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      1 page.title=<uses-feature>
      2 @jd:body
      3 
      4 <dl class="xml">
      5 
      6 <dt>syntax:</dt>
      7 <dd>
      8 <pre class="stx">&lt;uses-feature android:<a href="#name">name</a>="<em>string</em>"
      9               android:<a href="#required">required</a>=["true" | "false"]
     10               android:<a href="#glEsVersion">glEsVersion</a>="<em>integer</em>" /&gt;</pre>
     11 </dd>
     12 
     13 <dt>contained in:</dt>
     14 <dd><code><a
     15 href="{@docRoot}guide/topics/manifest/manifest-element.html">&lt;manifest&gt;</a></code></dd>
     16 
     17  <div class="sidebox-wrapper"> 
     18   <img id="rule" src="{@docRoot}assets/images/grad-rule-qv.png"> 
     19   <div id="qv-sub-rule"> 
     20     <img src="{@docRoot}assets/images/icon_market.jpg" style="float:left;margin:0;padding:0;"> 
     21     <p style="color:#669999;">Android Market and <code style="color:#669999;">&lt;uses-feature&gt;</code> elements</p>
     22     <p style="margin-top:1em;">Android Market filters the applications that are visible to users, so
     23 that users can see and download only those applications that are compatible with their
     24 devices. One of the ways Market filters applications is by feature compatibility.</p>
     25 
     26 <p style="margin-top:1em;">To do this, Market checks the
     27 <code>&lt;uses-feature&gt;</code> elements in each application's manifest, to
     28 establish the app's feature needs. Market then shows or hides the application to
     29 each user, based on a comparison with the features available on the user's
     30 device. </p>
     31 
     32 <p style="margin-top:1em;">By specifying the features that your application requires,
     33 you enable Android Market to present your application only to users whose
     34 devices meet the application's feature requirements, rather than presenting it
     35 to all users. </p>
     36 
     37 <p style="margin-top:1em;" class="caution">For important information about how
     38 Android Market uses features as the basis for filtering, please read <a
     39 href="#market-feature-filtering">Android Market and Feature-Based Filtering</a>,
     40 below.</p>
     41 </div>
     42 </div>
     43 
     44 <dt>description:</dt>
     45 <dd>Declares a single hardware or software feature that is used by the
     46 application.
     47 
     48 <p>The purpose of a <code>&lt;uses-feature&gt;</code> declaration is to inform
     49 any external entity of the set of hardware and software features on which your
     50 application depends. The element offers a <code>required</code> attribute that
     51 lets you specify whether your application requires and cannot function without
     52 the declared feature, or whether it prefers to have the feature but can function
     53 without it. Because feature support can vary across Android devices, the
     54 <code>&lt;uses-feature&gt;</code> element serves an important role in letting an
     55 application describe the device-variable features that it uses.</p>
     56 
     57 <p>The set of available features that your application declares corresponds to
     58 the set of feature constants made available by the Android {@link
     59 android.content.pm.PackageManager}, which are listed for
     60 convenience in the <a href="#features-reference">Features Reference</a> tables
     61 at the bottom of this document.
     62 
     63 <p>You must specify each feature in a separate <code>&lt;uses-feature&gt;</code>
     64 element, so if your application requires multiple features, it would declare
     65 multiple <code>&lt;uses-feature&gt;</code> elements. For example, an application
     66 that requires both Bluetooth and camera features in the device would declare
     67 these two elements:</p>
     68 
     69 <pre>
     70 &lt;uses-feature android:name="android.hardware.bluetooth" />
     71 &lt;uses-feature android:name="android.hardware.camera" />
     72 </pre>
     73 
     74 <p>In general, you should always make sure to declare
     75 <code>&lt;uses-feature&gt;</code> elements for all of the features that your
     76 application requires.</p>
     77 
     78 <p>Declared <code>&lt;uses-feature></code> elements are informational only, meaning
     79 that the Android system itself does not check for matching feature support on
     80 the device before installing an application. However, other services
     81 (such as Android Market) or applications may check your application's 
     82 <code>&lt;uses-feature></code> declarations as part of handling or interacting
     83 with your application. For this reason, it's very important that you declare all of
     84 the features (from the list below) that your application uses. </p>
     85 
     86 <p>For some features, there may exist a specfic attribute that allows you to define
     87 a version of the feature, such as the version of Open GL used (declared with
     88 <a href="#glEsVersion"><code>glEsVersion</code></a>). Other features that either do or do not
     89 exist for a device, such as a camera, are declared using the
     90 <a href="#name"><code>name</code></a> attribute.</p>
     91 
     92 
     93 <p>Although the <code>&lt;uses-feature></code> element is only activated for
     94 devices running API Level 4 or higher, it is recommended to include these
     95 elements for all applications, even if the <a href="uses-sdk-element.html#min"><code>minSdkVersion</code></a>
     96 is "3" or lower. Devices running older versions of the platform will simply
     97 ignore the element.</p>
     98 
     99 <p class="note"><strong>Note:</strong> When declaring a feature, remember
    100 that you must also request permissions as appropriate. For example, you must
    101 still request the {@link android.Manifest.permission#CAMERA}
    102 permission before your application can access the camera API. Requesting the
    103 permission grants your application access to the appropriate hardware and
    104 software, while declaring the features used by your application ensures proper
    105 device compatibility.</p>
    106 
    107 </dd> 
    108 
    109 
    110 <dt>attributes:</dt>
    111 
    112 <dd>
    113 <dl class="attr">
    114 
    115   <dt><a name="name"></a><code>android:name</code></dt>
    116   <dd>Specifies a single hardware or software feature used by the application,
    117 as a descriptor string. Valid descriptor values are listed in the <a
    118 href="#hw-features">Hardware features</a> and <a href="#sw-features">Software
    119 features</a> tables, below. </dd>
    120 
    121   <dt><a name="required"></a><code>android:required</code></dt>  <!-- added in api level 5 -->
    122   <dd>Boolean value that indicates whether the application requires
    123   the feature specified in <code>android:name</code>.
