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Features and APIs Overview  |  Android 12 Beta  |  Android Developers

 3 years ago
source link: https://developer.android.com/about/versions/12/features
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Features and APIs Overviewbookmark_border

Android 12 introduces great new features and APIs for developers. The sections below help you learn about features for your apps and get started with the related APIs.

For a detailed list of new, modified, and removed APIs, read the API diff report. For details on new APIs visit the Android API reference — new APIs are highlighted for visibility. Also, to learn about areas where platform changes may affect your apps, be sure to check out Android 12 behavior changes for apps that target Android 12 and for all apps.

New experiences

Widgets improvements

Android 12 revamps the existing Widgets API to improve the user and developer experience in the platform and launchers. We've created a guide to help you ensure your widget is compatible with Android 12 and to refresh it with new features.

See Android 12 widgets improvements for more information.

Audio-coupled haptic effect

Android 12 apps can generate haptic feedback derived from an audio session using the phone's vibrator. This provides an opportunity for more immersive game and audio experiences. For example, haptic-enhanced ringtones can help identify callers, or a driving game could simulate the feeling of rough terrain.

See the HapticGenerator reference documentation for more information.

Splash screen API

Android 12 introduces a new app launch animation for all apps that includes an into-app motion from the point of launch, a splash screen showing the app icon, and a transition to the app itself. See Splash screen API for more details.

New phone call notifications allowing for ranking importance of incoming calls

Android 12 adds the new notification style Notification.CallStyle for phone calls. Using this template lets your app indicate the importance of active calls by displaying a prominent chip that shows the time of the call in the status bar; the user can tap this chip to return to their call.

Because incoming and ongoing calls are the most critical to users, these notifications are given top ranking in the shade. This ranking also allows the system to potentially forward these prioritized calls to other devices.

Implement the following code for all types of calls.

// Create a new call with the user as caller.
val incoming_caller = Person.Builder()
    .setName("Jane Doe")
    .setImportant(true)
    .build()

Use forIncomingCall() to create a call style notification for an incoming call.

// Create a call style notification for an incoming call.
val builder = Notification.Builder(context, CHANNEL_ID)
    .setContentIntent(contentIntent)
    .setSmallIcon(smallIcon)
    .setStyle(
         Notification.CallStyle.forIncomingCall(caller, declineIntent, answerIntent))
    .addPerson(incoming_caller)

Use forOngoingCall() to create a call style notification for an ongoing call.

// Create a call style notification for an ongoing call.
val builder = Notification.Builder(context, CHANNEL_ID)
    .setContentIntent(contentIntent)
    .setSmallIcon(smallIcon)
    .setStyle(
         Notification.CallStyle.forOnGoingCall(caller, hangupIntent))
    .addPerson(second_caller)

Use forScreeningCall() to create a call style notification for screening a call.

// Create a call style notification for screening a call.
val builder = Notification.Builder(context, CHANNEL_ID)
    .setContentIntent(contentIntent)
    .setSmallIcon(smallIcon)
    .setStyle(
         Notification.CallStyle.forScreeningCall(caller, hangupIntent, answerIntent))
    .addPerson(second_caller)

Enriched image support for notifications

In Android 12, you can now enrich your app’s notification experience by providing animated images in MessagingStyle() and BigPictureStyle() notifications. Also, your app can now enable users to send image messages when they reply to messages from the notification shade.

Rounded corner APIs

Android 12 introduces RoundedCorner and WindowInsets.getRoundedCorner(int position), which provide the radius and center point for rounded corners. With these APIs, your app can avoid UI elements being truncated on screens with rounded corners.

When implemented in your app, these APIs have no effect on devices with non-rounded screens.

Image showing a rounded corners with radiuses and a center point

To implement this feature, get the RoundedCorner info through WindowInsets.getRoundedCorner(int position) relative to the bounds of the application. If the app doesn’t take up the whole screen, the API applies the rounded corner by basing the center point of the rounded corner on the window bounds of the app.

The following code snippet shows a simple example for an app to avoid UI truncations by setting a margin of the view based on the info from RoundedCorner. In this case, it is the top right rounded corner.

