title: UIView animation doesn't animate on the first try
body: <p>My issue is that my UIView animation only works after the first time. I have two different sets of animations. The first set works correctly, its the second set that is giving me issues. The first set slides 4 buttons onto the screen a little farther than where I want them. (These locations I call extendedState) The second set of animations slides them a little back to the position that I want. This gives the effect of bouncing back to the right spot.</p>
  
  <p>In between the two animations theres a brief second that will flash the buttons back to their starting position once the first set of animations complete. By setting that starting position to the extendedStates (the location they will be in when they stop animating), the buttons appear not to move between animations (which is good. thats what I want).</p>
  
  <p>Here's the order of operations:</p>
  
  <ol>
  <li>I tap a button that launches the first set of animations (which works perfectly fine)</li>
  <li>In the animationDidStop block, I launch the second set of animations (this is the one that doesn't animate on the first try)</li>
  </ol>
  
  <p>Here's the code for the button handler:</p>
  
  <pre><code>@IBAction func selectAnimal(sender: UIButton) {
  
      showButtons()
      bigCircle.enabled = false
      enableButtons()
  
      if(tapToSelectLabel.hidden) {
          animator.repositionButtonsToExtendedState(buttons) //sets the starting position to the extendedState so it appears not to move between animations
          animator.slideButtonsIntoScreen(buttons, delegate: self) //this is the first set of animations
  
      }
  
      if(sender.titleLabel != nil) {
  
          if(bigCircleLabel.text != "Choose an animal") {
  
              if let answer:String = bigCircleLabel.text {
                  solution = game.checkAnswer(answer, question: game.threeQuestions[game.questionIndex])
              }
  
              showResponse()
          }
      }
  }
  </code></pre>
  
  <p>Now here's the code inside the animationDidStop block </p>
  
  <pre><code>let buttonRects:[CGRect] = [CGRectMake(834, 120, 175, 175),
                                          CGRectMake(631, 198, 175, 175),
                                          CGRectMake(470, 365, 175, 175),
                                          CGRectMake(386, 578, 175, 175)]
  
              UIView.animateWithDuration(0.35, delay: 0, options: [.BeginFromCurrentState, ], animations: {
                          self.buttons[3].frame = buttonRects[3]
                      }, completion: { (value:Bool) in
                          self.buttons[3].enabled = true
  
                          UIView.animateWithDuration(0.25, delay: 0, options: [ ], animations: {
                              self.buttons[2].frame = buttonRects[2]
                              }, completion: { (value:Bool) in
                                  self.buttons[2].enabled = true
  
                                  UIView.animateWithDuration(0.4, delay: 0, options: [ ], animations: {
                                      self.buttons[1].frame = buttonRects[1]
                                      }, completion: { (value:Bool) in
                                          self.buttons[1].enabled = true
  
                                          UIView.animateWithDuration(0.5, delay: 0, options: [ ], animations: {
                                              self.buttons[0].frame = buttonRects[0]
                                              }, completion: { (value:Bool) in
                                                  self.buttons[0].enabled = true
                                          })
                                  })
                          })
                      })
  </code></pre>
  
  <p>^ This code slides the buttons a little backwards to the spot I want them to be in.</p>
  
  <p>Here's the code for my animator class</p>
  
  <p>animator.slideButtonsIntoScreen</p>
  
  <pre><code>func slideButtonsIntoScreen(buttons:[UIButton], delegate:UIViewController) {
  
      let center = CGPoint(x:delegate.view.frame.width, y:delegate.view.frame.height)
      let startAngles:[CGFloat] = [0.405, 0.75, 1.1, 1.48]
      let endAngles:[CGFloat] = [1.95, 2.25, 2.622, 2.98]
      let radii:[CGFloat] = [555, 559, 558.5, 551]
      let durations:[Double] = [1.75, 1.5, 1.25 , 1]
  
      for index in 0...3 {
          let path = UIBezierPath(arcCenter: center, radius: radii[index], startAngle: -startAngles[index], endAngle: -endAngles[index], clockwise: false)
          let anim = CAKeyframeAnimation(keyPath: "position")
          anim.path = path.CGPath
          anim.rotationMode = kCAAlignmentNatural
          anim.repeatCount = 0
          anim.duration = durations[index] - 0.25
          anim.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)
          anim.setValue("on", forKey: "type")
          anim.delegate = delegate
          buttons[index].layer.addAnimation(anim, forKey: "animate position along path"+String(index))
          anim.removedOnCompletion = true
  
      }
  
  }
  </code></pre>
  
  <p>animator.repositionButtonsToExtendedState</p>
  
  <pre><code>func repositionButtonsToExtendedState(buttons:[UIButton]) {
  
  
      let buttonExtendedRects:[CGRect] = [CGRectMake(755, 155, 175, 175),
                                          CGRectMake(585, 245, 175, 175),
                                          CGRectMake(450, 405, 175, 175),
                                          CGRectMake(393, 590, 175, 175)]
  
      for index in 0...3 {
          buttons[index].frame = buttonExtendedRects[index]
      }
  }
  </code></pre>
  
  <p>I set breakpoints and print statements, so I know for a fact that it reaches the animation on the first try, it just doesn't show the animation. It works exactly as it should every time after the first.</p>