Synopsis

class gtk.gdk.Visual(gobject.GObject):
    gtk.gdk.Visual(depth, visual_type)
    def get_screen()

Functions

    def gtk.gdk.list_visuals()
    def gtk.gdk.visual_get_best()
    def gtk.gdk.visual_get_best_depth()
    def gtk.gdk.visual_get_best_type()
    def gtk.gdk.visual_get_best_with_depth(depth)
    def gtk.gdk.visual_get_best_with_type(type)
    def gtk.gdk.visual_get_system()
    def gtk.gdk.query_depths()
    def gtk.gdk.query_visual_types()

Ancestry

+-- gobject.GObject
  +-- gtk.gdk.Visual

Attributes

Description

A gtk.gdk.Visual describes a particular video hardware display format. It includes information about the number of bits used for each color, the way the bits are translated into an RGB value for display, and the way the bits are stored in memory. For example, a piece of display hardware might support 24-bit color, 16-bit color, or 8-bit color; meaning 24/16/8-bit pixel sizes. For a given pixel size, pixels can be in different formats; for example the "red" element of an RGB pixel may be in the top 8 bits of the pixel, or may be in the lower 4 bits.

Usually you can avoid thinking about visuals in PyGTK. Visuals are useful to interpret the contents of a gtk.gdk.Image, but you should avoid gtk.gdk.Image precisely because its contents depend on the display hardware; use gtk.gdk.Pixbuf instead, for all but the most low-level purposes. Also, anytime you provide a gtk.gdk.Colormap, the visual is implied as part of the colormap (see the gtk.gdk.Colormap.get_visual() method), so you won't have to provide a visual in addition.

There are several standard visuals. The visual returned by the gtk.gdk.visual_get_system() function is the system's default visual. The gtk.gdk.rgb_get_visual() function returns the visual most suited to displaying full-color image data. If you use the calls in GdkRGB, you should create your windows using this visual (and the colormap returned by the gtk.gdk.rgb_get_colormap() function).

A number of functions are provided for determining the "best" available visual. For the purposes of making this determination, higher bit depths are considered better, and for visuals of the same bit depth, gtk.gdk.VISUAL_PSEUDO_COLOR is preferred at 8bpp, otherwise, the visual types are ranked in the order of (highest to lowest) gtk.gdk.VISUAL_DIRECT_COLOR, gtk.gdk.VISUAL_TRUE_COLOR, gtk.gdk.VISUAL_PSEUDO_COLOR, gtk.gdk.VISUAL_STATIC_COLOR, gtk.gdk.VISUAL_GRAYSCALE, then gtk.gdk.VISUAL_STATIC_GRAY.

Constructor

    gtk.gdk.Visual(depth, visual_type)

Creates a new gtk.gdk.Visual that is the best choice for the specified depth and visual_type. Color visuals and visuals with mutable colormaps are preferred over grayscale or fixed-colormap visuals and visuals with higher color depths are considered better. The value of visual_type must be one of:

Methods

    def get_screen()

Functions

    def gtk.gdk.list_visuals()

    def gtk.gdk.visual_get_best()

    def gtk.gdk.visual_get_best_depth()

    def gtk.gdk.visual_get_best_type()

    def gtk.gdk.visual_get_best_with_depth(depth)

    def gtk.gdk.visual_get_best_with_type(type)

    def gtk.gdk.visual_get_system()

    def gtk.gdk.query_depths()

    def gtk.gdk.query_visual_types()