Bug 180864 Change Allow Null option in Cascading Group.[0705]
Description: Change Allow Null option in Cascading Group. Build number:2.2.0.v20070404 Steps to reproduce: 1. New a cascading group and add sub parameter. Expected result: Is Required option in cascading group definition dialog. Actual result: Allow null value option in Cascading Group definition dialog Error log:N/A
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/CascadingParametersDialog.java
public void widgetSelected( SelectionEvent e )
			{
				popupFormatBuilder( true );
			}
		} );
		Group preview = new Group( formatArea, SWT.NULL );
		preview.setText( LABEL_PREVIEW_WITH_FORMAT );
		preview.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		preview.setLayout( new GridLayout( ) );
		previewLable = new Label( preview, SWT.CENTER
				| SWT.HORIZONTAL
				| SWT.VIRTUAL );
		previewLable.setText( "" ); 
		previewLable.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		createLabel( optionsGroup, LABEL_LIST_LIMIT, maxStrLengthOption );
		Composite composite = new Composite( optionsGroup, SWT.NULL );
		composite.setLayout( UIUtil.createGridLayoutWithoutMargin( 2, true ) );
		composite.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		Composite limitArea = new Composite( composite, SWT.NULL );
		limitArea.setLayout( UIUtil.createGridLayoutWithoutMargin( 2, true ) );
		limitArea.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		listLimit = new Text( limitArea, SWT.BORDER );
		GridData gridData = new GridData( );
		gridData.widthHint = 80;
		listLimit.setLayoutData( gridData );
		listLimit.addVerifyListener( new VerifyListener( ) {
			public void verifyText( VerifyEvent e )
			{
				e.doit = ( "0123456789\0\b\u007f".indexOf( e.character ) != -1 ); 
			}