Instead of delegating on the parent shell of a menu item/shell on a variety
of situations, Simplify event handling so:
1) Menu item selection is handled entirely on GtkMenuItem through crossing
events.
2) The deepmost menu shell handles clicks inside and outside of it.
This avoids the rather hard to follow gtk_widget_event() calls going on all
throughout the handling of crossing and button events, and makes menus work
again.
We now rely on toplevels receiving and forwarding all the events
the windowing should be able to handle. Event masks are no longer a
way to determine whether an event is deliverable ot a widget.
Events will always be delivered in the three captured/target/bubbled
phases, widgets can now just attach GtkEventControllers and let those
handle the events.
gtk_snapshot_pop() => removed
gtk_snapshot_pop_and_append() => gtk_snapshot_pop()
So now there is no way to get a rendernode out of the snapshotting API
until you gtk_snapshot_finish().
Add a new ::measure vfunc similar to GtkCssGadget's that widget
implementations have to override instead of the old get_preferred_width,
get_preferred_height, get_preferred_width_for_height,
get_preferred_height_for_width and
get_preferred_height_and_baseline_for_width.
With best-effort, try to use gdk_window_move_to_rect() more often, when
all pieces fit together. For the non-legacy paths to be triggered for
when gtk_menu_popup_for_device() or gtk_menu_popup() were used, the
following conditions must be met:
1) There is no custom positioning function specified
2) The menu is attached to a widget (using gtk_menu_attach_to_widget())
3) There is a associated grab device
https://bugzilla.gnome.org/show_bug.cgi?id=772922
And with it, gtk_widget_get_visual() and gtk_widget_set_visual() are
gone.
We now always use the RGBA visual (if available) and otherwise fall back
to the system visual.
The new positioning-related properties had some quality of
implementation issues, such as incorrect initial values and
excessive change notification. This broke the notify test.
Menus are placed vertically by definition, it does not make much sense
to support horizontal axis for scrolling.
Use GDK_EVENT_STOP/GDK_EVENT_PROPAGATE instead of TRUE/FALSE and add a
default case to return GDK_EVENT_PROPAGATE for unhandled events.
https://bugzilla.gnome.org/show_bug.cgi?id=765939
On X11, we get both smooth and emulated scroll events, whereas other
backends such as wayland will give smooth events only with touchpad
scrolling.
Discard emulated scroll events so that we get consistent behaviours
between backends.
Allow for both horizontal and vertical smooth events for scrolling so
that horizontal scrolling still works without emulated scroll events as
well, again for consistency between gdk backends.
https://bugzilla.gnome.org/show_bug.cgi?id=765939
Instead of having old and new style, now have a GtkCssStyleChange opaque
object that will compute the changes you are interested in for you.
This simplifies change signal handlers quite a bit and avoids lots of
repeated computation in every signal handler.
