Android Q features and APIs

Android Q introduces great new features and capabilities for users and developers. This document highlights what's new for developers.

To learn about the new APIs, read the API diff report or visit the Android API reference — new APIs are highlighted to make them easy to see. Also be sure to check out Android Q behavior changes (for apps targeting Q and for all apps), as well as privacy changes, to learn about areas where platform changes may affect your apps.

Security enhancements

Android Q introduces a number of security features, which the following sections summarize.

Improved biometric authentication dialogs

Android Q introduces the following improvements to the unified biometric authentication dialogs added in Android 9:

Specify user confirmation requirements

You can now provide a hint that tells the system not to require user confirmation after the user has authenticated using an implicit biometric modality. For example, you could tell the system that no further confirmation should be required after a user has authenticated using Face authentication.

By default, the system requires user confirmation. Typically, users want to confirm sensitive or high-risk actions (for example, making a purchase). However, if you have certain low-risk actions for your app, you can provide a hint to not require user confirmation by passing false to the setConfirmationRequired() method. Because this flag is passed as a hint to the system, the system may ignore the value if the user has changed their system settings for biometric authentication.

Figure 1.Face authentication with no user confirmation

Figure 2.Face authentication that requires user confirmation

Improved fallback support for device credentials

You can now tell the system to allow a user to authenticate using their device PIN, pattern, or password if they cannot authenticate using their biometric input for some reason. To enable this fallback support, use the setDeviceCredentialAllowed() method.

If your app currently uses createConfirmDeviceCredentialIntent() to fall back to device credentials, switch to using the new method instead.

Check device for biometric capability

You can now check if a device supports biometric authentication prior to invoking BiometricPrompt by using the canAuthenticate() method in the BiometricManager class.

Run embedded DEX code directly from APK

You can now tell the platform to run embedded DEX code directly from your app’s APK file. This option can help prevent an attack if an attacker ever managed to tamper with the locally compiled code on the device.

To enable this feature, set the value of the android:useEmbeddedDex attribute to true in the <application> element of your app’s manifest file. You must also build an APK that contains uncompressed DEX code that ART can access directly. Add the following options to your Gradle or Bazel configuration file to build an APK with uncompressed DEX code:

Gradle

aaptOptions {
   noCompress 'dex'
}

Bazel

android_binary(
   ...,
   nocompress_extensions = [“.dex”],
)

TLS 1.3 support

The platform's TLS implementation now supports TLS 1.3. TLS 1.3 is a major revision to the TLS standard that includes performance benefits and enhanced security. Our benchmarks indicate that secure connections can be established as much as 40% faster with TLS 1.3 compared to TLS 1.2.

For more details about our implementation of TLS 1.3, see the TLS section within the behavior changes for all apps page.

Public Conscrypt API

The Conscrypt security provider now includes a public API for TLS functionality. In the past, users could access this functionality via reflection. However, due to restrictions on calling non-public APIs added in P, this has been greylisted in Q and will be further restricted in future releases.

This update adds a collection of classes under android.net.ssl that contain static methods to access functionality not available from the generic javax.net.ssl APIs. The names for these classes can be inferred as the plural of the associated javax.net.ssl class. For example, code that operates on javax.net.ssl.SSLSocket instances can use methods from the new android.net.ssl.SSLSockets class.

Connectivity features

Android Q includes several improvements related to networking and connectivity.

Wi-Fi network request API for peer to peer connectivity

Android Q adds support for peer-to-peer connections. This feature enables your app to prompt the user to change the access point that the device is connected to by using WifiNetworkSpecifier to describe properties of a requested network. The peer-to-peer connection is used for non-network-providing purposes, such as bootstrapping configuration for secondary devices like Chromecast and Google Home hardware.

You will use the following flow when using this API:

1. Create a Wi-Fi network specifier using WifiNetworkSpecifier.Builder.

2. Set a network filter to match networks to connect to, along with required credentials.

3. Decide on a combination of SSID, SSID pattern, BSSID, and BSSID pattern to set the network filter in each request, subject to the following requirements:

   • Each request should provide at least one of SSID, SSID pattern, BSSID, or BSSID pattern
   • Each request can set only one of SSID or SSID pattern
   • Each request can set only one of BSSID or BSSID pattern

4. Add the specifiers to the network request along with a NetworkCallback instance to track the status of the request.

   If the user accepts the request and the connection to the network is successful, NetworkCallback.onAvailable() is invoked on the callback object. If the user denies the request or if the connection to the network is unsuccessful, NetworkCallback.onUnavailable() is invoked on the callback object.