    124 
    125 <ul>
    126 <li>When you declare <code>"android:required="true"</code> for a feature,
    127 you are specifying that the application <em>cannot function, or is not
    128 designed to function</em>, when the specified feature is not present on the
    129 device. </li>
    130 
    131 <li>When you declare <code>"android:required="false"</code> for a feature, it
    132 means that the application <em>prefers to use the feature</em> if present on
    133 the device, but that it <em>is designed to function without the specified
    134 feature</em>, if necessary. </li>
    135 
    136 </ul>
    137 
    138 <p>The default value for <code>android:required</code> if not declared is
    139 <code>"true"</code>.</p>
    140   </dd>
    141 
    142   <dt><a name="glEsVersion"></a><code>android:glEsVersion</code></dt>
    143   <dd>The OpenGL ES version required by the application. The higher 16 bits
    144 represent the major number and the lower 16 bits represent the minor number. For
    145 example, to specify OpenGL ES version 2.0, you would set the value as
    146 "0x00020000". To specify OpenGL ES 2.1, if/when such a version were made
    147 available, you would set the value as "0x00020001".
    148 
    149   <p>An application should specify at most one <code>android:glEsVersion</code>
    150 attribute in its manifest. If it specifies more than one, the
    151 <code>android:glEsVersion</code> with the numerically highest value is used and
    152 any other values are ignored.</p>
    153 
    154   <p>If an application does not specify an <code>android:glEsVersion</code>
    155 attribute, then it is assumed that the application requires only OpenGL ES 1.0,
    156 which is supported by all Android-powered devices.</p>
    157 
    158   <p>An application can assume that if a platform supports a given OpenGL ES
    159 version, it also supports all numerically lower OpenGL ES versions. Therefore,
    160 an application that requires both OpenGL ES 1.0 and OpenGL ES 2.0 must specify
    161 that it requires OpenGL ES 2.0.</p>
    162 
    163   <p>An application that can work with any of several OpenGL ES versions should
    164 only specify the numerically lowest version of OpenGL ES that it requires. (It
    165 can check at run-time whether a higher level of OpenGL ES is available.)</p>
    166   </dd>
    167 
    168 </dl>
    169 </dd>
    170 
    171 <!-- ##api level indication## -->
    172 <dt>introduced in:</dt>
    173 <dd>API Level 4</dd>
    174 
    175 <dt>see also:</dt>
    176 <dd>
    177   <ul>
    178     <li>{@link android.content.pm.PackageManager}</li>
    179     <li>{@link android.content.pm.FeatureInfo}</li>
    180     <li>{@link android.content.pm.ConfigurationInfo}</li>
    181     <li><a href="{@docRoot}guide/topics/manifest/uses-permission-element.html"><code>&lt;uses-permission&gt;</code></a></li>
    182     <li><a href="{@docRoot}guide/appendix/market-filters.html">Android Market Filters</a></li>
    183   </ul>
    184 </dd>
    185 
    186 </dl>
    187 
    188 
    189 <h2 id="market-feature-filtering">Android Market and Feature-Based Filtering</h2>
    190 
    191 <p>Android Market filters the applications that are visible to users, so that
    192 users can see and download only those applications that are compatible with
    193 their devices. One of the ways Market filters applications is by feature
    194 compatibility.</p>
    195 
    196 <p>To determine an application's feature compatibility with a given user's
    197 device, the Android Market service compares:</p>
    198 
    199 <ul>
    200 <li>Features required by the application &mdash; an application declares features in
    201 <code>&lt;uses-feature&gt;</code> elements in its manifest <br/>with...</li>
    202 <li>Features available on the device, in hardware or software &mdash;
    203 a device reports the features it supports as read-only system properties.</li>
    204 </ul>
    205 
    206 <p>To ensure an accurate comparison of features, the Android Package Manager
    207 provides a shared set of feature constants that both applications and devices
    208 use to declare feature requirements and support. The available feature constants
    209 are listed in the <a href="#features-reference">Features Reference</a> tables at
    210 the bottom of this document, and in the class documentation for {@link
    211 android.content.pm.PackageManager}.</p>
    212 
    213 <p>When the user launches the Market application, the application queries the
    214 Package Manager for the list of features available on the device by calling
    215 {@link android.content.pm.PackageManager#getSystemAvailableFeatures()}. The
    216 Market application then passes the features list up to the Android Market
    217 service when establishing the session for the user.</p>
    218 
    219 <p>Each time you upload an application to the Android Market Publisher Site,
    220 Android Market scans the application's manifest file. It looks for
    221 <code>&lt;uses-feature&gt;</code> elements and evaluates them in combination
    222 with other elements, in some cases, such as <code>&lt;uses-sdk&gt;</code> and
    223 <code>&lt;uses-permission&gt;</code> elements. After establishing the
    224 application's set of required features, it stores that list internally as
