Adapting macOS and iPadOS Apps for Apples TouchScreen MacBook and OLED iPad mini

struct TouchFriendlyButtonStyle: ButtonStyle {
    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .padding(12)                // ensures ≥44 pt total
            .background(Color.accentColor.opacity(configuration.isPressed ? 0.2 : 0.1))
            .cornerRadius(8)
    }
}

enum AppAction {
    case navigateBack
    case zoomIn
    case zoomOut
    // …
}

class FloatingPaletteController: NSObject {
    private var popover = NSPopover()
    private var trackingArea: NSTrackingArea?
    private weak var hostView: NSView?

    func attach(to view: NSView) {
        hostView = view
        trackingArea = NSTrackingArea(rect: view.bounds,
                                      options: [.mouseEnteredAndExited, .activeInKeyWindow],
                                      owner: self,
                                      userInfo: nil)
        view.addTrackingArea(trackingArea!)
    }

    override func mouseEntered(with event: NSEvent) {
        guard let view = hostView,
              let touch = event.touches(matching: .direct, in: view).first else { return }
        popover.show(relativeTo: touch.location(in: view), of: view, preferredEdge: .maxY)
    }
}

Button("Save") {
    viewModel.save()
}
.keyboardShortcut("s", modifiers: [.command])

import SwiftUI

@main
struct MyCrossPlatformApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
                .environment(\.colorScheme, .light) // optional override for testing
#if os(macOS)
                .windowStyle(HiddenTitleBarWindowStyle())
#endif
        }
    }
}

protocol TouchHandlerProtocol {
    func handleTap(at point: CGPoint)
    func handleDrag(start: CGPoint, current: CGPoint, velocity: CGVector)
    func handleLongPress(at point: CGPoint)
}

// UIKit implementation (iPadOS)
class UIKitTouchHandler: NSObject, TouchHandlerProtocol {
    func handleTap(at point: CGPoint) { /* … */ }
    func handleDrag(start: CGPoint, current: CGPoint, velocity: CGVector) { /* … */ }
    func handleLongPress(at point: CGPoint) { /* … */ }
}

// AppKit implementation (macOS)
class AppKitTouchHandler: NSObject, TouchHandlerProtocol {
    func handleTap(at point: CGPoint) { /* … */ }
    func handleDrag(start: CGPoint, current: CGPoint, velocity: CGVector) { /* … */ }
    func handleLongPress(at point: CGPoint) { /* … */ }
}

// In SwiftUI
struct CanvasView: View {
    @EnvironmentObject var touchHandler: TouchHandlerProtocol

    var body: some View {
        GeometryReader { geo in
            Color.clear
                .contentShape(Rectangle())
                .gesture(
                    DragGesture(minimumDistance: 0)
                        .onChanged { value in
                            touchHandler.handleDrag(start: value.startLocation,
                                                    current: value.location,
                                                    velocity: value.velocity)
                        }
                )
                .simultaneousGesture(
                    TapGesture()
                        .onEnded { _ in
                            // Convert to view‑local coordinates if needed
                            let pt = CGPoint(x: 0, y: 0) // placeholder
                            touchHandler.handleTap(at: pt)
                        }
                )
        }
    }
}

#if targetEnvironment(macCatalyst)
extension NSView {
    override func touchesBegan(with event: NSEvent) {
        guard let touch = event.touches(matching: .direct, in: self).first else { return }
        let pressure = touch.force / touch.maximumPossibleForce
        // Use pressure to adjust brush size
    }
}
#else
class PencilCanvasView: UIView {
    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let touch = touches.first else { return }
        let pressure = touch.force / touch.maximumPossibleForce
        // Same brush logic as macOS
    }
}
#endif

import Network

let parameters = NWParameters(tls: .init())
parameters.requiredInterfaceType = .wifi   // Prefer Wi‑Fi 6E
let connection = NWConnection(host: "api.example.com",
                              port: 443,
                              using: parameters)

