This is a very old X session management thing, and you
will be hard-pressed to find a session manager that can
make use of it, and even harder-pressed to find apps
using it to their advantage.
Change the all the begin_drag and begin_move apis in
GdkSurface and GtkWindow to expect surface coordinates.
Update the x11 implementation to translate to root
coordinates where it matters. Wayland is ignoring the
coordinates anyway.
Change gdk_surface_get/set_user_data to private
API and rename them to get/set_widget.
Also remove an unused associated function.
The last two places where the surface API is used
are in gtkroot.c and gtkwidget.c. Make them
use the private api.
The previous attempt at removing configure events entirely
was causing some dialogs not to show up under Wayland.
Presumably due to ordering issues with emitting ::size-change
out of the backend.
Instead, keep configure events in the event queue, but handle
them on the gdk side. This keeps the ordering intact, while
still removing configure events from the api. The dialogs
show up now.
This is to go along with the newly introduced GdkDrop.
This commit includes the necessary updates to the X11, Wayland
and Broadway backends. Other backends have to be updated separately.
In particular, this patch removes:
gdk_surface_get_events()
gdk_surface_set_events()
gdk_surface_get_device_events()
gdk_surface_set_device_events()
Event masks so far still exist for grabs.
This is the API used by GtkMenu to properly position menus on the screen
without requiring GTK to query the menu window's position or the work
area of where the window is positioned. It makes it possible to position
popup windows properly when using Wayland.
Make this API available to external users so custom popup windows can be
positioned properly as well.
Related: https://gitlab.gnome.org/GNOME/gtk/issues/997
Now that all Cairo contexts are ported to managing cairo surfaces
themselves, the old fallback code that didi the managing is no longer
needed.
Also clarify the behavior of gdk_cairo_context_cairo_create() wrt the
vfunc by doing the early exit and the clipping outside of it.
As they require a draw context and the draw context is already bound to
the surface, it makes much more sense and reduces abiguity by moving
these APIs to the draw context.
As a side effect, we simplify GdkSurface APIs to a point where
GdkSurface now does not concern itself with drawing anymore at all,
apart from being the object that creates draw contexts.
And make the GdkCairoContext as abstract.
The idea of this and thje following commits is to get rid of all
Cairo code in gdksurface.c (and $backend/gdksurface-$backend.c)
by moving that code into the Cairo context files.
In particular, the GdkSurfaceClass.begin_frame/end_frame()
functions (which are currently exclusively used by the Cairo code
should end up being moved to GdkDrawContextClass.begin/end_frame().
This has multiple benefits:
1. It unifies code between the different drawing contexts.
GL lives in GLContext, Vulkan in VulkanContext and Cairo in
CairoContext. In turn, this makes it way easier to reason about
what's going on in surface-specific code. Currently pretty much
all backends do things wrong when they want to sync to drawing
or to the frame clock.
2. It makes the API of GdkSurface smaller. No drawing code (apart
from creating the contexts) needs to remain.
3. It confines Cairo to the Drawcontext, thereby making it way
more obvious when backends are still using it in situations
where it may now conflict with OpenGL (like when doing the dnd
failed animation or in the APIs that I'm removing in this
branch).
4. We have 2 very different types of Cairo contexts: The X/win32
model, where we have a natively supported Cairo backend but do
double buffering ourselves and use similar surfaces and the
Wayland/Broadway model where we use image surfaces without any
Cairo backend support and have to submit the buffers manually.
By not sharing code between those 2 versions, we can make the
actual code way smaller. We also get around the need to create
1x1 image surfaces in the Wayland backend where we pretend
there's a native Cairo surface.
This does nothing but disallow passing NULL to gdk_surface_begin_paint()
and instead require this context.
The ultimate goal is to split out Cairo drawing into its own source file
so it doesn't clutter up the generic rendering path.
That way, we can store the right region there: The actual painted area
instead of the exposed area (which is way too small).
Also, the GL context is the only user of this data, so storing it there
seems way smarter.
Instead of calling gdk_surface_invalidate_region(), just
gdk_surface_queue_expose() and rely on the renderer computing the diff
from the previous rendering.
If you want transparent region, you can just render them transparent.
If you want input shaping, use gdk_surface_input_shape_combine_region().
Also remove gtk_widget_shape_combine_region().
