Developer Notes

  • Switch or Toggle Button - A switch is a visual toggle between two mutually exclusive states — on and off
  • You should use a native switch when at all possible vs a custom element, as it will automatically and correctly announce the role without additional development effort
  • A toggle should just toggle on or off. It should not automatically navigate the user to another field or screen when toggled, as that would most likely cause a change of context

Name

  • Name describes purpose while focus is on the control (or on the whole table row)
  • Best practice is to not include “button” in the name
  • Name should match the visible label, if any

  • 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
    • Match visible label
    • To hide labels from VoiceOver announcements, uncheck the Accessibility Enabled checkbox in the Identity Inspector or use isAccessibilityElement=false
    • If hiding visible label from screen reader, use accessibilityLabel on control
  • 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 overrides android: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

  • iOS Tips
    • Standard UISwitchControl
    • “double tap to toggle setting” is expected announcement
  • Android Tips
    • Standard RadioButton with RadioGroup when applicable
    • “double tap to activate” or “double tap to toggle” is expected announcement

Groupings

  • Group visible label with switch (label and switch can be grouped together in a tableview/row/blade - one swipe)

  • iOS Tips
    • accessibilityFrame
    • accessibilityFrameInContainerSpace
    • GroupView
    • Only the container class is an accessible element isAccessibilityElement=true and announces all elements in one announcement This makes child elements no longer accessible by screen reader
  • Android Tips
    • ViewGroup
    • Set the container objects android:screenReaderFocusable attribute to true, and each inner object’s android: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, on/off, checked/unchecked

  • iOS
    • Active: isEnabled property
    • Disabled: UIAccessibilityTraitNotEnabled
    • disabled/dimmed
    • on/off: isOn or setOn
    • Announcement: dimmed, on/off, “double tap to toggle setting”
  • Android
    • Active: android:enabled=true
    • Disabled: android:enabled=false
    • on/off: isChecked, setChecked
    • Announcement: disabled, on/off, “double tap to activate” or “double tap to toggle”

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

  • iOS
    • accessibilityElementIsFocused
    • isAccessibilityElement makes the element visible or not to the Accessibility API
    • accessibilityElementsHidden indicates that the children elements of the target element are visible or not to the Accessibility API
    • accessibilityViewIsModal 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
  • Android
    • importantForAccessibility makes the element visible to the Accessibility API
    • android:focusable
    • android=clickable
    • Implement an onClick( ) event handler for keyboard, as well as onTouch( )
    • 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