This reverts commit 56aad2ad60.
QWidget::mapFromGlobal() does not work correctly when the widget is
a child widget of another widget embedded into a QGraphicsView with a
transformation (scaling/rotation). It starts applying offsets going
up the widget tree (just as mapToGlobal) until it hits the embedded widget
not taking into account the transformation.
It would need to go in from to top to bottom or better be reimplemented
such that a QTransform for mapping coordinates from/to global is determined
which is then applied in reverse.
Task-number: QTBUG-50030
Task-number: QTBUG-50136
Change-Id: Iadeb891d793be1938c64942bfbf38d541a281c33
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
38c8af7231