title: Objective-C bindings - Binding an enum to an NSPopupButton
body: <p>I'm working on a project which would be ideally suit Cocoa bindings for the UI but I'm having an issue binding the value of an object property and can't find a suitable solution. The object is as follows:</p>
  
  <pre><code>typedef enum tagCSQuality {
      kQualityBest            = 0,
      kQualityWorst           = 1
  } CSQuality;
  
  @interface CSProfile : NSObject {
     NSString *identifier;
     NSString *name;
     CSQuality quality;
  }
  </code></pre>
  
  <p>In the XIB, I have an object controller whose content object is bound to a "currentSelection" property of the window controller which is an instance of the above object. I've then bound the name and identifier which all work as expected but I cannot see how I can bind the enums.</p>
  
  <p>Ideally I would like an NSPopupButton to display "Best" and "Worst" and pick the correct enum value. I have updated the enum to have an explicit numeric value and I believe that I need a value transformer to convert the values but I'm stuck on exactly how this could be implemented.</p>
  
  <p>Can anyone help me out or point me in the right direction?</p>
  
  <p>Thanks,
  J</p>