SYSTEM Cited by 1 source

TalkBack

Definition

TalkBack is Android's built-in screen reader, shipped by Google as part of the Android Accessibility Suite. It exposes UI elements to users with visual impairments by reading on- screen text, announcing focus changes, events (e.g. errors), and element roles, and surfacing a gesture-based navigation model over the touchscreen. TalkBack is the primary assistive technology Android accessibility fixes target.

Capabilities relevant to wiki coverage

• Swipe navigation — users swipe to move focus through elements; each focused element's name / role / state is announced.
• Focus-based announcements — when focus enters an element with an error state, TalkBack should announce the error without requiring the user to navigate to find it. (Failure mode documented in Slack's VPAT post: error not announced when OutlinedTextField or SKBanner received error state → user must sweep screen to discover it. Fixed at the component level.)
• CollectionInfo semantics — TalkBack announces list item counts ("N items in a list") when the user has Always speak number of list items enabled. The count comes from the Android a11y framework's CollectionInfo. When the underlying adapter includes decorative children (e.g. Slack's SK divider), the count is wrong unless overridden via an AccessibilityDelegate. See patterns/accessibility-delegate-override-for-semantic-fix.
• Custom actions — UI components can expose actions via AccessibilityNodeInfoCompat.addAction(...). TalkBack surfaces these in a context menu accessed by:
  • Three-finger tap on the element, or
  • Drawing gestures: L (upward) and r (downward) as the canonical invocations. This mechanism is the load-bearing alternative to gesture- only interactions like drag-and-drop. See patterns/custom-talkback-actions-as-gesture-alternative.

Platform-convention observations

• Strikethrough not interpreted — "Most screen readers don't interpret this format because doing so making it verbose and potentially confusing for screen reader users. They may interpret this strikethrough announcement as being part of the message itself." Slack chose to match this convention rather than inject strikethrough announcements. (Source: sources/2025-11-19-slack-android-vpat-journey)
• Top-app-bar titles are not headings on Android — unlike web WCAG 1.3.1 heading semantics, native Google apps do not mark the top-app-bar title as a heading. Slack followed this platform convention. Canonical instance of concepts/wcag-platform-applicability-gap. (Source: sources/2025-11-19-slack-android-vpat-journey)

Seen in

• sources/2025-11-19-slack-android-vpat-journey — eight- theme VPAT retrospective; seven of eight resolutions directly target TalkBack behaviour. Canonical source for TalkBack's custom-action mechanism and CollectionInfo semantics on the wiki.

Related

• systems/android-accessibility-framework — the API substrate.
• systems/slack-kit — example of a component library being extended to improve TalkBack behaviour.
• patterns/custom-talkback-actions-as-gesture-alternative
• patterns/accessibility-delegate-override-for-semantic-fix
• concepts/wcag-platform-applicability-gap
• concepts/redundant-error-signalling