1page.title=Accessibility Developer Checklist
2parent.title=Accessibility
3parent.link=index.html
4@jd:body
5
6<div id="qv-wrapper">
7<div id="qv">
8
9  <h2>In this document</h2>
10  <ol>
11    <li><a href="#requirements">Accessibility Requirements</a></li>
12    <li><a href="#recommendations">Accessibility Recommendations</a></li>
13    <li><a href="#special-cases">Special Cases and Considerations</a></li>
14  </ol>
15
16  <h2>See also</h2>
17  <ol>
18    <li><a href="{@docRoot}design/patterns/accessibility.html">Android Design: Accessibility</a></li>
19    <li><a href="{@docRoot}tools/testing/testing_accessibility.html">Accessibility Testing Checklist</a></li>
20    <li><a href="{@docRoot}training/accessibility/index.html">Training: Implementing Accessibility</a></li>
21    <li><a href="{@docRoot}training/design-navigation/index.html">Designing Effective Navigation</a></li>
22  </ol>
23
24</div>
25</div>
26
27<p>Making an application accessible is about a deep commitment to usability, getting the
28details right and delighting your users. This document provides a checklist of accessibility
29requirements, recommendations and considerations to help you make sure your application is
30accessible. Following this checklist does not guarantee your application is accessible, but it's a
31good place to start.</p>
32
33<p>Creating an accessible application is not just the responsibility of developers. Involve your
34design and testing folks as well, and make them are aware of the guidelines for these other stages
35of development:</p>
36
37<ul>
38  <li><a href="{@docRoot}design/patterns/accessibility.html">Android Design: Accessibility</a></li>
39  <li><a href="{@docRoot}tools/testing/testing_accessibility.html">Accessibility Testing
40    Checklist</a></li>
41</ul>
42
43<p>In most cases, creating an accessible Android application does not require extensive code
44restructuring. Rather, it means working through the subtle details of how users interact with your
45application, so you can provide them with feedback they can sense and understand. This checklist
46helps you focus on the key development issues to get the details of accessibility right.</p>
47
48
49<h2 id="requirements">Accessibility Requirements</h2>
50
51<p>The following steps must be completed in order to ensure a minimum level of application
52  accessibility.</p>
53
54<ol>
55  <li><strong>Describe user interface controls:</strong> Provide content
56    <a href="{@docRoot}guide/topics/ui/accessibility/apps.html#label-ui">descriptions</a> for user
57    interface components that do not have visible text, particularly
58    {@link android.widget.ImageButton}, {@link android.widget.ImageView}
59    and {@link android.widget.CheckBox} components. Use the
60    <a href="{@docRoot}reference/android/view/View.html#attr_android:contentDescription">
61    {@code android:contentDescription}</a> XML layout attribute or the {@link
62    android.view.View#setContentDescription} method to provide this information for accessibility
63    services. (Exception: <a href="#decorative">decorative graphics</a>)</li>
64  <li><strong>Enable focus-based navigation:</strong> Make sure
65    <a href="{@docRoot}guide/topics/ui/accessibility/apps.html#focus-nav">users can navigate</a>
66    your screen layouts using hardware-based or software directional controls (D-pads, trackballs,
67    keyboards and navigation gestures). In a few cases, you may need to make user interface components
68    <a href="{@docRoot}reference/android/view/View.html#attr_android:focusable">focusable</a>
69    or change the <a href="{@docRoot}guide/topics/ui/accessibility/apps.html#focus-order">focus
70    order</a> to be more logical for user actions.</li>
71  <li><strong>Custom view controls:</strong> If you build
72    <a href="{@docRoot}guide/topics/ui/custom-components.html">custom interface controls</a> for
73    your application, <a href="{@docRoot}guide/topics/ui/accessibility/apps.html#custom-views">
74    implement accessibility interfaces</a> for your custom views and provide content descriptions.
75    For custom controls that are intended to be compatible with versions of Android back to 1.6,
76    use the <a href="{@docRoot}tools/support-library/index.html">Support Library</a> to implement
77    the latest accessibility features.</li>
78  <li><strong>No audio-only feedback:</strong> Audio feedback must always have a secondary
79    feedback mechanism to support users who are deaf or hard of hearing. For example, a sound alert
80    for the arrival of a message must be accompanied by a system
81    {@link android.app.Notification}, haptic feedback (if available) or other visual alert.</li>
82  <li><strong>Test:</strong> Test accessibility by navigating your application
83    using directional controls, and using eyes-free navigation with TalkBack enabled.