// Get the top-right rounded corner from WindowInsets.
final WindowInsets insets = getRootWindowInsets();
final RoundedCorner topRight = insets.getRoundedCorner(POSITION_TOP_RIGHT);
if (topRight == null) {
   return;
}

// Get the location of the close button in window coordinates.
int [] location = new int[2];
closeButton.getLocationInWindow(location);
final int buttonRightInWindow = location[0] + closeButton.getWidth();
final int buttonTopInWindow = location[1];

// Find the point on the quarter circle with a 45 degree angle.
final int offset = (int) (topRight.getRadius() * Math.sin(Math.toRadians(45)));
final int topBoundary = topRight.getCenter().y - offset;
final int rightBoundary = topRight.getCenter().x + offset;

// Check whether the close button exceeds the boundary.
if (buttonRightInWindow < rightBoundary && buttonTopInWindow > topBoundary) {
   return;
}

// Set the margin to avoid truncating.
int [] parentLocation = new int[2];
getLocationInWindow(parentLocation);
FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) closeButton.getLayoutParams();
lp.rightMargin = Math.max(buttonRightInWindow - rightBoundary, 0);
lp.topMargin = Math.max(topBoundary - buttonTopInWindow, 0);
closeButton.setLayoutParams(lp);

Picture in Picture (PiP) improvements

Android 12 introduces new features for picture-in-picture (PiP) mode. See Picture-in-picture improvements for more information.

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. Apps can still protect from accidental gestures in full-screen gaming experiences so users don't accidentally quit out of their games while playing; all other full-screen or immersive experiences now allow users to navigate their phone with one swipe.

To make this possible, the existing behaviors for non-sticky immersive experiences (BEHAVIOR_SHOW_BARS_BY_TOUCH, BEHAVIOR_SHOW_BARS_BY_SWIPE) are deprecated starting in Android 12. They have been replaced with default behavior (BEHAVIOR_DEFAULT) that allows gestures with one swipe when hiding system bars. This flag exhibits different visual and functional behavior depending on the mode:

  • In three-button mode, visual and functional behavior is the same as immersive mode in versions of Android prior to 12.
  • In gestural navigation mode, the behavior is as follows:
    • Visually, it’s the same as immersive mode in Android 11 and lower.
    • Functionally, gestures are allowed even when the bar is hidden; system back requires only one swipe to invoke instead of the two swipes required for Android 11. No additional swipes are needed to pull down the notification bar or start going Home.

Sticky immersive mode (BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE) has not changed for Android 12. Note the following backward-compatibility for this feature:

Rich content insertion

Android 12 introduces a new unified API that lets you receive rich content from any available source: clipboard, keyboard, or drag and drop.

For more information, see Unified API for receiving content.

Camera

Quad bayer camera sensor support

Many Android devices today ship with ultra high-resolution camera sensors, typically with Quad / Nona Bayer patterns, and these offer great flexibility in terms of image quality and low-light performance. Android 12 introduces new platform APIs that let third-party apps take full advantage of these versatile sensors. The new APIs support the unique behavior of these sensors and take into account that they might support different stream configurations and combinations when operating in full resolution or ‘maximum resolution’ mode vs ‘default’ mode.

Graphics and images

Provide apps direct access to tombstone traces

Starting in Android 12, you can access your app's native crash tombstone as a protocol buffer through the ApplicationExitInfo.getTraceInputStream() method. The protocol buffer is serialized using this schema. Previously, the only way to get access to this information was through the Android Debug Bridge (adb).

Here’s one example of how to implement this in your app:

ActivityManager activityManager: ActivityManager = getSystemService(Context.ACTIVITY_SERVICE);
MutableList<ApplicationExitInfo> exitReasons = activityManager.getHistoricalProcessExitReasons(/* packageName = */ null, /* pid = */ 0, /* maxNum = */ 5);
for ( ApplicationExitInfo aei: exitReasons ) {
    if ( aei.getReason() == REASON_CRASH_NATIVE ) {
        // Get the tombstone input stream.
        InputStream tombstoneInputStream = aei.getTraceInputStream();
        // The tombstone parser built with protoc uses the tombstone schema, then parses the trace.
        Tombstone tombstone = Tombstone.parseFrom(trace);
    }
}

AVIF image support

Android 12 introduces support for images that use the AV1 Image File Format (AVIF). AVIF is a container format for images and sequences of images encoded using AV1. It takes advantage of the intra-frame encoded content from video compression. This dramatically improves image quality for the same file size when compared to older image formats, such as JPEG. For an in depth look at the advantages of this format, see Jake Archibald's blog post.

Easier blurs, color filters, and other effects

Android 12 adds the new RenderEffect that applies common graphics effects such as blurs, color filters, Android shader effects, and more to Views and rendering hierarchies. Effects can be combined as either chain effects (which compose an inner and outer effect) or blended effects. Different Android devices may or may not support the feature due to limited processing power.

