iOS animating a view including subviews

Question

I'm trying to make an animation for collapsing a view which includes some subviews.

[UIView beginAnimations:@"advancedAnimations" context:nil];
[UIView setAnimationDuration:3.0];

CGRect aFrame = aView.frame;
aView.size.height = 0;
aView.frame = aFrame;

[UIView commitAnimations];

This animation is doing fine, but for the aView only. Subviews doesn't collapse as expected. How do I make the subviews collapsing as well? Furthermore, is there a way to recalculate original size after collapsing?

THX

score 5 · Accepted Answer · answered May 15 '12 at 16:06

5

You have probably forgotten to apply some autoresizing mask to your subviews. If you do

for (UIView *subview in aView.subviews) {
    subview.autoresizingMask = (UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleTopMargin);
}

it should work.

BUT, personally I would use, as lamelas said

aView.transform = CGAffineTransformMakeScale(1.0,0.0);

answered May 15 '12 at 16:06

Zoleas

4,869
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Still good, but the thing I want to do is to collapse the view, hiding its content as it gets smaller. CGAffineTransformMakeScale scales the whole content. BTW, you can't use 0.0 in transformations. – toppless May 16 '12 at 06:53
Where did you see that we can't use 0.0 in transforms ? Anyway, I'm not sure what your question is… Do you want your subviews to scale to, or you want them to be cropped as the animation occurs ? – Zoleas May 16 '12 at 08:10
Try to set it to 0.0 and look what is animation will look like and compare it to setting to 0.001. I am tying not to resize the subviews, but to have a "slide door" effect, as the main view gets smaller. – toppless May 16 '12 at 10:03
Ok, so you just have to set the property clipToBounds of your main view to YES then. – Zoleas May 16 '12 at 10:10
Regarding setting a zero value in transforms (CGAffine + CA3D ones), iOS 6+ seems to let it slide and will animate appropriately. The ".001" trick is the way to go though for compatibility. – walkingbrad Apr 05 '13 at 00:10

score 4 · Answer 2 · answered May 15 '12 at 15:40

4

Try using this to animate:

aView.transform = CGAffineTransformMakeScale(1.0,0.0);

answered May 15 '12 at 15:40

lamelas

872
6
15

Works better, but the animation is a bit strange - tries to "squeeze" the view into the middle point. – toppless May 15 '12 at 16:01

score 0 · Answer 3 · answered May 15 '12 at 15:42

An educated guess:

[UIView beginAnimations:@"advancedAnimations" context:nil];
[UIView setAnimationDuration:3.0];

CGRect aFrame = aView.frame;
aView.size.height = 0;
aView.frame = aFrame;

for (UIView *subview in aView.subviews) {
    CGRect frame = subview.frame;
    frame.size.height = 0;
    subview.frame = frame;
}

[UIView commitAnimations];

Furthermore, is there a way to recalculate original size after collapsing?

You'll probably want to just save the height before collapsing.

score 0 · Answer 4 · answered Feb 10 '22 at 03:21

0

The Swift syntax for setting autoresizingMask is slightly different than ObjC:

for subview in view.subviews {
    subview.autoresizingMask = [.flexibleWidth, .flexibleLeftMargin, .flexibleRightMargin]
}

answered Feb 10 '22 at 03:21

WongWray

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iOS animating a view including subviews

4 Answers4