connection.stateUpdateHandler = { newState in
    switch newState {
    case .ready:
        print("Connection ready – N1 acceleration active")
    default:
        break
    }
}

connection.start(queue: .global(qos: .userInitiated))

import CoreML

guard let modelURL = Bundle.main.url(forResource: "ImageClassifier",
                                     withExtension: "mlmodelc") else {
    fatalError("Model not found")
}
let config = MLModelConfiguration()
config.computeUnits = .all   // CPU + GPU + Neural Engine
let model = try! MLModel(contentsOf: modelURL, configuration: config)

func classify(image: CGImage) {
    let input = ImageClassifierInput(image: image)
    let result = try! model.prediction(from: input)
    // result is produced at ~60 fps on A19 NE
}

class MockTouchHandler: TouchHandlerProtocol {
    var tappedPoints: [CGPoint] = []

    func handleTap(at point: CGPoint) { tappedPoints.append(point) }
    func handleDrag(start: CGPoint, current: CGPoint, velocity: CGVector) {}
    func handleLongPress(at point: CGPoint) {}
}

func testTapPropagation() {
    let mockHandler = MockTouchHandler()
    let view = CanvasView().environmentObject(mockHandler)

    // Simulate a tap at (100, 200) using XCTest
    let tap = XCTTapGesture(location: CGPoint(x: 100, y: 200))
    view.perform(tap)

    XCTAssertEqual(mockHandler.tappedPoints.last, CGPoint(x: 100, y: 200))
}

let device = XCDevice.shared
try device.setHardwareProfile("TouchScreenMacBook14")

let app = XCUIApplication()
app.launch()

// Simulate a three‑finger swipe left
let start = app.coordinate(withNormalizedOffset: CGVector(dx: 0.8, dy: 0.5))
let end = app.coordinate(withNormalizedOffset: CGVector(dx: 0.2, dy: 0.5))
start.press(forDuration: 0.1, thenDragTo: end, withVelocity: .fast, thenHoldForDuration: 0)

import PencilKit

// MARK: - Touch Handler
final class CanvasTouchHandler: ObservableObject, TouchHandlerProtocol {
    @Published var strokes: [PKStroke] = []
    private var currentPath = PKMutableStrokePath()
    private var currentStroke: PKStroke?

    func handleTap(at point: CGPoint) {
        // No‑op for drawing; could be used for UI toggles.
    }

    func handleDrag(start: CGPoint, current: CGPoint, velocity: CGVector) {
        currentPath.addLine(to: current)
        if currentStroke == nil {
            let ink = PKInk(.pen, color: .blue)
            currentStroke = PKStroke(ink: ink, path: currentPath)
        } else {
            currentStroke?.path = currentPath
        }
        objectWillChange.send()
    }

    func handleLongPress(at point: CGPoint) {
        if let stroke = currentStroke {
            strokes.append(stroke)
            currentPath = PKMutableStrokePath()
            currentStroke = nil
        }
    }
}

// MARK: - SwiftUI Canvas
struct DrawingCanvasView: View {
    @StateObject private var touchHandler = CanvasTouchHandler()

    var body: some View {
        ZStack {
            ForEach(touchHandler.strokes, id: \.self) { stroke in
                Path { path in
                    stroke.path.render(in: &path)
                }
                .stroke(stroke.ink.color, lineWidth: 4)
            }
            if let current = touchHandler.currentStroke {
                Path { path in
                    current.path.render(in: &path)
                }
                .stroke(current.ink.color, lineWidth: 4)
            }
        }
        .background(Color(white: 0.95))
        .ignoresSafeArea()
        .gesture(
            DragGesture(minimumDistance: 0)
                .onChanged { value in
                    touchHandler.handleDrag(start: value.startLocation,
                                            current: value.location,
                                            velocity: value.velocity)
                }
                .onEnded { _ in
                    touchHandler.handleLongPress(at: .zero)
                }
        )
    }
}

// MARK: - App Entry
@main
struct SketchApp: App {
    var body: some Scene {
        WindowGroup {
            DrawingCanvasView()
        }
    }
}