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diff --git a/docs/html/preview/api-overview.jd b/docs/html/preview/api-overview.jd deleted file mode 100644 index 87185b1..0000000 --- a/docs/html/preview/api-overview.jd +++ /dev/null @@ -1,931 +0,0 @@ -page.title=API Overview -excludeFromSuggestions=true -sdk.platform.apiLevel=20 -@jd:body - - -<div id="qv-wrapper"> -<div id="qv"> - -<h2>In this document - <a href="#" onclick="hideNestedItems('#toc44',this);return false;" class="header-toggle"> - <span class="more">show more</span> - <span class="less" style="display:none">show less</span></a></h2> - -<ol id="toc44" class="hide-nested"> - <li><a href="#Behaviors">Important Behavior Changes</a> - <ol> - <li><a href="#ART">New Android Runtime (ART)</a></li> - <li><a href="#BehaviorNotifications">If your app implements notifications...</a></li> - <li><a href="#BehaviorMediaControl">If your app uses RemoteControlClient...</a></li> -<li><a href="#BehaviorGetRecentTasks">If your app uses ActivityManager.getRecentTasks()...</a></li> -<li><a href="#64BitSupport">If you are using the Android Native Development Kit (NDK)...</a></li> - </ol> - </li> - <li><a href="#UI">User Interface</a> - <ol> - <li><a href="#MaterialDesign">Material design support</a></li> - <li><a href="#LockscreenNotifications">Lockscreen notifications</a></li> - <li><a href="#NotificationsMetadata">Notifications metadata</a></li> - <li><a href="#Recents">Concurrent documents and activities in the Recents screen</a></li> - <li><a href="#WebView">WebView updates</a></li> - </ol> - </li> - <li><a href="#Graphics">Graphics</a> - <ol> - <li><a href="#OpenGLES-3-1">Support for OpenGL ES 3.1</a></li> - <li><a href="#AndroidExtensionPack">Android Extension Pack</a></li> - </ol> - </li> - <li><a href="#Multimedia">Multimedia</a> - <ol> - <li><a href="#Camera-v2">Camera API for advanced camera capabilities</a></li> - <li><a href="#AudioPlayback">Audio playback</a></li> - <li><a href="#MediaPlaybackControl">Media playback control</a></li> - </ol> - </li> - <li><a href="#Storage">Storage</a> - <ol> - <li><a href="#DirectorySelection">Directory selection</a></li> - </ol> - </li> - <li><a href="#Wireless">Wireless and Connectivity</a> - <ol> - <li><a href="#Multinetwork">Multiple network connections</a></li> - <li><a href="#BluetoothBroadcasting">Bluetooth broadcasting</a></li> - <li><a href="#NFCEnhancements">NFC enhancements</a></li> - </ol> - </li> - <li><a href="#Power">Power Efficiency</a> - <ol> - <li><a href="#JobScheduler">Scheduling Jobs</a></li> - <li><a href="#PowerMeasurementTools">Developer tools for power measurement</a> - </ol> - </li> - <li><a href="#Enterprise">Enterprise</a> - <ol> - <li><a href="#ManagedProvisioning">Managed provisioning</a></li> - <li><a href="#TaskLocking">Task locking</a></li> - </ol> - </li> - <li><a href="#Printing">Printing Framework</a> - <ol> - <li><a href="#PDFRender">Render PDF as bitmap</a></li> - </ol> - </li> - <li><a href="#TestingA11y">Testing & Accessibility</a> - <ol> - <li><a href="#TestingA11yImprovements">Testing and accessibility improvements</a></li> - </ol> - </li> - <li><a href="#IME">IME</a> - <ol> - <li><a href="#Switching">Easier switching between input languages</a></li> - </ol> - </li> - <li><a href="#Manifest">Manifest Declarations</a> - <ol> - <li><a href="#ManifestFeatures">Declarable required features</a></li> - </ol> - </li> -</ol> - -</div> -</div> - -<p>The L Developer Preview gives you an advance look at the upcoming release -for the Android platform, which offers new features for users and app -developers. This document provides an introduction to the most notable APIs.</p> - -<p>The L Developer Preview is intended for <strong>developer early -adopters</strong> and <strong>testers</strong>. If you are interested in -influencing the direction of the Android framework, -<a href="{@docRoot}preview/setup-sdk.html">give the L Developer Preview a -try</a> and send us your feedback!</p> - -<p class="caution"><strong>Caution:</strong> Do not not publish apps -that use the L Developer Preview to the Google Play store.</p> - -<p class="note"><strong>Note:</strong> This document often refers to classes and -methods that do not yet have reference material available on <a -href="{@docRoot}">developer.android.com</a>. These API elements are -formatted in {@code code style} in this document (without hyperlinks). For the -preliminary API documentation for these elements, download the <a -href="http://storage.googleapis.com/androiddevelopers/preview/l-developer-preview-reference.zip">preview -reference</a>.</p> - -<h2 id="Behaviors">Important Behavior Changes</h2> - -<p>If you have previously published an app for Android, be aware that your app - might be affected by changes in the upcoming release.</p> - -<h3 id="ART">New Android Runtime (ART)</h3> - -<p>The 4.4 release introduced a new, experimental Android runtime, ART. Under -4.4, ART was optional, and the default runtime remained Dalvik. With the L -Developer Preview, ART is now the default runtime.</p> - -<p>For an overview of ART's new features, see -<a href="https://source.android.com/devices/tech/dalvik/art.html">Introducing -ART</a>. Some of the major new features are:</p> - -<ul> - <li>Ahead-of-Time (AOT) compilation</li> - <li>Improved garbage collection (GC)</li> - <li>Improved debugging support</li> -</ul> - -<p>Most Android apps should just work without change under ART. However, some -techniques that work on Dalvik do not work on ART. For information about the -most important issues, see -<a href="{@docRoot}guide/practices/verifying-apps-art.html">Verifying App -Behavior on the Android Runtime (ART)</a>. Pay particular attention if:</p> - -<ul> - <li>Your app uses Java Native Interface (JNI) to run C/C++ code.