android accessibility - the missing manual

Android AccessibilityThe Missing Manual

Ted Drake, Intuit Accessibility

Testing

Android Lint

AccessibilityChecks

• AccessibilityChecks released at Google IO 2015

• Open Source tests for Espresso and Robolectric

• Soon: Android app that lets you test on a device

• Goal: Adopt AccessibilityChecks for Appium

TalkBack

Turn on TalkBack

Gestures

Two Fingered Gestures

Android Accessibility Shortcut

Programming

accessibilityLiveRegion

• Based on the Live Region experience in HTML + ARIA

• Content is announced when it changes or appears on screen

• android:accessibilityLiveRegion =“polite”

AccessibilityAction

• Swipes and other hard to discover actions

• Actions are activated from the Local Context Menu

• Provide hints for actions

Create AccessibilityAction/** * @param actionId The id for this action. This should either be one of * the standard actions or a specific action for your app. In that case it * is required to use a resource identifier. */public AccessibilityAction(int id, CharSequence label) new AccessibilityAction(R.id.dismiss, getString(R.string.dismiss));new AccessibilityAction(ACTION_CLICK, getString(R.string.play_song)); !// Constants for all the standard actions with default label: AccessibilityAction.ACTION_CLICK

Handling a Custom ActioneventView.setAccessibilityDelegate(new AccessibilityDelegate { @Override public onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) { super.onInitializeAccessibilityNodeInfo(host, info); info.addAction(new AccessibilityAction(R.id.dismiss,}@OverridegetString(R.string.dismiss))); public boolean performAccessibilityAction(View host, int action, Bundle args) { if (action == R.id.dismiss) {} // Logic for action }});

android:importantForAccessibility

noHideDescendants

noHideDescendants

noHideDescendants

auto

ListPopupWindow

setModal(true)

Forms

Form Labels

Which is correct? • android:hint

• android:labelFor

• android:contentDescription

<TextView

android:layout_height="match_parent"

android:labelFor="@+id/edit_item_name"

android:text=“Invoice amount"/>

<EditText

android:id="@+id/edit_item_name"

android:layout_height="wrap_content"

android:hint=“Invoice Amount"/>

android:hint

android:hint

• This create a placeholder text string within an input

• This was the preferred method and is a hack

• The hint is removed when a user adds a value to the input

• Still a valid method of adding a label to an input

contentDescription

• Invisible description for TalkBack

• Should not be used directly on an input

• You can use it on an input’s container and combine with labelFor

textinputlayout<textinputlayout

android:labelfor="@id/signupemail"

android:contentdescription="Email"

android:accessibilityliveregion="polite">

<edittext

android:id="@id/signupemail"

android:hint="Email"

android:seterror="Create a valid email address"…/>

</textinputlayout>

Checking for TalkBackAccessibilityManager am = (AccessibilityManager) getSystemService(ACCESSIBILITY_SERVICE);

boolean isAccessibilityEnabled = am.isEnabled();

boolean isExploreByTouchEnabled = am.isTouchExplorationEnabled();

Android Documentation• Creating an Accessible App

• Developing an Accessible Service

• Android Fragments

• Android Properties and TalkBack

• Robolectric + Espresso

• Android Accessibility Design

• Accessibility Checks