Peer-to-peer connections do not require Location or Wi-Fi permissions. Initiating the request to connect to a peer device launches a dialog box on the same device, from which that device's user can accept the connection request.

Bypassing user approval

Once the user approves a network to connect to in response to a request from a specific app, the device stores the approval for the particular access point. If the app makes a specific request to connect to that access point again, the device will skip the user approval phase and automatically connect to the network. If the user chooses to forget the network while connected to a network requested by the API, then this stored approval for that combination of app and network is removed, and any future request from the app will need to be approved by the user again. If the app makes a non-specific (such as with an SSID or BSSID pattern) request, then the user will need to approve the request.

Code sample

The following code sample shows how to connect to an open network with a SSID prefix of "test" and a BSSID OUI of "10:03:23":

val specifier = WifiNetworkSpecifier.Builder()
    .setSsidPattern(PatternMatcher("test", PatternMatcher.PATTERN_PREFIX))
    .setBssidPattern(MacAddress.fromString("10:03:23:00:00:00"), MacAddress.fromString("ff:ff:ff:00:00:00"))
    .build()

val request = NetworkRequest.Builder()
    .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
    .removeCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
    .setNetworkSpecifier(specifier)
    .build()

val connectivityManager = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager

val networkCallback = object : ConnectivityManager.NetworkCallback() {
    ...
    override fun onAvailable(network: Network?) {
        // do success processing here..
    }

    override fun onUnavailable() {
        // do failure processing here..
    }
    ...
}
connectivityManager.requestNetwork(request, networkCallback)
...
// Release the request when done.
connectivityManager.unregisterNetworkCallback(networkCallback)

final NetworkSpecifier specifier =
  new WifiNetworkSpecifier.Builder()
  .setSsidPattern(new PatternMatcher("test", PatternMatcher.PATTERN_PREFIX))
  .setBssidPattern(MacAddress.fromString("10:03:23:00:00:00"), MacAddress.fromString("ff:ff:ff:00:00:00"))
  .build();

final NetworkRequest request =
  new NetworkRequest.Builder()
  .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
  .removeCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
  .setNetworkSpecifier(specifier)
  .build();

final ConnectivityManager connectivityManager = (ConnectivityManager)
  context.getSystemService(Context.CONNECTIVITY_SERVICE);

final NetworkCallback networkCallback = new NetworkCallback() {
  ...
  @Override
  void onAvailable(...) {
      // do success processing here..
  }

  @Override
  void onUnavailable(...) {
      // do failure processing here..
  }
  ...
};
connectivityManager.requestNetwork(request, networkCallback);
...
// Release the request when done.
connectivityManager.unregisterNetworkCallback(networkCallback);

Wi-Fi network suggestion API for internet connectivity

Android Q adds support for your app to add network credentials for a device to auto-connect to a Wi-Fi access point. You can supply suggestions for which network to connect to using WifiNetworkSuggestion. The platform ultimately chooses which access point to accept based on the input from your app and others.

The following code sample shows how to provide credentials for one open, one WPA2, and one WPA3 network:

val suggestion1 = WifiNetworkSuggestion.Builder()
        .setSsid("test111111")
        .setIsAppInteractionRequired() // Optional (Needs location permission)
        .build()

val suggestion2 = WifiNetworkSuggestion.Builder()
        .setSsid("test222222")
        .setWpa2Passphrase("test123456")
        .setIsAppInteractionRequired() // Optional (Needs location permission)
        .build()

val suggestion3 = WifiNetworkSuggestion.Builder()
        .setSsid("test333333")
        .setWpa3Passphrase("test6789")
        .setIsAppInteractionRequired() // Optional (Needs location permission)
        .build()

val suggestionsList = listOf(suggestion1, suggestion2, suggestion3)

val wifiManager = context.getSystemService(Context.WIFI_SERVICE) as WifiManager

val status = wifiManager.addNetworkSuggestions(suggestionsList);
if (status != WifiManager.STATUS_NETWORK_SUGGESTIONS_SUCCESS) {
    // do error handling here
}

// NOTE: The platform posts a notification asking the user to approve your
// app when the first set of network suggestions are added. As soon as the user
// approves your app via the notification, the network suggestions provided are
// considered for auto-connection.

