CODEWITHSUNDEEP
ioscocoa-touchuiscrollviewuibuttonios-simulator
DanielaM
DanielaM

Reputation: 591

ScrollView not scrolling when dragging on buttons

I have a scroll view that used to scroll when it didn't have buttons all over it. Now it does, and when dragging the mouse (on simulator) nothing happens (i think because the buttons are being pushed). How can I make this right?

Upvotes: 46

Views: 12970

Answers (5)

pugia
pugia

Reputation: 442

I founded this question looking for the swift solution for this problem, I "translated" it like this:

Swift 5

class UIButtonScrollView: UIScrollView {

    override func touchesShouldCancel(in view: UIView) -> Bool {
        if view.isKind(of: UIButton.self) {
          return true
        }

        return super.touchesShouldCancel(in: view)
    }    
}

hope this could help

Upvotes: 18

User18474728
User18474728

Reputation: 361

In my case, I solved it with this way.

in ViewDidLoad 

self.scrollView.panGestureRecognizer.delaysTouchesBegan = self.scrollView.delaysContentTouches;

in .m

- (BOOL)touchesShouldCancelInContentView:(UIView *)view {
    if ([view isKindOfClass:[UIControl class]]) return YES;
    return NO;
}

Upvotes: 0

William T. Mallard
William T. Mallard

Reputation: 1660

One thing to try if you're seeing this in a simulator is to run on an actual phone. I couldn't scroll in the simulator but no prob on my phone.

Upvotes: 1

Gregg
Gregg

Reputation: 1476

Swift 3 Solution

override func touchesShouldCancel(in view: UIView) -> Bool {
    if view is UIButton {
        return true
    }
    return super.touchesShouldCancel(in: view)
}

Upvotes: 7

Roman Kishchenko
Roman Kishchenko

Reputation: 1904

This is happening because UIButton subviews of the UIScrollView (I assume buttons are added as subviews in your case) are tracking the touches and not the scroll view. UIScrollView method touchesShouldCancelInContentView is the key here. According to its description: "The default returned value is YES if view is not a UIControl object; otherwise, it returns NO.", i.e. for UIControl objects (buttons), UIScrollView does not attempt to cancel touches which prevents scrolling.

So, to allow scrolling with buttons:

  1. Make sure UIScrollView property canCancelContentTouches is set to YES.
  2. Subclass UIScrollView and override touchesShouldCancelInContentView to return YES when content view object is a UIButton, like this:
- (BOOL)touchesShouldCancelInContentView:(UIView *)view
{
    if ( [view isKindOfClass:[UIButton class]] ) {
        return YES;
    }

    return [super touchesShouldCancelInContentView:view];
}

Upvotes: 105

Related Questions