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      1 page.title=Android 2.2 APIs
      2 excludeFromSuggestions=true
      3 sdk.platform.version=2.2
      4 sdk.platform.apiLevel=8
      5 sdk.platform.majorMinor=minor
      6 
      7 @jd:body
      8 
      9 <div id="qv-wrapper">
     10 <div id="qv">
     11 
     12 <h2>In this document</h2>
     13 <ol>
     14   <li><a href="#features">Platform Highlights</a></li>
     15   <li><a href="#api-level">API Level</a></li>
     16   <li><a href="#api">Framework API Changes</a>
     17 
     18     </ol>
     19   </li>
     20 </ol>
     21 
     22 <h2>Reference</h2>
     23 <ol>
     24 <li><a
     25 href="{@docRoot}sdk/api_diff/{@sdkPlatformApiLevel}/changes.html">API
     26 Differences Report &raquo;</a> </li>
     27 </ol>
     28 
     29 </div>
     30 </div>
     31 
     32 <p>
     33 <em>API Level:</em>&nbsp;<strong>{@sdkPlatformApiLevel}</strong></p>
     34 
     35 <p>Android {@sdkPlatformVersion} is a {@sdkPlatformMajorMinor} platform release including user
     36 features, developer features, API changes, and bug
     37 fixes. For  information on developer features and API changes, see the
     38 <a href="#api">Framework API</a> section.</p>
     39 
     40 <p>For developers, the Android {@sdkPlatformVersion} platform is available as a
     41 downloadable component for the Android SDK. The downloadable platform includes
     42 an Android library and system image, as well as a set of emulator skins and
     43 more. To get started developing or testing against Android {@sdkPlatformVersion},
     44 use the Android SDK Manager to download the platform into your SDK.</p>
     45 
     46 
     47 <h2 id="features">Platform Highlights</h2>
     48 
     49 <p>For a list of new user features and platform highlights, see the <a
     50 href="http://developer.android.com/about/versions/android-2.2-highlights.html">Android
     51 2.2 Platform Highlights</a> document.</p>
     52 
     53 
     54 <h2 id="api-level">API Level</h2>
     55 
     56 <p>The Android {@sdkPlatformVersion} platform delivers an updated version of
     57 the framework API. The Android {@sdkPlatformVersion} API
     58 is assigned an integer identifier &mdash;
     59 <strong>{@sdkPlatformApiLevel}</strong> &mdash; that is
     60 stored in the system itself. This identifier, called the "API Level", allows the
     61 system to correctly determine whether an application is compatible with
     62 the system, prior to installing the application. </p>
     63 
     64 <p>To use APIs introduced in Android {@sdkPlatformVersion} in your
     65 application, you need to set the proper value, "{@sdkPlatformApiLevel}", in the
     66 <code>android:minSdkVersion</code> attributes of the <code>&lt;uses-sdk&gt;</code>
     67 element in your application's manifest. </p>
     68 
     69 <p>For more information about how to use API Level, see the <a
     70 href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#ApiLevels">API Levels</a> document. </p>
     71 
     72 
     73 <h2 id="api">Framework API Changes</h2>
     74 
     75 <p>The sections below provide information about changes made to the application
     76 framework API provided by the Android {@sdkPlatformVersion} platform.</p>
     77 
     78 <h3 id="install-loc">App installation on external storage media</h3>
     79 
     80 <p>The Android platform now allows applications to request installation onto the
     81 device's external storage media (such as the SD card), as an alternative to
     82 installation onto the device's internal memory. </p>
     83 
     84 <p>Application developers can express the preferred installation location for
     85 their applications by means of a new attribute of <code>&lt;manifest&gt;</code>
     86 in the manifest file, <a
     87 href="{@docRoot}guide/topics/manifest/manifest-element.html#install"><code>
     88 android:installLocation</code></a>. The attribute supports three values:
     89 <code>"internalOnly"</code>, <code>"preferExternal"</code>, and
     90 <code>"auto"</code>. At install time, the system checks the value of
     91 <code>android:installLocation</code> and installs the application
     92 <code>.apk</code> according to the preferred location, if possible. If the
     93 application has requested external installation, the system installs it into a
     94 private, encrypted partition in the external media. Once an application .apk is
     95 installed externally, the system lets the user change the storage location of
     96 the .apk and move it onto the device's internal memory if needed (and vice
     97 versa), through Manage Applications in the user settings.</p>
     98 
     99 <p>By default, the system installs all applications onto the device's internal
    100 memory, except for those that explicitly request external installation. This
    101 means that the system will always install legacy applications onto internal
    102 memory, since they do not have access to the