    225 metadata associated with the application <code>.apk</code> and the application
    226 version. </p>
    227 
    228 <p>When a user searches or browses for applications using the Android Market
    229 application, the service compares the features needed by each application with
    230 the features available on the user's device. If all of an application's required
    231 features are present on the device, Android Market allows the user to see the
    232 application and potentially download it. If any required feature is not
    233 supported by the device, Android Market filters the application so that it is
    234 not visible to the user and not available for download. </p>
    235 
    236 <p>Because the features you declare in <code>&lt;uses-feature&gt;</code>
    237 elements directly affect how Android Market filters your application, it's
    238 important to understand how Android Market evaluates the application's manifest
    239 and establishes the set of required features. The sections below provide more
    240 information. </p>
    241 
    242 <h3 id="declared">Filtering based on explicitly declared features</h3>
    243 
    244 <p>An explicitly declared feature is one that your application declares in a
    245 <code>&lt;uses-feature&gt;</code> element. The feature declaration can include
    246 an <code>android:required=["true" | "false"]</code> attribute (if you are
    247 compiling against API level 5 or higher), which lets you specify whether the
    248 application absolutely requires the feature and cannot function properly without
    249 it (<code>"true"</code>), or whether the application prefers to use the feature
    250 if available, but is designed to run without it (<code>"false"</code>).</p>
    251 
    252 <p>Android Market handles explictly declared features in this way: </p>
    253 
    254 <ul>
    255 <li>If a feature is explicitly declared as being required, Android Market adds
    256 the feature to the list of required features for the application. It then
    257 filters the application from users on devices that do not provide that feature.
    258 For example:
    259 <pre>&lt;uses-feature android:name="android.hardware.camera" android:required="true" /&gt;</pre></li>
    260 <li>If a feature is explicitly declared as <em>not</em> being required, Android
    261 Market <em>does not</em> add the feature to the list of required features. For
    262 that reason, an explicity declared non-required feature is never considered when
    263 filtering the application. Even if the device does not provide the declared
    264 feature, Android Market will still consider the application compatible with the
    265 device and will show it to the user, unless other filtering rules apply. For
    266 example:
    267 <pre>&lt;uses-feature android:name="android.hardware.camera" android:required="false" /&gt;</pre></li>
    268 <li>If a feature is explicitly declared, but without an
    269 <code>android:required</code> attribute, Android Market assumes that the feature
    270 is required and sets up filtering on it. </li>
    271 </ul>
    272 
    273 <p>In general, if your application is designed to run on Android 1.6 and earlier
    274 versions, the <code>android:required</code> attribute is not available in the
    275 API and Android Market assumes that any and all
    276 <code>&lt;uses-feature&gt;</code> declarations are required. </p>
    277 
    278 <p class="note"><strong>Note:</strong> By declaring a feature explicitly and
    279 including an <code>android:required="false"</code> attribute, you can
    280 effectively disable all filtering on Android Market for the specified feature.
    281 </p>
    282 
    283 
    284 <h3 id="implicit">Filtering based on implicit features</h3>
    285 
    286 <p>An <em>implicit</em> feature is one that an application requires in order to
    287 function properly, but which is <em>not</em> declared in a
    288 <code>&lt;uses-feature&gt;</code> element in the manifest file. Strictly
    289 speaking, every application should <em>always</em> declare all features that it
    290 uses or requires, so the absence of a declaration for a feature used by an
    291 application should be considered an error. However, as a safeguard for users and
    292 developers, Android Market looks for implicit features in each application and
    293 sets up filters for those features, just as it would do for an explicitly
    294 declared feature. </p>
    295 
    296 <p>An application might require a feature but not declare it because: </p>
    297 
    298 <ul>
    299 <li>The application was compiled against an older version of the Android library
    300 (Android 1.5 or earlier) and the <code>&lt;uses-feature&gt;</code> element was
    301 not available.</li>
    302 <li>The developer incorrectly assumed that the feature would be present on all
    303 devices and a declaration was unnecessary.</li>
    304 <li>The developer omitted the feature declaration accidentally.</li>
    305 <li>The developer declared the feature explicitly, but the declaration was not
    306 valid. For example, a spelling error in the <code>&lt;uses-feature&gt;</code>
    307 element name or an unrecognized string value for the
    308 <code>android:name</code> attribute would invalidate the feature declaration.
