Developer notes
- Clickable textview that navigates the user outside the app (Ex: opens a browser)
- Button: even if the control visibly looks like a link, code as a button to cue the screen reader the action will keep them within the app
- Focus around an entire paragraph and activating an in-line link with double tap is an expected behavior. The link does not have isolated focus. (There can be only one active link in the paragraph)
- Links can also be focused separately within a paragraph or sentence. Since this would require 3 swipes to get through the sentence, this is not optimal.
iOS
Name
- Clickable text that describes the destination or purpose of the link
- Programmatic name matches 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 button’s title will overwrite the button’s
accessibilityLabel
.
- The button’s title will overwrite the button’s
- 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 tofalse
- To hide labels from VoiceOver using Interface Builder, uncheck
Accessibility Enabled
in the Identity Inspector.
- You can programmatically set the visible label with
- SwiftUI
- If no visible label, use view modifier
accessibilityLabel(_:)
. - If button has icon(s), hide the icon(s) from VoiceOver by using view modifier
accessibilityHidden(true)
.
- If no visible label, use view modifier
Role
-
When using non-native controls (custom controls), roles will need to be manually coded.
- UIKit
- Use
UIButton
- If necessary, set
accessibilityTraits
to.button
.
- Use
- SwiftUI
- Use native
Button
view - If necessary, use view modifier
accessibilityAddTraits(.isButton)
to assign the role as Button. - If applicable, use view modifier
accessibilityRemoveTraits(:)
to remove unwanted traits.
- Use native
Groupings
- Group visible label with button, if applicable, to provide a programmatic name for the button.
-
Group label with data to ensure reading order is logical. (Not label, label, data, data).
- UIKit
- Ensure that the child elements of the overarching view you want to group in has their
isAccessibilityElement
properties set to false. - Set
isAccessibilityElement
totrue
for the parent view. Then, adjustaccessibilityLabel
andaccessibilityTraits
accordingly.- If frame does not exist due to custom button, 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)
).
- You can also unionize two frames with
- 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.
- If frame does not exist due to custom button, use
- Ensure that the child elements of the overarching view you want to group in has their
- SwiftUI
- Use view modifier
accessibilityElement(children: .combine)
to merge the child accessibility element’s properties into the new accessibilityElement.
- Use view modifier
State
- UIKit
- For enabled: Set
isEnabled
totrue
. - For disabled: Set
isEnabled
tofalse
. 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.
- If necessary, you may change the accessibility trait of the button to
- For enabled: Set
- SwiftUI
- For selected, use
accessibilityAddTraits(.isSelected)
. - For disabled, use view modifier
disabled()
.
- For selected, use
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 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
totrue
- 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.
- If VoiceOver is not reaching a particular element, set the element’s
- 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 modifierfocused(_:)
to assign focus on a view with@FocusState
as the source of truth. - Use the property wrapper
@FocusState
in conjunction with the view modifierfocused(_:equals:)
to assign focus on a view, when the view is equal to a specific value.
- Use the property wrapper
- 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.
- For general focus management that impacts both screen readers and non-screen readers, use the property wrapper
Announcement examples
-
Announcement order can vary.
- “Label, link”
- “All text in paragraph including url, link” (link in paragraph)
- “Label, dimmed, link” (disabled)
Android
Name
- Clickable text that describes the destination or purpose of the link
- Programmatic name matches the visible text label
Role
- Ensure screen reader users can navigate to links from the Local Context Menu and Rotor
- Role is automatically announced if a native component is used
- When using non-native controls (custom controls), roles will need to be manually coded.
- Android Views
- TextView - Announces as “link”
- URLSpan / ClickableSpan
- Linkify Class
- Android Compose
- Compose does not have native support on Link in Text, a customized linkable text need to be added into Text composable or use a
AndroidView
to bring the Android View withLinkify
to build Compose composableGroupings
- Compose does not have native support on Link in Text, a customized linkable text need to be added into Text composable or use a
- Link text can be grouped with paragraph text automatically to make a larger touch target, provided there is only one interactive link in view.
- Android Views
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.
- Android Compose
Modifier.semantics(mergeDescendants = true) {}
for the child elements grouping/mergingFocusRequester.createRefs()
helps to request focus to inner elements with in the group
State
- Android Views
- Active:
android:enabled=true
- Disabled:
android:enabled=false
- Announcement: disabled
- Active:
- Android Compose
- Active: default state is active and enabled. Use
RadioButton(enabled = true)
to specify explicitly - Disabled:
RadioButton(enabled = false)
announces as disabled - Alternatively can use
modifier = Modifier.semantics { disabled() }
to announce as disabled - Use
modifier = Modifier.semantics { stateDescription = "" }
to have a customized state announcement
- Active: default state is active and enabled. Use
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
- 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 menu, picker, or modal is closed, the focus should return to the triggering element
- Android Views
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
)
- Android Compose
Modifier.focusTarget()
makes the component focusableModifier.focusOrder()
needs to be used in combination with FocusRequesters to define focus orderModifier.onFocusEvent()
,Modifier.onFocusChanged()
can be used to observe the changes to focus stateFocusRequester
allows to request focus to individual elements with in a group of merged descendant views- Example: To customize the focus events behaviour or the sequence of focus,
- 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
- step 1: define the focus requester prior.
Code Example
- Android Compose ```kotlin /**
- Custom Composable with AndroidView to support link in textView and the links accessibility features from talkback menu */ @Composable fun LinkText( modifier: Modifier = Modifier, textBody: String ) { AndroidView( modifier = modifier, factory = { context -> TextView(context).apply { text = SpannableString(textBody) LinkifyCompat.addLinks(this, Linkify.WEB_URLS) movementMethod = LinkMovementMethod.getInstance() } } ) } ```
Announcement examples
Options for announcements below depend on framework and versions. Announcement order can vary. “Double tap to activate” hint announcement varies with implementation.
- “Label, link”
- “Label, link, double tap to activate”
- “Label, double tap to activate, links available, tap with three fingers to view”
- “All text in paragraph including link name, links available, tap with three fingers to view” (link in paragraph)
- “Text in sentence, link name, link, remainder of sentence, double tap to activate, links available, tap with three fingers to view” (link in sentence with separate link focus)
- “Label, disabled” (disabled)