Introduce a function going up the widget hierarchy determining a QTransform
for mapping the coordinates applying the transformations of any QGraphicsView
instances found. In mapFromGlobal(), use the inverse of it. This fixes the
case of widget hierarchies embedded into QGraphicsView with transformations.
Increase fuzz in the tests due to float rounding errors.
Task-number: QTBUG-41135
Task-number: QTBUG-50030
Task-number: QTBUG-50136
Task-number: QTBUG-52507
Change-Id: I507e0bccd546250fe9c2d1b74ef38657d61490b4
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>