original

[gb-231r1-is01/Gingerbread_2.3.3_r1_IS01.git] / frameworks / base / docs / html / guide / appendix / market-filters.jd

page.title=Market Filters
@jd:body

<div id="qv-wrapper">
<div id="qv">

<h2>Quickview</h2>
<ul> <li>Android Market applies filters to that let you control whether your app is shown to a
user who is browing or searching for apps.</li> 
<li>Filtering is determined by elements in an app's manifest file,
aspects of the device being used, and other factors.</li> </ul>

<h2>In this document</h2>

<ol> <li><a href="#how-filters-work">How Filters Work in Android Market</a></li>
<li><a href="#manifest-filters">Filtering based on Manifest File Elements</a></li>
<li><a href="#other-filters">Other Filters</a></li> 
</ol>

<h2>See also</h2>
 <ol> 
<li><a
href="{@docRoot}guide/practices/compatibility.html">Compatibility</a></li>
<li style="margin-top:2px;"><code><a
href="{@docRoot}guide/topics/manifest/supports-screens-element.html">&lt;supports-screens&gt;</a></code></li>
<li><code><a
href="{@docRoot}guide/topics/manifest/uses-configuration-element.html">&lt;uses-configuration&gt;</a></code></li>
<li><code><a
href="{@docRoot}guide/topics/manifest/uses-feature-element.html">&lt;uses-feature&gt;</a></code></li>
<li><code><a
href="{@docRoot}guide/topics/manifest/uses-library-element.html">&lt;uses-library&gt;</a></code></li>
<li><code><a
href="{@docRoot}guide/topics/manifest/uses-permission-element.html">&lt;uses-permission&gt;</a></code></li>
<li><code><a
href="{@docRoot}guide/topics/manifest/uses-sdk-element.html">&lt;uses-sdk&gt;</code></a></li>
</ol>

<div id="qv-extra"> <img id="rule" src="{@docRoot}assets/images/grad-rule-qv.png">
<div id="qv-sub-rule"> <img src="{@docRoot}assets/images/icon_market.jpg"
style="float:left;margin:0;padding:0;"> <p style="color:#669999;">Interested in
publishing your app on Android Market?</p> <a id="publish-link"
href="http://market.android.com/publish">Go to Android Market &raquo;</a> </div>
</div>

</div> </div>

<p>When a user searches or browses in Android Market, the results are filtered, and
some applications might not be visible. For example, if an application requires a
trackball (as specified in the manifest file), then Android Market will not show
the app on any device that does not have a trackball.</p> <p>The manifest file and
the device's hardware and features are only part of how applications are filtered
&#8212; filtering also depends on the country and carrier, the presence or absence
of a SIM card, and other factors. </p>

<p>Changes to the Android Market filters are independent of changes 
to the Android platform itself. This document will be updated periodically to reflect 
any changes that occur. </p>

<h2 id="how-filters-work">How Filters Work in Android Market</h2>

<p>Android Market uses the filter restrictions described below to determine
whether to show your application to a user who is browsing or searching for
applications on a given device. When determining whether to display your app,
Market checks the device's hardware and software capabilities, as well as it's
carrier, location, and other characteristics. It then compares those against the
restrictions and dependencies expressed by the application itself, in its
manifest, <code>.apk</code>, and publishing details. If the application is
compatible with the device according to the filter rules, Market displays the
application to the user. Otherwise, Market hides your application from search
results and category browsing. </p>

<p> You can use the filters described below to control whether Market shows or
hides your application to users. You can request any combination of the
available filters for your app &#8212; for example, you could set a
<code>minSdkVersion</code> requirement of <code>"4"</code> and set
<code>smallScreens="false"</code> in the app, then when uploading the app to
Market you could target European countries (carriers) only. Android Market's
filters would prevent the application from being visible on any device that did
not match all three of these requirements. </p>

 <p>A filtered app is not visible within Market, even if a user specifically requests 
the app by clicking a deep link that points directly to the app's ID within Market. 
All filtering restrictions are associated with an application's version and can
change between versions. For example:</p> 

