What’s new in watchOS 8

Always-on display dimmed state

• Supported on series 5 and 6

• in watchOS 7, the always-on state showed your app’s UI blurred with the system time overlaid

• when you rebuild your app with the watchOS 8 SDK, your app’s UI will now be shown in a dimmed state instead, and is immediately interactive if someone taps the UI

• You can get notified of of this dimmed state via a new SwiftUI environment property isLuminanceReduced.

• You can respond to this state by highlighting information that’s especially important, and hiding information that should stay private

• In the watch simulator, you click the lock button in the simulator window to simulate a wrist-down event (triggering the dimmed state)

Guidance:

• the transition from active state to the always-on state should feel seamless

• don’t drastically alter the UI or reorganize information

• dim non-essential information and elements, to give more prominence to the piece of information you want to stay highlighted and visible

• if your UI has large elements that are filled with color or imagery, you may want to reduce those elements to be represented with a stroke or dimmed color

• redact or remove sensitive information

• reset animations

• use SwiftUI’s TimelineView to tell watchOS 8 that your inactive app needs to update its UI

UI Updates:

• Apps with an ongoing, active session (e.g. workout or audio session) can update your UI up to once per second

• other apps up to once per minute

• assume your app is visible longer than two minutes

HealthKit data

• background delivery of HealthKit data to Watch apps

• new results come up to once per hours

• if you have an active complication, up to four times per hour

• all received results count against background app refresh budget

Update frequency:

• immediate for critical data types (fall events, low blood oxygen saturation, heart rate events)

• hourly or longer for other events

Bluetooth

• from watchOS 4, Bluetooth devices can connect directly to Apple Watch and make use of Core Bluetooth.

• from watchOS 8, Bluetooth devices can connect during background app refresh opportunities that your app’s complications get when they’re on the active watch face

  • this means that your app’s complications can stay up to date with your Bluetooth device and display updated information throughout the day.

  • Background app refresh gives your app’s complications that are on the active watch face up to four opportunities per hour to connect and update.

  • these opportunities will count against your app’s overall background app refresh budget

Guidance:

• connect and process your data within a very short period of time

• new expiration handler on WKRefreshBackgroundTask, letting you know when you’re about to run out of time

Location

• new in watchOS 8, region-based user notifications

  • works similarly to iOS:

    • deliver pre-created local notifications

    • “when in use” location permission required

    • limit the number of regions to only include important POIs near someone or locations they’ve shown explicit intent for

• new Location button, for one-time location authorization without going through authorization prompts each time it’s tapped

• always-on altimeter API, no need location access

More enhancements

• respiratory rate API

• assistive touch

• large accessibility text size

• (Xcode 12.5+) Unit testing and UI testing

• Large titles

• text input improvements:

  • Scribble or Dictation preference is preserved per app

  • quick access to changing between input types while entering text

• SwiftUI’s .searchable API

• Swipe actions on List

• Buttons improvements:

  • new roles parameter to let the system know how to present and handle specific button types (e.g. destructive buttons)

  • new controlProminence view modifier, which will give those buttons an additional haptic when tapped.

• SwiftUI Canvas for rich programmatic drawing