SwiftUI On All Devices

SwiftUI is a common toolkit to learn once and use on all platforms (macOS, iOS / iPadOS, tvOS, watchOS)

Cross-platform common elements like the Toggle Cnotrol, Picker Control and the whole Layout System

One size doesn’t fit all devices

• But: “Learn once, apply anywhere” - base principle of SwiftUI

• Use appropriate design patterns for each screen size (e.g. List on iPhone UICollectionView on iPad)

• We still have to build 4 apps - for each platform

SwiftUI on Apple TV

• Carefully cosider what’s appropriate to show on a big screen in the living room

• Entire interface must support the tvOS feature focus which is supported by many SwiftUI elements, e.g. List

• Elements have commands like .focusable { isFocused in /* focus changed */ }, .onPlayPauseCommand { /* play/pause button pressed */ }, .onExitCommand { /* menu button pressed */ }

• iOS > tvOS adoption Demo at 15:20

SwiftUI on Mac

• Great device to provide more information (e.g. text)

• SwiftUI auto-adapts spacing and padding

• Access small- and mini-size controls using .controlSize() modifier

• Consider proper support of multiple windows if users of your app may want to:

  • Compare content across windows side-by-side

  • Focus on a single item in its own window

  • Spatially organize windows around Desktop and Spaces

• Support keyboard shortcuts

• Touch Bar

  • SwiftUI makes it easier than ever to support this element

  • Just call the .touchbar() modifier of a view with a TouchBar {} parameter and fill the closure with one or multiple Button controls

SwiftUI on Apple Watch

• The watch is all about showing the right information at the right time

• The most critical action of your app should be available within 2-3 taps

• .digitalCrownRotation API to control crown rotation and haptics

• Use ScrollView, List, HStack, VStack to group and layout your app

• Use .listStyle(.carousel) when you have a few cell count or cells with interactive controls