def mouseMoveEvent(self, event):
        """ mouseMoveEvent(event: QMouseEvent) -> None        
        Now set the timer preparing for dragging. Must use a timer in
        junction with QDrag in order to avoid problem updates stall of
        QGraphicsView, especially on Linux
        
        """
        if (self.dragging and
            (event.screenPos()-self.dragPos).manhattanLength()>2):
            self.dragging = False
            #the timer has undesirable effects on Windows
            if systemType not in ['Windows', 'Microsoft']:
                self.dragTimer.start(1)
            else:
                self.startDrag()
        QtGui.QGraphicsEllipseItem.mouseMoveEvent(self, event)
        # super(QGraphicsVersionItem, self).mouseMoveEvent(event)
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/gui/version_view.py/QGraphicsVersionItem.mouseMoveEvent/original