Bug 120218 Right click menu option to apply theme.
We should support the following right click menu. -- User right clicks int he report design layout area. -- The following menu items needs to be supported Theme --> Apply Theme -->Theme1 -->Theme2 ( similar to Apply style menu option )
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
slotID = ModuleHandle.COMPONENT_SLOT;
		}
		else if ( parent instanceof CellHandle )
		{
			slotID = CellHandle.CONTENT_SLOT;
		}
		else if ( parent instanceof RowHandle )
		{
			slotID = RowHandle.CONTENT_SLOT;
		}
		else if ( parent instanceof GridHandle )
		{
			slotID = GridHandle.ROW_SLOT;
		}
		else if ( parent instanceof ThemeHandle )
		{
			slotID = ThemeHandle.STYLES_SLOT;
		}
		return slotID;
	}
	/**
	 * Get the slot id of child
	 * 
	 * @param parent
	 * @param child
	 * @return slot ID
	 */
	public static int findSlotID( Object parent, Object child )
	{
		assert parent instanceof DesignElementHandle;