Bug 166315 Combo box doesn't allow blank when set string type in parameter editor
Combo box doesn't allow blank when set string type in parameter editor Steps to reproduce: 1.New a parameter, display type is Combo Box 2.Select data type as String Expected result: "Allow blank values" is enable. Actual result: "Allow blank values" is gray and can't be checked.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
else
		{
			IChoice choice = DATA_TYPE_CHOICE_SET.findChoiceByDisplayName( dataTypeChooser.getText( ) );
			type = DATA_TYPE_CHOICE_SET.findChoiceByDisplayName( dataTypeChooser.getText( ) )
					.getName( );
			type = choice.getName( );
		}
		return type;
	}
	/**
	 * Gets the internal name of the control type from the display name
	 */
	private String getSelectedControlType( )
	{
		String displayText = controlTypeChooser.getText( );
		if ( StringUtil.isBlank( displayText ) )
		{
			return getInputControlType( );
		}
		if ( DISPLAY_NAME_CONTROL_COMBO.equals( displayText ) )
		{
			return PARAM_CONTROL_COMBO;
		}
		if ( DISPLAY_NAME_CONTROL_LIST.equals( displayText ) )
		{
			return PARAM_CONTROL_LIST;
		}
		return CONTROL_TYPE_CHOICE_SET.findChoiceByDisplayName( displayText )
				.getName( );
	}