Moves the line to the given value and rebuilds it
        
        :param      value | <variant>

def setValue( self, value ):
        """
        Moves the line to the given value and rebuilds it
        
        :param      value | <variant>
        """
        scene = self.scene()
        point = scene.mapFromChart(value, None)
        
        self.setPos(point.x(), self.pos().y())
        self.rebuild(scene.gridRect())