kCAMediaTimingFunctionEaseInEaseOut not affecting UIImageView - ios

Question

I have a cycle of images I am trying to fade from one to the other using kCAMediaTimingFunctionEaseInEaseOut so its not so abrupt. My UIImageView is receiving the objects from a MutableArray. Here is the code I am using to achieve the fade affect.
imageViewContainer = [UIView new];
imageViewContainer.frame = CGRectMake(0, 0, 320, 620);
imageViewContainer.backgroundColor = [UIColor clearColor];
[self.view1 addSubview:imageViewContainer];
for (int i = 0; i < [homescreenPictureArray count]; i++) {
homescreenPictureView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 50, 320, 620)];
homescreenPictureView.animationImages = homescreenPictureArray;
homescreenPictureView.animationDuration = 15;
[homescreenPictureView setAlpha:1.0f];
homescreenPictureView.contentMode = UIViewContentModeScaleAspectFill;
[imageViewContainer.layer addAnimation:pictureDisolve forKey:nil];
[imageViewContainer addSubview:homescreenPictureView];
pictureDisolve = [CATransition animation];
pictureDisolve.duration = 1.0f;
pictureDisolve.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
pictureDisolve.type = kCATransitionFade;
[homescreenPictureView.layer addAnimation:pictureDisolve forKey:#"imageViewContainer"];
[homescreenPictureView startAnimating];
I receive no errors when compiling yet its not affecting the images. Clarification on why its not working would be appreciated. Thanks in advance!

Answer 1

The transition type you're using is wrong. You need to use kCATransitionFade.

Answer 2

You need to specify the key value. for example #"subviews".
it defines, when and what will be transitioned.
pictureDisolve = [CATransition animation];
pictureDisolve.duration = 1.0f;
pictureDisolve.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
pictureDisolve.type = kCATransition;
[homescreenPictureView.layer addAnimation:pictureDisolve forKey:#"subviews"];

Answer 3

So I'm working on a different project now but I figured I would give a good example of the kCATransitionFade for anyone who views this in the future.
`-(void) fadeIn {
view1.image = background1;
view2.image = background2;
CATransition *fadeIn = [CATransition animation];
fadeIn.duration = 2.0f;
fadeIn.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
fadeIn.type = kCATransitionFade;
fadeIn.delegate = self;
[self.view.layer addAnimation:fadeIn forKey:nil];
view1.hidden = YES;
view2.hidden = NO;
NSLog(#"Image 1");
}
-(void) fadeOut {
view1.image = background1;
view2.image = background2;
CATransition *fadeIn = [CATransition animation];
fadeIn.duration = 2.0f;
fadeIn.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
fadeIn.type = kCATransitionFade;
fadeIn.delegate = self;
[self.view.layer addAnimation:fadeIn forKey:nil];
view1.hidden = NO;
view2.hidden = YES;
NSLog(#"Image 2");
}
`
For my project I left it for use as [self fadeIn] or [self fadeOut] but if you would like you can combine them into single function by calling
-(void) fadeFunction {
if (self.view == view1) {
[self fadeIn];
} else {
[self fadeOut];
}
}