Effects can also be applied to the underlying RenderNode for Views by calling View.setRenderEffect(RenderEffect).

To implement a RenderEffect:

view.setRenderEffect(RenderEffect.createBlurEffect(radiusX, radiusY, SHADER_TILE_MODE))

Native animated image decoding

In Android 12, the NDK ImageDecoder API has been expanded to decode all frames and timing data from images that use the animated GIF and animated WebP file formats. When it was introduced in Android 11, this API decoded only the first image from animations in these formats.

Use ImageDecoder instead of third-party libraries to further decrease APK size and benefit from future updates related to security and performance.

For more details on the API, refer to the API reference and the sample on GitHub.

Media

Compatible media transcoding

Android 12 can automatically transcode HEVC(H.265) and HDR (HDR10 and HDR10+) videos recorded on the device to AVC (H.264), a format which is widely compatible with standard players. This takes advantage of modern codecs when they are available without sacrificing compatibility with older applications.

See compatible media transcoding for more details.

Performance class

Starting with Android 12, Android introduces a standard called performance class. A performance class specifies hardware capabilities beyond Android's baseline requirements. Each Android device declares the performance class that it supports. Developers can check the device's performance class at runtime and provide upgraded experiences that take full advantage of the device’s capabilities.

See Performance class for more details.

Video encoding improvements

Android 12 defines a standard set of keys for controlling the quantization parameter (QP) value for video encoding, allowing developers to avoid vendor-specific code.

The new keys are available in the MediaFormat API and also in the NDK Media library.

Starting with Android 12 video encoders enforce a minimum quality threshold. This guarantees that users don't experience extremely low quality when encoding videos with high scene complexity.

Audio focus

Starting with Android 12, when an app requests audio focus while another app has the focus and is playing, the framework fades out the playing app.

See audio focus improvements for more details.

MediaDrm updates

In order to determine whether a secure decoder component is required with the current MediaDrm APIs, you must follow these steps:

  1. Create a MediaDrm.
  2. Open a session to obtain a session id.
  3. Create a MediaCrypto using the session id.
  4. Call MediaCrypto.requiresSecureDecoderComponent(mimeType).

With the new methods requiresSecureDecoder(@NonNull String mime) and requiresSecureDecoder(@NonNull String mime, @SecurityLevel int level) you can determine this as soon as you create a MediaDrm.

Security and privacy

Bluetooth permissions

Android 12 introduces the BLUETOOTH_SCAN, BLUETOOTH_ADVERTISE, and BLUETOOTH_CONNECT permissions. These permissions make it easier for apps that target Android 12 to interact with Bluetooth devices, especially for apps that don't require access to device location.

Note: The Companion Device Manager provides a more streamlined method of connecting to companion devices. The system provides the pairing UI on behalf of your app. If you want more control over the pairing and connecting experience, use the new Bluetooth permissions.

Learn more in the guide about the new Bluetooth permissions.

Privacy Dashboard

A vertical timeline shows the different apps that have          accessed location information, and at what time the accesses occurredFigure 1. Location usage screen, part of the Privacy Dashboard.

On supported devices that run Android 12, a Privacy Dashboard screen appears in system settings. On this screen, users can access separate screens that show when apps access location, camera, and microphone information. Each screen shows a timeline of when different apps have accessed a particular type of data. Figure 1 shows the data access timeline for location information.

Your app can provide a rationale for users, to help them understand why your app accesses location, camera, or microphone information. This rationale can appear on the new Privacy Dashboard screen, your app's permissions screen, or both.

Show rationale for data access

To explain why your app accesses location, camera, and microphone information, complete the following steps:

  1. Declare the START_VIEW_PERMISSION_USAGE permission.
  2. Add an activity that, when started, provides some rationale for why your app performs a particular type of data access action.

