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
private ICellModifier cellModifier = new ICellModifier( ) {
		public boolean canModify( Object element, String property )
		{
			if ( element != selectedParameter )
			{
				return false;
			}
			if ( property.equals( COLUMN_NAME ) )
			{
				return true;
			}
			if ( COLUMN_DATA_SET.equals( property ) )
			{
				if ( isSingle( ) && getFirstParameter( ) != element )
				{
					return false;
				}
			}
			if ( element == newParameter )
			{
				if ( isSingle( ) )
				{
					if ( element == getFirstParameter( ) )
					{
						if ( !COLUMN_DATA_SET.equals( property ) )
						{
							return false;
						}
					}
					else