def drawGrid( self, painter ):
        """
        Draws the rulers for this scene.
        
        :param      painter | <QPainter>
        """
        # draw the minor grid lines
        pen = QPen(self.borderColor())
        painter.setPen(pen)
        painter.setBrush(self.baseColor())
        
        # draw the grid data
        painter.drawRect(self._buildData['grid_rect'])
        
        painter.setBrush(self.alternateColor())
        painter.setPen(Qt.NoPen)
        
        if ( self.alternatingRowColors() ):
            for alt_rect in self._buildData['grid_h_alt']:
                painter.drawRect(alt_rect)
        
        if ( self.alternatingColumnColors() ):
            for alt_rect in self._buildData['grid_v_alt']:
                painter.drawRect(alt_rect)
        
        if ( self.showGrid() ):
            painter.setPen(pen)
            
            grid = []
            if ( self.showRows() ):
                grid += self._buildData['grid_h_lines']
            
            if ( self.showColumns() ):
                grid += self._buildData['grid_v_lines']
            
            painter.drawLines(grid)
Draws the rulers for this scene.
        
        :param      painter | <QPainter>