page.title=Preview API Overview
meta.tags="wear", "wear-preview"
page.tags="wear"
page.image=images/cards/card-n-apis_2x.png
@jd:body

<div id="qv-wrapper">
<div id="qv">
  <h2>Key developer features</h2>
  <ol>
      <ul style="list-style-type:none;">
        <li><a href="#ui">User Interface Improvements</a>
          <ol>
            <li><a href="#complications">Complications</a></li>
            <li><a href="#drawers">Navigation and Action Drawers</a></li>
          </ol>
        </li>

        <li><a href="#notify">Notifications and Input</a>
          <ol>
            <li><a href="#expanded">Expanded Notification</a></li>
            <li><a href="#messaging">Messaging Style Notification</a></li>
            <li><a href="#smart-replies">Smart Reply</a></li>
            <li><a href="#content-action">Notification Content Action</a>
            <li><a href="#remote-input">Remote Input</a></li>
            <li><a href="#bridging">Bridging Mode</a></li>
            <li><a href="#imf">Input Method Framework</a></li>
          </ol>
        </li>

        <li><a href="#stand-alone">Standalone Devices</a>
          <ol>
            <li><a href="#wear-apk">Wear-Specific APKs</a></li>
            <li><a href="#network">Network Access</a></li>
            <li><a href="#auth">Authentication</a></li>
          </ol>
        </li>
      </ol>
</div>
</div>


<p>
  The Android Wear Preview API is still in active development, but you can try
  it now as part of the Wear 2.0 Developer Preview. The sections below
  highlight some of the new features for Wear developers.
</p>


<h2 id="ui">User Interface Improvements</h2>

<p>The preview introduces powerful additions to the user interface, opening up
exciting possibilities to developers.
A complication is any feature in a watch face that displays more than hours and
minutes. With the Complications API,
 watch faces can display extra information and separate apps can expose complication
  data.
The navigation and action drawers provide users with new ways to interact with apps.
</p>


<h3 id="complications">Complications</h3>
<img src="{@docRoot}wear/preview/images/complications-main-image.png"
  height="320" style="float:right;margin:10px 0 0 40px" />

<p>
  A <a href=
  "https://en.wikipedia.org/wiki/Complication_(horology)">complication</a> is a
  feature of a watch face that displays more than hours and minutes, such as a
  battery indicator or a step counter. The Complications API helps watch face
  developers create these features visual features and data connections they
  require.
</p>

<p>
  Watch faces that use this API can display extra information without needing
  code for getting the underlying data. Data providers can supply data to any
  watch face using the API.
</p>

<p>For examples of how to use this feature,
see <a href="{@docRoot}wear/preview/features/complications.html">
 Watch Face Complications</a>.
</p>


<h3 id="drawers">Navigation and Action drawers</h3>

<p>Wear 2.0 introduces two new widgets, navigation drawer and action drawer. These
 widgets give your users new ways to interact with your app. The navigation drawer
  appears at the top of the screen and allows users to navigate between app views.
   The  action drawer appears at the bottom of the screen and allows users to choose
    from a list of actions associated with the current usage context.  These drawers
     are accessible to users when they edge swipe from the top or bottom of the
     screen; they peek when users scroll in an opposite direction.
</p>

<div class="cols">
  <div class="col-2of6">
    <img src="{@docRoot}wear/preview/images/nav_drawer.gif"
      height="240" alt="" style="padding:.5em">
  </div>
  <div class="col-2of6">
    <img src="{@docRoot}wear/preview/images/action_drawer.gif"
      height="240" alt="" style="padding:.5em;">
  </div>
</div>

<p>
  To learn how to add these widgets to your app, see
  <a href="{@docRoot}wear/preview/features/ui-nav-actions.html">
  Wear Navigation and Actions</a>.
</p>


<h2 id="notify">Notifications and Input</h2>

<p>In Wear 2.0, we’ve redesigned the key experiences on the watch to be even more
 intuitive and provide users new ways to respond to messages. Some of the highlights
  are below; for a complete list of changes, see
  <a href="{@docRoot}wear/preview/features/notifications.html">Notification Changes in Wear 2.0</a>.


