Swift CGAffineTransformScale to a scale, not by a scale

Question

Let's say I scale a UILabel using a CGAffineTransformScale like so:

let scale = 0.5
text = UILabel(frame: CGRectMake(100, 100, 100, 100))
text.text = "Test"

UIView.animateWithDuration(2.0, delay: 0.0, options: UIViewAnimationOptions.CurveEaseIn, animations: {
    self.text.transform = CGAffineTransformScale(self.text.transform, scale, scale)
}, completion: {(value : Bool) in
    print("Animation finished")
})

This works great when I want to scale the UILabel by half. But if I were to call this same code again, it would end up with a scale of 0.25, as it scales again by half.

Would it be possible to use the CGAffineTransformScale to always scale to a size of half the original UILabel frame, instead of a scaling it cumulatively?

score 16 · Accepted Answer · answered Nov 04 '16 at 23:24

16

Swift 3:

text.transform = CGAffineTransform.identity
UIView.animate(withDuration: 0.25, animations: {
   self.text.transform = CGAffineTransform(scaleX: scale, y: scale)
})

answered Nov 04 '16 at 23:24

Dani Pralea

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score 6 · Answer 2 · answered Apr 21 '16 at 22:04

6

You are scaling the existing transform. Just create a new transform:

self.text.transform = CGAffineTransformMakeScale(scale, scale)

answered Apr 21 '16 at 22:04

rmaddy

314,917
42
532
579

1

or `CGAffineTransformScale(CGAffineTransformIdentity, scale, scale)` – Ozgur Vatansever Apr 21 '16 at 22:06

score 0 · Answer 3 · answered Apr 09 '21 at 14:27

0

Swift version:

self.text.transform = CGAffineTransform.init(scaleX: scaleFactorX, y: scaleFactorY)

answered Apr 09 '21 at 14:27

Henadzi Rabkin

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Swift CGAffineTransformScale to a scale, not by a scale

3 Answers3