// Optional (Wait for post connection broadcast to one of your suggestions)
val intentFilter = IntentFilter(WifiManager.ACTION_WIFI_NETWORK_SUGGESTION_POST_CONNECTION);

val broadcastReceiver = object : BroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent) {
        if (!intent.action.equals(WifiManager.ACTION_WIFI_NETWORK_SUGGESTION_POST_CONNECTION)) {
            return;
        }
        // do post connect processing here
    }
};
context.registerReceiver(broadcastReceiver, intentFilter);

final WifiNetworkSuggestion suggestion1 =
  new WifiNetworkSuggestion.Builder()
  .setSsid("test111111")
  .setIsAppInteractionRequired() // Optional (Needs location permission)
  .build()

final WifiNetworkSuggestion suggestion2 =
  new WifiNetworkSuggestion.Builder()
  .setSsid("test222222")
  .setWpa2Passphrase("test123456")
  .setIsAppInteractionRequired() // Optional (Needs location permission)
  .build()

final WifiNetworkSuggestion suggestion3 =
  new WifiNetworkSuggestion.Builder()
  .setSsid("test333333")
  .setWpa3Passphrase("test6789")
  .setIsAppInteractionRequired() // Optional (Needs location permission)
  .build()

final List<WifiNetworkSuggestion> suggestionsList =
  new ArrayList<WifiNetworkSuggestion> {{
    add(suggestion1);
    add(suggestion2);
    add(suggestion3);
  }};

final WifiManager wifiManager =
  (WifiManager) context.getSystemService(Context.WIFI_SERVICE);

final int status = wifiManager.addNetworkSuggestions(suggestionsList);
if (status != WifiManager.STATUS_NETWORK_SUGGESTIONS_SUCCESS) {
// do error handling here…
}

// NOTE: The platform will post a notification asking the user to approve your
// app when the first set of network suggestions are added. Once the user
// approves your app via the notification, the network suggestions provided will
// be considered for auto-connection.

// Optional (Wait for post connection broadcast to one of your suggestions)
final IntentFilter intentFilter =
  new IntentFilter(WifiManager.ACTION_WIFI_NETWORK_SUGGESTION_POST_CONNECTION);

final BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
  @Override
  public void onReceive(Context context, Intent intent) {
    if (!intent.getAction().equals(
      WifiManager.ACTION_WIFI_NETWORK_SUGGESTION_POST_CONNECTION)) {
      return;
    }
    // do post connect processing here..
  }
};
context.registerReceiver(broadcastReceiver, intentFilter);

The suggestions from the app must be approved by the user before the platform initiates a connection to them. This approval is provided by the user in response to a notification the first time the platform finds a network matching one of the suggestions from the app in scan results. When the platform connects to one of the network suggestions, the settings will show text that attributes the network connection to the corresponding suggester app.

Handling user disconnects

If the user uses the Wi-Fi picker to explicitly disconnect from one of the network suggestions when connected to it, then that network is blacklisted for 24 hours. During the blacklist period, that network will not be considered for auto-connection, even if the app removes and re-adds the network suggestion corresponding to the network.

Changing approval status for app

A user declining the network suggestion notification removes the CHANGE_WIFI_STATE permission from the app. The user can grant this approval later by going into the Wi-Fi control menu (Settings > Apps & notifications > Special App access > Wi-Fi Control > App name).

Improvements to Wi-Fi high-performance and low-latency modes

Android Q allows you to provide a hint to the underlying modem to minimize latency.

Android Q extends the Wi-Fi lock API to effectively support high-performance mode and low-latency mode. Wi-Fi power save is disabled for high-performance and low-latency mode, and further latency optimization may be enabled in low-latency mode, depending on modem support.

Low-latency mode is only enabled when the application acquiring the lock is running in the foreground and the screen is on. The low-latency mode is especially helpful for real-time mobile gaming applications.

Specialized lookups in DNS resolver

Android Q adds native support for specialized DNS lookups using both cleartext lookups and DNS-over-TLS mode. Previously, the platform DNS resolver supported only A and AAAA records, which allow looking up only the IP addresses associated with a name, but did not support any other record types. The DnsResolver API provides generic, asynchronous resolution, enabling you to look up SRV, NAPTR, and other record types. Note that parsing the response is left to the app to perform.

For NDK-based apps, see android_res_nsend.

Wi-Fi Easy Connect

Android Q enables you to use Easy Connect to provision Wi-Fi credentials to a peer device, as a replacement of WPS which has been deprecated. Apps can integrate Easy Connect into their setup and provisioning flow by using the ACTION_PROCESS_WIFI_EASY_CONNECT_URI intent. This intent requires a URI. The calling app can retrieve the URI through various methods, including scanning a QR code from a sticker or display, or through scanning Bluetooth LE or NFC advertisements.

