iosswiftuiios18

Adding a high priority drag gesture to a scrollable view in iOS 18 causes the scrollable view to become unscrollable

I'm trying to add a drag gesture over a vertically scrollable view like List (mainly to detect horizontal drag only). I want the drag gesture to work in higher priority than the scrollable view scrolling behavior. On iOS 17 or prior, the below code works, however on iOS 18 beta, I'm facing that the scrollable view becomes unscrollable.

I found a similar topic in the developer forum as well. https://forums.developer.apple.com/forums/thread/760551

This is the minimum reproducible example:

struct ContentView: View {
    var body: some View {
        List {
            ForEach(0..<100) {
                Text("\($0)")
            }
        }
        .highPriorityGesture(
            DragGesture()
                .onChanged({ value in
                    print("onChanged \(value)")
                })
                .onEnded({ value in
                    print("onEnded \(value)")
                })
        )
    }
}

Any workaround?

Solution

  • The issue looks solved if I set 15 to the minimumDistance of the DragGesture. (FYI: The default value is 10. It doesn't work with 14 so 15 seems to be the threshold)

    .highPriorityGesture(
    DragGesture(minimumDistance: 15)
    ...
)

    Note: I tried with iOS 18 beta 6

    Update: I noticed the issue does not reproduce in a real iPhone device (iOS 18 beta) in the first place :(