</li> - <li>You use development tools that generate non-standard code (such as some - obfuscators).</li> - <li>You use techniques that are incompatible with compacting garbage - collection. (ART does not currently implement compacting GC, but - compacting GC is under development in the Android Open-Source - Project.)</li> -</ul> - -<h3 id="BehaviorNotifications">If your app implements notifications...</h3> - -<p>Notifications are drawn with dark text atop white (or very light) -backgrounds to match the new material design widgets. Make sure that all your -notifications look right with the new color scheme:</p> - -<div class="figure" style="width:320px"> - <img src="images/hun-example.png" - srcset="images/hun-example@2x.png 2x" - alt="" width="320" height="541" id="figure1" /> - <p class="img-caption"> - <strong>Figure 1.</strong> Fullscreen activity showing a heads-up notification - </p> -</div> - -<ul> - - <li>Update or remove assets that involve color.</li> - - <li>The system automatically inverts action icons in notifications. Use - {@code android.app.Notification. Builder.setColor()} to set an accent color - in a circle behind your {@link android.app.Notification#icon} image.</li> - - <li>The system ignores all non-alpha channels in action icons and the main - notification icon. You should assume that these icons are alpha-only.</li> - -</ul> - -<p>If you are currently adding sounds and vibrations to your notifications by -using the {@link android.media.Ringtone}, {@link android.media.MediaPlayer}, -or {@link android.os.Vibrator} classes, remove this code so that -the system can present notifications correctly in Do -not Disturb mode. Instead, use the {@link android.app.Notification.Builder} -methods instead to add sounds and vibration.</p> - -<p>Notifications now appear in a small floating window -(also called a <em>heads-up notification</em>) when the device is active -(that is, the device is unlocked and its screen is on). These notifications -appear similar to the compact form of your notification, except that the -heads-up notification also shows action buttons. Users can act on, or dismiss, -a heads-up notification without leaving the current app.</p> - -<p>Examples of conditions that may trigger heads-up notifications include:</p> - -<ul> - <li>The user's activity is in fullscreen mode (the app uses -{@link android.app.Notification#fullScreenIntent}), or</li> - <li>The notification has high priority and uses ringtones or - vibrations</li> -</ul> - -<p>If your app implements notifications under those scenarios, make sure that -heads-up notifications are presented correctly.</p> - -<h3 id="BehaviorMediaControl">If your app uses RemoteControlClient...</h3> - -<p>Lockscreens in the L Developer Preview do not show transport controls for -your {@link android.media.RemoteControlClient}. Instead, your app can provide -media playback control from the lockscreen through a notification. This -gives your app more control over the presentation of media buttons, while -providing a consistent experience for users across the lockscreen and -unlocked device.</p> - -<p>The L Developer Preview introduces a new -{@code android.app.Notification.MediaStyle} template which is recommended for -this purpose. {@code MediaStyle} converts notification actions that you added -with -{@link android.app.Notification.Builder#addAction(int, java.lang.CharSequence, - android.app.PendingIntent) -Notification.Builder.addAction()} into compact buttons embedded in your app's -media playback notifications.</p> - -<p>If you are using the new -{@code android.media.session.MediaSession} class -(see <a href="#MediaPlaybackControl">Media Playback Control</a> below), attach -your session token with {@code Notification.MediaStyle.setMediaToken()} to -inform the system that this notification controls an ongoing media session.</p> - -<p>Call {@code -Notification.Builder.setVisibility(Notification.VISIBILITY_PUBLIC)} to mark a -notification as safe to show atop any lockscreen (secure or otherwise). For more -information, see <a href="#LockscreenNotifications">Lockscreen Notifications</a>.</p> - -<h3 id="BehaviorGetRecentTasks">If your app uses ActivityManager.getRecentTasks()...</h3> - -<p>With the introduction of the new <em>concurrent documents and activities -tasks</em> feature in the upcoming release (see <a href="#Recents">Concurrent -documents and activities in Recents screen</a> below), -the {@link android.app.ActivityManager#getRecentTasks -ActivityManager.getRecentTasks()} method is now deprecated to improve user -privacy. For backward compatibility, this method still returns a small subset of -its data, including the calling application’s own tasks and possibly some other -non-sensitive tasks (such as Home). If your app is using this method to retrieve -its own tasks, use {@code android.app.ActivityManager.getAppTasks()} instead to -retrieve that information.</p> - -<h3 id="64BitSupport">If you are using the Android Native Development Kit (NDK)...</h3> - -<p>The L Developer Preview introduces support for 64-bit systems and other - preview NDK APIs. The 64-bit enhancement adds needed address space as Android - usage diversifies and increases performance while still supporting existing - 32-bit apps fully. Use of OpenSSL for cryptography in the platform is also - faster. In addition, this release introduces new native audio and media NDK - APIs and native OpenGL ES (GLES) 3.1 support.