<img src="{@docRoot}wear/preview/images/expanded_diagram.png" height="340"
  style="float:left;margin:10px 20px 0 0" />
<h3 id="expanded">Expanded notifications</h3>

<p>
  When a user taps on a notification that is bridged from the phone to the
  watch or that lacks a
  <a href="{@docRoot}reference/android/support/v4/app/NotificationCompat.Builder.html#setContentIntent(android.app.PendingIntent)">
  {@code contentIntent}</a>, the user will be taken to the expanded view of
  that notification. When you <a href=
  "{@docRoot}training/wearables/notifications/pages.html">specify additional
  content pages</a> and actions for a notification, those are available to the
  user within the expanded notification. Each expanded notification follows
  <a href="https://google.com/design/spec-wear">Material Design for Android
  Wear</a>, so the user gets an app-like experience.
</p>


<h3 id="messaging">Messaging Style notification</h3>
<p> If you have a chat messaging app, your notifications should use
{@code Notification.MessagingStyle}, which is new in Android 6.0. Wear 2.0 uses
the chat messages included in a
<a href="{@docRoot}preview/features/notification-updates.html#style">{@code MessagingStyle}</a>
 notification
(see {@code addMessage()}) to provide a rich chat app-like experience in the
expanded notification.
</p>


<h3 id="smart-replies">Smart Reply</h3>

<p>Android Wear 2.0 introduces support for Smart Reply in
<a href="{@docRoot}wear/preview/features/notifications.html#messaging">{@code MessagingStyle}</a>
 notifications. Smart Reply provides the user with contextually relevant,
 touchable choices in the expanded notification and in
 <a href="{@docRoot}reference/android/app/RemoteInput.html">{@code RemoteInput}</a>.
</p>

<p>By enabling Smart Reply for your {@code MessagingStyle} notifications, you provide
users a fast (single tap), discreet (no speaking aloud), and reliable way to respond
 to chat messages they receive.
 </p>


<img src="{@docRoot}wear/preview/images/remoteinput.png" height="350"
  style="float:right;margin:10px 0 0 40px" />

<h3 id="remote-input">Remote Input</h3>

<p>Wear 2.0 users can choose between various input options from
<a href="{@docRoot}reference/android/app/RemoteInput.html">Remote Input</a>.
 These options include:
</p>
<ul>
<li>Dictation</li>
<li>Emoji</li>
<li>Canned responses</li>
<li>Smart Reply</i>
<li>Default IME </i>
</ul>

<p>
For messaging notifications with Smart Reply, the system-generated Smart Reply
 appears within <a href="{@docRoot}reference/android/app/RemoteInput.html">{@code RemoteInput}</a>
  above the developer-provided list of canned responses.
  You can also use the
  <a href="{@docRoot}reference/android/app/RemoteInput.Builder.html#setChoices(java.lang.CharSequence[])">setChoices()</a>
   method in the {@code RemoteInput} API to enable users to select from a list
   of canned responses.
</p>

<h3 id="bridging"> Bridging Mode </h3>
<p>By default, notifications are
<a href="{@docRoot}training/wearables/notifications/index.html">
bridged</a> (shared) from an app on a companion phone
to the watch. Since a phone app and a standalone watch app may be sources of the
 same notifications, the Android Wear 2.0 Preview includes a Bridging mode feature.
  Developers can begin planning to change the behavior of notifications with the
  following:
</p>

<ul>
<li>Specifying in the standalone app's Android manifest file that notifications from
 the corresponding phone app should not be bridged to the watch. </li>
<li>Setting a dismissal ID so notification dismissals (by users) are synced across
devices.</li>
</ul>

<p>For an example of how to use this feature, see <a href="{@docRoot}wear/preview/features/bridger.html">
Bridging Mode for Notifications</a>.</p>

<h3 id="imf">Input Method Framework</h3>

<p>Wear 2.0 extends the Android input method framework (IMF) to Android Wear.
This allows users to enter text on Wear using the system default IME or third party
 IMEs.  The Wear IME lets the user enter text via gesture typing as well as tapping
  individual keys. The IMF APIs used for Wear devices are the same as other form
  factors, though usage is slightly different due to limited screen real estate.
</p>

