Objective-c animation with constraints instability issue for trailing constraint - ios

Question

I'm developing an IOS app using objective-c. I came across with an instability problem when animating a view's constraints. The animation works well regarding the final position of the frame, but randomly, the trailing(right) constraint is omitted for the first animation block(left constraint never reach to -20 constant value), however leading(left), top and bottom constraints are working as expected.
Please see the video I uploaded. In the first tap, the animation is working as expected, but in the second tap the issue occurs. Please advice.
Video showing the problem
- (void)animateTransition:(nonnull id<UIViewControllerContextTransitioning>)transitionContext {
// 1
UIView *containerView = transitionContext.containerView;
UIViewController* toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
// 2
[containerView addSubview:toViewController.view];
if([toViewController isKindOfClass:[ImageViewController class]]){
ImageViewController *vcImage = (ImageViewController*)toViewController;
vcImage.constraintLeft.constant = 20;
vcImage.constraintTop.constant = self.selectedCardFrame.origin.y + 60.0;
vcImage.constraintRight.constant = 20.0;
vcImage.constraintBottom.constant = 0;//self.CollectionView.bounds.size.height - (self.selectedCardFrame.origin.y + self.selectedCardFrame.size.height);
[toViewController.view layoutIfNeeded];
NSTimeInterval duration = [self transitionDuration:transitionContext];
[toViewController.view layoutIfNeeded];
[UIView animateWithDuration:duration animations:^{
//First animation block
vcImage.constraintRight.constant = -20.0;
vcImage.constraintLeft.constant = -20.0;
vcImage.constraintTop.constant = -20.0;
vcImage.constraintBottom.constant = 0;
[toViewController.view layoutIfNeeded];
//toViewController.configureRoundedCorners(shouldRound: false)
} completion:^(BOOL finished) {
//Second animation block
[UIView animateWithDuration:duration animations:^{
vcImage.constraintLeft.constant = 0;
vcImage.constraintTop.constant = 0.0;
vcImage.constraintRight.constant = 0;
vcImage.constraintBottom.constant = 0;
[toViewController.view layoutIfNeeded];
//toViewController.configureRoundedCorners(shouldRound: false)
} completion:^(BOOL finished) {
[transitionContext completeTransition:finished];
}];
}];
}
}
Updated code after #Sh_Khan 's comment.
- (void)animateTransition:(nonnull id<UIViewControllerContextTransitioning>)transitionContext {
// 1
UIView *containerView = transitionContext.containerView;
UIViewController* toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
// 2
[containerView addSubview:toViewController.view];
if([toViewController isKindOfClass:[ImageViewController class]]){
ImageViewController *vcImage = (ImageViewController*)toViewController;
NSTimeInterval duration = [self transitionDuration:transitionContext];
[UIView animateWithDuration:0 animations:^{
vcImage.constraintLeft.constant = 20;
vcImage.constraintTop.constant = self.selectedCardFrame.origin.y + 60.0;
vcImage.constraintRight.constant = 20.0;
vcImage.constraintBottom.constant = 0;
[toViewController.view layoutIfNeeded];
} completion:^(BOOL finished) {
[UIView animateWithDuration:duration animations:^{
//First animation block
vcImage.constraintRight.constant = -20.0;
vcImage.constraintLeft.constant = -20.0;
vcImage.constraintTop.constant = -20.0;
vcImage.constraintBottom.constant = 0;
[toViewController.view layoutIfNeeded];
//toViewController.configureRoundedCorners(shouldRound: false)
} completion:^(BOOL finished) {
//Second animation block
[UIView animateWithDuration:duration animations:^{
vcImage.constraintLeft.constant = 0;
vcImage.constraintTop.constant = 0.0;
vcImage.constraintRight.constant = 0;
vcImage.constraintBottom.constant = 0;
[toViewController.view layoutIfNeeded];
//toViewController.configureRoundedCorners(shouldRound: false)
} completion:^(BOOL finished) {
[transitionContext completeTransition:finished];
}];
}];
}];
}
}

Answer 1

Before setting your imageView try reorienting the photo. Something tells me the image view is having a hard time determining the orientation of the image. I had this happen during a transition once and would explain why you are seeing the behavior only some of the time. I am a bit rusty with Objective C but give this a shot and use it to before setting your imageView image.
-(UIImage*)normalizeImage:(UIImage*)currentImage {
if (currentImage.imageOrientation == UIImageOrientationUp){
return currentImage;
}
UIGraphicsBeginImageContextWithOptions(currentImage.size, NO, currentImage.scale);
[currentImage drawInRect:CGRectMake(0, 0, currentImage.size.width, currentImage.size.height)];
UIImage *_newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return _newImage;
}