Release Notes

This page provides information about the milestone releases of the Android O Developer Preview, including known issues, limitations, and general advisories. Please review the notes before installing a device system image or filing bugs, to avoid duplication of effort.

See the Feedback page for details on how and where to report platform issues, app issues, and third-party SDK issues.

To discuss issues or ideas with other developers working with Android O, join the Developer Preview Google+ community.

Developer Preview 3

General advisories

This public beta release is for early adopters and is available for daily use, development, or compatibility testing. Please be aware of these general notes about the release:

• This public beta release may have various stability, battery, or performance issues on supported devices.
• Some apps may not function as expected on this public beta release. This includes Google's apps as well as other apps.
• This public beta release is Compatibility Test Suite (CTS) approved on supported devices. Apps that depend on CTS approved builds should work normally on these devices (Android Pay, for example).
• This public beta release is available on these supported devices: Nexus 5X, Nexus 6P, Nexus Player, Pixel C, Pixel, and Pixel XL.
• Android emulator system images are available for handsets, Android TV, and Android Wear.

Known Issues

Performance and battery

• System and app performance is known to be periodically slow/janky, and devices may become occasionally unresponsive. These problems may become more acute with prolonged use.
• Battery life may be regressed in this early release for screen-on and screen-off use cases.

Camera

• Camera may be slow to launch.

Bluetooth

• Occasional audio stuttering issues.

Wi-Fi

• Wi-Fi driver issue can prevent finding available Wi-Fi networks.

Media

• Music audio routed to device speaker instead of USB headset.
• Call audio routed to earpiece instead of Bluetooth when user connects/disconnects wired headset during call.

Backup & restore

• "No backups found" message displayed when new account created through cloud restore flow.

Multiwindow

• Docked apps may become invisible in landscape mode on unlocking device.
• Hotseat icons may fluctuate on sliding up docked app.
• PIP window is going to Full screen while launching system settings.

Launcher

• On Pixel devices, the launcher may render some homescreen UI elements, such as Quick Search Box, offscreen while in very short screen configurations (such as when the device is in split-screen multi-window mode in landscape orientation).

GCM/FCM

• Developers using FCM/GCM with Android O should update their Google Play services SDK to version ≥ 10.2.1, which is available from the SDK manager in Android Studio.

Android Wear

• Only the x86 emulator is currently supported.
• The WearableNavigationDrawerView class in the Wear UI library cannot be used if your app depends on the Wearable Support Library. If you attempt to use that class along with the Wearable Support Library, class cast exceptions are likely. For additional information about the WearableNavigationDrawerView class, see Action and Navigation Drawers in the Wear UI Library.

IME

• Device may not respond to input on paired bluetooth keyboard.

Enterprise

• Turning off work mode from the Quick Settings panel reboots devices with running work apps.
• Sensitive notifications might redact contents, even after unlock, on devices with a work profile. This affects notifications in the primary user and the work profile.
• Unlocking the work challenge, when opening an app in the profile, might display a blank green panel. Can be worked around by tapping the Home button and returning to the app via the Recents screen.

Preinstalled apps

• Dialer app may crash when ending emergency call made from the lock screen.
• Dialer app may crash when phone permission is revoked.
• Messages app may crash when sending MMS after permissions are revoked and re-granted.
• Gmail app may crash when running low on storage space.

API changes

This section lists notable changes in features, behavior, and APIs from O DP2 to DP3. For a complete list of all API changes, see the API diff reports:

• API level 25 to O DP3
• O DP2 to DP3

Picture-in-picture mode

The PictureInPictureArgs class has been renamed to PictureInPictureParams, and related classes and methods have been updated accordingly.

Developer Preview 2

General advisories

This public beta release is for early adopters and is available for daily use, development, or compatibility testing. Please be aware of these general notes about the release:

• This public beta release may have various stability, battery, or performance issues on supported devices.
• Some apps may not function as expected on this public beta release. This includes Google's apps as well as other apps.
• This public beta release is Compatibility Test Suite (CTS) approved on supported devices. Apps that depend on CTS approved builds should work normally on these devices (Android Pay, for example).
• This public beta release is available on these supported devices: Nexus 5X, Nexus 6P, Nexus Player, Pixel C, Pixel, and Pixel XL.
• Android emulator system images are available for handsets, Android TV, and Android Wear.

