Readthe length of the axes tuple.
"num_keys"Readthe length of the keys tuple
"source"Readthe type of this device - one of: gtk.gdk.SOURCE_MOUSE, gtk.gdk.SOURCE_PEN, gtk.gdk.SOURCE_ERASER, gtk.gdk.SOURCE_CURSOR


In addition to the normal keyboard and mouse input devices, PyGTK also contains support for extended input devices. In particular, this support is targeted at graphics tablets. Graphics tablets typically return sub-pixel positioning information and possibly information about the pressure and tilt of the stylus. Under X, the support for extended devices is done through the XInput extension. Because handling extended input devices may involve considerable overhead, they need to be turned on for each gtk.gdk.Window individually using gtk.gdk.Window.input_set_extension_events(). (Or, more typically, for gtk.Widget objects, using the gtk.Widget.set_extension_events() method). As an additional complication, depending on the support from the windowing system, its possible that a normal mouse cursor will not be displayed for a particular extension device. If an application does not want to deal with displaying a cursor itself, it can ask only to get extension events from devices that will display a cursor, by passing the gtk.gdk.EXTENSION_EVENTS_CURSOR value to the gtk.gdk.Window.input_set_extension_events() method. Otherwise, the application must retrieve the device information using the gtk.gdk.devices_list() function, check the has_cursor field, and, if it is FALSE, draw a cursor itself when it receives motion events.

Each pointing device is assigned a unique integer ID; events from a particular device can be identified by the deviceid attribute in the event structure. The events generated by pointer devices have also been extended to contain pressure, xtilt and ytilt attributes which contain the extended information reported as additional valuators from the device. The pressure attribute ranges from 0.0 to 1.0, while the tilt attributes range from -1.0 to 1.0. (With -1.0 representing the maximum tilt to the left or up, and 1.0 representing the maximum tilt to the right or down.) One additional attribute in each event is the source attribute, which contains an enumeration value describing the type of device; this currently can be one of gtk.gdk.SOURCE_MOUSE, gtk.gdk.SOURCE_PEN, gtk.gdk.SOURCE_ERASER, or gtk.gdk.SOURCE_CURSOR. This attribute is present to allow simple applications to (for instance) delete when they detect eraser devices without having to keep track of complicated per-device settings.

Various aspects of each device may be configured. The easiest way of creating a GUI to allow the user to configure such a device is to use the gtk.InputDialog widget in PyGTK. However, even when using this widget, application writers will need to directly query and set the configuration parameters in order to save the state between invocations of the application. The configuration of devices is queried using the gtk.gdk.devices_list() function. Each device must be activated using the set_mode() method, which also controls whether the device's range is mapped to the entire screen or to a single window. The mapping of the valuators of the device onto the predefined valuator types is set using the set_axis_use() method. And the source type for each device can be set with the set_source() method.

Devices may also have associated keys or macro buttons. Such keys can be globally set to map into normal X keyboard events. The mapping is set using the set_key() method. The interfaces in this section will most likely be considerably modified in the future to accommodate devices that may have different sets of additional valuators than the pressure xtilt and ytilt.



    def set_source(source)
source :the source type of the device

The set_source() method sets the source type for the input device to the value specified by source. The value of source must be one of:

gtk.gdk.SOURCE_MOUSEthe device is a mouse. (This will be reported for the core pointer, even if it is something else, such as a trackball.)
gtk.gdk.SOURCE_PENthe device is a stylus of a graphics tablet or similar device.
gtk.gdk.SOURCE_ERASERthe device is an eraser. Typically, this would be the other end of a stylus on a graphics tablet.
gtk.gdk.SOURCE_CURSORthe device is a graphics tablet "puck" or similar device.


    def set_mode(mode)
mode :the input mode
Returns :TRUE if the mode was successfully changed.

The set_mode() method sets the input device mode to the value specified by mode. The value of mode must be one of:

gtk.gdk.MODE_DISABLEDthe device is disabled and will not report any events.
gtk.gdk.MODE_SCREENthe device is enabled. The device's coordinate space maps to the entire screen.
gtk.gdk.MODE_WINDOWthe device is enabled. The device's coordinate space is mapped to a single window. The manner in which this window is chosen is undefined, but it will typically be the same way in which the focus window for key events is determined.


    def set_key(index, keyval, modifiers)
index :the index of the macro button to set.
keyval :the key value to generate.
modifiers :the modifiers to set.

The set_key() method sets the key event to generate when a macro button of a device is pressed. The macro button is specified by index. The key value and modifiers generated are specified by keyval and modifiers respectively.


    def set_axis_use(index, use)
index :the index of the axis.
use :how the axis is used.

The set_axis_use() method sets the axis (specified by index) of the input device to be used in the fashion specified by use. The value of use must be one of:

gtk.gdk.AXIS_IGNOREthe axis is ignored.
gtk.gdk.AXIS_Xthe axis is used as the x axis.
gtk.gdk.AXIS_Ythe axis is used as the y axis.
gtk.gdk.AXIS_PRESSUREthe axis is used for pressure information.
gtk.gdk.AXIS_XTILTthe axis is used for x tilt information.
gtk.gdk.AXIS_YTILTthe axis is used for y tilt information.
gtk.gdk.AXIS_WHEELthe axis is used for wheel information.
gtk.gdk.AXIS_LASTa constant equal to the numerically highest axis value.


    def get_state(window)
window :a gtk.gdk.Window
Returns :a tuple containing: a tuple containing the axes data; and, the modifiers in effect.

The get_state() method returns a tuple containing:

  • a tuple containing the axes data
  • the bitmask containing the set of key modifiers in effect

The state information is relative to the gtk.gdk.Window specified by window.


    def get_history(window, start, stop)
window :a gtk.gdk.Window
start :the earliest event time limit
stop :the latest event time limit
Returns :a tuple containing event tuples each with axes data and a timestamp

The get_history() method returns a tuple containing the motion history for the device with respect to the gtk.gdk.Window specified by window between the time limits specified by start and stop. The motion history is a tuple containing event motion tuples that each contain a timestamp for the event and a tuple with the axes data for the event.


    def get_axis(axes, use)
axes :a sequence of axes values
use :the axis use to match
Returns :the axis value from axes that matches the use type or None if there is no match.

The get_axis() method returns the value in axes whose axis matches the specified use.



    def gtk.gdk.devices_list()
Returns :a list containing the gtk.gdk.Device objects for the default display

The gtk.gdk.devices_list() function returns a list containing the gtk.gdk.Device objects fro the default display.


    def gtk.gdk.device_get_core_pointer()
Returns :the

The gtk.gdk.device_get_core_pointer() function returns the device that is used as the core pointer.