How do you detect a SwiftUI touchDown event with no movement or duration?

Question

I\'m trying to detect when a finger first makes contact with a view in SwiftUI. I could do this very easily with UIKit Events but can\'t figure this out in SwiftUI.

I

Answer 1

You can create a view modifier this way:

extension View {
    func onTouchDownGesture(callback: @escaping () -> Void) -> some View {
        modifier(OnTouchDownGestureModifier(callback: callback))
    }
}

private struct OnTouchDownGestureModifier: ViewModifier {
    @State private var tapped = false
    let callback: () -> Void

    func body(content: Content) -> some View {
        content
            .simultaneousGesture(DragGesture(minimumDistance: 0)
                .onChanged { _ in
                    if !self.tapped {
                        self.tapped = true
                        self.callback()
                    }
                }
                .onEnded { _ in
                    self.tapped = false
                })
    }
}

Now you can use it like:

struct MyView: View {
    var body: some View {
        Text("Hello World")
            .onTouchDownGesture {
                print("View did tap!")
            }
    }
}