<ul> 
<li>If you publish a new version of your app with stricter restrictions, the app
will not be visible to users for whom it is filtered, even if those users were
able see the previous version.</li>
<li>If a user has installed your application and you publish an upgrade that
makes the app invisible to the user, the user will not see that an upgrade is
available. </li>
</ul>

<h2 id="manifest-filters">Filtering based on Manifest Elements</h2>

<p>Most Market filters are triggered by elements within an application's
manifest file, <a
href="{@docRoot}guide/topics/manifest/manifest-intro.html">AndroidManifest.xml</a>,
although not everything in the manifest file can trigger filtering. The
table below lists the manifest elements that you can use to trigger Android
Market filtering, and explains how the filtering works.</p>

<p class="table-caption"><strong>Table 1.</strong> Manifest elements that
trigger filtering on Market.</p>
<table>
  <tr>
    <th>Manifest Element</th>
    <th>Filter Name</th>
    <th>How It Works</th>
  </tr>
  <tr>
    <td valign="top" style="white-space:nowrap;"><code><a href="{@docRoot}guide/topics/manifest/supports-screens-element.html">&lt;supports-screens&gt;</a></code>
      <!-- ##api level 4## --></td>
    <td valign="top">Screen Size</td>
    <td valign="top">

<p>An application indicates the screen sizes that it is capable of supporting by
setting attributes of the <code>&lt;supports-screens&gt;</code> element. When
the application is published, Market uses those attributes to determine whether
to show the application to users, based on the screen sizes of their
devices. </p>

<p>As a general rule, Market assumes that the platform on the device can adapt
smaller layouts to larger screens, but cannot adapt larger layouts to smaller
screens. Thus, if an application declares support for "normal" screen size only,
Market makes the application available to both normal- and large-screen devices,
but filters the application so that it is not available to small-screen
devices.</p>

<p>If an application does not declare attributes for
<code>&lt;supports-screens&gt;</code>, Market uses the default values for those
attributes, which vary by API Level. Specifically: </p>

<ul>
<li><p>In API level 3, the <code>&lt;supports-screens&gt;</code> element itself
is undefined and no attributes are available. In this case, Market assumes that
the application is designed for normal-size screens and shows the application to
devices that have normal or large screens. </p>

<p>This behavior is especially significant for applications that set their
<code><a
href="{@docRoot}guide/topics/manifest/uses-sdk-element.html">android:
minSdkVersion</a></code> to 3 or lower, since Market will filter them from
small-screen devices by default. Such applications can enable support for
small-screen devices by adding a <code>android:targetSdkVersion="4"</code>
attribute to the <code>&lt;uses-sdk&gt;</code> element in their manifest
files. For more information, see <a
href="{@docRoot}guide/practices/screens_support.html#strategies">Strategies for
Legacy Applications</a>.</p></li>

<li>In API Level 4, the defaults for all of the attributes is
<code>"true"</code>. If an application does not declare a
<code>&lt;supports-screens&gt;</code> element, Market assumes that the
application is designed for all screen sizes and does not filter it from any
devices. If the application does not declare one of the attributes, Market uses
the default value of <code>"true"</code> and does not filter the app for devices
of corresponding screen size.</li>
</ul>

