Migrating deprecated functions
Regarding the RegionGrabber: Qt Doc suggests to replace QPixmap::grabWindow() with QScreen::grabWindow. To get the QScreen, this commit calls the primaryScreen property of the QApplication. However, i couldn't test whether this change impacts multi monitor environments...
The second change replaces a deprecated MouseWheel event function. angleDelta() returns 8 segments per degree, which is different than the original function. Since the value is only checked for sign, it shouldn't have any impact on the original feature.