Today, Google has announced the release of Android P Developer Preview for Wear OS by Google. The initial preview update is currently available for the Huawei Watch 2 series only. In an official blog post, the company announced the availability of Android P Developer preview for the Wear OS by Google. The developer preview includes updated system images on the official Android Emulator and a downloadable system image for the Huawei Watch 2 Bluetooth or Huawei Watch 2 Classic Bluetooth.
In its blog post, Google highlights some changes made to Wear OS:
- Restriction related to non-SDK methods and fields: To improve app compatibility, Android P has started the process of restricting access to non-SDK methods and fields.
- Dark UI system theme: To enhance glanceability, Wear OS has switched to a UI theme with a darker / black background for the notifications stream and system launcher since the start of the year. This is now also the default for the system theme and should improve the glanceability for wear apps. Developers should check the accessibility of their app’s UI after this change.
- Limited background activity: To improve power, apps will no longer be allowed to run in the background unless the watch is on the charger. Developers should note that Wear OS is going further with Android’s app standby feature than some other form factors. Exceptions to this include watch faces and complications that the user currently has selected. This feature will be rolled out gradually in the developer preview, so you may not see it immediately on your device, but should build your apps accordingly by removing background services.
- Turning off radios when off body: To improve power, bluetooth, WiFi, and cellular radios will be turned off when the watch is detected to be off body for an extended period of time. Again, this feature will be rolled out gradually so you may not initially see it on your device. If this feature causes challenges in your development process, you can disable the feature via adb; please follow the instructions in the release notes.
- WiFi off when BT is disconnected: To improve power, the device will no longer automatically connect to wifi when disconnected from bluetooth. Exceptions include if an app is requesting a high bandwidth network or if the watch is on the charger. This feature will be rolled out gradually so you may not initially see it on your device.
You can run and test your app with the Wear OS by Google Preview in either of these ways:
- Install Wear OS on a supported watch, or
- Set up an emulator that is running the Wear OS Preview
If you want an environment for basic compatibility testing of your app, you can use your current APK and a supported watch or an emulator. As described below, you don’t necessarily need to update your full development environment to do basic testing.