Trouble with gesture recognizers in subviews

Question

I'm having a rather basic problem, I've looked around (here, google, etc) and haven't found a solution for this:

In my View Controller's viewDidLoad, I have this:

UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(myfunc:)];

//I have a UIScrollView named "containerView"
//here's some code that creates an UIView in a variable named "myView"

//this works fine, I can see "myView" when I run it
[containerView addSubview:myView];

[myView addGestureRecognizer:longPress];

and then I have this function in the same class:

- (void)myfunc:(UIRotationGestureRecognizer *)recognizer 
{
    NSLog(@"hola!"); //never runs
}

The call to NSLog never runs. What am I doing wrong?

EDIT

Some extra info: it seems no touch events are ever sent to the subview. However, I tried adding an UIView with a button inside, all in the UIScrollView, and the button receives the touch event just fine, so the problem is only with programmatically added subviews.

I think so :) just trolling around ^^ Your code looks perfectly, anyway. — , Apr 23 '12 at 19:41
Maybe you could 1. add the recognizer before you add YourView as a subview; 2. inserting it specifically on the top of any other views so no other view can intercept its touch events. — , Apr 23 '12 at 19:42
I tried #1, no luck. But, I tried adding a Round Rect Button inside the view and it doesn't seem to be responding to touch... any idea why this would happen? — cambraca, Apr 23 '12 at 19:54
well, they are already on top, it's just that UIScrollView and a bunch of calls to `addSubview` in different positions so they don't even overlap. So, they _are_ on the very top, right? Any change the scroll view thing is messing with me? — cambraca, Apr 23 '12 at 19:59
There _must_ be a way of receiving touch events in subviews of a UIScrollView :| :| :| — cambraca, Apr 23 '12 at 20:11

score 2 · Accepted Answer · answered Apr 26 '12 at 21:01

2

Strangely enough, adding a "container" UIView inside the UIScrollView, and then the other subviews inside this container, made it work. Now touch events are sent to the subviews.

answered Apr 26 '12 at 21:01

cambraca

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score 0 · Answer 2 · edited May 23 '17 at 11:59

0

How can a superview interecept a touch sequence before any of its subviews?

TLDR:

[containerView setCanCancelContentTouches:NO];

do it just as you add the gesture recogniser to the scroll view.

also look into

[containerView setDelaysContentTouches:NO];

If the above behaviour isn't quite right.

for more info: http://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIScrollView_Class/Reference/UIScrollView.html

edited May 23 '17 at 11:59

Community

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answered Apr 23 '12 at 20:46

jackslash

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I played with those properties, they didn't help. Look at my edit on the question, I added a subview manually on the interface editor, and it receives touch events, but not my programmatically added subviews... – cambraca Apr 23 '12 at 20:55

score 0 · Answer 3 · edited Jan 02 '16 at 06:16

0

I think on myFunc you must do somethings like that:

switch (reconiger.state)
{
    case UIGestureRecognizerBegin:
      //Do something when start recognizer
      break;
    case UIGestureRecognizerEnd:
      //Do something when end recognizer
      break;
}

edited Jan 02 '16 at 06:16

Pang

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answered Mar 12 '13 at 08:32

Scofield Tran

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Trouble with gesture recognizers in subviews

3 Answers3

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