    103 <code>android:installLocation</code> attribute. However, it is possible to
    104 configure and compile a legacy application such that it is installed internally
    105 on older versions of the platform and externally on Android 2.2 and later
    106 platforms, if necessary. </p>
    107 
    108 <p>Note that requesting installation onto the device's external media is not
    109 suitable for all applications, particularly because the external media may be
    110 removable and unmounting/remounting may disrupt the user experience and system
    111 settings.</p>
    112 
    113 <p>For more information about setting a preferred install location for your
    114 application, including a discussion of what types of applications should and
    115 should not request external installation, please read the <a
    116 href="{@docRoot}guide/topics/data/install-location.html">App Install Location</a>
    117 document. </p>
    118 
    119 <h3 id="backup-manager">Data backup</h3>
    120 
    121 <p>The platform now provides a generalized backup service that
    122 applications can use to backup and restore user data, to ensure that users can
    123 maintain their data when switching devices or reinstalling the application. The
    124 Backup Manager handles the work of transporting the application data to and from
    125 the backup storage area in the cloud. The Backup Manager can store any type of
    126 data, from arbitrary data to files, and manages backup and restore operations
    127 in an atomic manner. For more information, see <a
    128 href="{@docRoot}guide/topics/data/backup.html">Data Backup</a>.</p>
    129 
    130 <h3>Graphics</h3>
    131 
    132 <ul>
    133 <li>New OpenGL ES 2.0 APIs in {@link android.opengl.GLES20 android.opengl.GLES20}.</li>
    134 <li>New {@link android.opengl.ETC1}, {@link android.opengl.ETC1Util}, and {@link android.opengl.ETC1Util.ETC1Texture} classes and utility methods for using ETC1 for texture compression.</li>
    135 <li>New {@link android.graphics.ImageFormat} class.</li>
    136 <li>New {@link android.graphics.YuvImage YUV image format API} to enable compression from YUV to JPEG and manipulation of YUV data.</li>
    137 </ul>
    138 
    139 <h3>Media</h3>
    140 
    141 <ul>
    142 <li>New APIs in {@link android.media.AudioManager android.media.AudioManager} for managing audio focus, transport control, transient loss of audio focus, ducking.</li>
    143 <li>New broadcast intent for routing audio to SCO &mdash; {@link android.media.AudioManager#ACTION_SCO_AUDIO_STATE_CHANGED} with extras indicating new state.</li>
    144 <li>New APIs in {@link android.media.SoundPool} to detect completion of sound-loading.</li>
    145 <li>New APIs in {@link android.media.SoundPool} for auto pause and resume.</li>
    146 <li>New APIs in {@link android.media.MediaRecorder} for specifying audio settings for number of channels, encoding and sampling rates, sampling rate.</li>
    147 <li>New APIs for adding files to the media database, so that they are automatically scanned. See {@link android.media.MediaScannerConnection#scanFile(Context, String[], String[], OnScanCompletedListener) MediaScannerConnection.scanFile} and {@link android.media.MediaScannerConnection.OnScanCompletedListener MediaScannerConnection.OnScanCompletedListener}.</li>
    148 </ul>
    149 
    150 <h3>Speech recognition and third-party recognition engines</h3>
    151 
    152 <ul>
    153 <li>The platform provides new speech-recognition APIs that allow applications to have a richer interaction with the available voice recognizer. For example, the APIs are sufficient to integrate voice recognition deeply into an IME.</li>
    154 <li>The platform also provides a {@link android.speech.RecognitionService} base class that lets third-party developers create plug-in recognition engines. </li>
    155 <li>New {@link android.speech.RecognitionListener} interface to receive callbacks.</li>
    156 <li>New {@link android.speech.RecognizerIntent} extras that let a requester app specify details as preferred language, minimum length in milliseconds, and so on.</li>
    157 </ul>
    158 
    159 <h3>Camera and camcorder</h3>
    160 
    161 <ul>
    162 <li>Changes to camera preview API to improve efficieny of preview pipeline. </li>
    163 <li>New display orientation for camera (it can now work in portrait orientation).</li>
    164 <li>New APIs in {@link android.hardware.Camera android.hardware.Camera} for managing zoom level.</li>
    165 <li>New APIs {@link android.hardware.Camera.Parameters android.hardware.Camera.Parameters} for querying and setting device camera settings such as focal length, exposure, zoom level, view angle, and others.</li>
    166 <li>New {@link android.media.ThumbnailUtils thumbnail} utility for video and image thumbnails.</li>
    167 <li>New {@link android.media.CamcorderProfile} and {@link android.media.CamcorderProfile} classes enable apps to determine device hardware camera capablities.</li>