Once the URI is available, you can provision the peer device’s Wi-Fi credentials with the ACTION_PROCESS_WIFI_EASY_CONNECT_URI intent. This allows the user to select a Wi-Fi network to share and securely transfers the credentials.

Easy Connect does not require Location or Wi-Fi permissions.

Wi-Fi Direct connection API

The WifiP2pConfig and WifiP2pManager API classes have updates in Android Q to support fast connection establishment capabilities to Wi-Fi Direct using predetermined information. This information is shared via a side channel, such as Bluetooth or NFC.

The following code sample shows how to create a group using predetermined information:

val manager = getSystemService(Context.WIFI_P2P_SERVICE) as WifiP2pManager
val channel = manager.initialize(this, mainLooper, null)

// prefer 5G band for this group
val config = WifiP2pConfig.Builder()
    .setNetworkName("networkName")
    .setPassphrase("passphrase")
    .enablePersistentMode(false)
    .setGroupOperatingBand(WifiP2pConfig.GROUP_OWNER_BAND_5GHZ)
    .build()

// create a non-persistent group on 5GHz
manager.createGroup(channel, config, null)

WifiP2pManager manager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
Channel channel = manager.initialize(this, getMainLooper(), null);

// prefer 5G band for this group
WifiP2pConfig config = new WifiP2pConfig.Builder()
.setNetworkName("networkName")
.setPassphrase("passphrase")
.enablePersistentMode(false)
.setGroupOperatingBand(WifiP2pConfig.GROUP_OWNER_BAND_5GHZ)
.build();

// create a non-persistent group on 5GHz
manager.createGroup(channel, config, null);

To join a group using credentials, replace manager.createGroup() with the following:

manager.connect(channel, config, null)

manager.connect(channel, config, null);

Bluetooth LE Connection Oriented Channels (CoC)

Android Q enables your app to use BLE CoC connections to transfer larger data streams between two BLE devices. This interface abstracts Bluetooth and connectivity mechanics to simplify implementation.

Telephony features

Android Q includes several improvements related to telephony.

Call screening and caller ID

Android Q provides your app with a means to identify calls not in the user's address book as potential spam calls, and to have spam calls silently rejected on behalf of the user. Information about these blocked calls is logged as blocked calls in the call log to provide greater transparency to the user when they are missing calls. Use of this new API eliminates the requirement to obtain READ_CALL_LOG permissions from the user to provide call screening and caller ID functionality.

Call redirection service API

Android Q changes how call intents are handled. The NEW_OUTGOING_CALL broadcast is deprecated and is replaced with the CallRedirectionService API. The CallRedirectionService API provides interfaces for you to modify outgoing calls made by the Android platform. For example, third-party apps might cancel calls and reroute them over VoIP.

Improvements in creating files on external storage

In addition to introducing the scoped storage privacy behavior change, Android Q provides more flexibility in writing files and introduces capabilities to help you influence where those files get saved on an external storage device.

Pending status for new media files

Android Q introduces the IS_PENDING flag, which gives your app exclusive access to a media file as it's written to disk.

The following code snippet shows how to use the IS_PENDING flag when creating a new image in your app:

val values = ContentValues().apply {
    put(MediaStore.Images.Media.DISPLAY_NAME, "IMG1024.JPG")
    put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg")
    put(MediaStore.Images.Media.IS_PENDING, 1)
}

val resolver = context.getContentResolver()
val collection = MediaStore.Images.Media
        .getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
val item = resolver.insert(collection, values)

resolver.openFileDescriptor(item, "w", null).use { pfd ->
    // Write data into the pending image.
}

// Now that we're finished, release the "pending" status, and allow other apps
// to view the image.
values.clear()
values.put(MediaStore.Images.Media.IS_PENDING, 0)
resolver.update(item, values, null, null)

ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.DISPLAY_NAME, "IMG1024.JPG");
values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
values.put(MediaStore.Images.Media.IS_PENDING, 1);

ContentResolver resolver = context.getContentResolver();
Uri collection = MediaStore.Images.Media.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY);
Uri item = resolver.insert(collection, values);

try (ParcelFileDescriptor pfd = resolver.openFileDescriptor(item, "w", null)) {
    // Write data into the pending image.
} catch (IOException e) {
    e.printStackTrace();
}

// Now that we're finished, release the "pending" status, and allow other apps
// to view the image.
values.clear();
values.put(MediaStore.Images.Media.IS_PENDING, 0);
resolver.update(item, values, null, null);

Influence on storage location

Android Q introduces several capabilities to help you organize the files that your app contributes to external storage.

