Bug 122869 Drag a parameter from data explorer view into a table in library, a new parameter is created automatically.
Description:Drag a parameter from data explorer view into a table in library, a new parameter is created automatically. Steps to reproduce: 1. Add a cascading parameter and a table in a library file. 2. Drag a parameter from data explorer view into a table cell in layout editor. 3. Find that a new parameter was added in data explorer view automatically.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dialogs/ExpressionTreeSupport.java
Assert.isNotNull( tree );
		DragSource dragSource = new DragSource( tree, DND.DROP_COPY );
		dragSource.setTransfer( new Transfer[]{
			TextTransfer.getInstance( )
		} );
		dragSource.addDragListener( new DragSourceAdapter( ) {
			public void dragStart( DragSourceEvent event )
			{
				TreeItem[] selection = tree.getSelection( );
				if ( selection.length <= 0
						|| selection[0].getData( ITEM_DATA_KEY_TEXT ) == null
						|| !( (Boolean) selection[0].getData( ITEM_DATA_KEY_ENABLED ) ).booleanValue( ) )
				{
					event.doit = false;
					return;
				}
			}
			public void dragSetData( DragSourceEvent event )
			{
				if ( TextTransfer.getInstance( )
						.isSupportedType( event.dataType ) )
				{
					TreeItem[] selection = tree.getSelection( );
					if ( selection.length > 0 )
					{
						event.data = selection[0].getData( ITEM_DATA_KEY_TEXT );
					}
				}
			}
		} );