    309 </li>
    310 </ul>
    311 
    312 <p>To account for the cases above, Android Market attempts to discover an
    313 application's implied feature requirements by examining <em>other elements</em>
    314 declared in the manifest file, specifically,
    315 <code>&lt;uses-permission&gt;</code> elements.</p>
    316 
    317 <p>If an application requests hardware-related permissions, Android Market
    318 <em>assumes that the application uses the underlying hardware features and
    319 therefore requires those features</em>, even though there might be no
    320 corresponding to <code>&lt;uses-feature&gt;</code> declarations. For such
    321 permissions, Android Market adds the underlying hardware features to the
    322 metadata that it stores for the application and sets up filters for them.</p>
    323 
    324 <p>For example, if an application requests the <code>CAMERA</code> permission
    325 but does not declare a <code>&lt;uses-feature&gt;</code> element for
    326 <code>android.hardware.camera</code>, Android Market considers that the
    327 application requires a camera and should not be shown to users whose devices do
    328 not offer a camera.</p>
    329 
    330 <p>If you don't want Android Market to filter based on a specific implied
    331 feature, you can disable that behavior. To do so, declare the feature explicitly
    332 in a <code>&lt;uses-feature&gt;</code> element and include an 
    333 <code>android:required="false"</code> attribute. For example, to disable
    334 filtering derived from the <code>CAMERA</code> permission, you would declare
    335 the feature as shown below.</p>
    336 
    337 <pre>&lt;uses-feature android:name="android.hardware.camera" android:required="false" /&gt;</pre>
    338 
    339 <p class="caution">It's important to understand that the permissions that you
    340 request in <code>&lt;uses-permission&gt;</code> elements can directly affect how
    341 Android Market filters your application. The reference section <a
    342 href="permissions-features">Permissions that Imply Feature Requirements</a>,
    343 below, lists the full set of permissions that imply feature requirements and
    344 therefore trigger filtering.</p>
    345 
    346 <h3 id="bt-permission-handling">Special handling for Bluetooth feature</h3>
    347 
    348 <p>Android Market applies slightly different rules than described above, when
    349 determining filtering for Bluetooth.</p>
    350 
    351 <p>If an application declares a Bluetooth permission in a
    352 <code>&lt;uses-permission&gt;</code> element, but does not explicitly declare
    353 the Bluetooth feature in a <code>&lt;uses-feature&gt;</code> element, Android
    354 Market checks the version(s) of the Android platform on which the application is
    355 designed to run, as specified in the <code>&lt;uses-sdk&gt;</code> element. </p>
    356 
    357 <p>As shown in the table below, Android Market enables filtering for the
    358 Bluetooth feature only if the application declares its lowest or targeted
    359 platform as Android 2.0 (API level 5) or higher. However, note that Android
    360 market applies the normal rules for filtering when the application explicitly
    361 declares the Bluetooth feature in a <code>&lt;uses-feature&gt;</code> element.
    362 </p>
    363 
    364 <p class="caption"><strong>Table 1.</strong> How Android Market determines the
    365 Bluetooth feature requirement for an application that requests a Bluetooth
    366 permission but does not declare the Bluetooth feature in a
    367 <code>&lt;uses-feature&gt;</code> element.</p>
    368 
    369 <table style="margin-top:1em;">
    370 <tr>
    371 <th><nobr>If <code>minSdkVersion</code> is ...</nobr></th>
    372 <th><nobr>or <code>targetSdkVersion</code> is</nobr></th>
    373 <th>Result</th>
    374 </tr>
    375 <tr>
    376 <td><nobr>&lt;=4 (or uses-sdk is not declared)</nobr></td>
    377 <td>&lt;=4</td>
    378 <td>Android Market <em>will not</em> filter the application from any devices
    379 based on their reported support for the <code>android.hardware.bluetooth</code>
    380 feature.</td>
    381 </tr>
    382 <tr>
    383 <td>&lt;=4</td>
    384 <td>&gt;=5</td>
    385 <td rowspan="2">Android Market filters the application from any devices that
    386 do not support the <code>android.hardware.bluetooth</code> feature (including
    387 older releases).</td>
    388 </tr>
    389 <tr>
    390 <td>&gt;=5</td>
    391 <td>&gt;=5</td>
    392 </tr>
    393 </table>
    394 
    395 <p>The examples below illustrate the different filtering effects, based on how
    396 Android Market handles the Bluetooth feature. </p>
    397 
    398 <dl>
    399 <dt>In first example, an application that is designed to run on older API levels
    400 declares a Bluetooth permission, but does not declare the Bluetooth feature in a
    401 <code>&lt;uses-feature&gt;</code> element.</dt>
    402 <dd><em>Result:</em> Android Market does not filter the application from any device.</dd>
    403 </dl>
    404 
    405 <pre>&lt;manifest ...>
    406 ...
    407     &lt;uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    408     &lt;uses-sdk android:minSdkVersion="3" />
    409 ...
    410 &lt;/manifest></pre>
    411 
    412 <dl>
    413 <dt>In the second example, below, the same application also declares a target
    414 API level of "5". </dt>
    415 <dd><em>Result:</em> Android Market now assumes that the feature is required and
    416 will filter the application from all devices that do not report Bluetooth support,
    417 including devices running older versions of the platform. </dd>
    418 </dl>
    419 
    420 <pre>&lt;manifest ...>
    421 ...