Directory hints

When your app contributes media on a device running Android Q, the media is organized based on its type by default. For example, new image files are placed in a "pictures" directory by default.

If your app is aware of a specific location where files should be stored, such as Pictures/MyVacationPictures, you can set MediaColumns.RELATIVE_PATH to provide the system a hint for where to store the newly-written files. Similarly, you can move files on disk during a call to update() by changing MediaColumns.RELATIVE_PATH or MediaColumns.DISPLAY_NAME.

Device selection

In Android 9 (API level 28) and lower, all files saved to external storage devices appear under a single volume called external. Android Q, on the other hand, gives each external storage device a unique volume name. This new naming system helps you efficiently organize and index content, and it gives you control over where new content is stored.

The primary shared storage device is always called VOLUME_EXTERNAL_PRIMARY. You can discover other volumes by calling MediaStore.getExternalVolumeNames().

To query, insert, update, or delete a specific volume, pass the volume name to any of the getContentUri() methods available in the MediaStore API, such as in the following code snippet:

// Publish an audio file onto a specific external storage device.
val values = ContentValues().apply {
    put(MediaStore.Audio.Media.RELATIVE_PATH, "Music/My Album/My Song")
    put(MediaStore.Audio.Media.DISPLAY_NAME, "My Song.mp3")
}

// Assumes that the storage device of interest is the 2nd one
// that your app recognizes.
val volumeNames = MediaStore.getExternalVolumeNames(context)
val selectedVolumeName = volumeNames[1]
val collection = MediaStore.Audio.Media.getContentUri(selectedVolumeName)
val item = resolver.insert(collection, values)

Media and graphics

Android Q introduces the following new media and graphics features and APIs:

Sharing audio input

Android Q adds the ability for two apps to share the audio input simultaneously. For full information, see Sharing audio input.

Audio playback capture

Android Q gives an app the ability to capture audio playback from other apps. For full information, see Playback capture.

Seekbar in MediaStyle notifications

In Android Q, MediaStyle notifications display a seekbar. The seekbar shows the playback progress from PlaybackState.getPosition(), and in some cases the seekbar can be used to seek to a location in the playing program. The seekbar appearance and behavior is controlled by these rules:

• The seekbar appears if there is an active MediaSession and its duration (specified by MediaMetadata.METADATA_KEY_DURATION) is greater than zero. This means that the bar does not appear for indeterminate streams like livestreams and radio broadcasts.
• If the session implements ACTION_SEEK_TO the user can drag the seekbar to control the playback location.

Native MIDI API

The Android Native MIDI API (AMidi) gives application developers the ability to send and receive MIDI data with C/C++code, integrating more closely with their C/C++ audio/control logic and minimizing the need for JNI.

For more information, see Android Native MIDI API.

MediaCodecInfo improvements

There are new methods in MediaCodecInfo that reveal more information about a codec:

isSoftwareOnly()

Returns true if the codec runs in software only. Software codecs make no guarantees about rendering performance.

isHardwareAccelerated()

Returns true if a codec is accelerated by hardware.

isVendor()

Returns true if the codec is provided by the device vendor or false if provided by the Android platform.

isAlias()

MediaCodecList may contain additional entries for the same underlying codec using an alternate codec name/s (alias/es). This method returns true if the codec in this entry is an alias for another codec.

In addition, MediaCodec.getCanonicalName() returns the underlying codec name for codecs created via an alias.

Performance Points

A performance point represents a codec's ability to render video at a specific height, width and frame rate. For example, the UHD_60 performance point represents Ultra High Definition video (3840x2160 pixels) rendered at 60 frames per second.

The method MediaCodecInfo.VideoCapabilities.getSupportedPerformancePoints() returns a list of PerformancePoint entries that the codec can render or capture.

You can check whether a given PerformancePoint covers another by calling PerformancePoint.covers(PerformancePoint). For example, UHD_60.covers(UHD_50) returns true.

A list of performance points is provided for all hardware-accelerated codecs. This could be an empty list if the codec does not meet even the lowest standard performance point.

Note that devices which have been upgraded to Q without updating the vendor image will not have performance point data, because this data comes from the vendor HAL. In this case, getSupportedPerformancePoints() returns null.

ANGLE

With the release of Android Q, Android developers and partners have the option to run using ANGLE, a project in the Chrome organization that layers ES on top of Vulkan, instead of using the vendor-provided ES driver.

For details, see ANGLE.

