| # Accessibility focus |
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| ## Overview |
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| The Accessibility Focus (or the a11y focus), tracks which element on the screen a user using some assistive technology is focusing on. At the moment, only the Fuchsia Screen Reader keeps track of the a11y focus. |
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| More specifically, the a11y focus is the currently focused [semantic node][semantics] of the Scenic view That is the [terminal view of the focus chain][focus-chain]. |
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| It is important to also understand that [input focus][input-focus] normally matches, but is not, the same thing as the a11y focus. It can be the case that a user is focusing an input text field with the Screen Reader on, in which case the input focus and the a11y focus would match. However, if the keyboard for a text field is shown but the user is exploring other parts of the screen with the Screen Reader, the a11y focus is different from the input focus. |
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| ## Recoverable a11y Focus |
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| The a11y focus is permanent, even when the user changes to a different view. This means that the a11y manager caches the semantic node that is focused in a view, referencing the view by its viewref KoID. If the [focus chain][focus-chain] is updated to point to a view and a node was previously focused there, the a11y focus will be updated to point to that same node. |
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| This is necessary, for example, to allow users to save their location in an application, even when they switch between views displaying content. In a traditional desktop environment, this could be the simple use case of having a tab open, then doing an alt tab to change some music in a music player, and then returning to the tab. The location of where the user was on the page would be restored and they could continue from there. |
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| ## Changes in the Accessibility Focus |
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| Changes in the a11y focus cause the Screen Reader to speak the new focused semantic node, so that users are aware of a navigational change. |
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| ## Accessibility Focus recovery strategies |
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| For now, if a semantic node that had the a11y focus is destroyed, the strategy to recover the a11y focus is to traverse the semantic tree in Breadth First Search and select [the first describable semantic node][describable-nodes]. |
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| Other strategies exist and are expected to be implemented as the platform matures. |
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| ## Future work |
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| Other assistive technologies may benefit from the a11y focus, such as a switch access. "Switch access" feature is not implemented yet. |
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| [semantics]: /docs/concepts/accessibility/semantics.md |
| [focus-chain]: /docs/development/graphics/scenic/concepts/focus_chain.md |
| [input-focus]: https://bugs.fuchsia.dev/p/fuchsia/issues/detail?id=95672 |
| [describable-nodes]: https://bugs.fuchsia.dev/p/fuchsia/issues/detail?id=96257 |
