将 SwiftUI 中的多点触控支持添加到 DragGesture

Question

我目前正在开发一个

SwiftUI

项目，我需要在包含多个按钮的视图上实现真正的多点触控支持。现有的实现支持拖动这些按钮来更新

activeButtonIndex

状态，突出显示当前拖动的按钮。但目前仅支持单点触控交互。我想增强它以支持多点触控，如果使用多个手指，可以同时激活多个按钮。

我想保留所有当前功能。具体来说，我正在寻找一种仅限

SwiftUI

的解决方案，而不求助于

UIKit

互操作。

我尝试参考Apple的开发者文档文章编写SwiftUI手势无济于事。

这是我当前代码的简化版本：

import SwiftUI

struct ContentView: View {
    @State private var activeButtonIndex: Int? = nil
    @State private var buttonFrames: [CGRect] = Array(repeating: .zero, count: 11)
    private let buttonCount = 11
    
    var body: some View {
        VStack {
            activeButtonView
            buttonsView
        }
        .gesture(dragGesture)
    }
    
    private var activeButtonView: some View {
        Text("Active Button \(activeButtonIndex.map { "\n\($0 + 1)" } ?? "\nNone")")
            .multilineTextAlignment(.center)
            .padding()
    }
    
    private var buttonsView: some View {
        ScrollView(.horizontal) {
            LazyHStack {
                ForEach(0 ..< buttonCount, id: \.self) { index in
                    Button(action: {}) {
                        EmptyView()
                    }
                    .frame(width: 70, height: 210)
                    .background(backgroundForButton(at: index))
                    .overlay(GeometryReader { geometry in
                        Color.clear.onAppear {
                            buttonFrames[index] = geometry.frame(in: .global)
                        }
                    })
                }
            }
        }
    }
    
    private func backgroundForButton(at index: Int) -> Color {
        activeButtonIndex == index ? .green : .blue
    }
    
    private var dragGesture: some Gesture {
        DragGesture(minimumDistance: 0, coordinateSpace: .global)
            .onChanged { value in
                updateActiveButton(with: value.location)
            }
            .onEnded { _ in
                activeButtonIndex = nil
            }
    }
    
    private func updateActiveButton(with location: CGPoint) {
        for (index, frame) in buttonFrames.enumerated() {
            if frame.contains(location) {
                activeButtonIndex = index
                return
            }
        }
        activeButtonIndex = nil
    }
}

有没有人实现了类似的东西，或者可以指导我如何在这种情况下添加多点触控支持？任何建议或例子将不胜感激。

Answer 1

你尝试过

simultaneousGesture

吗？
我认为这将有助于多点触控支持。

VStack(spacing: 100) {
            Text("First button")
                .gesture(
                    DragGesture()
                        .onEnded { _ in
                            print("First button tapped")
                        }
                )
            
            Text("Second button")
                .simultaneousGesture(
                    DragGesture()
                        .onEnded { _ in
                            print("Second button tapped")
                        }
                )
        }