SwiftUI Floating Debug Menu

FloatDebugMenu.swift

import SwiftUI

/// Float Debug Menu
///
/// Usage: (It's simple! Just one line!)
///
/// ```swift
/// FloatDebugMenu.registerTrigger("send1", action: { /* your custom logic */})
/// FloatDebugMenu.registerTrigger("send2", action: { /* here */ })
/// ```
///
/// Note:
/// - The FloatDebugView will appear on the keyWindow after first call to ``registerTrigger``
/// - The order of items are sorted by title
/// - The older trigger with same title will be removed
public enum FloatDebugMenu {
    public static func registerTrigger(_ title: String, action: @escaping () -> Void) {
        let item = FloatDebugManager.TriggerItem(title: title, action: action)
        FloatDebugManager.shared.items[title] = item
    }
}
class FloatDebugManager: ObservableObject {
    static let shared = FloatDebugManager()
    @Published var items: [String: TriggerItem] = [:] {
        didSet {
            FloatDebugHostingController.shared.updateItems()
        }
    }
    struct TriggerItem: Identifiable, Hashable, Comparable {
        let title: String
        let action: () -> Void
        let id: UUID = UUID()

        func hash(into hasher: inout Hasher) {
            hasher.combine(id)
        }
        static func == (lhs: Self, rhs: Self) -> Bool {
            lhs.id == rhs.id
        }
        static func < (lhs: FloatDebugManager.TriggerItem, rhs: FloatDebugManager.TriggerItem) -> Bool {
            lhs.title < rhs.title
        }
    }

}
class FloatDebugHostingController: UIHostingController<FloatDebugView> {
    static let shared = FloatDebugHostingController()

    func updateItems() {
        if !FloatDebugManager.shared.items.isEmpty {
            show()
        }
        view.frame.size = view.intrinsicContentSize
    }

    private init() {
        super.init(rootView: FloatDebugView())
        view.backgroundColor = nil
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        view.frame.size = view.intrinsicContentSize
    }

    func show() {
        guard let window = UIApplication.shared.keyWindow else { return }
        guard self.view.superview == nil else { return }
        window.addSubview(self.view)
        view.frame.origin.y = 200
        Timer.scheduledTimer(withTimeInterval: 3, repeats: true) { [weak self, weak window] _ in
            guard let self, let window else { return }
            window.bringSubviewToFront(self.view)
        }
    }
}

struct FloatDebugView: View {
    @ObservedObject private var manager = FloatDebugManager.shared
    @State private var offset: CGSize = .zero
    var body: some View {
        VStack(spacing: 0) {
            Image(systemName: "ant.fill")
                .foregroundColor(.secondary)
                .frame(height: 32)
            // Temporarily not using List because of `scrollContentBackground` is only available iOS 16+
            ForEach(manager.items.values.sorted(by: <), id: \.self) { item in
                Divider()
                Button {
                    item.action()
                } label: {
                    Text(item.title)
                        .minimumScaleFactor(0.8)
                        .lineLimit(1)
                }
                .frame(minWidth: 50, maxWidth: 120)
                .frame(height: 30)
            }
        }
        .padding(4)
        .modifier(FloatBG())
        .cornerRadius(8)
        .overlay(
            RoundedRectangle(cornerRadius: 8)
                .stroke(Color.secondary.opacity(0.6), lineWidth: 1 / UIScreen.main.scale)
        )
        .offset(offset)
        .gesture(
            DragGesture()
                .onChanged { gesture in
                    self.offset = gesture.translation
                }
                .onEnded { gesture in
                    self.offset = .zero
                    let origin = FloatDebugHostingController.shared.view.frame.origin
                    let target = CGPoint(x: origin.x + gesture.translation.width,
                                         y: origin.y + gesture.translation.height)
                    FloatDebugHostingController.shared.view.frame.origin = target
                }
        )
    }
}

struct FloatBG: ViewModifier {
    func body(content: Content) -> some View {
        if #available(iOS 15, *) {
            content
                .background(.ultraThinMaterial)
        } else {
            content
                .background(Color.gray.opacity(0.6))
        }
    }
}