<p>Wear provides user settings on the watch that let the user:</p>
<ul>
<li>Enable multiple IMEs from the list of installed IMEs.</li>
<li>Set a single default IME from the list of enabled IMEs.</li>
<li>Change languages for various IMEs.</li>
</ul>

<p>To learn how to create an IME for Wear, see <a href="{@docRoot}wear/preview/features/ime.html">
Input Method Framework</a>.
</p>


<h2 id="stand-alone">Standalone Devices</h2>

<p>Standalone watches will enable Android Wear apps to work independently of phone
 apps. This means your app can continue to offer full functionality even if the
 paired phone is far away or turned off. </p>

<h3 id="wear-apk">Wear-Specific APKs</h3>

<p>For delivery to a watch, an Android Wear app is currently embedded in its corresponding
phone app. This delivery method can result in an increased download size for users,
 regardless of whether they have an Android Wear device.
</p>

<p>With standalone devices, the
<a href ="{@docRoot}google/play/publishing/multiple-apks.html">Multi-APK</a>
 delivery method will be used. Developers will have the ability to release Android
  Wear apps independently of the corresponding phone apps. Please stay tuned for
   more information about this change.
</p>

<h3 id="network">Network Access</h3>

<p>Since Android Wear apps will work independently of phone apps, Android Wear's
 network access will no longer require the
 <a href="{@docRoot}training/wearables/data-layer/index.html">
 Wearable Data Layer API</a>. Android Wear apps will have the ability to make
 their own network requests. Additionally, they will be able to directly use
 Google Cloud Messaging.
</p>

<p>No APIs for network access or GCM are specific to Android Wear; refer to the
existing documentation about
<a href="{@docRoot}training/basics/network-ops/connecting.html">
Connecting to the Network</a> and
<a href="https://developers.google.com/cloud-messaging/">Cloud Messaging</a>.
</p>

<p>We recommend using the following libraries:</p>
<ul>
<li><a href="{@docRoot}reference/android/app/job/JobScheduler.html">
JobScheduler</a> for asynchronous jobs, including polling at regular intervals
</li>
<li>Multi-networking APIs if you need to connect to specific network types; see
the <a href="{@docRoot}about/versions/android-5.0.html#Wireless">
Multiple Network Connections</a>
</li>
</ul>

<p>You will still be able to use the
<a href="{@docRoot}training/wearables/data-layer/index.html">
 Wearable Data Layer API</a> to communicate with a phone app.
 However, use of this API to connect to a network will be discouraged.
 </p>


<h3 id="auth">Authentication</h3>

<p>Since Android Wear apps will work independently of phone apps, Android Wear's
 authentication capabilities will be more powerful; apps will have new ways to
 authenticate.</p>

<h4>Users can enter a username and password on a watch</h4>

<p>Google Keyboard will be standard on Android Wear, allowing for direct text
entry. This feature will work as expected with standard
<a href="{@docRoot}reference/android/widget/EditText.html">EditText widgets</a>.
For passwords, the {@code textPassword} attribute will be used.</p>

<h4>Utilizing Account Manager</h4>

<p>Android Wear will include the
<a href="{@docRoot}reference/android/accounts/AccountManager.html">
AccountManager</a>, which will be accessible for syncing and storing account
data, as it is on an Android phone.</p>

<h4>Authentication tokens can be passed over the Wearable Data Layer</h4>

<p>For Android-paired watches (only), a phone securely
transfers authentication credentials to a watch app via the
<a href="{@docRoot}training/wearables/data-layer/index.html">
Wearable Data Layer API</a>. The credentials can be transferred as
messages or data items.</p>

<p>If your watch app needs to determine if your phone app is installed, you can
advertise a capability on the phone app and retrieve the capability on the
watch. For more information, see the following sections of
<a href="{@docRoot}training/wearables/data-layer/messages.html">
Sending and Receiving Messages</a>:</p>

<ul>
  <li>Advertise Capabilities</li>
  <li>Retrieve the Nodes with the Required Capabilities</li>
</ul>