docs/html/wear/preview/features/ime.jd

page.title=Wear Input Method Framework
meta.tags="wear", "wear-preview", "input-method", "ime"
page.tags="wear"

@jd:body


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

    <h2>In this document</h2>
    <ol>
      <li><a href="#creating">Creating an Input Method for Wear</a></li>
      <li><a href="#invoking">Invoking IME</a></li>
      <li><a href="#considerations">General IME Considerations</a></li>
    </ol>

</div>
</div>


<p>Wear 2.0 supports input methods beyond voice by extending the Android 
Input Method Framework (IMF) to Android Wear. IMF allows for virtual, on-screen
 keyboards and other input methods to be used for text entry. 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 2.0 comes with the system default Input Method Editor (IME) 
and opens up the IMF APIs for third-party developers to create custom input 
methods for Wear.</p>

<p><img src="{@docRoot}wear/preview/images/new_input_methods.png"></p>
<p><b>Figure 1</b>. Sample input methods </p>

<h2 id="creating">Creating an Input Method for Wear</h2>
<p>The Android platform provides a standard framework for creating IMEs. To create
 a Wear-specific IME, you need to optimize your IME for limited screen size.
  </p>

<p>This document provides guidance that can help you create a Wear-specific IME.
Before you continue with this guide, it's important that you read the
documentation for
<a href="{@docRoot}guide/topics/text/creating-input-method.html">Creating an Input Method</a>
 on handsets.
</p>


<h2 id="invoking">Invoking an Input Method</h2>
If you are developing an IME for Wear, remember that the 
feature is supported only on Android 6.0 (API level 23) and higher versions of 
the platform. 
To ensure that your IME can only be installed on Wearables that support input 
methods beyond voice, add the following to your app's manifest:
<pre>
&lt;uses-sdk android:minSdkVersion="23" />
</pre>
This indicates that your app requires Android 6.0 or higher. 
For more information, see <a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#ApiLevels">API Levels</a>
 and the documentation for the <a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html">&lt;uses-sdk></a> 
element.
<p>
To control how your app is filtered from devices that do not support Wear
IMEs (for example, on Phone), add the following to your app's manifest:
</p>
<pre>
&lt;uses-feature android:required="true" android:name="android.hardware.type.watch" />
</pre>

<p>Wear provides user settings on the watch that lets the user to enable multiple
 IMEs from the list of installed IMEs. Once the users enable your IME, they 
 can invoke your IME from:</p>
<ul>
<li>A notification or an app using the 
<a href="{@docRoot}reference/android/support/v4/app/RemoteInput.html">RemoteInput</a></code> API.</li>
<li>Wear apps with an 
<a href="{@docRoot}reference/android/widget/EditText.html">EditText</a>
 field. Touching a text field places the cursor in the field and automatically 
 displays the IME on focus.</li>
</ul>


<h2 id="considerations">General IME Considerations</h2>

<p>Here are some things to consider when implementing IME for Wear:</p>

<ul>
<li><strong>Set Default Action</strong>
<p>
<a href="http://developer.android.com/reference/android/support/v4/app/RemoteInput.html">{@code RemoteInput}</a> 
and Wear apps expect only single-line text entry. The ENTER key should always trigger
 a call to <a href="{@docRoot}reference/android/inputmethodservice/InputMethodService.html#sendDefaultEditorAction(boolean)">sendDefaultEditorAction</a>,
  which causes the app to dismiss the keyboard and continue on to the next step 
  or action.</p>
</li>

<li><Strong>Use full-screen-mode IME</strong>
<p>
Input methods on Wear consume most of the screen, leaving very little of the
 app visible; using full-screen mode ensures an optimal user experience regardless
  of the app UI.  In full-screen mode, an 
  <a href="{@docRoot}reference/android/view/inputmethod/ExtractedText.html">{@code ExtractEditText}</a> provides a mirrored
   view of the text field being edited and can be styled to blend with the rest of
    the input method UI. For more details on full-screen mode, see 
    <a href="{@docRoot}reference/android/inputmethodservice/InputMethodService.html">InputMethodService</a>.
</p>
</li>

<li><strong>Handle InputType flags</strong>
<p>
For privacy reasons, at a minimum you should handle the {@code InputType} 
flag {@code TYPE_TEXT_VARIATION_PASSWORD} in your IME. When your IME is in 
password mode, make sure that your keyboard is optimized for single key press 
(auto spelling correction, auto completion and gesture input are disabled). 
Most importantly, keyboard in password mode should support ASCII symbols 
regardless of the input language.  For more details, see 
<a href="{@docRoot}training/keyboard-input/style.html">Specifying The Input Method Type</a>.
</p>
</li>

<li><strong>Provide a key for switching to the next input method</strong>
<p>
Android allows users to easily switch between all IMEs supported by the platform.
 In your IME implementation, set the boolean 
 <a href="{@docRoot}guide/topics/text/creating-input-method.html#Switching">supportsSwitchingToNextInputMethod = true</a>
 to enable your IME to support the switching mechanism 
 (so that apps can switch to the next platform-supported IME).
</p>
</li>
</ul>