Bug 120503 Cascading Parameter can not drop into layout
Details: Cascading Parameter can not drop into layout Step: 1.Open a report design and Create a Sample Data Source and data set by "select * from CLASSICMODELS.CUSTOMERS" 2.New a cascading parameter and create CUSTOMERSNUMBER and CUSTOMERSNAME in parameter named number and name. Press OK 3.Drop parameter name into layout. Actual results: The parameter in Cascading Parameter Group can not drop to layout
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
int slotId )
	{
		List list = new ArrayList( );
		ISlotDefn slotDefn = parent.getDefn( ).getSlot( slotId );
		if ( slotDefn != null )
		{
			list.addAll( slotDefn.getContentExtendedElements( ) );
			list.removeAll( notSupportList );
		}
		
		List availableList = new ArrayList( );
		for ( int i = 0; i < list.size( ); i++ )
		{
			if ( parent.canContain( slotId, ( (IElementDefn) list.get( i ) )
					.getName( ) ) )
			{
				availableList.add( list.get( i ) );
			}
		}
		return availableList;
	}
	/**
	 * Get the containable element type list of give slot handle
	 * 
	 * @param slotHandle
	 */
	public static List getElementSupportList( SlotHandle slotHandle )
	{
		return getElementSupportList( slotHandle.getElementHandle( ),
				slotHandle.getSlotID( ) );