Developer notes

• A check box lets the user choose between two opposite states, actions or values
• You should use a native control when at all possible vs a custom element, as it will automatically and correctly announce the role without additional development effort
• A check box should just toggle between checked and unchecked. It should not automatically navigate the user to another field or screen when activated, as that may cause a change of context. Revealing new information on the same screen as a result of activating a checkbox is usually ok, as it is not a change of context.
• Name, Role, State must be announced when focus is on the control. Announcing the label in a separate swipe before the checkbox does not meet this requirement.

iOS

Name

• Programmatic name describes the purpose of the control.
• If visible text label exists, the programmatic name should match the visible text label.
  • Note: Setting a programmatic name while a visible text label exists may cause VoiceOver to duplicate the announcement of the name. If this happens, hide the visible text label from VoiceOver recognization.
• UIKit
  • You can programmatically set the visible label with setTitle().
    • The checkbox’s title will overwrite the checkbox’s accessibilityLabel.
  • If a visible label is not applicable in this case, set the button’s accessibilityLabel to the label of your choice.
    • To do this in Interface Builder, set the label using the Identity Inspector
  • To hide labels from VoiceOver programmatically, set the label’s isAccessibilityElement property to false
  • To hide labels from VoiceOver using Interface Builder, uncheck Accessibility Enabled in the Identity Inspector.
• SwiftUI
  • By default, the visible label of a Toggle is the accessibility label
  • If no visible label, use view modifier accessibilityLabel(_:).

Role

• When using non-native controls (custom controls), roles will need to be manually coded.

• UIKit
  • Since there is no native checkbox in UIKit, implementing a custom checkbox may be necessary using UIButton, UISwitch, UIControl, or another class.
  • If necessary, set accessibilityTraits to .button. Be sure to set the accessibility value to either “Checked” or “Unchecked” to indicate that this control behaves as a checkbox.
  • An alternative to setting the accessibility trait to .button is removing and hiding the accessibility trait using accessibilityTraits.remove(:). Then, append “, Checkbox” to the programmatic name
• SwiftUI
  • Use native Toggle view with toggleStyle(.checkbox)

Groupings

• Group visible label with checkbox, if applicable, to provide a programmatic name for the checkbox.
• Group label with data to ensure reading order is logical. (Not label, label, data, data).

• Group the units such that the label, role, and state of the checkbox is announced in a single announcement.

• UIKit
  1. Ensure that the child elements of the overarching view you want to group in has their isAccessibilityElement properties set to false.
  2. Set isAccessibilityElement to true for the parent view. Then, adjust accessibilityLabel and accessibilityTraits accordingly.
     • If frame does not exist, use accessibilityFrameInContainer to set the custom control’s frame to the parent view’s container or view of your choice.
       • You can also unionize two frames with frame.union (i.e. titleLabel.frame.union(subtitleLabel.frame)).
     • Use shouldGroupAccessibilityElement for a precise order if the native order should be disrupted.
     • Use shouldGroupAccessibilityChildren to indicate whether VoiceOver must group its children views. This allows making unique vocalizations or define a particular reading order for a part of the page.
• SwiftUI
  • Use view modifier accessibilityElement(children: .combine) to merge the child accessibility element’s properties into the new accessibilityElement.
  • If the tap gesture is removed due to grouping logic, restore the tap gesture functionality using bindings to bind the tap gesture of the container with the state of the checkbox.

State

• UIKit
  • For checked state: Set accessibilityValue to “Checked”
  • For unchecked state: Optionally, set accessibilityValue to “Unchecked”
  • For enabled state: Set isEnabled to true.
  • For disabled: Set isEnabled to false. Announcement for disabled is “Dimmed”.
    • If necessary, you may change the accessibility trait of the button to notEnabled, but this may overwrite the current accessibility role of the button.
• SwiftUI
  • For checked state, if necessary: Set accessibility value to “Checked” with accessibility(:)
  • For unchecked state, if necessary: Set accessibility value to “Unchecked” with accessibilityValue(:)
  • For disabled, use view modifier disabled().

Focus

• Use the device’s default focus functionality.
• Consider how focus should be managed between child elements and their parent views.
• External keyboard tab order often follows the screen reader focus, but sometimes this functionality requires additional development to manage focus.
• Initial focus on a screen should land in a logical place, such as back button, screen title, first text field, or first heading.
• When a bottom navigation bar element is activated, the next screen’s initial focus should move to the top of the screen. It should not stay in the bottom navigation bar.

• When a menu, picker, or modal is closed, the focus should return to the triggering element.

