Bug 129886 Delect a column contain the marge row which contain some item, Error message pop up
Details: Delect a column contain the marge row which contain some item, Error message pop up Setp: 1.New a library and add a 3*3 grid 2.Insert a label in cell(1,1) 3.Marge the cell of (1,1) and (1,2) 4.Delete column 1. Actual result: An error message pop up
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/editparts/TableEditPart.java
if ( innerLayers == null )
			return null;
		IFigure layer = innerLayers.getLayer( key );
		if ( layer != null )
			return layer;
		if ( printableLayers == null )
			return null;
		return printableLayers.getLayer( key );
	}
	/**
	 * Creates the top-most set of layers on the given layered pane.
	 * 
	 * @param layeredPane
	 *            the parent for the created layers
	 */
	protected void createLayers( LayeredPane layeredPane )
	{
		layeredPane.add( createGridLayer( ), GRID_LAYER );
		layeredPane.add( getPrintableLayers( ), PRINTABLE_LAYERS );
		layeredPane.add( new FreeformLayer( ), HANDLE_LAYER );
		layeredPane.add( new GuideLayer( ), GUIDE_LAYER );
	}
	/**
	 * Creates a {@link GridLayer grid}. Sub-classes can override this method
	 * to customize the appearance of the grid. The grid layer should be the
	 * first layer (i.e., beneath the primary layer) if it is not to cover up
	 * parts on the primary layer. In that case, the primary layer should be
	 * transparent so that the grid is visible.
	 * 
	 * @return the newly created GridLayer