    <p><strong>Example 1</strong><br />
    The manifest declares <code>&lt;uses-sdk android:minSdkVersion="3"&gt;</code>
    and does not does not include a <code>&lt;supports-screens&gt;</code> element.
    <strong>Result</strong>: Android Market will not show the app to a user of a
    small-screen device, but will show it to users of normal and large-screen
    devices,  users, unless  other filters apply. </p>
    <p><strong>Example 2<br />
    </strong>The manifest declares <code>&lt;uses-sdk android:minSdkVersion="3"
    android:targetSdkVersion="4"&gt;</code> and does not include a
    <code>&lt;supports-screens&gt;</code> element.
    <strong>Result</strong>: Android Market will show the app to users on all 
    devices, unless other filters apply. </p>
    <p><strong>Example 3<br />
    </strong>The manifest declares <code>&lt;uses-sdk android:minSdkVersion="4"&gt;</code>
    and does not include a <code>&lt;supports-screens&gt;</code> element.
    <strong>Result</strong>: Android Market will show the app to all users,
    unless  other filters apply. </p>
    <p>For more information on how to declare support for screen sizes in your
    application, see <code><a
    href="{@docRoot}guide/topics/manifest/supports-screens-element.html">&lt;supports-screens&gt;</a></code>
    and <a href="{@docRoot}guide/practices/screens_support.html">Supporting Multiple
    Screens</a>.</p>
</td>
  </tr>
  <tr>
    <td valign="top" style="white-space:nowrap;"><code><a href="{@docRoot}guide/topics/manifest/uses-configuration-element.html">&lt;uses-configuration&gt;</a></code>
      <!-- ##api level 3## --></td>
    <td valign="top">Device
    Configuration: <br />
    keyboard, navigation, touch screen</td>
    <td valign="top"><p>An application can
    request certain hardware features, and Android Market will  show the app only on devices that have the required hardware.</p>
      <p><strong>Example 1<br />
      </strong>The manifest includes <code>&lt;uses-configuration android:reqFiveWayNav=&quot;true&quot; /&gt;</code>, and a user is searching for apps on a device that does not have a five-way navigational control. <strong>Result</strong>: Android Market will not show the app to the user. </p>
      <p><strong>Example 2<br />
      </strong>The manifest does not include a <code>&lt;uses-configuration&gt;</code> element. <strong>Result</strong>: Android Market will show the app to all users, unless other filters apply.</p>
<p>For more details, see  <a
href="{@docRoot}guide/topics/manifest/uses-configuration-element.html"><code>&lt;uses-configuration&gt;</code></a>.</p></td>
  </tr>
  <tr>
    <td rowspan="2" valign="top" style="white-space:nowrap;"><code><a
href="{@docRoot}guide/topics/manifest/uses-feature-element.html">&lt;uses-feature&gt;</a>
</code>
      <!-- ##api level 4## --></td>
    <td valign="top">Device Features<br />
      (<code>name</code>)</td>
    <td valign="top"><p>An application can require certain device features to be
present on the device. This functionality was introduced in Android 2.0 (API
Level 5).</p>
      <p><strong>Example 1<br />
      </strong>The manifest includes <code>&lt;uses-feature
android:name=&quot;android.hardware.sensor.light&quot; /&gt;</code>, and a user
is searching for apps on a device that does not have a light sensor.
<strong>Result</strong>: Android Market will not show the app to the user. </p>
      <p><strong>Example 2<br />
      </strong>The manifest does not include a <code>&lt;uses-feature&gt;</code>
element. <strong>Result</strong>: Android Market will show the app to all users,
unless other filters apply.</p>
      <p>For complete information, see <code><a
href="{@docRoot}guide/topics/manifest/uses-feature-element.html">&lt;uses-feature&gt;</a>
</code>.</p>
      <p><em>Filtering based on implied features:</em> In some cases, Android
Market interprets permissions requested through
<code>&lt;uses-permission&gt;</code> elements as feature requirements equivalent
to those declared in <code>&lt;uses-feature&gt;</code> elements. See <a
href="#uses-permission-filtering"><code>&lt;uses-permission&gt;</code></a>,
below.</p>
</td>
  </tr>
  <tr>
    <td valign="top">OpenGL-ES
    Version<br />
(<code>openGlEsVersion</code>)</td>
    <td valign="top"><p>An application can require that the device support a specific
      OpenGL-ES version using the <code>&lt;uses-feature
        android:openGlEsVersion=&quot;int&quot;&gt;</code> attribute.</p>
      <p><strong>Example 1<br />
      </strong>An app
        requests multiple OpenGL-ES versions by specifying <code>openGlEsVersion</code> multiple times in the
        manifest.  <strong>Result</strong>: Market assumes that the app requires the highest of the indicated versions.</p>
<p><strong>Example 2<br />
</strong>An app
        requests OpenGL-ES version 1.1, and a user is searching for apps on a device that supports OpenGL-ES version 2.0. <strong>Result</strong>: Android Market will show the app to the user, unless other filters apply. If a
  device reports that it supports OpenGL-ES version <em>X</em>,  Market assumes that it
  also supports any version earlier than <em>X</em>.
</p>
<p><strong>Example 3<br />
</strong>A user is searching for apps on a device that does not