• UIKit
  • If VoiceOver is not reaching a particular element, set the element’s isAccessibilityElement to true
    • Note: You may need to adjust the programmatic name, role, state, and/or value after doing this, as this action may overwrite previously configured accessibility.
  • Use accessibilityViewIsModal to contain the screen reader focus inside the modal.
  • To move screen reader focus to newly revealed content, use UIAccessibility.post(notification:argument:) that takes in .screenChanged and the newly revealed content as the parameter arguments.
  • To NOT move focus, but dynamically announce new content: use UIAccessibility.post(notification:argument:) that takes in .announcement and the announcement text as the parameter arguments.
  • UIAccessibilityContainer protocol: Have a table of elements that defines the reading order of the elements.
• SwiftUI
  • For general focus management that impacts both screen readers and non-screen readers, use the property wrapper @FocusState to assign an identity of a focus state.
    • Use the property wrapper @FocusState in conjunction with the view modifier focused(_:) to assign focus on a view with @FocusState as the source of truth.
    • Use the property wrapper @FocusState in conjunction with the view modifier focused(_:equals:) to assign focus on a view, when the view is equal to a specific value.
  • If necessary, use property wrapper @AccessibilityFocusState to assign identifiers to specific views to manually shift focus from one view to another as the user interacts with the screen with VoiceOver on.

Announcement examples

• Appending checkbox to label:
• “Label checkbox, checked, button”
• “Label checkbox, not checked, button” (not checked or unselected are acceptable)
• Not appending to label:
• “Label, checked, button”
• “Label, not checked, button” (both “not checked” or unselected are acceptable)

Android

Code example

val checkedState = remember { mutableStateOf(true) }
val stateNotSubscribed = "Not Selected"
val stateSubscribed = "Selected"
Row(
  modifier = Modifier
        .semantics {
            stateDescription = if (checkedState.value) { stateSubscribed } else { stateNotSubscribed }
            contentDescription = "Subscribe"
        }
        .toggleable(
            value = checkedState.value,
            onValueChange = { checkedState.value = it },
            role = Role.Checkbox
        )
  ) {
    Checkbox(
            modifier = Modifier.align(Alignment.CenterVertically),
            checked = checkedState.value,
            onCheckedChange = null
    )
        Text(text = "Subscription")
    }

Name

• Programmatic name describes the purpose of the control

• Programmatic name matches the visible text label

• Android Views
  • android:text XML attribute
  • Optional: use contentDescription for a more descriptive name, depending on type of view and for elements (icons) without a visible label
  • contentDescription overrides android:text
  • Use labelFor attribute to associate the visible label with the control (Best practice)
• Android Compose
  • By default, the simple checkbox composable is readout & focused separately from its label text, which makes it hard to understand the context.
  • Use Row composable and toggleable(role = Role.Checkbox) with inner element as Checkbox composable (recommended practice) to have entire row including its label focused for selection, so it allows screenreader to read the name and role together.
  • Optional: use Modifier.semantics { contentDescription = "" } for a more descriptive name

Role

• When not using native controls (custom controls), roles will need to be manually coded.

• Android Views
  • CheckBox Class
  • Announced as “checkbox”
• Android Compose
  • Simple checkbox composable.
  • Alternatively use checkbox composable in combination with Row and toggleable(role = Role.Checkbox). Code example above.
  • Announced as “checkbox”

Groupings

• Group visible label with button (if applicable) to provide a programmatic name for the button

• Android Views
  • ViewGroup
  • Set the container object’s 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.
  • use labelFor
• Android Compose
  • Modifier.semantics(mergeDescendants = true) {} is equivalent to importantForAccessibility when compared to android views.
  • To allow checkbox grouping, specify onCheckedChange = null on inner simple checkbox composable when combined with Row composable and toggleable(value = checkedState.value, onValueChange = { checkedState.value = it }). This makes the entire row group selectable including its label.
  • FocusRequester can be used to request focus to individual components with in the group. More on FocusRequester in the focus section below.

State

• When native code is not available for a state, add the state to the programmatic name (label). Add logic when needed.

• Android Views
  • Active: android:enabled=true, isChecked, setChecked
  • Disabled: android:enabled=false announced as: “disabled”
• Android Compose
  • Checked: Checkbox(checked = true) announced as: “checked”
  • Enabled: Checkbox(enabled = true)
  • Disabled: Checkbox(enabled = false) announced as: “disabled”
  • When using checkbox composable with row and toggleable, need to specify Modifier.toggleable(enabled = false) along with Checkbox(enabled = false)
  • Use modifier = Modifier.semantics { stateDescription = "" } to have a customized state announcement.

Focus

• Only manage focus when needed. Primarily, let the device manage default focus
• Consider how focus should be managed between child elements and their parent views

• External keyboard tab order often follows the screen reader focus, but sometimes needs focus management

• Android Views
  • 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
  • For a ViewGroup, set screenReaderFocusable=true and each inner object’s attribute to keyboard focus (focusable=false)
• Android Compose
  • Modifier.focusTarget() makes the component focusable
  • Modifier.focusOrder() needs to be used in combination with FocusRequesters to define focus order
  • Modifier.onFocusEvent(), Modifier.onFocusChanged() can be used to observe the changes to focus state
  • FocusRequester allows to request focus to individual elements with in a group of merged descendant views
  • Example: To customize the focus events behaviour
    • step 1: define the focus requester prior. val (first, second) = FocusRequester.createRefs()
    • step 2: update the modifier to set the order. modifier = Modifier.focusOrder(first) { this.down = second }
    • focus order accepts following values: up, down, left, right, previous, next, start, end
    • step 3: use second.requestFocus() to gain focus

Announcement examples

• “Checked, label, checkbox, double tap to toggle”
• “Not checked, label, checkbox, double tap to toggle”