    422     &lt;uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    423     &lt;uses-sdk android:minSdkVersion="3" android:targetSdkVersion="5" />
    424 ...
    425 &lt;/manifest></pre>
    426 
    427 <dl>
    428 <dt>Here the same application now specifically declares the Bluetooth feature.</dt>
    429 <dd><em>Result:</em> Identical to the previous example (filtering is applied).</dd>
    430 </dl>
    431 
    432 <pre>&lt;manifest ...>
    433 ...
    434     &lt;uses-feature android:name="android.hardware.bluetooth" />
    435     &lt;uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    436     &lt;uses-sdk android:minSdkVersion="3" android:targetSdkVersion="5" />
    437 ...
    438 &lt;/manifest></pre>
    439 
    440 <dl>
    441 <dt>Finally, in the case below, the same application adds an
    442 <code>android:required="false"</code> attribute.</dt>
    443 <dd><em>Result:</em> Android Market disables filtering based on Bluetooth
    444 feature support, for all devices.</dd>
    445 </dl>
    446 
    447 <pre>&lt;manifest ...>
    448 ...
    449     &lt;uses-feature android:name="android.hardware.bluetooth" android:required="false" />
    450     &lt;uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    451     &lt;uses-sdk android:minSdkVersion="3" android:targetSdkVersion="5" />
    452 ...
    453 &lt;/manifest></pre>
    454 
    455 
    456 
    457 <h3>Testing the features required by your application</h3>
    458 
    459 <p>You can use the <code>aapt</code> tool, included in the Android SDK, to
    460 determine how Android Market will filter your application, based on its declared
    461 features and permissions. To do so, run  <code>aapt</code> with the <code>dump
    462 badging</code> command. This causes <code>aapt</code> to parse your
    463 application's manifest and apply the same rules as used by Android Market to
    464 determine the features that your application requires. </p>
    465 
    466 <p>To use the tool, follow these steps: </p>
    467 
    468 <ol>
    469 <li>First, build and export your application as an unsigned <code>.apk</code>.
    470 If you are developing in Eclipse with ADT, right-click the project and select
    471 <strong>Android Tools</strong> &gt; <strong>Export Unsigned Application
    472 Package</strong>. Select a destination filename and path and click
    473 <strong>OK</strong>. </li>
    474 <li>Next, locate the <code>aapt</code> tool, if it is not already in your PATH.
    475 If you are using SDK Tools r8 or higher, you can find <code>aapt</code> in the
    476 <code>&lt;<em>SDK</em>&gt;/platform-tools/</code> directory.
    477 <p class="note"><strong>Note:</strong> You must use the version of
    478 <code>aapt</code> that is provided for the latest Platform-Tools component available. If
    479 you do not have the latest Platform-Tools component, download it using the <a
    480 href="{@docRoot}sdk/adding-components.html">Android SDK and AVD Manager</a>.
    481 </p></li>
    482 <li>Run <code>aapt</code> using this syntax: </li>
    483 </ol>
    484 
    485 <pre>$ aapt dump badging &lt;<em>path_to_exported_.apk</em>&gt;</pre>
    486 
    487 <p>Here's an example of the command output for the second Bluetooth example, above: </p>
    488 
    489 <pre>$ ./aapt dump badging BTExample.apk
    490 package: name='com.example.android.btexample' versionCode='' versionName=''
    491 <strong>uses-permission:'android.permission.BLUETOOTH_ADMIN'</strong>
    492 <strong>uses-feature:'android.hardware.bluetooth'</strong>
    493 sdkVersion:'3'
    494 targetSdkVersion:'5'
    495 application: label='BT Example' icon='res/drawable/app_bt_ex.png'
    496 launchable activity name='com.example.android.btexample.MyActivity'label='' icon=''
    497 uses-feature:'android.hardware.touchscreen'
    498 main
    499 supports-screens: 'small' 'normal' 'large'
    500 locales: '--_--'
    501 densities: '160'
    502 </pre>
    503 
    504 
    505 <h2 id=features-reference>Features Reference</h2>
    506 
    507 <p>The tables below provide reference information about hardware and software
    508 features and the permissions that can imply them on Android Market. </p>
    509 
    510 <h3 id="hw-features">Hardware features</h3>
    511 
    512 <p>The table below describes the hardware feature descriptors supported by the
    513 most current platform release. To signal that your application uses or requires
    514 a hardware feature, declare each value in a <code>android:name</code> attribute
    515 in a separate <code>&lt;uses-feature&gt;</code> element. </p>
    516 
    517   <table>
    518     <tr>
    519        <th>Feature Type</th>
    520        <th>Feature Descriptor</th>
    521        <th>Description</th>
