One less magic function. Also refactored it to make it easier to
implement. It now returns TRUE if it beeped and FALSE if it failed to do
so. A default implementation exists that just returns FALSE for all the
backends that can't beep windows (read: everything but X11 with XKB -
and why on earth do keyboard libs implement beeping?)
Trying to get rid of all the _gdk_windowing_something() functions that
we expect backends to magically know about and instead put them in a
proper interface (mostly GdkWindowImplClass).
We subclass GdkWindowImplQuartz into a new GdkRootWindowImplQuartz,
and override the get_context method in order to do this cleanly.
Also made release_context a virtual method, since the root window has
to release its CGContextRef differently compared to normal windows.
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.
Mainly fixes to properly differentiate between toplevel and offscreen
windows, since these sometimes need different treatment. Furthermore,
usage of gdk_window_get_effective_foo() instead of gdk_window_get_foo()
where applicable.
The window move code needs special attention for multiple reasons:
- invalid areas for expose events need to be modified
- self-copy is not supported by Cairo
- in X11, copying from an overlapped Window might cause unexposed areas
to be copied in, spo expose events for those need to be generated.
This was all special cased in various parts of the code. By making it an
explicit vfunc, we can work around it.
Includes fixing all callers to use the cairo region API instead. This is
usually just replacing the function names, the only difference is
gdk_region_get_rectangles() being replaced by
cairo_region_num_rectangles() and cairo_region_get_rectangle() which
required a bit more work.
https://bugzilla.gnome.org/show_bug.cgi?id=613284
