Screen Reader:
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When Screen Reader is turned on, on Android devices, it automatically announces what element is in focus.
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It is recommended to use views that Android provides which include view’s role and content required by Accessibility service. If you need a custom button, you extend the Button rather than starting from scratch with a View.
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In most cases, set element’s contentDescription attribute, without including its type/role. Screen readers automatically announce both the element’s description and type. For example for a Camera ImageButton, set contentDescription as “Camera”. It will announce it as “Camera button, double tap to activate”
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Make sure contentDescription is unique, for example in a list of movies, contentDescription of each item could the movie title.
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Exclude TextViews, since Android accessibility services automatically announce the text itself as the description.
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Set android:importantForAccessibility attributes to “no” if there’s element added for decoration purpose only, for example background ImageView or an element which is not clickable in production but used for testing purpose.
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labelFor can be used along with EditText fields, to announce what the EditText field is meant for. For example Username: [EditText] add labelFor attribute to TextView created for Username: label which is a label for Username EditText.
<TextView
android:id = "@+id/tvUserName
...
android:labelFor = "id/etUserName"/>
<EditText
android:id = "@+id/etUserName
...
/>
- When required to be added description of an item dynamically we can make use of StringBuilder
val contentDescription = StringBuilder()
contentDescription.append("list item").append(movieList[position])
listItemView.setContentDescription(contentDescription);
- To override default accessibility screen reader announcements, AccessibilityDelegate can be used on all the views. Examples:
For a camera ToggleButton, announce as “Turn off camera button, double tap to toggle”
cameraToggleButton.setChecked(true);
cameraToggleButton.setTextOn("Turn Off");
cameraToggleButton.setTextOff("Turn On");
ViewCompat.setAccessibilityDelegate(cameraToggleButton, new AccessibilityDelegateCompat() {
private boolean didPerformAccessibilityAction = false
@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
super.onInitializeAccessibilityNodeInfo(host, info);
info.contentDescription = "Camera"
info.setRoleDescription = "Button"
}
});
On a Movie list item, announce as “double tap to view movie detail” and “long tap and hold to add to favorites”
ViewCompat.setAccessibilityDelegate(itemView, new AccessibilityDelegateCompat() {
override fun onInitializeAccessibilityNodeInfo(
host: View, info: AccessibilityNodeInfoCompat) {
super.onInitializeAccessibilityNodeInfo(host, info)
val click =
AccessibilityNodeInfoCompat.AccessibilityActionCompat(
AccessibilityNodeInfo.ACTION_CLICK,"view movie detail")
val longClick =
AccessibilityNodeInfoCompat.AccessibilityActionCompat(
AccessibilityNodeInfo.ACTION_LONG_CLICK, "add to favorites")
info.addAction(click)
info.addAction(longClick)
}
});