</p> - -<p>To use this enhancement, download and install NDK Revision 10 from the -<a href="{@docRoot}tools/sdk/ndk/index.html">Android NDK page</a>. Refer to the -Revision 10 <a href="{@docRoot}tools/sdk/ndk/index.html#Revisions">release notes</a> -for more information about important changes and bug fixes to the NDK.</p> - -<p>If you are using the NDK and want to use the features provided in the L - Developer Preview, download the {@code android-ndk64-r10} package for your - target platform. Due to a - <a href="https://code.google.com/p/android/issues/detail?id=73705">known issue</a>, - you must still download the 64-bit package even if you only want to compile - apps for 32-bit systems. The package also includes - the {@code gcc-4.9} compiler for both 32- and 64-bit apps. The L Developer - Preview API library is located under the {@code platforms/android-L/} API directory.</p> - -<h2 id="UI">User Interface</h2> - -<h3 id="MaterialDesign">Material design support</h3> - -<p>The upcoming release adds support for Android's new <em>material</em> design -style. You can create apps with material design that are visually dynamic and -have UI element transitions that feel natural to users. This support includes:</p> - -<ul> - - <li>The material theme</li> - <li>View shadows</li> - <li>The {@code RecyclerView} widget</li> - <li>Drawable animation and styling effects</li> - <li>Material design animation and activity transition effects</li> - <li>Animators for view properties based on the state of a view</li> - <li>Customizable UI widgets and app bars with color palettes that you control</li> -</ul> - -<p>To learn more about adding material design functionality to your app, see -<a href="{@docRoot}preview/material/index.html">Material Design</a>.</p> - -<h3 id="LockscreenNotifications">Lockscreen notifications</h3> -<p>Lockscreens in the L Developer Preview have the ability to present -notifications. Users can choose via <em>Settings</em> whether to allow -sensitive notification content to be shown over a secure lockscreen.</p> - -<p>Your app can control the level of detail visible when its notifications are -displayed over the secure lockscreen. To control the visibility level, call -{@code android.app.Notification.Builder.setVisibility()} and specify one of these -values:</p> - -<ul> -<li>{@code VISIBILITY_PRIVATE}. Shows basic information, such as the -notification’s icon, but hides the notification’s full content.</li> -<li>{@code VISIBILITY_PUBLIC}. Shows the notification’s full content.</li> -<li>{@code VISIBILITY_SECRET}. Shows nothing, excluding even the -notification’s icon.</li> -</ul> - -<p>When {@code VISIBILITY_PRIVATE} is set, you can also provide a redacted -version of the notification content that hides personal details. For example, -an SMS app might display a notification that shows "You have 3 new text messages." -but hides the message content and senders. To provide this alternative -notification, first create the replacement notification using -{@link android.app.Notification.Builder}. When you create the private -notification object, attach the replacement notification to it through the -{@code Notification.Builder.setPublicVersion()} method.</p> - -<h3 id="NotificationsMetadata">Notifications metadata</h3> -<p>The L Developer Preview uses metadata associated with your app notifications -to sort the notifications more intelligently. To set the metadata, call the -following methods in {@code android.app.Notification.Builder} when you -construct the notification:</p> - -<ul> -<li>{@code setCategory()}. Depending on the message category, this tells -the system how to handle your app notifications when the device is -in <em>Do not Disturb</em> mode (for example, if your notification represents an -incoming call, instant message, or alarm). -<li>{@code setPriority()}. Notifications with the priority field set to -{@code PRIORITY_MAX} or {@code PRIORITY_HIGH} will appear in a small floating -window if the notification also has sound or vibration.</li> -<li>{@code addPerson()}. Allows you to add a list of people to a notification. -Your app can use this to signal to the system that it should group together -notifications from the specified people, or rank notifications from these -people as being more important.</li> -</ul> - -<h3 id="Recents">Concurrent documents and activities in the Recents screen</h3> - -<p>In previous releases, the -<a href="{@docRoot}design/get-started/ui-overview.html">Recents screen</a> -could only display a single task for each app that the user interacted with -most recently. Now your app can open more tasks as -needed for additional concurrent activities for documents. -This feature facilitates multitasking by letting users quickly switch between -individual activities and documents from the Recents screen, with a consistent -switching experience across all apps. -Examples of such concurrent tasks might include open tabs in a web -browser app, documents in a productivity app, concurrent matches in -a game, or chats in a messaging app. Your app can manage its tasks -through the {@code android.app.ActivityManager.AppTask} class.