reports FB7367473: SwiftUI's `.onMove()` stops working if a view has a double-click tap action on macOS

Date: 2019-10-11
Resolution: Open
Area: SwiftUI Framework
OS: macOS 10.15
Type: Incorrect/Unexpected Behavior

Description

I have a list of rows that can be reordered with dragging, but I also want to add the ability to double-click a row to edit it. The problem is that when I add .onTapGesture(count: 2) {} to a row, the row can no longer be dragged and dropped.

I have attached an Xcode project that clearly illustrates the problem, I'm also including the code inline here as it's not much:

import SwiftUI

// 1. "Build & run" and then drag a row and notice the blue line indicating support for drag and drop.

struct ContentView: View {
    var body: some View {
		List {
			ForEach(0...5, id: \.self) { index in
				Text("Hello World \(index)")
					.frame(maxWidth: .infinity, maxHeight: .infinity)
					// 2. Uncomment this, "build & run", and notice how there's no longer a blue line indicator when you try to drag a row.
					// .onTapGesture(count: 2) {}
			}
			.onMove { (indexSet, index) in }
		}
    }
}