        report an OpenGL-ES version (for example, a device running Android 1.5 or earlier). <strong>Result</strong>: Android Market assumes that the device
  supports only OpenGL-ES 1.0. Market will only show the user apps that do not specify <code>openGlEsVersion</code>, or apps that do not specify an OpenGL-ES version higher than 1.0. </p>
      <p><strong>Example 4<br />
      </strong>The manifest does not specify <code>openGlEsVersion</code>. <strong>Result</strong>: Android Market will show the app to all users, unless other filters apply. </p>
<p>For more details, see <a
href="{@docRoot}guide/topics/manifest/uses-feature-element.html"><code>&lt;uses-feature&gt;</code></a>.</p></td>
  </tr>
  <tr>
    <td valign="top" style="white-space:nowrap;"><code><a href="{@docRoot}guide/topics/manifest/uses-library-element.html">&lt;uses-library&gt;</a></code></td>
    <td valign="top">Software Libraries</td>
    <td valign="top"><p>An application can require specific
    shared libraries to be present on the device. </p>
      <p><strong>Example 1<br />
      </strong>An app requires the <code>com.google.android.maps</code> library, and a user is searching for apps on a device that does not have the <code>com.google.android.maps</code> library. <strong>Result</strong>: Android Market will not show the app to the user. </p>
      <p><strong>Example 2</strong><br />
        The manifest does not include a <code>&lt;uses-library&gt;</code> element. <strong>Result</strong>: Android Market will show the app to all users, unless other filters apply.</p>
<p>For more details, see <a
href="{@docRoot}guide/topics/manifest/uses-library-element.html"><code>&lt;uses-library&gt;</code></a>.</p></td>
  </tr>
  <tr id="uses-permission-filtering">
    <td valign="top" style="white-space:nowrap;"><code><a href="{@docRoot}guide/topics/manifest/uses-permission-element.html">&lt;uses-permission&gt;</a></code></td>
    <td valign="top">&nbsp;</td>
    <td valign="top">Strictly, Android Market does not filter based on
<code>&lt;uses-permission&gt;</code> elements. However, it does read the
elements to determine whether the application has hardware feature requirements
that may not have been properly declared in <code>&lt;uses-feature&gt;</code>
elements. For example, if an application requests the <code>CAMERA</code>
permission but does not declare a <code>&lt;uses-feature&gt;</code> element for
<code>android.hardware.camera</code>, Android Market considers that the
application requires a camera and should not be shown to users whose devices do
not offer a camera.</p>
    <p>In general, if an application requests hardware-related permissions,
Android Market assumes that the application requires the underlying hardware
features, even though there might be no corresponding to
<code>&lt;uses-feature&gt;</code> declarations. Android Market then sets up
filtering based on the features implied by the <code>&lt;uses-feature&gt;</code>
declarations.</p>
    <p>For a list of permissions that imply hardware features, see
the documentation for the <a
href="{@docRoot}guide/topics/manifest/uses-feature-element.html#permissions-features"><code>&lt;uses-feature&gt;</code></a>
element.</p>
</td>
  </tr>
  <tr>
    <td rowspan="2" valign="top" style="white-space:nowrap;"><code><a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html">&lt;uses-sdk&gt;</a></code></td>
    <td valign="top">Minimum Framework Version (<code>minSdkVersion</code>)</td>
    <td valign="top"><p>An application can require a minimum API level.  </p>
      <p><strong>Example 1</strong><br />
        The manifest includes <code>&lt;uses-sdk
      android:minSdkVersion=&quot;3&quot;&gt;</code>, and the app uses APIs that were introduced in API Level 3. A user is searching for apps on a device that has API Level 2. <strong>Result</strong>: Android Market will not show the app to the user. </p>
      <p><strong>Example 2</strong><br />
      The manifest does not include <code>minSdkVersion</code>, and the app uses APIs that were introduced in API Level 3. A user is searching for apps on a device that has API Level 2. <strong>Result</strong>: Android Market assumes that <code>minSdkVersion</code> is &quot;1&quot; and that the app is compatible with all versions of Android. Market  shows the app to the user and allows the user to download the app. The app crashes at runtime. </p>
    <p>Because you want to avoid this second scenario, we recommend that you always declare a <code>minSdkVersion</code>. For details, see <a
href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#min"><code>android:minSdkVersion</code></a>.</p></td>
  </tr>
  <tr>
    <td valign="top">Maximum Framework Version (<code>maxSdkVersion</code>)</td>
    <td valign="top"><p><em>Deprecated.</em> Android
    2.1 and later do not check or enforce the <code>maxSdkVersion</code> attribute, and
    the SDK will not compile if <code>maxSdkVersion</code> is set in an app's manifest. For devices already
    compiled with <code>maxSdkVersion</code>, Market will respect it and use it for
    filtering.</p>
<p> Declaring <code>maxSdkVersion</code> is <em>not</em> recommended. For details, see <a
href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#max"><code>android:maxSdkVersion</code></a>.</p></td>
  </tr>
</table>

