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      1 page.title=Packaging Wearable Apps
      2 
      3 @jd:body
      4 
      5 <div id="tb-wrapper">
      6 <div id="tb">
      7 
      8 <h2>This lesson teaches you to</h2>
      9 <ol>
     10   <li><a href="#Studio">Package with Android Studio</a></li>
     11   <li><a href="#PackageManually">Package Manually</a></li>
     12   <li><a href="#AssetCompression">Turn off Asset Compression</a></li>
     13 </ol>
     14 </div>
     15 </div>
     16 
     17 <p>When publishing to users, you must package a wearable app inside of a handheld app, 
     18 because users cannot browse and install apps directly on the wearable. If packaged properly,
     19 when users download the handheld app, the system automatically pushes the wearable app to the
     20 paired wearable.
     21 </p>
     22 
     23 <p class="note"><b>Note:</b> This feature doesn't work when you are signing your apps with
     24 a debug key when developing. While developing, installing apps with <code>adb install</code> or
     25 Android Studio directly to the wearable is required.</p>
     26 
     27 
     28 <h2 id="Studio">Package with Android Studio</h2>
     29 <p>To properly package a wearable app in Android Studio:</p>
     30 
     31 <ol>
     32   <li>Declare a Gradle dependency in the handheld app's <code>build.gradle</code> file
     33   that points to the wearable app module:
     34 <pre>
     35 dependencies {
     36    compile 'com.google.android.gms:play-services:5.0.+@aar'
     37    compile 'com.android.support:support-v4:20.0.+''
     38    <b>wearApp project(':wearable')</b>
     39 }
     40 </pre>
     41   </li>
     42   <li>Click <b>Build > Generate Signed APK...</b> and follow the on-screen instructions
     43   to specify your release keystore and sign your app. Android Studio exports the signed
     44   handheld app with the wearable app embedded in it automatically into your project's root folder.
     45 
     46   <p>Alternatively, you can create a <code>signingConfig</code> rule in the wearable and handheld
     47   modules' <code>build.gradle</code> file to sign them with your release key. Both apps must be
     48   signed to have the automatic pushing of the wearable app work.
     49 
     50 <pre>
     51 android {
     52   ...
     53   signingConfigs {
     54     release {
     55       keyAlias 'myAlias'
     56       keyPassword 'myPw'
     57       storeFile file('path/to/release.keystore')
     58       storePassword 'myPw'
     59     }
     60   }
     61   buildTypes {
     62     release {
     63       ...
     64       signingConfig signingConfigs.release
     65     }
     66   }
     67   ...
     68 }
     69 </pre>
     70   <p>Build the handheld app by clicking the Gradle button on the right vertical toolbar of
     71   Android Studio and running the <b>assembleRelease</b> task. The task is located under
     72   <b>Project name > Handheld module name > assembleRelease</b>.
     73   </p>
     74 
     75 <p class="note"><b>Note:</b>This example embeds the password in your Gradle file, which might be undesirable. See
     76 <a href="{@docRoot}sdk/installing/studio-build.html#configureSigning">Configure signing settings</a>
     77 for information about how to create an environment variable for the passwords instead.
     78 </p>
     79 </ol>
     80 
     81 <h3>Signing the wearable and handheld app separately</h3>
     82 <p>If your build process requires signing the wearable app separately from the handheld app,
     83 you can declare the following Gradle rule in the handheld module's <code>build.gradle</code> to
     84 embed the previously-signed wearable app:</p>
     85 
     86 <pre>
     87 dependencies {
     88   ...
     89   wearApp files('/path/to/wearable_app.apk')
     90 }
     91 </pre>
     92 
     93 <p>You then sign your handheld app in any manner you wish (either with the Android Studio
     94 <b>Build > Generate Signed APK...</b> menu item or with Gradle <code>signingConfig</code> rules as
     95 described in the previous section.</p>
     96 
     97 <h2 id="PackageManually">Package Manually</h2>
     98 <p>
     99 It's still possible to package the wearable app into the handheld app manually
    100 if you are using another IDE or another method of building.
    101 </p>
    102 
    103 <ol>
    104   <li>Copy the signed wearable app to your handheld project's <code>res/raw</code> directory. We'll
    105   refer to the APK as <code>wearable_app.apk</code>.</li>
    106   <li>Create a <code>res/xml/wearable_app_desc.xml</code> file that contains the version and
    107   path information of the wearable app. For example:
    108 <pre>
    109 &lt;wearableApp package="wearable.app.package.name"&gt;
    110   &lt;versionCode&gt;1&lt;/versionCode&gt;
    111   &lt;versionName&gt;1.0&lt;/versionName&gt;
    112   &lt;rawPathResId>wearable_app&lt;/rawPathResId&gt; <!-- Do not include the .apk extension -->
    113 &lt;/wearableApp&gt;
    114 </pre>
    115 
    116 <p>
    117 The <code>package</code>, <code>versionCode</code>, and <code>versionName</code> are the
    118 same values specified in the wearable app's <code>AndroidManifest.xml</code> file. 
    119 The <code>rawPathResId</code> is the static variable name of the APK resource. For example, 
    120 for <code>wearable_app.apk</code>, the static variable name is <code>wearable_app</code>.
    121 </p>
    122 </li>
    123 <li>
    124 Add a <code>meta-data</code> tag to your handheld app's <code>&lt;application&gt;</code> tag to
    125 reference the <code>wearable_app_desc.xml</code> file.
    126 <pre>
    127   &lt;meta-data android:name="com.google.android.wearable.beta.app" 
    128                  android:resource="&#64;xml/wearable_app_desc"/&gt;
    129 </pre>
    130 </li>
    131 <li>Build and sign the handheld app.</li>
    132 </ol>
    133 
    134 <h2 id="AssetCompression">Turn off Asset Compression</h2>
    135 <p>Many build tools automatically compress any files added to the <code>res/raw</code>
    136 directory of an Android app. Because the wearable APK is already zipped, these tools re-compress the
    137 wearable APK and the wearable app installer can no longer read the wearable app.
    138 </p>
    139 
    140 <p>When this happens, the installation fails. On the handheld app, the <code>PackageUpdateService</code>
    141 logs the following error: "this file cannot be opened as a file descriptor; it is probably compressed."
    142 </p>
    143 
    144 <p>Android Studio doesn't compress your APK by default, but if you are using another build process,
    145 ensure that you don't doubly compress the wearable app.</p>
    146