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
private boolean isCustom( )
	{
		if ( DesignChoiceConstants.STRING_FORMAT_TYPE_CUSTOM.equals( formatCategroy )
				|| DesignChoiceConstants.NUMBER_FORMAT_TYPE_CUSTOM.equals( formatCategroy )
				|| DesignChoiceConstants.DATETIEM_FORMAT_TYPE_CUSTOM.equals( formatCategroy ) )
		{
			return true;
		}
		return false;
	}
	private void setExpression( Combo chooser, String key )
	{
		chooser.deselectAll( );
		key = StringUtil.trimString( key );
		if ( StringUtil.isBlank( key ) )
		{
			chooser.setText( "" ); 
			return;
		}
		for ( int i = 0; i < columnList.size( ); i++ )
		{
			if ( key.equals( DEUtil.getExpression( columnList.get( i ) ) ) )
			{
				chooser.select( i );
				return;
			}
		}
		chooser.setText( key );
	}
}