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
List clients = ( (TemplateParameterDefinition) element )
					.getClientList( );
			if ( clients.size( ) != 0 )
				return false;
		}
		return true;
	}
	/**
	 * Determines if the slot can contain a given element.
	 * 
	 * @param module
	 *            the module
	 * @param slotId
	 *            the slot id
	 * @param element
	 *            the element to insert
	 * @return a list containing exceptions.
	 */
	public final boolean canContain( Module module, int slotId,
			DesignElement element )
	{
		List errors = checkContainmentContext( module, slotId, element );
		if ( !errors.isEmpty( ) )
			return false;
		return true;
	}
	/**
	 * Determines if the slot can contain a given element.
	 * 
	 * @param module