</p> - -<p>To insert a logical break so that the system treats your activity as a new -task, use {@code android.content.Intent.FLAG_ACTIVITY_NEW_DOCUMENT} when -launching the activity with {@link android.app.Activity#startActivity(android.content.Intent) -startActivity()}. You can also get this behavior by declaring the -<a href="{@docRoot}guide/topics/manifest/activity-element.html"><activity></a> -attribute {@code documentLaunchMode="intoExisting"} or {@code ="always"} in your -manifest.</p> - -<p>You can also mark that a task should be removed from the Recents screen -when all its activities are closed. To do this, use {@code -android.content.Intent.FLAG_ACTIVITY_AUTO_REMOVE_FROM_RECENTS} when starting the -root activity for -the task. You can also set this behavior for an activity by declaring the -<a href="{@docRoot}guide/topics/manifest/activity-element.html"><activity></a> -attribute {@code autoRemoveFromRecents=“true”} in your manifest.</p> - -<p>To avoid cluttering the Recents screen, you can set the maximum number of -tasks from your app that can appear in that screen. To do this, set the -<a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a> -attribute {@code android:maxRecent}. The current maximum that can be specified -is 100 tasks per user.</a></p> - -<h3 id="WebView">WebView updates</h3> -<p>The L Developer Preview updates the {@link android.webkit.WebView} -implementation to Chromium M36, bringing security and stability enhancements, -as well as bug fixes. The default user-agent string for a -{@link android.webkit.WebView} running on the L Developer Preview has -been updated to incorporate 36.0.0.0 as the version number.</p> - -<p>Additionally, this release brings support for the -<a href="http://webaudio.github.io/web-audio-api/" class="external-link">WebAudio</a>, -<a href="https://www.khronos.org/webgl/" class="external-link">WebGL</a>, and -<a href="http://www.webrtc.org/" class="external-link">WebRTC</a> open standards. To learn more about -the new features included in this release, see <a href="https://developer.chrome.com/multidevice/webview/overview" class="external-link">WebView for Android</a>.</p> - -<h2 id="Graphics">Graphics</h2> - -<h3 id="OpenGLES-3-1">Support for OpenGL ES 3.1</h3> -<p>The L Developer Preview adds Java interfaces and native support for OpenGL -ES 3.1. Key new functionality provided in OpenGL ES 3.1 includes:</p> - -<ul> -<li>Compute shaders -<li>Separate shader objects -<li>Indirect draw commands -<li>Multisample and stencil textures -<li>Shading language improvements -<li>Extensions for advanced blend modes and debugging -<li>Backward compatibility with OpenGL ES 2.0 and 3.0 -</ul> - -<p>The Java interface for OpenGL ES 3.1 on Android is provided with {@code GLES31}. When -using OpenGL ES 3.1, be sure that you declare it in your manifest file with the -<a href="{@docRoot}guide/topics/manifest/uses-feature-element.html">{@code <uses-feature>}</a> -tag and the {@code android:glEsVersion} attribute. For example:</p> - -<pre> -<manifest> - <uses-feature android:glEsVersion="0x00030001" /> - ... -</manifest> -</pre> - -<p>For more information about using OpenGL ES, including how to check the -device’s supported OpenGL ES version at runtime, see the -<a href="{@docRoot}guide/topics/graphics/opengl.html">OpenGL ES API guide</a>.</p> - -<h3 id="AndroidExtensionPack">Android Extension Pack</h3> - -<p>In addition to OpenGL ES 3.1, this release provides an extension pack with Java interfaces and -native support for advanced graphics functionality. These extensions are treated as a single -package by Android. (If the {@code ANDROID_extension_pack_es31} extension is present, your app can -assume all extensions in the package are present and enable the shading language features with -a single {@code #extension} statement.</p> -<p>The extension pack supports:</p> -<ul> -<li>Guaranteed fragment shader support for shader storage buffers, images, and - atomics (fragment shader support is optional in OpenGL ES 3.1.)</li> -<li>Tessellation and geometry shaders</li> -<li>ASTC (LDR) texture compression format</li> -<li>Per-sample interpolation and shading</li> -<li>Different blend modes for each color attachment in a frame buffer</li> -</ul> - -<p>The Java interface for the extension pack is provided with {@code GLES31Ext}. -In your app manifest, you can declare that support for the extension pack is -required, with the -<a href="{@docRoot}guide/topics/manifest/uses-feature-element.html">{@code <uses-feature>}</a> -tag, but the precise syntax is not finalized in the L Developer Preview.</p> - -<h2 id="Multimedia">Multimedia</h2> - -<h3 id="Camera-v2">Camera API for advanced camera capabilities</h3> - -<p>The L Developer Preview introduces the new {@code android.hardware.camera2} -API to facilitate fine-grain photo capture and image processing. You can now -programmatically access the camera devices available to the system with {@code -CameraManager.getCameraIdList()} and connect to a specific device with {@code -CameraManager.openCamera()}. To start capturing images, create a {@code -CameraCaptureSession} and specify the {@link android.view.Surface} objects for -the captured images. The {@code CameraCaptureSession} can be configured to take -single shots or multiple images in a burst.</p> - -<p>To be notified when new images are captured, implement the -{@code CameraCaptureSession.CaptureListener()} interface and set it in your -capture request. Now when the system completes the image capture request, your -{@code CameraCaptureSession.CaptureListener()} receives a call to -{@code onCaptureCompleted()}, providing you with the image capture metadata in a -{@code CaptureResult}.