def cursorAtSpaceEnd(block):
            cursor = QTextCursor(block)
            cursor.setPosition(block.position() + len(blockIndentation(block)))
            return cursor
def tag(self, g):
        self.g = g
        self.g.beginPath()
        self.g.fillText("%d, %d"%(self.x, self.y),self.x, self.y)
        self.g.stroke()