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
{
				choices = new String[3];
			}
			else
			{
				choices = new String[4];
			}
		}
		else
		{
			choices = new String[2];
		}
		if ( controlTypeChooser.getItemCount( ) != choices.length )
		{
			String originalSelection = controlTypeChooser.getText( );
			if ( isStatic( ) )
			{
				if ( DesignChoiceConstants.PARAM_TYPE_BOOLEAN.equals( type ) )
				{
					choices[0] = CONTROL_TYPE_CHOICE_SET.findChoice( DesignChoiceConstants.PARAM_CONTROL_CHECK_BOX )
							.getDisplayName( );
				}
				else
				{
					choices[0] = CONTROL_TYPE_CHOICE_SET.findChoice( DesignChoiceConstants.PARAM_CONTROL_TEXT_BOX )
							.getDisplayName( );
					
					choices[1] = DISPLAY_NAME_CONTROL_COMBO;
				}