mrview: pan_event: removed updateGL() which causes pan gestures to remain in state Qt::GestureUpdated, never reaching Qt::GestureFinished on macOS #761. no negative side effects - I think
mrview: pan_event: removed updateGL() which causes pan gestures to remain in state Qt::GestureUpdated, never reaching Qt::GestureFinished on macOS #761. no negative side effects - I think

MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3