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 CellEditor[] cellEditors;
	private boolean givenName;
	private static final IChoiceSet DATA_TYPE_CHOICE_SET = DEUtil.getMetaDataDictionary( )
			.getElement( ReportDesignConstants.SCALAR_PARAMETER_ELEMENT )
			.getProperty( ScalarParameterHandle.DATA_TYPE_PROP )
			.getAllowedChoices( );
	private CascadingParameterGroupHandle inputParameterGroup;
	private ScalarParameterHandle selectedParameter;
	
	protected ScalarParameterHandle newParameter = null;
	private String defaultValue;
	private String formatPattern;
	private String formatCategroy;
	private boolean loading = true;
	private Button allowNull;
	private int maxStrLengthProperty;
	private int maxStrLengthOption;
	private String PROPERTY_LABEL_STRING[] = {
			LABEL_PARAM_NAME,
			LABEL_GROUP_PROMPT_TEXT,
			LABEL_PARAMTER_PROMPT_TEXT,
			LABEL_DATA_TYPE,
			LABEL_DISPLAY_TYPE,
			LABEL_DEFAULT_VALUE
	};
	private String OPTION_LABEL_STRING[] = {
			LABEL_HELP_TEXT, LABEL_FORMAT_AS, LABEL_LIST_LIMIT
	};
	protected int getMaxStrLength( String string[], Control control )
	{