Thermal API

When devices get too warm, they may throttle the CPU and/or GPU, and this can affect apps and games in unexpected ways. Apps using complex graphics, heavy computation, or sustained network activity are more likely to hit issues, and those can vary across devices based on chipset and core frequencies, levels of integration, and also device packaging and form factor.

Now in Android Q, apps and games can use a thermal API to monitor changes on the device and take action to maintain lower power usage to restore normal temperature. Apps register a listener in PowerManager, through which the system reports ongoing thermal status ranging from light and moderate to severe, critical, emergency, and shutdown.

When the device reports thermal stress, apps and games can help by backing off ongoing activities to reduce power usage on various ways. For example, streaming apps could reduce resolution/bit rate or network traffic, a camera app could disable flash or intensive image enhancement, a game could reduce frame rate or polygon tesselation, a media app could reduce speaker volume, and a maps app could turn off GPS.

The thermal API requires a new device HAL layer—it's currently supported on Pixel devices running Android Q and we’re working with our device-maker partners to bring broad support to the ecosystem as quickly as possible.

Camera and images

Android Q introduces the following new camera- and image-related features:

Monochrome camera support

Android 9 (API level 28) first introduced monochrome camera capability. Android Q adds several enhancements to monochrome camera support:

• New Y8 stream format support to improve memory efficiency.
• Support for monochrome raw DNG capture.
• Introduction of MONO and NIR CFA enumerations to distinguish between regular monochrome camera and near infrared cameras.

You may use this feature to capture a native monochrome image. A logical multi-camera device may use a monochrome camera as a physical sub-camera to achieve better low-light image quality.

Dynamic Depth Format

Starting in Android Q, cameras can store the depth data for an image in a separate file, using a new schema called Dynamic Depth Format (DDF). Apps can request both the JPG image and its depth metadata, using that information to apply any blur they want in post-processing without modifying the original image data.

To read the specification for the new format, see Dynamic Depth Format.

High Efficiency Image File format

High Efficiency Image File (HEIF) format is a standard image and video format that introduces higher-quality encoding and smaller file size when compared to other file formats.

For more information about the file format, see HEIC.

Improvements in multi-camera

Android Q improves the fusing of multiple cameras into a single logical camera, a feature introduced in Android 9 (API level 28). The following were added to the Camera2 API:

• isSessionConfigurationSupported(SessionConfiguration sessionConfig)—enables you to query whether or not the passed session configuration can be used to create a camera capture session.

• LOGICAL_MULTI_CAMERA_ACTIVE_PHYSICAL_ID—enables you to determine the ID of the active physical camera backing a logical camera device. You can use the IDs returned to request logical streams and physical subcamera streams to achieve better power efficiency.

Accessibility services API

Android Q introduces the following new accessibility service features and APIs:

AccessibilityNodeInfo entry key flag

In Android Q, AccessibilityNodeInfo has been enhanced with a new flag designating whether it represents a text entry key. You can access this flag using the method AccessibilityNodeInfo.isTextEntryKey().

Accessibility dialog spoken feedback

When an accessibility service requires the user to repeat the accessibility shortcut to start the service, the dialog can now be accompanied by a text-to-speech prompt if the service requests it.

Accessibility shortcut when gesture navigation enabled

When the gesture navigation feature is enabled in Android Q, users no longer access the accessibility services menu by pressing the accessibility button. Instead, users perform one of the following gestures:

• Two-finger swipe up.
• Two-finger swipe up and hold.

Accessibility shortcut for physical keyboards

In Android Q, users can now trigger the accessibility shortcut on a physical keyboard by pressing Control+Alt+Z.

Soft keyboard controller enhancement

In Android Q, accessibility services can now request that the soft keyboard be displayed even when the device detects a hard keyboard attached. Users can override this behavior.

User-defined accessibility timeouts

Android Q introduces the API method AccessibilityManager.getRecommendedTimeoutMillis(), providing support for user-defined timeouts for interactive and non-interactive Accessibility UI elements. The return value is influenced by both user preferences and accessibility service APIs.

Autofill improvements

Android Q contains the following improvements to the autofill service.

Compatibility-related autofill requests

You can now use the FillRequest.FLAG_COMPATIBILITY_MODE_REQUEST flag to determine whether an autofill request was generated via compatibility mode.

Save username and password simultaneously

You can now support cases where an application uses multiple activities to display username, password, and other fields by using the SaveInfo.FLAG_DELAY_SAVE flag.

User interaction with the Save UI

You can now show and hide a password field in a save dialog by setting an action listener on the dialog and changing the visibility of the corresponding password remote view.

