ChampionSelectorVC.m

/**
 * Promise style method
 */
- (void)animateUi
{
  const CGFloat valDestStatsBottom = self.conStatsBottomSpacing.constant;

  const CGFloat valDestLeftArrowTrailing = self.conLeftArrowTrailing.constant;
  const CGFloat valDestRightArrowLeading = self.conRightArrowLeading.constant;

  const CGFloat valDestBtnRollTheDiceHeight = self.conBtnRollTheDiceHeight.constant;

  //TODO: clean this up by separating the methods and pulling out
  //constraints from the storyboard before resetting to 0.
  {
    //set initial states

    //move arrows before animating
    self.conLeftArrowTrailing.constant = 0;
    self.conRightArrowLeading.constant = 0;

    self.conBtnRollTheDiceHeight.constant = 0;

    self.conStatsBottomSpacing.constant += 20;

    //apply constraints
    [self.view layoutIfNeeded];

    //set alphas
    self.imgChampionPortrait.alpha = 0;
    self.portraitBorderView.alpha = 0;

    self.btnRightArrow.alpha = 0;
    self.btnLeftArrow.alpha = 0;

    self.btnRollTheDice.alpha = 0;

    self.uivStatsContainer.alpha = 0;

    self.lblDescription.alpha = 0;
  }

  [UIView promiseWithDuration:.5f delay:.3f options:UIViewAnimationOptionCurveEaseIn animations:^{
    self.imgChampionPortrait.alpha = 1;
    self.portraitBorderView.alpha = .5;
  }].then(^{
    //wait to start the arrow movement
    return PMKAfter(.25f);
  }).thenOn(dispatch_get_main_queue(), ^{
    //set up final arrow constraints
    self.conLeftArrowTrailing.constant = valDestLeftArrowTrailing;
    self.conRightArrowLeading.constant = valDestRightArrowLeading;

    //animate the arrow opacity and constraints
    return [UIView promiseWithDuration:.25f delay:0.0f options:UIViewAnimationOptionCurveEaseInOut animations:^{
      [self.view layoutIfNeeded];
      self.btnRightArrow.alpha = .35;
      self.btnLeftArrow.alpha = .35;
    }];
  }).then(^{
    //animate rtd button
    self.conBtnRollTheDiceHeight.constant = valDestBtnRollTheDiceHeight;

    return [UIView promiseWithDuration:.5f delay:0.0 options:UIViewAnimationOptionCurveEaseOut animations:^{
      [self.view layoutIfNeeded];
      self.btnRollTheDice.alpha = 1;
    }];
  }).then(^{
    //start button glow
    [self.btnRollTheDice startGlowing];

    //move stats in from bottom
    self.conStatsBottomSpacing.constant = valDestStatsBottom;
    return [UIView promiseWithDuration:.5f delay:0.0f options:UIViewAnimationOptionCurveEaseOut animations:^{
      [self.view layoutIfNeeded];
      self.uivStatsContainer.alpha = 1;
      self.lblDescription.alpha = 1;
    }];
  });
}

/**
 * Original Callback Nested Style
 */
- (void)oldAnimationMethod {

  const CGFloat valDestStatsBottom = self.conStatsBottomSpacing.constant;

  const CGFloat valDestLeftArrowTrailing = self.conLeftArrowTrailing.constant;
  const CGFloat valDestRightArrowLeading = self.conRightArrowLeading.constant;

  const CGFloat valDestBtnRollTheDiceHeight = self.conBtnRollTheDiceHeight.constant;

  [UIView animateWithDuration:.5f delay:.3f options:UIViewAnimationOptionCurveEaseIn animations:^{

    self.imgChampionPortrait.alpha = 1;
    self.portraitBorderView.alpha = .5;

    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(.5f * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{

      //set up final arrow constraints
      self.conLeftArrowTrailing.constant = valDestLeftArrowTrailing;
      self.conRightArrowLeading.constant = valDestRightArrowLeading;
      //start animating arrows
      [UIView animateWithDuration:.25f delay:0.0f options:UIViewAnimationOptionCurveEaseInOut animations:^{
        [self.view layoutIfNeeded];
        self.btnRightArrow.alpha = .35;
        self.btnLeftArrow.alpha = .35;
      } completion:^(BOOL isFinished) {
        //animate rtd button
        self.conBtnRollTheDiceHeight.constant = valDestBtnRollTheDiceHeight;
        [UIView animateWithDuration:.5f delay:0.0f options:UIViewAnimationOptionCurveEaseInOut animations:^{
          [self.view layoutIfNeeded];
          self.btnRollTheDice.alpha = 1;
        } completion:^(BOOL isFinished) {
          [self.btnRollTheDice startGlowing];

          self.conStatsBottomSpacing.constant = valDestStatsBottom;
          [UIView animateWithDuration:.5f delay:0.0 options:UIViewAnimationOptionCurveEaseOut animations:^{
            [self.view layoutIfNeeded];
            self.uivStatsContainer.alpha = 1;
            self.lblDescription.alpha = 1;
          } completion:^(BOOL isFinished) {
          }];

        }];
      }];
    });

  } completion: nil];
}