QWidget's mapToGlobal() and mapFromGlobal() functions assumed that
if the widget reports it's a window or if it has no parent widget, it
must be a top level window whose coordinates are in global coordinates.
This is not true for child QWindows or embedded native windows
(QAxWidgets).
Changed the logic for mapping coordinates to use equivalent methods
from QWindow if widget has a window handle, and changed QWindow's
methods to map coordinates using native methods if window is embedded.
Also fixed newly failing accessibility autotest. The geometry related
failures there popped up because now the position of the rect returned
by accessible interface is actually correct while widget geometry still
reports position 0,0 before widget has shown up.
Task-number: QTBUG-26436
Change-Id: I658fafd0ce01eb1604ba255efeeba3073ca0189f
Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>
ede4f5e23b