get to an UIView frame a zoom animation

Question

I am trying to add one UIView with a transition style zoom animation like this:

     ^
     |
 <---.--->
     |
     v

The view start with a little frame (centerParent.x, centerParent.y,20, 20) and then change to (centerParent.x, centerParent.y,300, 300).

But when I change the frame I have to change it since the postion (0.0) of the view, not for it's center point. Does anyone know how to do it?

Thanks

could you plz describe your animation? the graph is difficult for us to understand. — lu yuan, Jun 29 '12 at 12:21
Maybe you can embedded it in an UIScrollView and use the method zoomToRect:animated: to get the same effect. — lu yuan, Jun 29 '12 at 12:39

score 7 · Accepted Answer · edited Jun 10 '13 at 11:35

7

With the methodology you're currently using (not using a transform but simply resizing the view) you just need to reset the origin or center of the view). The easiest is the center:

 view.frame = CGRectMake(0, 0, 20, 20);
    CGPoint center = view.center;
    [UIView animateWithDuration: 1.0f animations:^{
        view.frame = CGRectMake(0, 0, 300, 300);
        view.center = center;
    }];

You can also reset the origin by moving subtracting 1/2 the difference of the size change from the x and y, but this is more math:

view.frame = CGRectMake(0, 0, 20, 20);
    CGPoint origin = view.frame.origin.
    [UIView animateWithDuration: 1.0f animations:^{
        origin.x -= (300 - 20) / 2;
        origin.y -= (300 - 20) / 2;
        view.frame = CGRectMake(origin.x, origin.y, 300, 300);
    }];

edited Jun 10 '13 at 11:35

Vinodh

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answered Jun 29 '12 at 13:01

Aaron Hayman

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I use the second solution. No re scaling working fine! Thanks :) – damacri86 Jul 03 '12 at 09:53
@Aaron Hayman - Can you please tell me how to shrink the view with animation . Thanks in advance. – Pankaj Gupta Dec 15 '16 at 12:49
@PankajGupta You just need to use the same math as I described in the answer. Basically, take the origin and subtract out half the difference between the new size and the old size. Set the view frame to the new origin + size inside the animation block. – Aaron Hayman Dec 16 '16 at 17:39

score 1 · Answer 2 · answered Jun 29 '12 at 12:37

To make a view zoom out, while keeping it's own center is easy but you need to use transform. here is a code. Just add and connect a view, named it zoomerView.

In this example, I just add this to the main view touches ended.

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    CGPoint center = zoomerView.center;
    [UIView animateWithDuration:1 animations:^{
        zoomerView.transform = CGAffineTransformScale(zoomerView.transform, 1.2, 1.2);
    }];
}

Hope this helps you

Thanks by the answer but I use set frame because I need a good resolution. — damacri86, Jul 03 '12 at 09:52

score 0 · Answer 3 · answered Jun 29 '12 at 12:40

0

try this

[UIView animateWithDuration:secs delay:1.0 options:option
                     animations:^{
                         yourview.transform = CGAffineTransformScale(view.transform, 100.0, 100.0);
                     }
                     completion:nil];

answered Jun 29 '12 at 12:40

Madhumitha

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This probably would work, but the view would not constantly re-render so if the animation was even the slightest bit long, it would be very poor quality. – pasawaya Jun 29 '12 at 14:20

get to an UIView frame a zoom animation

3 Answers3

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