Bug 151959 inappropriate screen operation
steps to reproduce: - create a report - add a grid item (3x3) - switch to Outline view - expand the grid item to see its rows and cells - select the grid item, and drag it into any of its own cell expected behavior: - is it an invalid screen operation? if it is, it should be banned actual behavior: - the grid item was disappeared surprisingly
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
if ( ev.getDeliveryPath( ) != NotificationEvent.STYLE_CLIENT )
				ev.setDeliveryPath( NotificationEvent.DESCENDENT );
			Iterator iter = derived.iterator( );
			while ( iter.hasNext( ) )
			{
				( (DesignElement) iter.next( ) ).broadcast( ev, module );
			}
		}
	}
	/**
	 * Returns <code>true</code> if the element is within a child element
	 * which extends from another. Returns <code>false</code> otherwise. <br>
	 * <strong>Notice: </strong> <br>
	 * If the element is a virtual element, it must have defined a <code>
	 * baseId<code> which point to the ID of its virtual parent. 
	 * 
	 * @return Returns <code>true</code> if the element is within a child element
	 * which extends from another.
	 */
	public final boolean isVirtualElement( )
	{
		return baseId != NO_BASE_ID;
	}
	/**
	 * Copied the structure from the parent element to the element itself. Local
	 * properties of the contents will all be cleared.Please note that the
	 * containment relationship is kept while property values of the content