    168 <li>New support in {@link android.media.ExifInterface android.media.ExifInterface} for retrieving GPS and focal length.</li>
    169 </ul>
    170 
    171 <h3>Device policy manager</h3>
    172 
    173 <p>New device policy management APIs allow developers to write "device
    174 administrator" applications that can control security features of the device,
    175 such as the minimum password strength, data wipe, and so on. Users can select
    176 the administrators that are enabled on their devices. For more information, see
    177 the {@link android.app.admin android.app.admin} classees or the example
    178 application code in <a
    179 href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/DeviceAdminSample.html">DeviceAdminSample.java</a>.</p>
    180 
    181 <h3>UI Framework</h3>
    182 
    183 <ul>
    184 <li>New UI modes "car mode" and "night mode" and {@link android.app.UiModeManager} let applications adjust their application UI for specific user modes. </li>
    185 <li>New {@link android.view.ScaleGestureDetector} that lets Views detect and handle transformation gestures that involve more than one pointer (multitouch) using the supplied MotionEvents. </li>
    186 <li>Improvements in the way that multitouch events are reported in {@link android.view.MotionEvent} objects.</li>
    187 <li>The layout attribute <code>fill_parent</code> is renamed to <code>match_parent</code>. This affects both XML and Java code (see {@link android.view.ViewGroup.LayoutParams}). Note that the platform will continue to honor uses of <code>fill_parent</code> in legacy applications. </li>
    188 <li>New layout attributes {@link android.R.attr#tabStripEnabled}, {@link android.R.attr#tabStripRight}, and {@link android.R.attr#tabStripLeft} let developers customize the bottom strip of TabWidgets.</li>
    189 <li>Better support for managed dialogs in Activity.</li>
    190 </ul>
    191 
    192 <h3>Accounts and sync</h3>
    193 
    194 <ul>
    195 <li>New method {@link android.content.ContentResolver#addPeriodicSync(Account, String, Bundle, long) AddPeriodicSync()} lets you schedule a periodic sync with a specific account, authority, and extras at the given frequency.</li>
    196 </ul>
    197 
    198 <h3>New manifest elements and attributes</h3>
    199 
    200 <ul>
    201 <li>For specifying the application's preferred install location (see <a href="#install-loc">App Installation on External Storage Media</a>, above):
    202 
    203 <ul>
    204   <li>New <code>android:installLocation</code> attribute of the <code>&lt;manifest&gt;</code> element. Specifies the default install location defined by an application.</li>
    205 </ul>
    206 </li>
    207 
    208 <li>For managing user data backup (see <a href="#backup-manager">Backup manager</a>, above, for more information):
    209 
    210 <ul>
    211   <li> New <code>android:backupAgent</code> attribute of the
    212 <code>&lt;application&gt;</code> element. Specifies the component name of the
    213 BackupAgent subclass provided by the application to handle backup/restore
    214 operations, if any.</li>
    215   <li> New <code>android:restoreAnyVersion</code> attribute of the
    216 <code>&lt;application&gt;</code> element. Boolean value that indicates whether
    217 the application is prepared to attempt a restore of any backed-up dataset, even
    218 if the backup is apparently from a newer version of the application than is
    219 currently installed on the device.</li>
    220 </ul>
    221 </li>
    222 
    223 <li>For managing the platform's JIT compiler:
    224 
    225 <ul>
    226 <li>New <code>android:vmSafeMode</code> attribute of the <code>&lt;application&gt;</code> element. Boolean value that specifies whether to disable JIT compiler optimizations when running the application.</li>
    227 </ul>
    228 </li>
    229 </ul>
    230 
    231 <h3>Permissions</h3>
    232 
    233 <ul>
    234 <li><code>android.permission.BIND_DEVICE_ADMIN</code> &mdash; Any device administration broadcast receiver must require this permission, to ensure that only the system can interact with it.</li>
    235 <li><code>android.permission.KILL_BACKGROUND_PROCESSES</code> &mdash; Allows an application to call {@link android.app.ActivityManager#killBackgroundProcesses(String)}.
    236 <li><code>android.permission.BIND_WALLPAPER</code> &mdash; Any {@link android.service.wallpaper.WallpaperService} must require this permission, to ensure that only the system can interact with it.</li>
    237 <li><code>android.permission.SET_TIME</code> &mdash; Allows an application to set the system time.</li>
    238 </ul>
    239 
    240 <h3 id="api-diff">API differences report</h3>
    241 
    242 <p>For a detailed view of all API changes in Android {@sdkPlatformVersion} (API
    243 Level {@sdkPlatformApiLevel}), see the <a
    244 href="{@docRoot}sdk/api_diff/{@sdkPlatformApiLevel}/changes.html">API
    245 Differences Report</a>.</p>
    246 
    247 
    248 
    249