CODEWITHSUNDEEP
iosiphoneuiviewcore-animation
bohanl
bohanl

Reputation: 1925

iOS - Core Animation - How to set origin when transform property is changed

I have a UIView added as a subview inside its parent view. When the user taps on this UIView, I want it to be transformed so it takes the entire screen.

I am trying to do so by changing its transform property and I was able to make its size match its parent view but not its position.

I read the Apple documentation and found frame cannot be used with transform. How do I make its position line up with its parent view?

Also, without using transform, is it a good idea to do so by changing its constraints, e.g., NSLayoutAttributeHeight?

Upvotes: 0

Views: 1819

Answers (1)

Xu Yin
Xu Yin

Reputation: 3940

i think you can simply change the frame after you scale it by transform like this:

//i am using 5 for testing purpose
self.backgroundImageView.transform = CGAffineTransformMakeScale(5, 5);

self.backgroundImageView.frame = CGRectMake(0, 0, self.backgroundImageView.frame.size.width, self.backgroundImageView.frame.size.height);

OR change the anchor point before the scale:

self.backgroundImageView.layer.anchorPoint = CGPointMake(0.5, 0.5);
self.backgroundImageView.transform = CGAffineTransformMakeScale(5, 5);

Update: if you use Autolayout in your UIView, the solution might depends on how you set up your constraints, For example, if you set up your image constraints like this:

enter image description here

I would suggest still using the scale transform, but change the top and left constraint to 0.

or you set up your image constraint like this:

enter image description here

I would change the center alignment x and y to the center point of the super view

Maybe you can let me know how you set up you constraints, i can do some test for you on my local.

Upvotes: 1

Related Questions