</p> - -<p>To see an example of how to use the updated Camera API, refer to the {@code Camera2Basic} -and {@code Camera2Video} implementation samples in this release.</p> - -<h3 id="AudioPlayback">Audio playback</h3> -<p>This release includes the following changes to - {@link android.media.AudioTrack}:</p> -<ul> - <li>Your app can now supply audio data in floating-point format -({@code android.media.AudioFormat.ENCODING_PCM_FLOAT}). This permits greater -dynamic range, more consistent precision, and greater headroom. Floating-point -arithmetic is especially useful during intermediate calculations. Playback -end-points use integer format for audio data, and with lower bit-depth. (In the -L Developer Preview, portions of the internal pipeline are not yet -floating-point.) - <li>Your app can now supply audio data as a {@link java.nio.ByteBuffer}, in -the same format as provided by {@link android.media.MediaCodec}. - <li>The {@code WRITE_NON_BLOCKING} option can simplify buffering and - multithreading for some apps. -</ul> - -<h3 id="MediaPlaybackControl">Media playback control</h3> -<p>You can now build your own media controller app with the new -{@code android.media.session.MediaController} class, which provides -simplified transport controls APIs that replace those in -{@link android.media.RemoteControlClient}. The {@code MediaController} class -allows thread-safe control of playback from a non-UI process, making it easier -to control your media playback service from your app’s user interface. - -<p>You can also create multiple controllers to send playback commands, -media keys, and other events to the same ongoing -{@code android.media.session.MediaSession}. When you add a controller, you must -call {@code MediaSession.getSessionToken()} to request an access -token in order for your app to interact with the session.</p> - -<p>You can now send transport commands such as "play", "stop", "skip", and -"set rating" by using {@code MediaController.TransportControls}. To handle -in-bound media transport commands from controllers attached to the session, -override the callback methods in -{@code MediaSession.TransportControlsCallback}.</p> - -<p>You can also create rich notifications that allow playback control tied to a -media session with the new {@code android.app.Notification.MediaStyle} class. By -using the new notification and media APIs, you will ensure that the System UI -knows about your playback and can extract and show album art.</p> - -<h2 id="Storage">Storage</h2> - -<h3 id="DirectorySelection">Directory selection</h3> - -<p>The L Developer Preview extends the <a href="{@docRoot}guide/topics/providers/document-provider.html">Storage Access Framework</a> to let users select an entire directory subtree, -giving apps read/write access to all contained documents without requiring user -confirmation for each item.</p> - -<p>To select a directory subtree, build and send an -{@code android.intent.action.OPEN_DOCUMENT_TREE} {@link android.content.Intent}. -The system displays all -{@link android.provider.DocumentsProvider} instances that support subtree selection, -letting the user browse and select a directory. The returned URI represents access to the selected -subtree. You can then use {@code DocumentsContract.buildChildDocumentsUriUsingTree()} -and {@code DocumentsContract.buildDocumentUriUsingTree()} along with -{@code ContentResolver.query()} to explore the subtree.</p> - -<p>The new {@code DocumentsContract.createDocument()} method lets you create -new documents or directories anywhere under the subtree. To manage -existing documents, use {@code DocumentsContract.renameDocument()} and -{@code DocumentsContract.deleteDocument()}. Check {@code DocumentsContract.Document.COLUMN_FLAGS} -to verify provider support for these calls before issuing them.</p> - -<p>If you're implementing a {@link android.provider.DocumentsProvider} and want -to support subtree selection, implement {@code DocumentsProvider.isChildDocument()} -and include {@code Documents.Contract.FLAG_SUPPORTS_IS_CHILD} in your -{@code Root.COLUMN_FLAGS}.</p> - -<p>The L Developer Preview also introduces new package-specific directories on -shared storage where your app can place media files for inclusion in -{@link android.provider.MediaStore}. The new -{@code android.content.Context.getExternalMediaDirs()} returns paths to these -directories on all shared storage devices. Similarly to -{@link android.content.Context#getExternalFilesDir(java.lang.String) Context.getExternalFilesDir()}, -no additional permissions are needed by your app to access the returned paths. The -platform periodically scans for new media in these directories, but you can also -use {@link android.media.MediaScannerConnection} to explicitly scan for new -content.</p> - -<h2 id="Wireless">Wireless & Connectivity</h2> - -<h3 id="Multinetwork">Multiple network connections</h3> -<p>The L Developer Preview provides new multi-networking APIs. These let your app -dynamically scan for available networks with specific capabilities, and -establish a connection to them. This is useful when your app requires a -specialized network, such as an SUPL, MMS, or carrier-billing network, or if -you want to send data using a particular type of transport protocol.</p> - -<p>To select and connect to a network dynamically from your app follow these -steps:</p> - -<ol> - <li>Create a {@link android.net.ConnectivityManager}.</li> - <li>Create a - {@code android.net.NetworkRequest} to specify the network features and transport - type your app is interested in.