def OnLeftUp(self, evt):
        if not self.dragImage or not self.dragNode:
            self.dragImage = None
            self.dragNode = None
            return

        # Hide the image, end dragging, and nuke out the drag image.
        self.dragImage.Hide()
        self.dragImage.EndDrag()
        self.dragImage = None

        dc = wx.ClientDC(self)
        # reposition and draw the shape
        self.dragNode.model.pos = (
            self.dragNode.model.pos[0] + evt.GetPosition()[0] - self.dragStartPos[0],
            self.dragNode.model.pos[1] + evt.GetPosition()[1] - self.dragStartPos[1]
            )