84    For more accessibility testing information, see the
85    <a href="{@docRoot}tools/testing/testing_accessibility.html">Accessibility Testing
86    Checklist</a>.</li>
87</ol>
88
89
90<h2 id="recommendations">Accessibility Recommendations</h2>
91
92<p>The following steps are recommended for ensuring the accessibility of your application. If you
93  do not take these actions, it may impact the overall accessibility and quality of your
94  application.</p>
95
96<ol>
97  <li><strong>Android Design Accessibility Guidelines:</strong> Before building your layouts,
98    review and follow the accessibility guidelines provided in the
99    <a href="{@docRoot}design/patterns/accessibility.html">Design guidelines</a>.</li>
100  <li><strong>Framework-provided controls:</strong> Use Android's built-in user interface
101    controls whenever possible, as these components provide accessibility support by default.</li>
102  <li><strong>Temporary or self-hiding controls and notifications:</strong> Avoid having user
103    interface controls that fade out or disappear after a certain amount of time. If this behavior
104    is important to your application, provide an alternative interface for these functions.</li>
105</ol>
106
107
108<h2 id="special-cases">Special Cases and Considerations</h2>
109
110<p>The following list describes specific situations where action should be taken to ensure an
111  accessible app. Review this list to see if any of these special cases and considerations apply to
112  your application, and take the appropriate action.</p>
113
114<ol>
115  <li><strong>Text field hints:</strong> For {@link android.widget.EditText} fields, provide an
116    <a href="{@docRoot}reference/android/widget/TextView.html#attr_android:hint">android:hint</a>
117    attribute <em>instead</em> of a content description, to help users understand what content is
118    expected when the text field is empty and allow the contents of the field to be spoken when
119    it is filled.</li>
120  <li><strong>Custom controls with high visual context:</strong> If your application contains a
121    <a href="{@docRoot}guide/topics/ui/custom-components.html">custom control</a> with a high degree
122    of visual context (such as a calendar control), default accessibility services processing may
123    not provide adequate descriptions for users, and you should consider providing a
124    <a href="{@docRoot}guide/topics/ui/accessibility/apps.html#virtual-hierarchy">virtual
125    view hierarchy</a> for your control using
126    {@link android.view.accessibility.AccessibilityNodeProvider}.</li>
127  <li><strong>Custom controls and click handling:</strong> If a custom control in your
128    application performs specific handling of user touch interaction, such as listening with
129    {@link android.view.View#onTouchEvent} for {@link android.view.MotionEvent#ACTION_DOWN
130    MotionEvent.ACTION_DOWN} and {@link android.view.MotionEvent#ACTION_UP MotionEvent.ACTION_UP}
131    and treating it as a click event, you must trigger an {@link
132    android.view.accessibility.AccessibilityEvent} equivalent to a click and provide a way for
133    accessibility services to perform this action for users. For more information, see
134    <a href="{@docRoot}guide/topics/ui/accessibility/apps.html#custom-touch-events">Handling custom
135    touch events</a>.</li>
136  <li><strong>Controls that change function:</strong> If you have buttons or other controls
137    that change function during the normal activity of a user in your application (for example, a
138    button that changes from <strong>Play</strong> to <strong>Pause</strong>), make sure you also
139    change the <a href="{@docRoot}reference/android/view/View.html#attr_android:contentDescription">
140    {@code android:contentDescription}</a> of the button appropriately.</li>
141  <li><strong>Prompts for related controls:</strong> Make sure sets of controls which provide a
142    single function, such as the {@link android.widget.DatePicker}, provide useful audio feedback
143    when an user interacts with the individual controls.</li>
144  <li><strong>Video playback and captioning:</strong> If your application provides video
145    playback, it must support captioning and subtitles to assist users who are deaf or hard of
146    hearing. Your video playback controls must also clearly indicate if captioning is available for
147    a video and provide a clear way of enabling captions.</li>
148  <li><strong>Supplemental accessibility audio feedback:</strong> Use only the Android accessibility
149    framework to provide accessibility audio feedback for your app. Accessibility services such as
150    <a href="https://play.google.com/store/apps/details?id=com.google.android.marvin.talkback"
151    >TalkBack</a> should be the only way your application provides accessibility audio prompts to
152    users. Provide the prompting information with a
153    <a href="{@docRoot}reference/android/view/View.html#attr_android:contentDescription">{@code
154    android:contentDescription}</a> XML layout attribute or dynamically add it using accessibility
155    framework APIs. For example, if your application takes action that you want to announce to a
156    user, such as automatically turning the page of a book, use the {@link
157    android.view.View#announceForAccessibility} method to have accessibility services speak this
158    information to the user.</li>
159  <li><strong>Custom controls with complex visual interactions:</strong> For custom controls that
160    provide complex or non-standard visual interactions, provide a
161    <a href="{@docRoot}guide/topics/ui/accessibility/apps.html#virtual-hierarchy">virtual view
162    hierarchy</a> for your control using {@link android.view.accessibility.AccessibilityNodeProvider}
163    that allows accessibility services to provide a simplified interaction model for the user. If
164    this approach is not feasible, consider providing an alternate view that is accessible.</li>
165  <li><strong>Sets of small controls:</strong> If you have controls that are smaller than
166    the minimum recommended touch size in your application screens, consider grouping these controls
167    together using a {@link android.view.ViewGroup} and providing a
168    <a href="{@docRoot}reference/android/view/View.html#attr_android:contentDescription">{@code
169    android:contentDescription}</a> for the group.</li>
170  <li id="decorative"><strong>Decorative images and graphics:</strong> Elements in application
171    screens that are purely decorative and do not provide any content or enable a user action should
172    not have accessibility content descriptions.</li>
173</ol>
174