This new function takes a GdkRGBA in order to set the background to
an alpha color. Keep in mind that RGBA visuals and a composited environment
are still necessary to have an alpha background displayed.
GdkRGBA is a boxed struct similar to GdkColor, with the difference
that it stores alpha information as well, and colors are stored in
[0..1] doubles, in the cairo spirit.
gdk_cairo_set_source_rgba() has been also added to allow easier handling
of this new type.
The feature can and should be implemented manually using
gdk_window_get_background() and Cairo drawing. A non-cairo drawing API
does not make sense in GDK anymore.
In particular, the following functions are gone:
- gdk_screen_get_default_colormap()
- gdk_screen_set_default_colormap()
- gdk_screen_get_system_colormap()
- gdk_screen_get_rgba_colormap()
The 3 functions in question were:
- gdk_pixbuf_render_threshold_alpha()
- gdk_pixbuf_render_pixmap_and_mask()
- gdk_pixbuf_render_pixmap_and_mask_for_colormap()
All of them can be replaced using Cairo if they have to. The
functionality is only needed to talk to old X interfaces and normal apps
do fine without them.
Now the window background is a cairo_pattern_t. The backends will try to
set this as good as they can on the windowing system, but no guarantees
are made on wether the windowing system supports the pattern.
Also gets rid of GDK_NO_BG as undefined behavior is not a good idea to
support, and GDK_NO_BG effectively made the window's contents undefined.
It wasn't effectively used in GTK anyway.
This removes gdk_window_shape_combine_mask() and
gdk_window_input_shape_combine_mask(). GdkBitmap is going away and a
replacement exists via the combine_region() functions and
gdk_cairo_region_create_from_surface().
The function converts the given surface into an alpha bitmap mask. This
is mostly useful for setting shape regions.
Also adds a new internal function _gdk_cairo_surface_extents() that
computes a surface's extents.
* add per-display gdk_x11_display_error_trap_push()
(X11-specific because gdk_error_trap_push() probably
should have been)
* make gdk_error_trap_push() handle only GDK displays
not displays opened without a GDK wrapper
* make gdk_error_trap_pop() and gdk_x11_display_error_trap_pop()
automatically sync only if needed, so manual gdk_flush() is not
required
* add gdk_error_trap_pop_ignored() which just asynchronously
ignores errors, so never needs to sync
* add G_GNUC_WARN_UNUSED_RESULT to plain pop(), because
if you use plain pop() and don't need the return value,
the async gdk_error_trap_pop_ignored() should be used
instead. This results in lots of warnings to clean
up in a later patch.
The main objective here was to avoid the need to sync just
to ignore an error. Now, syncing is automatic, and only
happens when we need to know the error code.
https://bugzilla.gnome.org/show_bug.cgi?id=629608