</li> - <li>To scan for suitable networks, call - {@code ConnectivityManager.requestNetwork()} or - {@code ConnectivityManager.registerNetworkCallback()}, and pass in the - {@code NetworkRequest} object and an implementation of - {@code ConnectivityManager.NetworkCallbackListener}.</li> - -</ol> - -<p>When the system detects a suitable network, it connects to the network and -invokes the {@code NetworkCallbackListener.onAvailable()} callback. You can use -the {@code android.net.Network} object from the callback to get additional -information about the network, or to direct traffic to use the selected -network.</p> - -<h3 id="BluetoothBroadcasting">Bluetooth broadcasting</h3> -<p>Android 4.3 introduced platform support for - <a href="{@docRoot}guide/topics/connectivity/bluetooth-le.html">Bluetooth Low Energy</a> -(BLE) in the central role. In the L Developer Preview, an Android device can now -act as a Bluetooth LE <em>peripheral device</em>. Apps can use this capability -to make their presence known to -nearby devices. For instance, you can build apps that allow a device to -function as a pedometer or health monitor and communicate its data with another -BLE device.</p> - -<p>The new {@code android.bluetooth.le} APIs enable your apps to broadcast -advertisements, scan for responses, and form connections with nearby BLE devices. -You must add the {@code android.permission.BLUETOOTH_ADMIN} permission in your -manifest in order for your app to use the new advertising and scanning features.</a> - -<p>To begin Bluetooth LE advertising so that other devices can discover -your app, call {@code android.bluetooth.le.BluetoothAdvertiser.startAdvertising()} -and pass in an implementation of the -{@code android.bluetooth.le.AdvertiseCallback} class. The callback object -receives a report of the success or failure of the advertising operation.</p> - -<p> The L Developer Preview introduces the {@code -android.bluetooth.le.ScanFilter} class so that your app can scan for only the -specific types of devices it is interested in. To begin scanning for Bluetooth -LE devices, call {@code android.bluetooth.le.BluetoothLeScanner.startScan()} and -pass in a list of filters. In the method call, you must also provide an -implementation of {@code android.bluetooth.le.ScanCallback} to report if a -Bluetooth LE advertisement is found. </p> - -<h3 id="NFCEnhancements">NFC enhancements</h3> -<p>The L Developer Preview adds these enhancements to enable wider and more -flexible use of NFC:</p> - -<ul> -<li>Android Beam is now available in the share menu. -<li>Your app can invoke the Android Beam on the user’s device to share data by -calling {@code android.nfc.NfcAdapter.invokeBeam()}. This avoids the need for -the user to manually tap the device against another NFC-capable device to -complete the data transfer. -<li>You can use the new {@code android.nfc.NdefRecord.createTextRecord()} method -to create an NDEF record containing UTF-8 text data. -<li>If you are developing a payment app, you now have the ability to -register an NFC application ID (AID) dynamically by calling -{@code android.nfc.cardemulation.CardEmulation.registerAidsForService()}. -You can also use {@code android.nfc.cardemulation.CardEmulation.setPreferredService()} -to set the preferred card emulation service that should be used when a specific -activity is in the foreground. -</ul> - -<h2 id="Power">Power Efficiency</h2> - -<h3 id="JobScheduler">Scheduling jobs</h3> -<p>The L Developer Preview provides a new {@code android.app.job.JobScheduler} -API that lets you optimize battery life by defining jobs for the system to run -asynchronously at a later time or under specified conditions (such as when the -device is charging). This is useful in such situations as:</p> -<ul> - <li>The app has non-user-facing work that you can defer.</li> - <li>The app has work you'd prefer to do when the unit is plugged in.</li> - <li>The app has a task that requires network access (or requires a Wi-Fi - connection).</li> - <li>The app has a number of tasks that you want to run as a batch on a regular - schedule.</li> - -</ul> - -<p>A unit of work is encapsulated by a {@code android.app.job.JobInfo} object. -This object provides an exact description of the criteria to be used for -scheduling.</p> - -<p>Use the {@code android.app.job.JobInfo.Builder} to configure how the -scheduled task should run. You can schedule the task to run under specific -conditions, such as:</p> - -<ul> - <li>The device is charging</li> - <li>The device is connected to an unmetered network</li> - <li>The system deems the device to be idle</li> - <li>Completion with a minimum delay or within a specific deadline.</li> -</ul> - -<p>For example, you can add code like this to run your task on an -unmetered network:</p> - -<pre> -JobInfo uploadTask = new JobInfo.Builder(mJobId, mServiceComponent) - .setRequiredNetworkCapabilities(JobInfo.NetworkType.UNMETERED) - .build(); - -JobScheduler jobScheduler = - (JobScheduler) context.getSystemService(Context.JOB_SCHEDULER_SERVICE) -jobScheduler.schedule(uploadTask); -</pre> - -<p>To see an example of how to use the {@code JobScheduler} API, refer to the -{@code JobSchedulerSample} implementation sample in this release.</p> - -<h3 id="PowerMeasurementTools">Developer tools for power measurement</h3> -<p>The L Developer Preview provides several new developer tools and APIs to help -you better measure and understand your app's power usage.