Support for updating datasets

Autofill can now update existing passwords. For example, if a user has already stored a password, and they save a new password, Autofill now prompts the user to update the existing password instead of saving a new one.

Field Classification improvements

Android Q contains the following improvements to the Field Classification API.

UserData.Builder constructor

The UserData.Builder constructor has changed to better align to the Builder pattern.

Allow a Value to be mapped to multiple types of Category IDs

When using UserData.Builder in Android Q, you can now map a value to multiple types of category IDs. In previous releases, an exception was thrown if a value was added more than once.

Improved support for credit card numbers

Field classification can now detect four-digit numbers as the last four digits of a credit card number.

Support for app-specific field classification

Android Q adds FillResponse.setUserData(), which allows you to set app-specific user data for the duration of the session. This helps the autofill service detect types for fields with app-specific content.

UI and system controls

Android Q provides the following user-interface improvements:

Support JVMTI PopFrame caps

Android Q adds support for the can_pop_frames capability in the Android JVMTI implementation. When debugging, this feature allows you to re-run functions after pausing at a breakpoint and adjusting locals, globals, or implementation of a function. For more information, see Oracle's Pop Frame reference page.

Surface control API

Android Q provides a SurfaceControl API for low-level access to the system-compositor (SurfaceFlinger). For most users, SurfaceView is the correct way to leverage the compositor. The SurfaceControl API can be useful in certain cases, for example:

• Synchronization of multiple surfaces
• Cross-process surface embedding
• Lower-level lifetime management

The SurfaceControl API is available in both SDK and NDK bindings. The NDK implementation includes an API for manual exchange of buffers with the compositor. This provides an alternative for users who have run up against the limitations of BufferQueue.

WebView hung renderer detection

Android Q introduces a new WebViewRenderProcessClient abstract class, which apps can use to detect if a WebView has become unresponsive. To use this class:

1. Define your own subclass and implement its onRenderProcessResponsive() and onRenderProcessUnresponsive() methods.
2. Attach an instance of your WebViewRenderProcessClient to one or more WebView objects.
3. If the WebView becomes unresponsive, the system calls the client's onRenderProcessUnresponsive() method, passing the WebView and WebViewRenderProcess. (If the WebView is single-process, the WebViewRenderProcess parameter is null.) Your app can take appropriate action, such as showing a dialog box to the user asking if they want to halt the rendering process.

If the WebView remains unresponsive, the system calls onRenderProcessUnresponsive() periodically (no more than once every five seconds), but takes no other action. If the WebView becomes responsive again, the system calls onRenderProcessResponsive() just once.

Settings panels

Android Q introduces Settings Panels, an API which allows apps to show settings to users in the context of their app. This prevents users from needing to go into Settings to change things like NFC or Mobile data in order to use the app.

For example, suppose a user opens a web browser while their device is in airplane mode. Prior to Android Q, the app could only display a generic message asking the user to open Settings to restore connectivity. With Android Q, the browser app can display an inline panel showing key connectivity settings such as airplane mode, Wi-Fi (including nearby networks), and mobile data. With this panel, users can restore connectivity without leaving the app.

To display a settings panel, fire an intent with the one of the new Settings.Panel actions:

val panelIntent = Intent(Settings.Panel.settings_panel_type)
startActivityForResult(panelIntent)

Intent panelIntent = new Intent(Settings.Panel.settings_panel_type);
startActivityForResult(panelIntent);

settings_panel_type can be one of:

ACTION_INTERNET_CONNECTIVITY

Shows settings related to internet connectivity, such as Airplane mode, Wi-Fi, and Mobile Data.

ACTION_WIFI:

Shows Wi-Fi settings, but not the other connectivity settings. This is useful for apps that need a Wi-Fi connection to perform large uploads or downloads.

ACTION_NFC

Shows all settings related to near-field communication (NFC).

ACTION_VOLUME

Shows volume settings for all audio streams.

We are planning to introduce an AndroidX wrapper for this functionality. When called on devices running Android 9 (API level 28) or lower, the wrapper will open the most-appropriate page in the Settings app.

Sharing improvements

Android Q provides a number of improvements to sharing. For full information, see Sharing improvements in Android Q.

Dark theme

Android Q offers a new Dark theme that applies to both the Android system UI and apps running on the device. For full information, see Dark theme.

Foreground service types

Android Q introduces a new XML manifest attribute, foregroundServiceType, that you include in the definition of several specific services. It's possible, though rarely appropriate, to assign multiple foreground service types to a particular service.