    522        <th>Comments</th>
    523     </tr>
    524     <tr>
    525        <td>Audio</td>
    526        <td><code>android.hardware.audio.low_latency</td>
    527        <td>The application uses a low-latency audio pipeline on the device and
    528 is sensitive to delays or lag in sound input or output.</td>
    529 <td>
    530 </td>
    531     </tr>
    532     <tr>
    533        <td>Bluetooth</td>
    534        <td><code>android.hardware.bluetooth</td>
    535        <td>The application uses Bluetooth radio features in the device.</td>
    536 <td>
    537 </td>
    538     </tr>
    539     <tr>
    540        <td rowspan="4">Camera</td>
    541        <td><code>android.hardware.camera</code></td>
    542        <td>The application uses the device's camera. If the device supports
    543            multiple cameras, the application uses the camera that facing
    544            away from the screen.</td>
    545        <td></td>
    546     </tr>
    547 <tr>
    548   <td><code>android.hardware.camera.autofocus</code></td>
    549   <td>Subfeature. The application uses the device camera's autofocus capability.</td>
    550   <td rowspan="3">If declared with the <code>"android:required="true"</code>
    551 attribute, these subfeatures implicitly declare the
    552 <code>android.hardware.camera</code> parent feature. </td>
    553 </tr>
    554 <tr>
    555   <td><code>android.hardware.camera.flash</code></td>
    556   <td>Subfeature. The application uses the device camera's flash.</td>
    557 </tr>
    558 <tr>
    559   <td><code>android.hardware.camera.front</code></td>
    560   <td>Subfeature. The application uses a front-facing camera on the device.</td>
    561 </tr>
    562 
    563 <tr>
    564   <td rowspan="3">Location</td>
    565   <td><code>android.hardware.location</code></td>
    566   <td>The application uses one or more features on the device for determining
    567 location, such as GPS location, network location, or cell location.</td>
    568   <td></td>
    569 </tr>
    570 <tr>
    571   <td><code>android.hardware.location.network</code></td>
    572   <td>Subfeature. The application uses coarse location coordinates obtained from
    573 a network-based geolocation system supported on the device.</td>
    574   <td rowspan="2">If declared with the <code>"android:required="true"</code>
    575 attribute, these subfeatures implicitly declare the
    576 <code>android.hardware.location</code> parent feature. </td>
    577 </tr>
    578 <tr>
    579   <td><code>android.hardware.location.gps</code></td>
    580   <td>Subfeature. The application uses precise location coordinates obtained
    581 from a Global Positioning System receiver on the device. </td>
    582 </tr>
    583 <tr>
    584   <td>Microphone</td>
    585   <td><code>android.hardware.microphone</code></td>
    586   <td>The application uses a microphone on the device.
    587   </td>
    588   <td></td>
    589 </tr>
    590 <tr>
    591   <td>Near Field Communications</td>
    592   <td><code>android.hardware.nfc</td>
    593   <td>The application uses NFC radio features in the device.</td>
    594   <td></td>
    595 </tr>
    596 <tr>
    597   <td rowspan="6">Sensors</td>
    598   <td><code>android.hardware.sensor.accelerometer</code></td>
    599   <td>The application uses motion readings from an accelerometer on the
    600 device.</td>
    601   <td></td>
    602 </tr>
    603 <tr>
    604   <td><code>android.hardware.sensor.barometer</code></td>
    605   <td>The application uses the device's barometer.</td>
    606   <td></td>
    607 </tr>
    608 <tr>
    609   <td><code>android.hardware.sensor.compass</code></td>
    610   <td>The application uses directional readings from a magnetometer (compass) on
    611 the device.</td>
    612   <td></td>
    613 </tr>
    614 <tr>
    615   <td><code>android.hardware.sensor.gyroscope</code></td>
    616   <td>The application uses the device's gyroscope sensor.</td>
    617   <td></td>
    618 </tr>
    619 <tr>
    620   <td><code>android.hardware.sensor.light</code></td>
    621   <td>The application uses the device's light sensor.</td>
    622   <td></td>
    623 </tr>
    624 <tr>
    625   <td><code>android.hardware.sensor.proximity</code></td>
    626   <td>The application uses the device's proximity sensor.</td>
    627   <td></td>
    628 </tr>
    629 <tr>
    630   <td rowspan="2">SIP/VOIP</td>
    631   <td><code>android.hardware.sip</code></td>
    632   <td>The application uses SIP service on the device.
    633   </td>
    634   <td></td>
    635 </tr>
    636 <tr>
    637   <td><code>android.hardware.sip.voip</code></td>
    638   <td>Subfeature. The application uses SIP-based VOIP service on the device.
