Developer Notes
- Use a radio button when a user is to select an item from a predefined list of options
- Except in a rare case where a mixed state is needed, radio buttons should be mutually exclusive
- You should use a native element rather than a custom element because it will announce the correct built-in screen reader announcements without additional development effort
- A radio button should just change between checked and unchecked states. It should not automatically navigate the user to another field or screen when checked, as that may cause a change of context. Revealing new information on the same screen as a result of activating a checkbox is usually not a change of context.
- Name, Role, State must be announced when focus is on the control. Announcing the label before the radio button does not meet this requirement.
Name
- Programmatic name describes purpose while focus is on the control (or on the whole table row/blade)
-
Programmatic name matches the visible text label
- iOS Tips
- Set a label in Interface Builder in the Identity Inspector
- Group visible text label and the control in the same view container:
accessibilityFrameInContainerSpace
setTitle( )
method- If no visible label, use
accessibilityLabel
on control Hint
is used sparingly and if the results of interacting with it are not obvious from the control’s label- To hide labels from VoiceOver announcements, uncheck the Accessibility Enabled checkbox in the Identity Inspector or use
isAccessibilityElement=false
- Android Tips
android:text
XML attribute- Optional: use
contentDescription
for a more descriptive name, depending on type of view and for elements without a visible label contentDescription
overridesandroid:text
- Use
labelFor
attribute to associate the visible label with the control (Best practice)
Role
- Role is automatically announced if a native component is used
-
When not using native controls (custom controls), roles will need to be manually coded.
- iOS
- Standard UIButton
- Announce as “button”
- Android
- Standard RadioButton with RadioGroup when applicable
- Announcement: “double tap to activate”
Groupings
- Group visible label with radio button (label and radio button can be grouped together in a tableview/row/blade - one swipe) to provide a programmatic name for the button
-
Or use
labelFor
(Android) - iOS Tips
accessibilityFrame
accessibilityFrameInContainerSpace
- Create a wrapper as an accessible element
- Define action upon double-tap
shouldGroupAccessibilityElement
attribute: For a precise order if the native order should be disrupted.GroupView
shouldGroupAccessibilityChildren
attribute indicates whether VoiceOver must group it’s children views. This allows making unique vocalizations or define a particular reading order for a part of the page
- Android Tips
- ViewGroup
- Set the container object’s
android:screenReaderFocusable
attribute to true, and each inner object’sandroid:focusable
attribute to false. In doing so, accessibility services can present the inner elements’contentDescription
or names, one after the other, in a single announcement
State
-
States can be selected, dimmed/disabled, checked/unchecked, on/off
- iOS
UIControlState
orisSelected
,UIAccessibilityTraitNotEnabled
- Selected: Announced as “checked” or “selected”
- Not selected: Announced as “not checked” (optional)
- Active:
isEnabled property
- Disabled:
UIAccessibilityTraitNotEnabled
. Announced as “dimmed”
- Android
- Active:
android:enabled=true
- Disabled:
android:enabled=false
- on/off:
isChecked
,setChecked
- Announcement: disabled, checked/not checked
- Active:
Focus
- Only manage focus when needed. Primarily, let the device manage default focus order.
- Consider how focus should be managed between child elements and their parent views or containers
-
External keyboard tab order often follows the screen reader focus, but sometimes needs focus management
- iOS
accessibilityElementIsFocused
isAccessibilityElement
makes the element visible or not to the Accessibility APIaccessibilityElementsHidden
indicates that the children elements of the target element are visible or not to the Accessibility APIaccessibilityViewIsModal
contains the screen reader focus inside the Modal- To move screen reader focus to newly revealed content:
UIAccessibilityLayoutChangedNotification
- To NOT move focus, but dynamically announce new content:
UIAccessibilityAnnouncementNotification
UIAccessibilityContainer
protocol: Have a table of elements that defines the reading order of the elements.
- Android
importantForAccessibility
makes the element visible to the Accessibility APIandroid:focusable
android=clickable
- Implement an
onClick( )
event handler for keyboard, as well asonTouch( )
nextFocusDown
nextFocusUp
nextFocusRight
nextFocusLeft
accessibilityTraversalBefore
(or after)- To move screen reader focus to newly revealed content:
Type_View_Focused
- To NOT move focus, but dynamically announce new content:
accessibilityLiveRegion
(set to polite or assertive) - To hide controls:
Important_For_Accessibility_false
- For a
ViewGroup
, setscreenReaderFocusable=true
and each inner object’s attribute to keyboard focus (focusable=false
)