Known Issues

Performance and battery

• System and app performance is known to be periodically slow/janky, and devices may become occasionally unresponsive. These problems may become more acute with prolonged use.
• Battery life may be regressed in this early release for screen-on and screen-off use cases.

System UI

• Device wallpaper changes with largest font and large display size.

Camera

• Camera may be slow to launch.

Bluetooth

• Occasional audio stuttering issues.

Wi-Fi

• Wi-Fi driver issue can prevent finding available Wi-Fi networks.
• Notification sounds may be audible when playing YouTube videos through Cast.

External storage

• On Nexus Player, users may be unable to explore or browse portable storage contents.

Setup wizard

• NFC service crash observed in Set-Up Wizard.

Backup & restore

• Wi-Fi data not restored after performing restore from another device/cloud restore.

Multiuser

• Device may get stuck in Finishing touches when adding new user.

Settings

• Unable to access Vision settings in welcome screen after navigating back from language selection list.

GCM/FCM

• Developers using FCM/GCM with Android O should update their Google Play services SDK to version ≥ 10.2.1, which is available from the SDK manager in Android Studio.

Android Wear

• Only the x86 emulator is currently supported.

Android TV

• Keyboard characters are not displayed in the text field across all screens during initial set up process if talkback is on.
• PIP window is not dismissed on playing movies from Google Play Movies and TV app.
• Talkback stops working on selecting OK button when any non-selectable Settings sub-options are spoken out.

Enterprise

• Downloading DPC (Device Policy Controller) with a Google Account doesn’t complete. The workaround for a profile owner is, download and install the DPC manually from Google Play and add the account manually in the work profile. For a Device Owner, use QR or NFC provisioning instead.
• Tapping the managed device text in Quick Settings shows a blank Device monitoring dialog.
• TestDPC app crashes when attempting to set a new reset-password token.
• Device rebooted upon turning off work mode from QS panel.

Preinstalled apps

• Dialer app may crash after boot up after build loading.
• SMS reply for Phone does not launch Messages app.
• YouTube app freezes after returning from PiP mode
• After video ends, Chrome app crash observed after dismissing PIP window;

IME

• Google Indic Keyboard crashes on tapping ? button next to Hide keyboard button;

API changes

This section lists notable changes in features, behavior, and APIs from O DP1 to DP2. For a complete list of all API changes, see the API diff reports:

• API level 25 to O DP2
• O DP1 to DP2

Framework

All versions of the findViewById() method now return <T extends View> T instead of View. For more information, see Android O Features and APIs.

Background execution limits

The following changes have been made to background execution limits for DP2:

• Even for apps not targeting O, users can use the Settings screen to enable background execution limits.
• The method NotificationManager.startServiceInForeground() (introduced in DP1) is now deprecated. To start a foreground service, use Context.startForegroundService().
• A number of broadcasts have been exempted from, or added to, the restrictions on implicit broadcasts. Implicit Broadcast Exceptions has been updated to reflect these changes.

For more information, see Background Execution Limits.

Wi-Fi Aware

In DP1, the method for creating a method specifier is createNetworkSpecifier(). Beginning with DP2, the methods for creating a method specifier are now either createNetworkSpecifierOpen() for unencrypted connections or createNetworkSpecifierPassphrase() for encrypted connections. For more information, see WifiAwareSession and DiscoverySession. For more information, see Wi-Fi Aware.

WebView

Several classes and methods have different functionality in DP2 to account for the new Android Autofill Framework support. For more details, see Web form autofill.

App Analysis at Runtime

In Android O DP2, several classes were added to the java.lang.reflect package, which makes it easier to discover information at runtime about the parameters, methods, and constructors within your app's logic.

For more information about Java 8 language features available in Android O, see Use Java 8 language features.

ICU4J Support

Android O updates the following ICU4J Android Framework APIs:

• android.icu.lang
• android.icu.text
• android.icu.util

For the most recent information about these classes, consult their API reference documentation.

Autofill Framework

In Android O DP2, the Autofill Framework provides a View.setAutofillHints() method and android:autofillHints attribute, which you can use to provide the system with hints about the input type that is expected in each field.

For more information about this and other changes to the Autofill Framework, consult the Autofill Framework page.

Downloadable Fonts

Android O DP2 adds several classes and methods to enable your app to download fonts from a font provider. This feature is available in Android O as well as in Support Library 26 to support devices running Android API version 14 and higher.

For the most recent information about this feature, see Downloadable Fonts.

