Welcome to Android 12 Developer Preview! Please give us feedback early and often, and help us make Android 12 the best release yet!

Behavior changes: all apps

The Android 12 platform includes behavior changes that may affect your app. The following behavior changes apply to all apps when they run on Android 12, regardless of targetSdkVersion. You should test your app and then modify it as needed to support these properly, where applicable.

Make sure to also review the list of behavior changes that only affect apps targeting Android 12.

User experience

Foreground service notifications UX delay

To provide a streamlined experience for short-running foreground services on Android 12, the system can delay the display of foreground service notifications by 10 seconds for certain foreground services. This change gives short-lived tasks a chance to complete before their notifications appear.

If a foreground service has at least one of the following characteristics, the system shows the associated notification immediately after the service starts:

  • The service is associated with a notification that includes action buttons.
  • The service has a foregroundServiceType of mediaPlayback, mediaProjection, or phoneCall.
  • The service provides a use case related to phone calls, navigation, or media playback, as defined in the notification's category attribute.

  • The service has opted out of the behavior change by calling setShowForegroundImmediately() when setting up the notification.

Immersive mode improvements for gesture navigation

Android 12 simplifies immersive mode to make gesture navigation easier and more consistent with the rest of the experience of activities such as watching a video and reading a book. To learn more, see the corresponding entry on the features page.

Privacy

Netlink MAC restriction

Android 12 expands the scope of apps that are affected by the MAC address availability changes that were introduced in Android 11. On Android 12, the changes affect all apps regardless of target SDK version.

Related APIs return empty or placeholder values, depending on your app's target SDK version:

  • If your app targets Android 12, the API returns null.
  • If your app targets Android 11 or lower, the API returns the following placeholder value: 02:00:00:00:00:00.

In particular, if your app calls getHardwareAddress() while on a device that runs Android 12, the following message appears in Logcat:

CompatibilityChangeReporter: Compat change id reported: 170188668;

If your app targets Android 12, you can temporarily have the affected APIs return the placeholder value instead of null by disabling the RETURN_NULL_HARDWARE_ADDRESS compatibility flag.

As a reminder, when you perform network connectivity operations in your app, use ConnectivityManager instead of lower-level APIs like NetworkInterface, getifaddrs(), or Netlink sockets.

Security

Untrusted touch events are blocked

To preserve system security and a good user experience, Android 12 prevents apps from consuming touch events where an overlay obscures the app in an unsafe way. In other words, the system blocks touches that pass through certain windows, with a few exceptions.

Affected apps

This change affects apps that choose to let touches pass through their windows, for example by using the FLAG_NOT_TOUCHABLE flag. Several examples include, but aren't limited to, the following:

Exceptions

In the following cases, "pass-through" touches are allowed:

  • Interactions within your app. Your app shows the overlay, and the overlay appears only when the user is interacting with your app.
  • Trusted windows. These windows include (but aren't limited to) the following:

  • Invisible windows. The window's root view is GONE or INVISIBLE.

  • Completely transparent windows. The alpha property is 0.0 for the window.

  • Sufficiently translucent system alert windows. The system considers a set of system alert windows to be sufficiently translucent when the combined opacity is less than or equal to the system's maximum obscuring opacity for touches. In Developer Preview 2, this maximum opacity is 0.8, but this value might change later in the Developer Preview.

Detect when an untrusted touch is blocked

If a touch action is blocked by the system, Logcat logs the following message:

Untrusted touch due to occlusion by PACKAGE_NAME

Test the change

Untrusted touches are blocked by default on devices that run Android 12 Developer Preview 2. To allow untrusted touches, run the following ADB command in a terminal window:

# A specific app
adb shell am compat disable BLOCK_UNTRUSTED_TOUCHES com.example.app

# All apps
# If you'd still like to see a Logcat message warning when a touch would be
# blocked, use 1 instead of 0.
adb shell settings put global block_untrusted_touches 0

To revert the behavior to the default (untrusted touches are blocked), run the following command:

# A specific app
adb shell am compat reset BLOCK_UNTRUSTED_TOUCHES com.example.app

# All apps
adb shell settings put global block_untrusted_touches 2

Apps can't close system dialogs

To improve user control when interacting with apps and the system, the ACTION_CLOSE_SYSTEM_DIALOGS intent action is deprecated as of Android 12. Except for a few special cases, when your app tries to invoke an intent that contains this action, the system does one of the following based on your app's target SDK version:

  • If your app targets Android 12, a SecurityException occurs.
  • If your app targets Android 11 (API level 30) or lower, the intent doesn't execute, and the following message appears in Logcat:

    E ActivityTaskManager Permission Denial: \
    android.intent.action.CLOSE_SYSTEM_DIALOGS broadcast from \
    com.package.name requires android.permission.BROADCAST_CLOSE_SYSTEM_DIALOGS, \
    dropping broadcast.
    

Exceptions

In the following cases, an app can still close system dialogs on Android 12:

  • Your app is running an instrumentation test.
  • Your app targets Android 11 or lower and is showing a window that is on top of the notification drawer.

  • Your app targets Android 11 or lower. In addition, the user has interacted with a notification, possibly using the notification's action buttons, and your app is processing a service or broadcast receiver in response to that user action.

Updated non-SDK interface restrictions

Android 12 includes updated lists of restricted non-SDK interfaces based on collaboration with Android developers and the latest internal testing. Whenever possible, we make sure that public alternatives are available before we restrict non-SDK interfaces.

If your app does not target Android 12, some of these changes might not immediately affect you. However, while you can currently use some non-SDK interfaces (depending on your app's target API level), using any non-SDK method or field always carries a high risk of breaking your app.

If you are unsure if your app uses non-SDK interfaces, you can test your app to find out. If your app relies on non-SDK interfaces, you should begin planning a migration to SDK alternatives. Nevertheless, we understand that some apps have valid use cases for using non-SDK interfaces. If you cannot find an alternative to using a non-SDK interface for a feature in your app, you should request a new public API.

To learn more about the changes in this release of Android, see Updates to non-SDK interface restrictions in Android 12. To learn more about non-SDK interfaces generally, see Restrictions on non-SDK interfaces.