</p> - -<dl> -<dt><strong>batterystats</strong></dt> -<dd> -<p>The {@code dumpsys batterystats} command allows you to generate interesting -statistical data about battery usage on a device, organized by unique user ID -(UID). The statistics generated by the tool include:</p> - -<ul> -<li>History of battery related events -<li>Global statistics for the device -<li>Approximated power use per UID and system component -<li>Per-app mobile ms per packet -<li>System UID aggregated statistics -<li>App UID aggregated statistics -</ul> - -<p>Use the {@code --help} option to learn about the various options for -tailoring the output. For example, to print battery usage -statistics for a given app package since the device was last charged, run this -command: -<pre> -$ adb shell dumpsys batterystats --charged <package-name> -</pre> -</dd> - -<dt><strong>Battery Historian</strong></dt> -<dd> -<p>The Battery Historian tool ({@code historian.par}) analyzes Android -bug reports from the L Developer Preview and creates an HTML visualization of -power-related events. It can -also visualize power consumption data from a power monitor, and attempts to -map power usage to the wake locks seen. You can find the Battery Historian tool -in {@code <sdk>/tools}.</p> - -<img src="images/battery_historian.png" - srcset="images/battery_historian@2x.png 2x" - alt="" width="760" height="462" - id="figure2" /> -<p class="img-caption"> - <strong>Figure 2.</strong>HTML visualization generated by the Battery - Historian tool. -</p> - -<p>For best results, you should first enable full wake lock reporting, to allow -the Battery Historian tool to monitor uninterrupted over an extended period of -time:</p> -<pre> -$ adb shell dumpsys batterystats --enable full-wake-history -</pre> - -<p>You should also reset battery statistics at the beginning of a -measurement:</p> -<pre> -$ adb shell dumpsys batterystats --reset -</pre> - -<p>To generate an HTML visualization:</p> -<pre> -$ historian.par [-p powerfile] bugreport.txt > out.html -</pre> -</dd> - -</dl> - -<h2 id="Enterprise">Enterprise</h2> -<h3 id="ManagedProvisioning">Managed provisioning</h3> - -<div class="figure" style="width:360px"> - <img src="images/managed_apps_launcher.png" - srcset="images/managed_apps_launcher@2x.png 2x" - alt="" width="360" height="609" id="figure3" /> - <p class="img-caption"> - <strong>Figure 3.</strong> Launcher screen showing managed apps (marked with - a lock badge) - </p> -</div> - -<p>The L Developer Preview provides new functionality for running apps within -an enterprise environment. A -<a href="{@docRoot}guide/topics/admin/device-admin.html">device administrator</a> can -initiate a managed provisioning process to add a co-present but separate <em>managed profile</em> to a device, if the user has an existing personal account. -Apps that are associated with managed profiles will appear alongside -non-managed apps in the user’s Launcher, Recent apps screen, and notifications.</p> - -<p>To start the managed provisioning process, send {@code -ACTION_PROVISION_MANAGED_PROFILE} in an {@link android.content.Intent}. If the -call is successful, the system triggers the {@code -android.app.admin.DeviceAdminReceiver. onProfileProvisioningComplete()} callback. -You can then call {@code app.admin.DevicePolicyManager. setProfileEnabled()} to -enable this managed profile.</p> - -<p>If you are developing a Launcher app, you can use the new {@code -android.content.pm.LauncherApps} class to get a list of launchable activities -for the current user and any associated managed profiles. Your Launcher can make -the managed apps visually prominent by appending a “work” badge to the icon -drawable with {@code android.os.UserManager. getBadgeDrawableForUser()}.</p> - -<p>To see an example of how to use the new functionality, refer to the -{@code BasicManagedProfile} implementation sample in this release.</p> - -<h3 id="TaskLocking">Task locking</h3> -<p>The L Developer Preview introduces a new task locking API that -lets you temporarily restrict users from leaving your app or being interrupted -by notifications. This could be used, for example, if you are developing an -education app to support high stakes assessment requirements on Android. -Once your app activates this mode, users will not be able to see -notifications, access other apps, or return to the Home screen, until your -app exits the mode.</p> - -<p>To prevent unauthorized usage, only authorized apps can activate task locking. -Furthermore, task locking authorization must be granted by a -specially-configured <em>device owner</em> app, through the {@code android.app.admin.DevicePolicyManager.setLockTaskComponents()} method.</p> - -<p>To set up a device owner, follow these steps:</p> -<ol> -<li>Attach a device running an Android <a href="https://source.android.com/source/building-running.html" class="external-link">{@code userdebug}</a> build to your development machine.</li> -<li>Install your device owner app.</li> -<li>Create a {@code device_owner.xml} file and save it to the {@code /data/system} -directory on the device. -<pre> -$ adb root -$ adb shell stop -$ rm /tmp/device_owner.xml -$ echo "<?xml version='1.0' encoding='utf-8' standalone='yes' ?>" ->> /tmp/device_owner.xml -$ echo "<device-owner package=\"<your_device_owner_package>\" -name=\"*<your_organization_name>\" />" >> /tmp/device_owner.xml -$ adb push /tmp/device_owner.xml /data/system/device_owner.xml -$ adb reboot -</pre> -</li> -</ol> - -<p>Before using the task locking API in your app, verify that your activity is -authorized by calling {@code DevicePolicyManager.isLockTaskPermitted()}.