Change constructors to reflect that.
While doing so, also add a fallback argument to the cursor constructors,
so it is now possible to create cursors with fallback.
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.
Switch code to use gdk_display_is_composited() instead.
The new code also doesn't use a vfunc to query the property but rather
requires the backend to call set_composited()/set_rgba() to change the
value.
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.
We used to switch to the objects tab when an object is
picked, but now may have two places with picker buttons:
the objects tab and the interactive tab.
So, just don't do that anymore.
Previously, the inspector would not change the hilight while the
previous hilight was still flashing.
This is inconvenient while arrowing through the object selection
treeview though where you want the currently selected row to hilight
when arrowing quickly.
This helps isolate the inspector from some of the changes that
it can trigger. To specify a different display, set
GTK_INSPECTOR_DISPLAY to the name of the display to use for
the inspector window. If no display is specified, GTK+ will
use a separate connection to the default display.
We still need to possibly scan the toplevel after selecting
a widget, since we don't monitor the list of toplevels, so
the window may not be in our tree yet. This was broken in
commit e7bd73f2b0.
What was happening that the button press event that we use
to select a widget caused another clicked signal emission of
the inspect button, starting another pick action.
In contrast to the flashing, where we blink the widget a
few times, this is explicitly turned on and off.
It will be used for indicating widgets that are part of
a size group, in the next commit.
Moving the inspector into libgtk lets use reuse internals without
having to add public API for everything or inventing awkward private
call conventions.
https://bugzilla.gnome.org/show_bug.cgi?id=730095
