code: def leaveEvent( self, event ):
          
          hitem = self.hoveredItem()
          hcol  = self.hoveredColumn()
          
          if ( hitem != None ):
              self._hoveredItem   = None
              self._hoveredColumn = -1
              
              rect = self.visualItemRect(hitem)
              rect.setWidth(self.viewport().width())
              self.viewport().update(rect)
          
          super(XTreeWidget, self).leaveEvent(event)
docs: Dismisses the hovered item when the tree is exited.
          
          :param      event | <QEvent>