<h2 id="other-filters">Other Filters</h2>
<p>Android Market uses other application characteristics to determine whether to show or hide an application for a particular user on a given device, as described in the table below. </p>

<p class="table-caption"><strong>Table 2.</strong> Application and publishing characteristics that affect filtering on Market.</p>
<table> <tr>
    <th>Filter Name</th> <th>How It Works</th> </tr>

  <tr>
    <td valign="top">Publishing Status</td> <td valign="top"><p>Only published applications will appear in
      searches and browsing within Android Market.</p> <p>Even if an app is unpublished, it can
        be installed if users can see it in their Downloads area among their purchased,
        installed, or recently uninstalled apps.</p> <p>If an application has been
  suspended, users will not be able to reinstall or update it, even if it appears in their Downloads.</p> </td></tr>
  <tr>
  <td valign="top">Priced
    Status</td> <td valign="top"><p>Not all users can see paid apps. To show paid apps, a device
must have a SIM card and be running Android 1.1 or later, and it must be in a
country (as determined by SIM carrier) in which paid apps are available.</p></td>
</tr> <tr>
  <td valign="top">Country / Carrier Targeting</td> <td valign="top"> <p>When you upload your app to
    the Android Market, you can select specific countries to target. The app will only
    be visible to the countries (carriers) that you select, as follows:</p>
    <ul><li><p>A device's country is determined based on the carrier, if a carrier is
      available. If no carrier can be determined, the Market application tries to
      determine the country based on IP.</p></li> <li><p>Carrier is determined based on
      the device's SIM (for GSM devices), not the current roaming carrier.</p></li></ul>
</td> </tr> <tr>
  <td valign="top">Native Platform</td> <td valign="top"><p>An application that includes native
    libraries that target a specific platform (ARM EABI v7, for example) will only be
    visible on devices that support that platform. For details about the NDK and using
    native libraries, see <a href="{@docRoot}sdk/ndk/index.html#overview">What is the
      Android NDK?</a></p> </tr> <tr>
        <td valign="top">Forward-Locked Applications</td> <td valign="top"><p>To
          forward lock an application, set copy protection to "On" when you upload the
          application to Market. Market will not show copy-protected applications on
developer devices or unreleased devices.</p></td> </tr> </table>