title: UIKit Dynamics/Blocks - Remove UIPushBehavior on Complete
body: <p>I applied a UIPushBehavior to an object. It moves. How can I trigger a method on completion of this movement? (e.g. When it's movement velocity drops to below a certain threshold). </p>
  
  <p>As far as I see there is no "StateEnded" callback I could use to trigger such a method. There is however a action block that is called on each step</p>
  
  <pre><code>- (void)viewDidLoad {
  ...
      _parentViewController.pushBehavior.action =  ^{
         //Called on each animation/dynamics step
  
      };
  ...
  }
  </code></pre>
  
  <p>But I cannot get current values inside that block. Any ideas how to trigger an action based on current values inside the block? ... or a different way to do make the object do something based on it's movement/velocity state?</p>