Using an LSR image on a UIButton - objective-c

Question

I am creating a tvOS app and I want to use parallax images on a couple of buttons. From the docs:
To incorporate parallax images in your app:
Create a UIImage object.
You load the image differently depending on whether the image is included in your app bundle or whether you have downloaded the
image.
Bundle—Load images using imageNamed:.
Downloaded file—Load images using imageWithContentsOfFile:.
Create a new UIImageView object using the loaded images.
If the UIImageView is part of another view, set adjustsImageWhenAncestorFocused to YES on the UIImageView.
I know it says UIImageView there, but I was hoping to make the same effect happen on a UIButton, like the home screen app icons.
I've created the artwork, made a stack in the asset catalog, and loaded the image with imageNamed:, but the UIButton does not behave like a parallax image. It does not sway around like the home-screen icons do. It just looks like a flat image.
Is there something else I have to enable in order for the UIButton to behave like the home screen app icons?
UIButton* quitGame = [[UIButton alloc] initWithFrame:rectWithNewX(playAgain.frame, 985)];
[quitGame setImage:[UIImage imageNamed:#"quit.lsr"] forState:UIControlStateNormal];
[quitGame setAdjustsImageWhenHighlighted:YES];
fadeIn(quitGame, self.view, 0.5);

Answer 1

As of right now, this is not possible with just UIButtons, however, I did find a workaround.
Instead, create a UIImageView that will fill the size of the UIButton and make it a subview of the UIButton. Then call the adjustsImageWhenAncestorFocused: and set it to true. Voila!
UIButton* playAgain = [[UIButton alloc] initWithFrame:CGRectMake(centerX(650, self.view), sh() - 250, 300, 180)];
[playAgain setAdjustsImageWhenHighlighted:YES];
[playAgain addTarget:self action:#selector(playAgain) forControlEvents:UIControlEventPrimaryActionTriggered];
fadeIn(playAgain, self.view, 0.5);
UIImageView* playAgainIGV = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 300, 180)];
[playAgainIGV setImage:[UIImage imageNamed:#"playagain.lsr"]];
[playAgainIGV setAdjustsImageWhenAncestorFocused:YES];
[playAgain addSubview:playAgainIGV];

Answer 2

I've had issues when setting files or precompiled LSRs.
Creating the LSR in XCode Asset Catalogue through Asset Catalogue -> New Apple TV Image Stack and dragging in the PNGs, then setting the image either through Interface Builder or through this works:
-(void) setLsr:(UIButton *)button lsrNamed:(NSString *)lsr {
[button setAdjustsImageWhenHighlighted:YES];
UIImageView *biv = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, button.frame.size.width, button.frame.size.height)];
[biv setImage:[UIImage imageNamed:lsr]];
[biv setAdjustsImageWhenAncestorFocused:YES];
[button addSubview:biv];
}

Answer 3

Regarding the answer of david I made a simple Swift method to create a parallax effect button:
func createParallaxButton(button: UIButton, imageNamed: String) {
button.adjustsImageWhenHighlighted = true
let buttonBg = UIImageView(image: UIImage(named: imageNamed))
buttonBg.adjustsImageWhenAncestorFocused = true
buttonBg.frame = button.bounds
button.addSubview(buttonBg)
}
createParallaxButton(myButton, imageNamed: "myButtonimage.lsr")