    Note: If your app targets Android 12, you must explicitly define a value for the android:exported attribute.
  3. Add the following intent filter to the newly-added activity:

    <!-- android:exported required if you target Android 12. -->
    <activity android:name=".DataAccessRationaleActivity"
              android:permission="android.permission.START_VIEW_PERMISSION_USAGE"
              android:exported="true">
           <!-- VIEW_PERMISSION_USAGE shows a selectable information icon on
                your app permission's page in system settings.
                VIEW_PERMISSION_USAGE_FOR_PERIOD shows a selectable information
                icon on the Privacy Dashboard screen. -->
        <intent-filter
           android:action="android.intent.action.VIEW_PERMISSION_USAGE"
           android:action="android.intent.action.VIEW_PERMISSION_USAGE_FOR_PERIOD" ... >
        </intent-filter>
    </activity>
  4. Decide what your data access rationale activity should show. For example, you might show your app's website or a help center article. To provide a more detailed explanation about the types of data that your app accesses, as well as when the access occurred, handle the extras that the system includes when it invokes the permission usage intent:

Depending on which intent filters you add, users see an information icon next to your app's name on certain screens:

  • If you add the intent filter that contains the VIEW_PERMISSION_USAGE action, users see the icon on your app's permissions page in system settings.
  • If you add the intent filter that contains the VIEW_PERMISSION_USAGE_FOR_PERIOD action, users see the icon next to your app's name whenever your app appears in the Privacy Dashboard screen.

When users select that icon, your app's rationale activity is started.

Hide application overlay windows

To give developers more control over what users see when they interact with the developer's app, Android 12 introduces the ability to hide overlay windows that are drawn by apps that have the SYSTEM_ALERT_WINDOW permission.

After declaring the HIDE_OVERLAY_WINDOWS permission, an app can call setHideOverlayWindows() to indicate that all windows of type TYPE_APPLICATION_OVERLAY should be hidden when the app's own window is visible. Apps might choose to do this when displaying sensitive screens, such as transaction confirmation flows.

Apps that show windows of type TYPE_APPLICATION_OVERLAY should consider alternatives that may be more appropriate for their use case, such as picture-in-picture or bubbles.

Known signers permission protection flag

Android 12 introduces the knownCerts attribute for signature-level permissions. This attribute allows you to refer to the digests of known signing certificates at declaration time.

Your app can declare this attribute and use the new knownSigner flag in the protectionLevel attribute for a given signature-level permission. When your app does this, the system grants the permission to a requesting app if any signer in the requesting app's signing lineage, including the current signer, matches one of the digests that's declared with the permission in the knownCerts attribute.

The knownSigner flag allows devices and apps to grant signature permissions to other apps without having to sign the apps at the time of device manufacturing and shipment.

Device properties attestation

Android 12 expands the set of apps that can verify the device properties that are in an attestation certificate when these apps generate a new key.

As of Android 9 (API level 28), device policy owners (DPOs) that use Keymaster 4.0 or higher can verify the device properties in these attestation certificates. Starting in Android 12, any app that targets Android 12 can perform this verification using the setDevicePropertiesAttestationIncluded() method.

The generated device properties include the following Build fields:

  • BRAND
  • DEVICE
  • MANUFACTURER
  • MODEL
  • PRODUCT

Secure lockscreen notification actions

Android 12 adds the new setAuthenticationRequired flag to Notification.Action.Builder. This flag lets you add an extra layer of security to notifications on locked devices.

When this flag is applied with a value of true to a given notification action, a user invoking that action on a locked device always results in an authentication request. Previously, the system requested authentication on locked devices only if the user’s invoking of a notification action launched an activity or was a direct reply.

To implement this feature, add setAuthenticationRequired to a notification action:

Notification n1 = new Notification.Builder(context, NotificationListenerVerifierActivity.TAG)
...
.addAction(new Notification.Action.Builder(R.drawable.ic_stat_charlie,
context.getString(R.string.action_test_title), makeBroadcastIntent(context))

// Make sure this notification action will always request authentication when
// invoked from a lock screen
.setAuthenticationRequired(true).build())

.build();

Connectivity

Bandwidth estimation improvements

In Android 12, the bandwidth estimation capabilities provided by getLinkDownstreamBandwidthKbps() and getLinkUpstreamBandwidthKbps() are improved for both Wi-Fi and cellular connectivity. The values returned now represent the user’s all-time weighted average throughput per carrier or WiFi SSID, network type, and signal level, across all applications on the device. This can return a more-accurate and realistic estimate of expected throughput, provide estimates on a cold start of your application, and requires fewer cycles when compared to using other throughput estimation methods.

Keeping companion apps awake

To support the need of companion apps to stay running to manage the device, Android 12 introduces APIs that do the following:

  • Enable you to wake an app when a companion device is within range.
  • Guarantee that the process will continue running while the device stays within range.

To use the APIs, your devices must be connected using Companion Device Manager. For more information, see CompanionDeviceManager.startObservingDevicePresence() and CompanionDeviceService.onDeviceAppeared().

