title: How do you "ping pong" a UIView image sequence animation
body: <p>I have a UIImageView which has a png image sequence loaded into it.</p>
  
  <p>My question is - Do you know of any way I can "ping pong" the animation sequence? 
  So that it plays forward from 1-24 then plays backwards from 24-1 and loops.</p>
  
  <p>(technically it should be : 1-24 then 23-1 then 2-24 then 23-1...etc)</p>
  
  <pre><code>- (void) loadAnim01 {
  mon01 = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"mon01_01.png"]];
  mon01.center = CGPointMake(258,69);
  NSMutableArray *array = [NSMutableArray array];
  for (int i = 1; i &lt;= 24; i++) 
      [array addObject:[UIImage imageNamed:[NSString stringWithFormat:@"mon01_%02d.png",i]]];
  mon01.animationImages = array;
  mon01.animationDuration = 1.0;
  mon01.animationRepeatCount = 0;
  [self.view addSubview:mon01];
  [mon01 release];
  </code></pre>
  
  <p>}</p>
  
  <p>Thank a lot!</p>