This is a problematic struct, and giving direct access to it
has kept us from making improvements to GtkTextView. Drop it
from the public API, together with the auxiliary APIs. If
it turns out that this functionality is needed, we should add
individual getters.
If the widget has been destroyed since a DBus message had been sent,
we could be in a condition that the widget pointer exists but it does
not have a window.
This bails as if the widget didn't exist if there is no available
GdkWindow.
We also set the extents to 0 to be defensive since this is a vfunc
implementation.
https://bugzilla.gnome.org/show_bug.cgi?id=746586
This commit exposes the get_type() functions and standard
headers for accessible implementations. This makes it possible
to derive from the GTK accessible implementations without
GType magic tricks. This is necessary, because we require the
a11y type hierarchy to be parallel to the widget type hierarchy.
So, if you derive a widget and need to adjust its a11y implementation,
you have to be able to derive its accessible implementation.
This commit probably exposes more than is absolutely necessary,
it also exposes accessibles of widgets that are unlikely candidates
for deriving from.
There was some regressions from the recent display line fix;
while fixing it improve the test coverage and make GtkEntry
and GtkTextView return identical results.
