优化自定控件的辅助功能体验

5:01 - Improve accessibility for coffee dispenser

// Improve accessibility for coffee dispenser

import SwiftUI

struct CoffeeDispenserView: View {
    @State var coffee: Double = 0.0
    var body: some View {
        CoffeeSlider(value: coffee)
            .accessibilityElement()
            .accessibilityLabel("Coffee Dispenser")
            .accessibilityValue("\(Int(coffee)) ounces")
            .accessibilityAddTraits(.adjustable)
            .accessibilityAdjustableAction { direction in
                switch direction {
                case .increment:
                    increaseCoffeeAmount()
                case .decrement:
                    decreaseCoffeeAmount()
                }
            }
    }
}

7:05 - Set the accessibility activation point

// Set the accessibility activation point
import SwiftUI

struct CoffeeDispenserView: View {
    @State var coffee: Double = 0.0

    var body: some View {
        CoffeeSlider(value: coffee)
            .accessibilityActivationPoint(
                UnitPoint(x: 0.5, y: 1 - coffee)
            )
    }
}

7:27 - Post accessibility announcements

// Post accessibility announcements 

import SwiftUI

struct CoffeeDispenserView: View {
    @State var coffee: Double = 0.0
  
    var body: some View {
        CoffeeSlider(value: coffee)
            // ...
            .onChange(of: coffee) { _, newValue in
                if sufficientTimeSinceLastAnnouncement() && valueHasChanged() {
                    cacheLastSpokenValue(newValue)
                    AccessibilityNotification
                        .Announcement(newValue)
                        .post()
                }
            }
    }
}

10:13 - Add custom actions

// Add custom actions

import SwiftUI
                                                          
struct EqualizerView: View {
    var body: some View {
        EqualizerPad()
            .accessibilityActions("Move Up") {
                increaseY(by: 10)
            }
            .accessibilityActions("Move Right") {
                increaseX(by: 10)
            }
            .accessibilityActions("Move Down") {
                decreaseY(by: 10)
            }
            .accessibilityActions("Move Left") {
                decreaseX(by: 10)
            }
     }
 }

12:47 - Customize accessibility for the interactive cat surface

// Customize accessibility for the interactive cat surface

import SwiftUI

struct VirtualCat: View {
    var cat: CatModel
    var body: some View {
        InteractiveCatSurface()
            .accessibilityLabel("Virtual Cat")
            .accessibilityValue(cat.currentReaction.description)
            .accessibilityDirectTouch([.requiresActivation])
     }
}