android_frameworks_base/docs/html/tools/testing/testing_accessibility.jd

page.title=Accessibility Testing Checklist
parent.title=Testing
parent.link=index.html
@jd:body

<div id="qv-wrapper">
  <div id="qv">
  <h2>In this document</h2>
  <ol>
    <li><a href="#goals">Testing Goals</a></li>
    <li><a href="#requirements">Testing Requirements</a></li>
    <li><a href="#recommendations">Testing Recommendations</a></li>
    <li><a href="#special-cases">Special Cases and Considerations</a></li>
    <li><a href="#how-to">Testing Accessibility Features</a>
      <ol>
        <li><a href="#test-audibles">Testing audible feedback</a></li>
        <li><a href="#test-navigation">Testing focus navigation</a></li>
        <li><a href="#test-gestures">Testing gesture navigation</a></li>
      </ol>
    </li>
  </ol>

  <h2>See Also</h2>
    <ol>
      <li>
        <a href="{@docRoot}guide/topics/ui/accessibility/checklist.html">
        Accessibility Developer Checklist</a>
      </li>
      <li>
        <a href="{@docRoot}design/patterns/accessibility.html">
        Android Design: Accessibility</a>
      </li>
      <li>
        <a href="{@docRoot}guide/topics/ui/accessibility/apps.html">
        Making Applications Accessible</a>
      </li>
    </ol>
  </div>
</div>
<p>
  Testing is an important part of making your application accessible to users with varying
  abilities. Following <a href="{@docRoot}design/patterns/accessibility.html">design</a> and
  <a href="{@docRoot}guide/topics/ui/accessibility/checklist.html">development</a> guidelines for
  accessibility are important steps toward that goal, but testing for accessibility can uncover
  problems with user interaction that are not obvious during design and development.</p>

<p>This accessibility testing checklist guides you through the important aspects of
  accessibility testing, including overall goals, required testing steps, recommended testing and
  special considerations. This document also discusses how to enable accessibility features on
  Android devices for testing purposes.</p>


<h2 id="goals">Testing Goals</h2>

<p>Your accessibility testing should have the following, high level goals:</p>

<ul>
  <li>Set up and use the application without sighted assistance</li>
  <li>All task workflows in the application can be easily navigated using directional controls and
    provide clear and appropriate feedback</li>
</ul>


<h2 id="requirements">Testing Requirements</h2>

<p>The following tests must be completed in order to ensure a minimum level of application
  accessibility.</p>

<ol>
  <li><strong>Directional controls:</strong> Verify that the application can be operated
    without the use of a touch screen. Attempt to use only directional controls to accomplish the
    primary tasks in the application. Use the keyboard and directional-pad (D-Pad) controls in the
    Android <a href="{@docRoot}tools/devices/emulator.html">Emulator</a> or use
    <a href="http://support.google.com/nexus/bin/answer.py?hl=en&answer=2700718">gesture
    navigation</a> on devices with Android 4.1 (API Level 16) or higher.
    <p class="note"><strong>Note:</strong> Keyboards and D-pads provide different navigation paths
    than accessibility gestures. While gestures allow users to focus on nearly any on-screen
    content, keyboard and D-pad navigation only allow focus on input fields and buttons.</p>
    </li>
  <li><strong>TalkBack audio prompts:</strong> Verify that user interface controls that provide
    information (graphics or text) or allow user action have clear and accurate audio descriptions
    when <a href="#testing-talkback">TalkBack is enabled</a> and controls are focused. Use
    directional controls to move focus between application layout elements.</li>
  <li><strong>Explore by Touch prompts:</strong> Verify that user interface controls that
    provide information (graphics or text) or allow user action have appropriate audio descriptions
    when <a href="#testing-ebt">Explore by Touch is enabled</a>. There should be no
    regions where contents or controls do not provide an audio description.</li>
  <li><strong>Touchable control sizes:</strong> All controls where a user can select or take an
    action must be a minimum of 48 dp (approximately 9mm) in length and width, as recommended by
    <a href="{@docRoot}design/patterns/accessibility.html">Android Design</a>.</li>
  <li><strong>Gestures work with TalkBack enabled:</strong> Verify that app-specific gestures,
    such as zooming images, scrolling lists, swiping between pages or navigating carousel controls
    continue to work when <a href="#testing-talkback">TalkBack is enabled</a>. If these gestures do
    not function, then an alternative interface for these actions must be provided.</li>
  <li><strong>No audio-only feedback:</strong> Audio feedback must always have a secondary
    feedback mechanism to support users who are deaf or hard of hearing, for example: A sound alert
    for the arrival of a message should also be accompanied by a system
    {@link android.app.Notification}, haptic feedback (if available) or another visual alert.</li>
</ol>


