android_frameworks_base/docs/html/guide/topics/manifest/uses-feature-element.jd

page.title=<uses-feature>
@jd:body

<dl class="xml">

<dt>syntax:</dt>
<dd>
<pre class="stx">
&lt;uses-feature android:<a href="#glEsVersion">glEsVersion</a>="<em>integer</em>"
              android:<a href="#name">name</a>="<em>string</em>" /&gt;
</pre>
</dd>

<dt>contained in:</dt>
<dd><code><a href="{@docRoot}guide/topics/manifest/manifest-element.html">&lt;manifest&gt;</a></code></dd>

<dt>description:</dt>
<dd>This element declares a specific feature used by the application.
Android provides some features that may not be equally supported by all
Android devices. In a manner similar to the <code><a href="uses-sdk-element.html">&lt;uses-sdk></a></code> 
element, this element allows an application to specify which device-variable
features it uses. In this way, the application
will not be installed on devices that do not offer the feature.</p>

<p>For example, an application might specify that it requires a camera with auto-focus capabilities.
If a device does not provide a camera with auto-focus, then it will not allow
installation of the application.</p>

<p>In order to maintain strict device compatibility, it's very important that you use
this element to declare all features that your application uses. Failure to declare
a feature may result your application being installed on a device
that does not support the feature and your application failing.</p>

<p>For some features, there may exist a specfic attribute that allows you to define
a version of the feature, such as the version of Open GL used (declared with
<a href="#glEsVersion">{@code glEsVersion}</a>). Other features that either do or do not
exist for a device, such as camera auto-focus, are declared using the
<a href="#name">{@code name}</a> attribute.</p>

<p>Any software or hardware features that may vary among Android-powered
devices will be listed on this page among the attributes below. If you see any features
here that you use in your application, you should include a {@code
&lt;uses-feature>} element for each one. For example, if your application uses the device
camera, then you should include the following in your {@code AndroidManifest.xml}:</p>

<pre>
&lt;uses-feature android:name="android.hardware.camera" />
</pre>

<p>If you declare "android.hardware.camera", then your application is considered
compatible with all devices that include a camera, regardless of whether auto-focus is
available or not. If you also use the auto-focus features (available through the {@link
android.hardware.Camera Camera API}), then you need to include an additional
{@code &lt;uses-feature>} element that declares the "android.hardware.camera.autofocus"
feature. Also note that you must still request the {@link android.Manifest.permission#CAMERA
CAMERA permission}. Requesting permission grants your application access to the
appropriate hardware and software, while declaring the features used by
your application ensures proper device compatibility.</p>

<p>Although the {@code &lt;uses-feature>} element is only activated for devices running 
API Level 4 or higher, it is safe to include this for applications that declare 
a <a href="uses-sdk-element.html#min">{@code minSdkVersion}</a> 
of "3" or lower. Devices running older versions of the platform 
will simply ignore this element, but newer devices will recognize it and enforce 
installation restrictions based on whether the device supports the feature.</p>

<p class="note"><strong>Note:</strong>
For each feature required by your application, you must include a new {@code
&lt;uses-feature>} element. Multiple features cannot be declared in one 
instance of this element.</p>

</dd> 


<dt>attributes:</dt>

<dd>
<dl class="attr"><dt><a name="glEsVersion"></a>{@code android:glEsVersion}</dt>
  <dd>The GLES version needed by the application.
     The higher 16 bits represent the major number and the lower 16 bits
     represent the minor number. For example, for GL 1.2 referring to
     0x00000102, the actual value should be set as 0x00010002.
  </dd>
</dl>
</dd>

<dd>
<dl class="attr"><dt><a name="name"></a>{@code android:name}</dt>
  <dd>The name of a feature required by the application. 
  The value must be one of the following accepted strings:
  
  <table> 
    <tr> 
       <th>Feature</th>
       <th>Value</th> 
       <th>Description</th> 
    </tr><tr> 
       <td rowspan="3">Camera</td>
       <td>"{@code android.hardware.camera}"</td> 
       <td>The application requires a camera.</td> 
    </tr><tr> 
       <td>"{@code android.hardware.camera.autofocus}"</td> 
       <td>The application requires a camera with auto-focus capability.
       As a prerequisite, "{@code android.hardware.camera}" must also be declared
       with a separate {@code &lt;uses-feature>} element.
       </td>
     <tr>
       <td colspan="2">
         <strong>Note:</strong> Any application that requests the 
         {@link android.Manifest.permission#CAMERA CAMERA permission} but does <em>not</em>
         declare any camera features with the {@code &lt;uses-feature>} element will be assumed
         to use all camera features (such as auto-focus). Thus, the application will not
         be compatible with devices that do not support all features. Please use 
         {@code &lt;uses-feature>} to declare only the camera features that your 
         application needs.
       </td>
     </tr>
    </tr>
  </table>
  
  </dd>
</dl>
</dd>

<!-- ##api level indication## -->
<dt>introduced in:</dt>
<dd>API Level 4</dd>

<dt>see also:</dt>
<dd>
  <ul>
    <li>{@link android.content.pm.ConfigurationInfo}</li>
  </ul>
</dd>

</dl>