</p> - -<p>To activate task locking, call -{@code android.app.Activity.startLockTask()} from your authorized activity.</p> - -<p>When task locking is active, the following behavior takes effect:</p> - -<ul> -<li>The status bar is blank, and user notifications and status information is -hidden.</li> -<li>The Home and Recent Apps buttons are hidden.</li> -<li>Other apps may not launch new activities.</li> -<li>The current app may start new activities, as long as doing so does not -create new tasks.</li> -<li>The user remains locked on your app until an authorized activity calls -{@code Activity.stopLockTask()}.</li> -</ul> - -<h2 id="Printing">Printing Framework</h2> - -<h3 id="PDFRender">Render PDF as bitmap</h3> -<p>You can now render PDF document pages into bitmap images for printing by -using the new {@code android.graphics.pdf.PdfRenderer} class. You must specify a -{@link android.os.ParcelFileDescriptor} that is seekable (that is, the content -can be randomly accessed) on which the system writes the the printable content. -Your app can obtain a page for rendering with {@code openPage()}, then call -{@code render()} to turn the opened {@code PdfRenderer.Page} into a bitmap. You -can also set additional parameters if you only want to convert a portion of the -document into a bitmap image (for example, to implement -<a href="http://en.wikipedia.org/wiki/Tiled_rendering" class="external-link">tiled rendering</a> in -order to zoom in on the document).</p> - -<h2 id="TestingA11y">Testing & Accessibility </h2> - -<h3 id="TestingA11yImprovements">Testing and accessibility improvements</h3> -<p>The L Developer Preview adds the following support for testing and -accessibility:</p> - -<ul> -<li>You can use the new {@code android.app.UiAutomation.getWindowAnimationFrameStats()} -and {@code android.app.UiAutomation.getWindowContentFrameStats()} methods to -capture frame statistics for window animations and content. This lets you -write instrumentation tests to evaluate if the app under test is rendering -frames at a sufficient refresh frequency to provide a smooth user experience. - -<li>You can execute shell commands from your instrumentation test with the new -{@code android.app.UiAutomation.executeShellCommand()}. The command execution -is similar to running {@code adb shell} from a host connected to the device. This -allows you to use shell based tools such as {@code dumpsys}, {@code am}, -{@code content}, and {@code pm}. - -<li>Accessibility services and test tools that use the accessibility APIs -(such as <a href="{@docRoot}tools/help/uiautomator/index.html">uiautomator</a>) -can now retrieve detailed information about the properties of windows on the -screen that sighted users can interact with. To retrieve a list of -{@code android.view.accessibility.AccessibilityWindowInfo} objects -representing the windows information, call the new -{@code android.accessibilityservice.AccessibilityService.getWindows()} method. -<li>You can use the new {@code android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction} to define standard or customized -actions to perform on an {@link android.view.accessibility.AccessibilityNodeInfo}. -The new {@code AccessibilityAction} class replaces the actions-related APIs -previously found in {@code AccessibilityNodeInfo}. -</ul> - -<h2 id="IME">IME</h2> - -<h3 id="Switching">Easier switching between input languages</h3> - -<p>Beginning in the L Developer Preview, users can more easily switch between -all <a href="{@docRoot}guide/topics/text/creating-input-method.html">input -method editors (IME)</a> supported by the platform. Performing the designated -switching action (usually touching a Globe icon on the soft keyboard) will cycle -among all such IMEs. This change takes place in -{@link android.view.inputmethod.InputMethodManager#shouldOfferSwitchingToNextInputMethod -InputMethodManager.shouldOfferSwitchingToNextInputMethod()}.</p> - -<p>In addition, the framework now checks whether the next IME includes a -switching mechanism at all (and, thus, whether that IME supports switching to -the IME after it). An -IME with a switching mechanism will not cycle to an IME without one. This -change takes place in -{@link android.view.inputmethod.InputMethodManager#switchToNextInputMethod -InputMethodManager.switchToNextInputMethod}. - -<p>To see an example of how to use the updated IME-switching APIs, refer to the -updated soft-keyboard implementation sample in this release.</p> - -<h2 id="Manifest">Manifest Declarations</h2> - -<h3 id="ManifestFeatures">Declarable required features</h3> -<p>The following values are now supported in the -<a href="{@docRoot}guide/topics/manifest/uses-feature-element.html">{@code <uses-feature>}</a> -element, so you can ensure that your app is installed only on devices that provide the features -your app needs.</p> - -<ul> -<li>{@code FEATURE_LEANBACK}. Declares that your app must be installed only on -devices that support the -<a href="{@docRoot}training/tv/index.html">Android TV</a> user interface. -Example: -<pre> -<uses-feature android:name="android.software.leanback" - android:required="true" /> -</pre> - -<li>{@code FEATURE_WEBVIEW}. Declares that your app must only be installed on -devices that fully implement the {@code android.webkit.*} APIs. Example: -<pre> -<uses-feature android:name="android.software.webview" - android:required="true" /> -</pre> -</ul> - -<p class="note">For a detailed view of all API changes in the L Developer Preview, see the -<a href="{@docRoot}preview/reference.html">API Differences Report</a>.</p> |