    639   </td>
    640   <td>If declared with the <code>"android:required="true"</code> attribute, this
    641 subfeature implicitly declares the <code>android.hardware.sip</code>
    642 parent feature.</td>
    643 </tr>
    644 
    645 <tr>
    646   <td rowspan="3">Telephony</td>
    647   <td><code>android.hardware.telephony</code></td>
    648   <td>The application uses telephony features on the device, such as telephony
    649 radio with data communication services.</td>
    650   <td></td>
    651 </tr>
    652 <tr>
    653   <td><code>android.hardware.telephony.cdma</code></td>
    654   <td>Subfeature. The application uses CDMA telephony radio features on the
    655 device. </td>
    656   <td rowspan="2">If declared with the <code>"android:required="true"</code>
    657 attribute, these subfeatures implicitly declare the
    658 <code>android.hardware.telephony</code> parent feature. </td>
    659 </tr>
    660 <tr>
    661   <td><code>android.hardware.telephony.gsm</code></td>
    662   <td>Subfeature. The application uses GSM telephony radio features on the
    663 device.</td>
    664 </tr>
    665 
    666 <tr>
    667   <td rowspan="4">Touchscreen</td>
    668   <td><code>android.hardware.touchscreen</code></td>
    669   <td>The application uses touchscreen capabilities on the device.</td>
    670   <td></td>
    671 </tr>
    672 <tr>
    673   <td><code>android.hardware.touchscreen.multitouch</code></td>
    674   <td>Subfeature. The application uses basic two-point multitouch capabilities on the device
    675 screen.</td>
    676   <td>If declared with the <code>"android:required="true"</code> attribute, this
    677 subfeature implicitly declares the <code>android.hardware.touchscreen</code>
    678 parent feature. </td>
    679 </tr>
    680 <tr>
    681   <td><code>android.hardware.touchscreen.multitouch.distinct</code></td>
    682   <td>Subfeature. The application uses advanced multipoint multitouch
    683 capabilities on the device screen, such as for tracking two or more points fully
    684 independently.</td>
    685   <td rowspan="2">If declared with the <code>"android:required="true"</code> attribute, this
    686 subfeature implicitly declares the
    687 <code>android.hardware.touchscreen.multitouch</code> parent feature. </td>
    688 </tr>
    689 <tr>
    690   <td><code>android.hardware.touchscreen.multitouch.jazzhand</code></td>
    691   <td>Subfeature. The application uses advanced multipoint multitouch
    692 capabilities on the device screen, for tracking up to five points fully
    693 independently.</td>
    694 </tr>
    695 
    696 <tr>
    697   <td>Wifi</td>
    698   <td><code>android.hardware.wifi</code></td>
    699   <td>The application uses 802.11 networking (wifi) features on the device.</td>
    700   <td></td>
    701 </tr>
    702 
    703   </table>
    704 
    705 <h3 id="sw-features">Software features</h3>
    706 
    707 <p>The table below describes the software feature descriptors supported by the
    708 most current platform release. To signal that your application uses or requires
    709 a software feature, declare each value in a <code>android:name</code> attribute
    710 in a separate <code>&lt;uses-feature&gt;</code> element. </p>
    711 
    712 
    713   <table>
    714     <tr> 
    715        <th>Feature</th>
    716        <th>Attribute Value</th> 
    717        <th>Description</th>
    718     </tr>
    719     <tr>
    720       <td>Live Wallpaper</td>
    721       <td><code>android.software.live_wallpaper</code></td>
    722       <td>The application uses or provides Live Wallpapers.
    723       </td>
    724     </tr>
    725   </table>
    726 
    727 
    728 <h3 id="permissions">Permissions that Imply Feature Requirements</h3>
    729 
    730 <p>Some feature constants listed in the tables above were made available to
    731 applications <em>after</em> the corresponding API; for example, the
    732 <code>android.hardware.bluetooth</code> feature was added in Android 2.2 (API
    733 level 8), but the bluetooth API that it refers to was added in Android 2.0 (API
    734 level 5). Because of this, some apps were able to use the API before they had
    735 the ability to declare that they require the API via the
    736 <code>&lt;uses-feature&gt;</code> system. </p>
    737 
    738 <p>To prevent those apps from being made available unintentionally,  Android
    739 Market assumes that certain hardware-related permissions indicate that the
    740 underlying hardware features are required by default. For instance, applications
    741 that use Bluetooth must request the <code>BLUETOOTH</code> permission in a
    742 <code>&lt;uses-permission&gt;</code> element &mdash; for legacy apps, Android
    743 Market assumes that the permission declaration means that the underlying
    744 <code>android.hardware.bluetooth</code> feature is required by the application
    745 and sets up filtering based on that feature. </p>
    746 
    747 <p>The table below lists permissions that imply feature requirements
    748 equivalent to those declared in <code>&lt;uses-feature&gt;</code> elements. Note
    749 that <code>&lt;uses-feature&gt;</code> declarations, including any declared
