CGAffineTransformScale modified after device rotation

Question

I have a view that I am performing a transform on

originalTransform = self.appContainer.transform;
self.appContainer.transform = CGAffineTransformMakeScale(.8, .8);

Original Rotation

If I do not rotate the device I can revert this back to the original by using

self.appContainer.transform = CGAffineTransformScale(originalTransform, 1, 1);

Unfortunately, if I rotate the device, the transformation matrix for the view gets modified by the view rotation and breaks the original scale. If I undo the scale after rotation I am left with the UIView not returning to its original full size.

After Rotation

After Original Scale

I'm sure that I need to make calculations between the original transformation matrix and the new one but I am unsure how to do this. The only thing I have been able to do to make this work is to revert the scale back to 1 before rotation

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    self.appContainer.transform = CGAffineTransformScale(originalTransform, 1, 1);
}

And then rescale it with the newly modified transformation after the

-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation               {
    self.appContainer.transform = CGAffineTransformMakeScale(.8, .8);
}

This makes it work as I expect, but instead of going back to full screen, and then back to .8 scale, I'd like it to go from its new transformation to the correct .8 scale.

Have you finally handled this? I'm looking for solution. – Krzysztof Przygoda May 04 '14 at 10:47 — Krzysztof Przygoda, May 04 '14 at 10:47
I'm looking for solution too.. – Pipiks Jan 19 '16 at 16:12 — Pipiks, Jan 19 '16 at 16:12

score 0 · Answer 1 · answered May 09 '12 at 16:10

0

If you want to revert it to original, try setting the transform to CGAffineTransformIdentity.

self.appContainer.transform = CGAffineTransformIdentity;

answered May 09 '12 at 16:10

JingJam Laddoo

44
4

this doesn't work because the view's transformation is being modified by the device rotation event. By setting it back to identity I am getting the same results. After the device rotation event, the view's transformation needs to be taken to .8 scale of that orientation. – MobileOverlord May 09 '12 at 16:15

score 0 · Answer 2 · answered Mar 15 '13 at 09:14

0

I think you have to remove all autoresizing masks using.....

[self.appContainer setAutoresizingMask:UIViewAutoresizingNone];

answered Mar 15 '13 at 09:14

Nirav Gadhiya

6,342
2
37
76

CGAffineTransformScale modified after device rotation

2 Answers2