Not able to press an UIButton below UIView with corner radius

Question

I have added to a view an UIView and an UIButton that is placed below the view under left bottom corner.

I've added corner radius to the UIView object this way:

self.myView.layer.cornerRadius = self.myView.frame.size.width/2;
self.myView.layer.masksToBounds = YES;

Now it has the shape of a circle, and my button is visible. See the picture below: enter image description here

The problem is that I can't press the button (it's not highlighting). How can I make it touchable?

I know that placing the button to front will solve the problem, but I would like to know if is there a way to press it by keeping below the view.

A dirty fix maybe, but making the topview 0.01% transparant will allow touches to pass to the view underneath. I had experimented with this in the past. It might be fixed though, but worth a try. It's either that or implement a recursive hittest function. — Totumus Maximus, Jun 02 '14 at 14:07
@TotumusMaximus thanks for your suggestion, but it didn't work. — iOS Dev, Jun 02 '14 at 14:13
Have you looked into this: http://stackoverflow.com/questions/1694529/allowing-interaction-with-a-uiview-under-another-uiview ? This example shows how you calculate by a recursive hittest function if a view is hit from point of impact. — Totumus Maximus, Jun 02 '14 at 14:20
@TotumusMaximus Thanks a lot. I've tried the accepted answer of SO question shared by you and it does what I need. — iOS Dev, Jun 02 '14 at 14:32
@TotumusMaximus I guess you can add your comment as answer, to accept it. It may help other people with same issue. — iOS Dev, Jun 02 '14 at 14:36
Hah, I hate doing that, makes me feel like a rep junkie xD. But you are right, and so it is done. — Totumus Maximus, Jun 02 '14 at 14:40

score 2 · Accepted Answer · edited May 23 '17 at 12:33

2

This question was solved by following this link: Allowing interaction with a UIView under another UIView

The recursive hittest is the one I recommend using. But the accepted answer is quite interesting as well (making views transparant for touches or something).

edited May 23 '17 at 12:33

Community

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answered Jun 02 '14 at 14:39

Totumus Maximus

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robert · Answer 2 · 2016-08-26T08:54:27.490

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You need to subclass UIView for use as your circle and overwrite the following method:

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
    CGFloat radius = self.frame.size.width/2;
    CGFloat distance = sqrtf(powf(point.x-self.frame.size.width/2, 2)+powf(point.y-self.frame.size.height/2, 2));
    if(distance<radius)
        return [super hitTest:point withEvent:event];
    return nil;
}

This makes the view only accept touches inside the circle. You may need to adjust the logic to fit your view.

edited Aug 26 '16 at 08:54

answered Jun 02 '14 at 14:44

robert

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Instead of returning `self`, you should return the result of `[super hitTest:point withEvent:event]` to allow touches on the circle and its subviews. – meaning-matters Aug 22 '16 at 07:33

score 1 · Answer 3 · answered Jun 02 '14 at 14:03

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Your button is probably being covered. You could either add the button after, or use this method to bring it to the front, [parentView bringSubviewToFront:childView];

answered Jun 02 '14 at 14:03

mginn

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I would like to know if is there a way to press the button by keeping it below the view. – iOS Dev Jun 02 '14 at 14:20

score 1 · Answer 4 · answered Jun 02 '14 at 14:14

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Setting the userInteractionEnabled property of your circle view to NO will pass the touch through to the button.

self.myView.userInteractionEnabled = NO;

answered Jun 02 '14 at 14:14

hgwhittle

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It's true, but I need it to be enabled. – iOS Dev Jun 02 '14 at 14:15
Can you add the button as a subview of `myView`? – hgwhittle Jun 02 '14 at 14:16
No, the hierarchy should remain unchanged. – iOS Dev Jun 02 '14 at 14:18

score 1 · Answer 5 · answered Aug 22 '16 at 07:34

@robert's answer, with small correction, in swift:

override func hitTest(point: CGPoint, withEvent event: UIEvent?) -> UIView?
{
    let radius   = self.frame.size.width / 2
    let distance = sqrt(pow(point.x - self.frame.size.width  / 2, 2) +
                        pow(point.y - self.frame.size.height / 2, 2))

    return distance < radius ? super.hitTest(point, withEvent: event) : nil
}

score 0 · Answer 6 · answered Jun 02 '14 at 13:59

0

There are different ways; depends on what you mean by "touchable"

You can just add a target action to the button to allow operations to take place when pressing the button. You'd do this by saying

[button addTarget:self action:@selector(methodForTouchingButton) forControlEvents:UIControlEventTouchUpInside];

then you have to declare this method

- (void) methodForTouchingButton
{ NSLog(@"Button Touched!"); }

Another way you could do is try adding it to the top level view. Doing so would be

[self.myView addSubview:button];

and that should do it.

Hope this helps!!

answered Jun 02 '14 at 13:59

user2277872

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I've added a target. By touchable I meant that it is not even highlighting. – iOS Dev Jun 02 '14 at 14:01
well just add onto the top level with [self.myView addSubview:button]; and that'll work – user2277872 Jun 02 '14 at 14:04

score 0 · Answer 7 · answered Jun 02 '14 at 14:01

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Put the button on top of the view, not underneath. The view is covering the button, even though you have a corner radius. Views use their frame rectangle to determine which view gets a tap.

answered Jun 02 '14 at 14:01

Duncan C

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I know that placing the button to front will solve the problem, but I would like to know if is there a way to press it by keeping below the view. – iOS Dev Jun 02 '14 at 14:05
If your view has user interaction enabled then it will get the touches rather than the button when the view covers the button. You might be able to code a custom view that has code to figure out that the tap is outside the circle and pass the touch event to the button. In that case you would probably want the button to be a subview of your circle view, and your circle view to be a custom class of your creation. – Duncan C Jun 02 '14 at 15:01

Not able to press an UIButton below UIView with corner radius

7 Answers7