    750 <code>android:required</code> attribute, always take precedence over features
    751 implied by the permissions below. </p>
    752 
    753 <p>For any of the permissions below, you can disable filtering based on the
    754 implied feature by explicitly declaring the implied feature explicitly, in a
    755 <code>&lt;uses-feature&gt;</code> element, with an
    756 <code>android:required="false"</code> attribute. For example, to disable any
    757 filtering based on the <code>CAMERA</code> permission, you would add this
    758 <code>&lt;uses-feature&gt;</code> declaration to the manifest file:</p>
    759 
    760 <pre>&lt;uses-feature android:name="android.hardware.camera" android:required="false" /&gt;</pre>
    761 
    762 <table id="permissions-features" >
    763   <tr> 
    764     <th>Category</th>
    765     <th>This Permission...</th>
    766     <th>Implies This Feature Requirement</th>
    767     <!-- <th>Comments</th> -->
    768   </tr>
    769 
    770 
    771 <tr>
    772   <td rowspan="2">Bluetooth</td>
    773   <td><code>BLUETOOTH</code></td>
    774   <td><code>android.hardware.bluetooth</code>
    775 <p>(See <a href="#bt-permission-handling">Special handling for Bluetooth feature</a> for details.)</p></td>
    776 <!--  <td></td> -->
    777 </tr>
    778 <tr>
    779   <td><code>BLUETOOTH_ADMIN</code></td>
    780   <td><code>android.hardware.bluetooth</code></td>
    781 <!--  <td></td> -->
    782 </tr>
    783 
    784 <tr>
    785   <td>Camera</td>
    786   <td><code>CAMERA</code></td>
    787   <td><code>android.hardware.camera</code> <em>and</em>
    788 <br><code>android.hardware.camera.autofocus</code></td>
    789 <!--  <td></td> -->
    790 </tr>
    791 
    792 <tr>
    793   <td rowspan="5">Location</td>
    794   <td><code>ACCESS_MOCK_LOCATION</code></td>
    795   <td><code>android.hardware.location</code></td>
    796 <!--  <td></td> -->
    797 </tr>
    798 <tr>
    799   <td><code>ACCESS_LOCATION_EXTRA_COMMANDS</code></td>
    800   <td><code>android.hardware.location</code></td>
    801 <!--  <td></td> -->
    802 </tr>
    803 <tr>
    804   <td><code>INSTALL_LOCATION_PROVIDER</code></td>
    805   <td><code>android.hardware.location</code></td>
    806 <!--  <td></td> -->
    807 </tr>
    808 <tr>
    809   <td><code>ACCESS_COARSE_LOCATION</code></td>
    810   <td><code>android.hardware.location.network</code> <em>and</em>
    811 <br><code>android.hardware.location</code></td>
    812 <!--  <td></td> -->
    813 </tr>
    814 <tr>
    815   <td><code>ACCESS_FINE_LOCATION</code></td>
    816   <td><code>android.hardware.location.gps</code> <em>and</em>
    817 <br><code>android.hardware.location</code></td>
    818 <!--  <td></td> -->
    819 </tr>
    820 
    821 <tr>
    822   <td>Microphone</td>
    823   <td><code>RECORD_AUDIO</code></td>
    824   <td><code>android.hardware.microphone</code></td>
    825 <!--  <td></td> -->
    826 </tr>
    827 
    828 <tr>
    829   <td rowspan="11">Telephony</td>
    830   <td><code>CALL_PHONE</code></td>
    831   <td><code>android.hardware.telephony</code></td>
    832 <!--  <td></td> -->
    833 </tr>
    834 <tr>
    835   <td><code>CALL_PRIVILEGED</code></td>
    836   <td><code>android.hardware.telephony</code></td>
    837 <!--  <td></td> -->
    838 </tr>
    839 
    840 <tr>
    841   <td><code>MODIFY_PHONE_STATE</code></td>
    842   <td><code>android.hardware.telephony</code></td>
    843 <!--  <td></td> -->
    844 </tr>
    845 <tr>
    846   <td><code>PROCESS_OUTGOING_CALLS</code></td>
    847   <td><code>android.hardware.telephony</code></td>
    848 <!--  <td></td> -->
    849 </tr>
    850 <tr>
    851   <td><code>READ_SMS</code></td>
    852   <td><code>android.hardware.telephony</code></td>
    853 <!--  <td></td> -->
    854 </tr>
    855 <tr>
    856   <td><code>RECEIVE_SMS</code></td>
    857   <td><code>android.hardware.telephony</code></td>
    858 <!--  <td></td> -->
    859 </tr>
    860 <tr>
    861   <td><code>RECEIVE_MMS</code></td>
    862   <td><code>android.hardware.telephony</code></td>
    863 <!--  <td></td> -->
    864 </tr>
    865 <tr>
    866   <td><code>RECEIVE_WAP_PUSH</code></td>
    867   <td><code>android.hardware.telephony</code></td>
    868 <!--  <td></td> -->
    869 </tr>
    870 <tr>
    871   <td><code>SEND_SMS</code></td>
    872   <td><code>android.hardware.telephony</code></td>
    873 <!--  <td></td> -->
    874 </tr>
    875 <tr>
    876   <td><code>WRITE_APN_SETTINGS</code></td>
    877   <td><code>android.hardware.telephony</code></td>
    878 <!--  <td></td> -->
    879 </tr>
    880 <tr>
    881   <td><code>WRITE_SMS</code></td>
    882   <td><code>android.hardware.telephony</code></td>
    883 <!--  <td></td> -->
    884 </tr>
    885 
    886 <tr>
    887   <td rowspan="3">Wifi</td>
    888   <td><code>ACCESS_WIFI_STATE</code></td>
    889   <td><code>android.hardware.wifi</code></td>
    890 <!--  <td></td> -->
    891 </tr>
    892 <tr>
    893   <td><code>CHANGE_WIFI_STATE</code></td>
    894   <td><code>android.hardware.wifi</code></td>
    895 <!--  <td></td> -->
    896 </tr>
    897 <tr>
    898   <td><code>CHANGE_WIFI_MULTICAST_STATE</code></td>
    899   <td><code>android.hardware.wifi</code></td>
    900 <!--  <td></td> -->
    901 </tr>
    902 </table>