In SwiftUI, how can I perform a gesture but forward gestures to the view behind it?

Question

I am creating a tooltip system.

I want to dismiss the tooltip if the user touches anywhere outside the tooltip.

I would like it so that a touch outside the tooltip both dismisses the tooltip and activates any controls the user tapped on. (So you could have a tooltip open and still click a button outside the tooltip and have it activate on the first tap.)

To do this, I have an invisible view handling the tap gesture and dismissing the tooltip, but I do not know how to make SwiftUI not intercept and cancel the tap gestures. On the web, it's the equivalent of not calling event.stopPropagation() and event.preventDefault(), or calling super in touchesBegan: in UIKit.

Any ideas?

Answer 1

Here is a demo of possible approach. Tested with Xcode 11.4 / iOS 13.4

struct ContentView: View {
    var body: some View {
        VStack {
            Button("Button") { print("> button tapped")}
        }
        .frame(width: 200, height: 200)
        .contentShape(Rectangle())       // makes all area tappable
        .simultaneousGesture(TapGesture().onEnded({
             print(">>> tooltip area here")
        }))
        .border(Color.red)   // just for demo show area
    }
}

Answer 2

You need to use this modifier:

.allowsHitTesting(false)