Companion Device Manager profiles

Partner apps that target Android 12 and higher can now use companion device profiles when connecting to a watch. Using a profile simplifies the enrollment process by bundling the granting of a device-type-specific set of permissions into one step.

Screenshot of a phone showing a prompt offering to grant permissions

The bundled permissions are granted to the companion app once the device connects, and last only while the device is associated. Deleting the app or removing the association removes the permissions.

For more information, see AssociationRequest.Builder.setDeviceProfile().

Wi-Fi Aware (NAN) enhancements

Android 12 adds some enhancements to Wi-Fi Aware:

  • On devices running Android 12 and higher, you can use the onServiceLost() callback to be alerted when your app has lost a discovered service due to the service stopping or moving out of range.
  • The way that multiple data-paths (NAN Data Paths) are set up is changing to be more efficient. Earlier versions used L2 messaging to exchange peer information of the initiators, which introduced latency. On devices running Android 12 and higher, the responder (server) can be configured to accept any peer—that is, it doesn’t need to know the initiator information upfront. This speeds up datapath bringup and enables multiple point-to-point links with only one network request.
  • To prevent the framework from rejecting discovery or connection requests due to running out of resources, on devices running Android 12 and higher, you can call WifiAwareManager.getAvailableAwareResources(). This method's return value lets you get the number of available data paths, the number of available publish sessions, and the number of available subscribe sessions.

Concurrent Peer-to-Peer + Internet Connection

When devices targeting Android 12 and higher run on devices with hardware support, using Peer-to-peer connections will not disconnect your existing Wi-Fi connection when creating the connection to the peer device. To check for support for this feature, use WifiManager.isMultiStaConcurrencySupported().

Storage

Android 12 introduces several changes to storage management APIs, which the following sections describe.

New directory for voice recordings

The system recognizes the audio files that are stored in the new Environment.DIRECTORY_RECORDINGS folder as recordings. When your app performs queries on the system's media store, you can retrieve recordings by using the IS_RECORDING flag.

Media management access

Users might trust a particular app to perform media management, such as making frequent edits to media files. If your app targets Android 11 (API level 30) or higher and isn’t the device's default gallery app, you must show a confirmation dialog to the user each time your app attempts to modify or delete a file.

If your app targets Android 12, you can request users to give your app permission to do each of the following without needing to prompt the user for each file operation:

To do so, complete the following steps:

  1. Declare the new MANAGE_MEDIA permission and the READ_EXTERNAL_STORAGE permission in your app's manifest file.

    In order to call createWriteRequest() without showing a confirmation dialog, declare the ACCESS_MEDIA_LOCATION permission as well.

  2. In your app, show a UI to the user to explain why they might want to grant media management access to your app.

  3. Invoke the ACTION_REQUEST_MANAGE_MEDIA intent action. This takes users to the Media management apps screen in system settings. From here, users can grant the special app access.

App storage access

An app can declare and create a custom activity that, when launched, allows the user to manage the data that the app has stored on the user's device. Apps declare this custom "manage space" activity using the android:manageSpaceActivity attribute in the manifest file. File manager apps can launch this "manage space" activity even when the app doesn't export the activity; that is, when the activity sets android:exported to false.

On Android 12, apps that have both the MANAGE_EXTERNAL_STORAGE permission and the QUERY_ALL_PACKAGES permission—such as file management apps—can use the new getManageSpaceActivityIntent() to send users to another app's custom "manage space" activity, if one is defined for that other app.

The getManageSpaceActivityIntent() method takes in a package name and a request code, and it returns one of the following:

  • A PendingIntent, if the app with the specified package name has defined a custom "manage space" activity. The app that called the getManageSpaceActivityIntent() method can then invoke the returned intent to send users to the custom activity.
  • null, if the app with the specified package name doesn't define a "manage space" activity.

Extended file access support

The getMediaUri() method now supports MediaDocumentsProvider URIs, in addition to the existing support for ExternalStorageProvider URIs. The system now grants these URIs to the caller before returning them.

Additionally, the media URIs that are granted by createWriteRequest() now support the APIs in the File class. These APIs provide the ability to read, write, rename, and delete files.

Core functionality

Automatic app updates

Android 12 introduces the setRequireUserAction() method for apps that use the PackageInstaller API. This method allows installer apps to perform app updates without requiring the user to confirm the action.

Device chipset information

Android 12 adds two constants to android.os.Build that expose the SoC chipset vendor and model information via the SDK. You can retrieve this information by calling Build.SOC_MANUFACTURER and Build.SOC_MODEL respectively.


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