The following table shows the different foreground service types and the services where it's appropriate to declare a specific type:

Kotlin

Android Q includes the following updates for Kotlin development.

Nullability annotations for libcore APIs

Android Q improves the coverage of nullability annotations in the SDK for libcore APIs. These annotations enable app developers who are using either Kotlin or Java nullability analysis in Android Studio to get nullness information when interacting with these APIs.

Normally, nullability contract violations in Kotlin result in compilation errors. To ensure compatibility with your existing code, any new annotations are limited to @RecentlyNullable and @RecentlyNonNull. This means that nullability violations result in warnings instead of errors.

In addition, any @RecentlyNullable or @RecentlyNonNull annotations that were added in Android 9 are changing to @Nullable and @NonNull, respectively. This means that nullability violations now lead to errors instead of warnings.

For more information about annotation changes, see Android Pie SDK is now more Kotlin-friendly on the Android Developers Blog.

NDK

Android Q includes the following NDK changes.

Improved debugging of file descriptor ownership

Android Q adds fdsan, which helps you find and fix file descriptor ownership issues more easily.

Bugs related to mishandling of file descriptor ownership, which tend to manifest as use-after-close and double-close, are analogous to the memory allocation use-after-free and double-free bugs, but tend to be much more difficult to diagnose and fix. fdsan attempts to detect and/or prevent file descriptor mismanagement by enforcing file descriptor ownership.

For more information about crashes related to these issues, see Error detected by fdsan. For more information about fdsan, see the Googlesource page on fdsan.

ELF TLS

Applications built using the NDK with a minimum API level 29 no longer need to use emutls, but can instead use ELF TLS. Dynamic and static linker support has been added to support the new method of handling thread-local variables.

For apps built for API level 28 and lower, improvements have been implemented for libgcc/compiler-rt to work around some emutls issues.

For more information, see Android changes for NDK developers.

Runtime

Android Q includes the following runtime change.

Mallinfo-based garbage collection triggering

When small platform Java objects reference huge objects in the C++ heap, the C++ objects can often be reclaimed only when the Java object is collected and, for example, finalized. In previous releases, the platform estimated the sizes of many C++ objects associated with Java objects. This estimation was not always accurate and occasionally resulted in greatly increased memory usage, as the platform failed to garbage collect when it should have.

In Q, the garbage collector (GC) tracks the total size of the heap allocated by system malloc(), ensuring that large malloc() allocations are always included in GC-triggering calculations. Apps interleaving large numbers of C++ allocations with Java execution might see an increase in garbage collection frequency as a result. Other apps might see a small decrease.

Testing and debugging

Android Q includes the following improvements for testing and debugging.

Improvements for on-device system tracing

You can now specify limits for the size and duration of a trace when you perform an on-device system trace. When you specify either value, the system performs a long trace, periodically copying the trace buffer to the destination file while the trace is recorded. The trace completes when the size or duration limits that you specified are reached.

Use these additional parameters to test different use cases than you would test with a standard trace. For example, you might be diagnosing a performance bug that only occurs after your app has been running for a long period of time. In this case, you could record a long trace over an entire day, and then analyze the CPU scheduler, disk activity, app threads, and other data in the report to help you determine the cause of the bug.

TextClassifier improvements

Android Q provides additional text classification functionality in the TextClassifier interface.

Language detection

TextClassifier now features the detectLanguage() method. This method works similarly to existing classification methods, receiving a TextLanguage.Request object and returning a TextLanguage object.

The new TextLanguage object consists of a list of ordered pairs. Each pair contains a locale and a corresponding confidence score for the requested text sample.

Suggested conversation actions

TextClassifier now features the suggestConversationActions() method. This method works similarly to existing classification methods, receiving a ConversationActions.Request object and returning a ConversationActions object.

The new ConversationActions object consists of a list of ConversationAction objects. Each ConversationAction object includes a potential suggested action and its confidence score.

Smart replies/actions in notifications

Android 9 introduced the ability to display suggested replies within a notification. Beginning in Android Q, notifications can also include suggested intent-based actions. Furthermore, the system can now generate these suggestions automatically. Apps can still provide their own suggestions, or opt out of system-generated suggestions.

The API used to generate these replies is part of TextClassifier, and has also been directly exposed to developers in Android Q. Please read the section on TextClassifier improvements for more information.

If your app provides its own suggestions, the platform doesn't generate any automatic suggestions. If you don't want your app's notifications to display any suggested replies or actions, you can opt out of system-generated replies and actions by using setAllowGeneratedReplies() and setAllowSystemGeneratedContextualActions().