Bug 154832 Wrong node is added to Report Parameters for cascading parameter in Palette view
Description: Wrong node is added to Report Parameters for cascading parameter in Palette view. Steps to reproduce: 1. New a report, add a cascading parameter 2. Switch to Script tab in Editor view, and then switch to Palette view 3. Expand Report Parameters node Expected result: A cascading parameter group is added to Report Parameters node Actual result: Expect a cascading parameter group is added to Report Parameters node, the children of the cascading parameter group are added as scalar parameters
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dialogs/ExpressionTreeSupport.java
dropTarget.setTransfer( new Transfer[]{
			TextTransfer.getInstance( )
		} );
		dropTarget.addDropListener( new DropTargetAdapter( ) {
			public void dragEnter( DropTargetEvent event )
			{
				text.setFocus( );
				if ( event.detail == DND.DROP_DEFAULT )
					event.detail = DND.DROP_COPY;
				if ( event.detail != DND.DROP_COPY )
					event.detail = DND.DROP_NONE;
			}
			public void dragOver( DropTargetEvent event )
			{
				event.feedback = DND.FEEDBACK_SCROLL
						| DND.FEEDBACK_INSERT_BEFORE;
			}
			public void dragOperationChanged( DropTargetEvent event )
			{
				dragEnter( event );
			}
			public void drop( DropTargetEvent event )
			{
				if ( event.data instanceof String )
					insertText( (String) event.data );
			}
		} );
	}
	/**
	 * Disposes resources.