Module a11y_tree 

The retained accessibility tree: a stable, frame-to-frame semantic model of the running UI.

The toolkit re-derives a fresh tree each call, which is fine for pushing a whole tree at AccessKit but gives no stable identity or diff. A SemanticTree is the retained counterpart: it keys nodes by a stable SemanticId and, on each refresh, diffs the freshly-walked UI against the previous frame, returning a TreeDelta while preserving identity for every node that recurs. This is what an AT-SPI incremental push, a screen reader’s change narration or an agent’s introspection builds on.

Structs

SemanticAction

One thing an assistive client can do to a SemanticNode, addressable by a stable name.

SemanticId

Stable identity of a semantic node, preserved across refresh as long as the backing widget or resource recurs.

SemanticNode

One node of the retained semantic tree.

SemanticTree

The retained accessibility tree. Persists node identity across frames and diffs each refresh against the previous.

SetPlace

Where a node sits in its collection and how deep, from its AccessNode’s pos_in_set, set_size and level.

TreeDelta

What changed between two refreshes. Ids that appear in neither list are present and byte-identical in both frames — their identity and content survived unchanged.

Enums

SemanticActionKind

How a SemanticAction is carried out when invoked.