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.editors.schematic/src/org/eclipse/birt/report/designer/internal/ui/editors/script/TreeViewPalettePage.java
/**
	 * The PaletteViewerProvider that is used to create the PaletteViewer
	 */
	protected PaletteViewerProvider provider;
	/**
	 * The PaletteViewer created for this page
	 */
	protected Tree tree;
	private ExpressionTreeSupport treeCommon;
	/**
	 * Constructor
	 * 
	 */
	public TreeViewPalettePage( )
	{
		treeCommon = new ExpressionTreeSupport( );
	}
	/**
	 * Creates the palette viewer and its control.
	 * 
	 * @see Page#createControl(org.eclipse.swt.widgets.Composite)
	 */
	public void createControl( Composite parent )
	{
		if(getViewer()==null)
		{
			return;
		}
		tree = new Tree( parent, SWT.NONE );
		treeCommon.setTree( tree );