title: UIControlEvents and subclassing UIControl
body: <p>I have a UIControl subclass for a custom slider type control (one that behaves differently from UISlider). At the moment I use my own target and action variables to send a message to the target whenever the slider value changes. But this doesn't play nice with Apple's UIControlEvent constants. I wasn't sure if I should use these, and if so, where can I put my custom "value changed" detection?</p>
  
  <p>I overrode beginTrackingWithTouch: and continueTrackingWithTouch: to return YES but the action is never dispatched.</p>