Fonts in XML

The Fonts in XML feature is now available through Support Library 26 to support devices running Android API version 14 and higher.

For the most recent information about this feature, review Fonts in XML.

Autosizing TextViews

The Autosizing TextView feature is now available through Support Library 26 to support devices running Android API version 14 and higher.

For more information about this feature, see Autosizing TextView.

Input and Navigation

The following changes have been made to Android input and navigation capabilities for DP2:

• The View class has added an attribute and a method to allow for more fine-grained control over UI element highlighting.

For more information, see Input and navigation.

Telephony Permissions

Several new permissions related to telephony have been added in DP2.

For more information, see Permissions.

Developer Preview 1

General advisories

This Developer Preview release is for app developers only for compatibility testing and development. This release is not intended for daily use or . Please be aware of these general notes about the release:

• This release has various stability and performance issues on all devices that make it not suitable for daily use on phone or tablet, especially for non-developers.
• System and app performance is known to be periodically slow / janky, and device may become occasionally unresponsive. These problems may become more acute with prolonged use.
• Battery life may be regressed in this early release for screen-on and screen-off use cases.
• Some apps may not function normally on Developer Preview 1. This includes Google’s apps as well as other apps.
• This early build is not Compatibility Test Suite (CTS) approved. Apps that depend on CTS approved builds (Android Pay for example) won’t work.
• This preview release supports the following devices: Nexus 5X, Nexus 6P, Nexus Player, Pixel C, Pixel, and Pixel XL.
• Android emulator system images are available for handsets, Android TV, and Android Wear.
• This initial release of O Developer Preview is available by manual download only. OTA update through the Android Beta Program is not supported for this release. Android Beta remains focused on Nougat at this time, but Android O will be available through Android Beta later this year.

Known Issues

Performance and battery

• System and app performance is known to be periodically slow / janky, and device may become occasionally unresponsive. These problems may become more acute with prolonged use.
• Battery life may be regressed in this early release for screen-on and screen-off use cases.

System UI

• System UI crash after toggling screen brightness, then going to Overview (recents) and selecting a new app.
• Occasional issues navigating Home, with incomplete transition making the device unusable.
• Taps in Quick Settings may be registered in another location.
• When using Autofill, an “Android system app displaying on top" message is sometimes shown, but it can be ignored (if it's turned off, it will disable Autofill).

GCM/FCM

• FCM doesn't work in a secondary profile unless the app is also installed on the primary profile. If the app is not installed on the primary profile, an FCM token is not generated in the secondary profile.
• Developers using FCM/GCM with Android O should updated their Google Play services SDK to version 10.2.1, which is available from the SDK manager in Android Studio.

Android TV

• Setting up a restricted profile then restarting the device causes the device to be unusable.
• Typing in the search bar causes a crash.
• PIP image does not fill the window.
• Launching applications via voice command does not work.
• Application size is not displayed in Application Settings.
• Microphone button on remote control does not work.
• Factory reset does not work on Fugu.
• Connected remote control device disconnects intermittently.
• USB connected drive cannot be formatted. The Setup as device storage formatting option does not work properly for drive attached via USB.
• Device may freeze with blank homescreen when plug is inserted.
• Location status in Settings may become disabled with user unable to re-enable.
• Not able to reorder games in the apps and games row.
• Content may not play after relaunching media apps.

Wi-Fi

• 611 call can’t be made on a Wi-Fi profile.

Voice search and hotword

• Occasional repeated action suggestions after hotword detection.

Android for Work

• Enabling a Work Profile may cause a crash in Settings app. To work around this issue, remove and re-add the Work Profile.

Android Device Manager

• Selecting the Settings > Security and Screen Lock > Android Device Manager menu item may cause a crash. Updating to the latest version of Google Play services will resolve this issue.

Android Wear

• Embedded app installation from Play Store can sometimes crash. Side-loading can be used to work around this issue.
• Only the x86 emulator is currently supported.
• Default watch face complications may not load until you switch watch faces or otherwise touch watch face settings, or reboot the device.

Other

• Using the Google Drive app’s PDF viewer to load a PDF document may cause the device to freeze.
• Apps or games may hit ANRs in GLThread, such as with AssetManager::open, that cause crash or failure to load properly.
• Games using Google Play games services may have problems with sign-in.
• The latest release of Android Auto may not work properly on Developer Preview 1.
• The NDK cannot build targeting Android O DP1 (an upcoming r15 release will fix).