Disable 2 finger scrolling in UIScrollView

Question

I'd like to disable two-finger scrolling in my UIScrollView.
I subclassed it and tweaked its built-in gesture recognizers with the following code:

for (UIGestureRecognizer *mgestureRecognizer in scroller.gestureRecognizers) {     
    if ([mgestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]])
    {
        UIPanGestureRecognizer *mpanGR = (UIPanGestureRecognizer *) mgestureRecognizer;
        mpanGR.minimumNumberOfTouches = 1; 
        mpanGR.maximumNumberOfTouches = 1;

    }

    if ([mgestureRecognizer isKindOfClass:[UISwipeGestureRecognizer class]])
    {
        UISwipeGestureRecognizer *mswipeGR = (UISwipeGestureRecognizer *) mgestureRecognizer;
        mswipeGR.numberOfTouchesRequired = 1;
    }

For some reason, maximumNumberOfTouches does not seem to work. I can still scroll with one or two fingers. If I change both properties to 2, I can successfully disable one-finger scrolling and require two touches.

Any ideas?

score 21 · Answer 1 · answered Jan 21 '12 at 03:56

21

I realize this is an old thread, but it took me a long time to figure this out, so I thought I would share. Here's what I did to disable two-finger scrolling:

// set up a two-finger pan recognizer as a dummy to steal two-finger scrolls from the scroll view
// we initialize without a target or action because we don't want the two-finger pan to be handled
UIPanGestureRecognizer *twoFingerPan = [[UIPanGestureRecognizer alloc] init];
twoFingerPan.minimumNumberOfTouches = 2;
twoFingerPan.maximumNumberOfTouches = 2;
[scrollView addGestureRecognizer:twoFingerPan];

answered Jan 21 '12 at 03:56

Jake Stoeffler

2,662
24
27

shouldn't it be *1* for the minimum and the maximum ? (instead of 2 ?) – yonel Jun 19 '12 at 19:41
1

The code disables 2-finger panning by eating the 2-finger pan gestures. So min and max touches should be 2. – Jake Stoeffler Jun 20 '12 at 03:04
Worked for me and couldn't find any other way of doing it. Thanks very much! – Theo Nov 23 '12 at 20:25
Thank you for the tip. Made our app behave much better. – Dan Abramov Feb 08 '13 at 21:02

score 3 · Answer 2 · answered May 13 '13 at 06:43

if you are using iOS SDK over 5.0, maybe you can use ui pan gesture recognizer directly.

@property (strong, nonatomic) IBOutlet UIScrollView *scrollView;

......

[self.scrollView.panGestureRecognizer setMinimumNumberOfTouches:1];
[self.scrollView.panGestureRecognizer setMaximumNumberOfTouches:1];

score 0 · Answer 3 · answered May 10 '15 at 19:07

I can confirm this is still an issue in iOS 8, but only when the UIPanGestureRecognizer is underlying a UIScrollView. Creating a UIView with a fresh UIPanGestureRecognizer and setting its maximumNumberOfTouches property works as expected.

Submitted rdar://20890684 and copied to http://openradar.appspot.com/radar?id=6191825677189120. Please feel free to dupe.

score 0 · Answer 4 · edited May 23 '17 at 12:06

PROBLEM:

When the UIPanGestureRecognizer is underlying a UIScrollView (which unfortunately does also effect UIPageViewController) the maximumNumberOfTouches is not behaving as expected - the minimumNumberOfTouches however always limits the lower end correctly.

When monitoring these parameters they seem to do their job - it's just that UIScrollView doesn't honor them and ignores their values!

REMEDY:

You can find the solution in my answer to:

UIScrollView scrolling only with one finger

Disable 2 finger scrolling in UIScrollView

4 Answers4

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