<h2 id="recommendations">Testing Recommendations</h2>

<p>The following tests are recommended for ensuring the accessibility of your application. If you
  do not test these items, it may impact the overall accessibility and quality of your
  application.</p>

<ol>
  <li><strong>Repetitive audio prompting:</strong> Check that closely related controls (such as
    items with multiple components in a list) do not simply repeat the same audio prompt. For
    example, in a contacts list that contains a contact picture, written name and title, the prompts
    should not simply repeat “Bob Smith” for each item.</li>
  <li><strong>Audio prompt overloading or underloading:</strong> Check that closely related
    controls provide an appropriate level of audio information that enables users to understand and
    act on a screen element. Too little or too much prompting can make it difficult to understand
    and use a control.</li>
</ol>


<h2 id="special-cases">Special Cases and Considerations</h2>

<p>The following list describes specific situations that should be tested to ensure an
  accessible app. Some, none or all of the cases described here may apply to your application. Be
  sure to review this list to find out if these special cases apply and take appropriate action.</p>

<ol>
  <li><strong>Review developer special cases and considerations:</strong> Review the list of
    <a href="{@docRoot}guide/topics/ui/accessibility/checklist.html#special-cases">special cases</a>
     for accessibility development and test your application for the cases that apply.</li>
  <li><strong>Prompts for controls that change function:</strong> Buttons or other controls
    that change function due to application context or workflow must provide audio prompts
    appropriate to their current function. For example, a button that changes function from play
    video to pause video should provide an audio prompt which is appropriate to its current state.</li>
  <li><strong>Video playback and captioning:</strong> If the application provides video
    playback, verify that it supports captioning and subtitles to assist users who are deaf or hard
    of hearing. The video playback controls must clearly indicate if captioning is available for a
    video and provide a clear way of enabling captions.</li>
</ol>


<h2 id="how-to">Testing Accessibility Features</h2>

<p>Testing of accessibility features such as TalkBack, Explore by Touch and accessibility Gestures
requires setup of your testing device. This section describes how to enable these features for
accessibility testing.</p>


<h3 id="test-audibles">Testing audible feedback</h3>

<p>Audible accessibility feedback features on Android devices provide audio prompts that speaks
  the screen content as you move around an application. By enabling these features on an Android
  device, you can test the experience of users with blindness or low-vision using your application.
</p>

<p>Audible feedback for users on Android is typically provided by TalkBack accessibility service and
the Explore by Touch system feature. The TalkBack accessibility service comes preinstalled on most
Android devices and can also be downloaded for free from
<a href="https://play.google.com/store/apps/details?id=com.google.android.marvin.talkback">Google
Play</a>. The Explore by Touch system feature is available on devices running Android 4.0 and later.
</p>

<h4 id="testing-talkback">Testing with TalkBack</h4>

<p>The <em>TalkBack</em> accessibility service works by speaking the contents of user interface
controls as the user moves focus onto controls. This service should be enabled as part of testing
focus navigation and audible prompts.</p>

<p>To enable the TalkBack accessibility service:</p>
<ol>
  <li>Launch the <strong>Settings</strong> application.</li>
  <li>Navigate to the <strong>Accessibility</strong> category and select it.</li>
  <li>Select <strong>Accessibility</strong> to enable it.</li>
  <li>Select <strong>TalkBack</strong> to enable it.</li>
</ol>

<p class="note">
  <strong>Note:</strong> While TalkBack is the most available Android accessibility service for
  users with disabilities, other accessibility services are available and may be installed by users.
</p>

<p>For more information about using TalkBack, see
<a href="http://support.google.com/nexus/bin/answer.py?hl=en&answer=2700928">Use TalkBack</a>.</p>

<h4 id="testing-ebt">Testing with Explore by Touch</h4>

<p>The <em>Explore by Touch</em> system feature is available on devices running Android 4.0 and
  later, and works by enabling a special accessibility mode that allows users to drag a finger
  around the interface of an application and hear the contents of the screen spoken. This feature
  does not require screen elements to be focused using an directional controller, but listens for
  hover events over user interface controls.
</p>

<p>To enable Explore by Touch on Android 4.0 and later:</p>
<ol>
  <li>Launch the <strong>Settings</strong> application.</li>
  <li>Navigate to the <strong>Accessibility</strong> category and select it.</li>
  <li>Select the <strong>TalkBack</strong> to enable it.
      <p class="note"><strong>Note:</strong> On Android 4.1 (API Level 16) and higher, the system
      provides a popup message to enable Explore by Touch. On older versions, you must follow the
      step below.</p>
  </li>
  <li>Return to the <strong>Accessibility</strong> category and select <strong>Explore by
Touch</strong> to enable it.
    <p class="note"><strong>Note:</strong> You must turn on TalkBack <em>first</em>, otherwise this
option is not available.</p>
  </li>
</ol>

<p>For more information about using the Explore by Touch features, see
<a href="http://support.google.com/nexus/bin/answer.py?hl=en&answer=2700722">Use Explore by
Touch</a>.</p>

<h3 id="test-navigation">Testing focus navigation</h3>

<p>Focus navigation is the use of directional controls to navigate between the individual user
  interface elements of an application in order to operate it. Users with limited vision or limited
  manual dexterity often use this mode of navigation instead of touch navigation. As part of
  accessibility testing, you should verify that your application can be operated using only
  directional controls.</p>

<p>You can test navigation of your application using only focus controls, even if your test devices
  does not have a directional controller. The <a href="{@docRoot}tools/help/emulator.html">Android
  Emulator</a> provides a simulated directional controller that you can use to test navigation. You
  can also use a software-based directional controller, such as the one provided by the
  <a href="https://play.google.com/store/apps/details?id=com.googlecode.eyesfree.inputmethod.latin"
  >Eyes-Free Keyboard</a> to simulate use of a D-pad on a test device that does not have a physical
  D-pad.</p>


<h3 id="test-gestures">Testing gesture navigation</h3>

<p>Gesture navigation is an accessibility navigation mode that allows users to navigate Android
  devices and applications using specific
  <a href="http://support.google.com/nexus/bin/answer.py?hl=en&answer=2700718">gestures</a>. This
  navigation mode is available on Android 4.1 (API Level 16) and higher.</p>

<p class="note"><strong>Note:</strong> Accessibility gestures provide a different navigation path
than keyboards and D-pads. While gestures allow users to focus on nearly any on-screen
content, keyboard and D-pad navigation only allow focus on input fields and buttons.</p>

<p>To enable gesture navigation on Android 4.1 and later:</p>
<ul>
  <li>Enable both TalkBack and the Explore by Touch feature as described in the
    <a href="#testing-ebt">Testing with Explore by Touch</a>. When <em>both</em> of these
    features are enabled, accessibility gestures are automatically enabled.</li>
  <li>You can change gesture settings using <strong>Settings &gt; Accessibility &gt; TalkBack &gt;
    Settings &gt; Manage shortcut gestures</strong>.
</ul>

<p>For more information about using Explore by Touch accessibility gestures, see
<a href="http://support.google.com/android/bin/topic.py?hl=en&topic=2492346">Accessibility
gestures</a>.</p>

<p class="note">
  <strong>Note:</strong> Accessibility services other than TalkBack may map accessibility gestures
  to different user actions. If gestures are not producing the expected actions during testing, try
  disabling other accessibility services before proceeding.</p>