AccessibilityTree

Remarks

This is the traversal, and it is the only one. Two rules decide what the accessibility tree is, and they used to live in a test-support assembly:

⚠ An element that is not a node is walked through rather than skipped. Its children rise to its parent's depth, which is what ARIA's none means and is the difference between a tree a screen reader can read and thirty nested groups.

⚠ An element reached by Owns is emitted under its owner and not where the element tree has it. A Select's list is a child of the document root — an overlay inside the field that opens it would be clipped — and the relation is how the control says so. Reproducing that wrongly gives a screen reader a combo box with nothing in it and a pile of loose lists at the end.

AccessibilitySnapshot.Render is a renderer over this and no longer a second walk, which is what makes this repository's accessibility test discipline a bridge's evidence rather than a parallel universe: the string a control's snapshot test asserts on is rendered from the same nodes a screen reader would be handed.

Fields and properties (3)

• public IReadOnlyList<AccessibilityNode> Roots

  The tops of the tree.

• public int Count

  How many nodes there are, at every depth.

• public IReadOnlyList<AccessibilityNode> Nodes

  Every node, in the order the walk reached them, which is document order.

Methods (3)

• public static AccessibilityTree Capture(UiElement root)

  Captures the accessibility tree under an element.

• public static IReadOnlyList<AccessibilityChange> Diff(AccessibilityTree? previous, AccessibilityTree current)

  What changed between two captures.

• public AccessibilityNode? Node(int id)

  The node with an id, if this capture has one.

Used by (3)

• AccessibilitySnapshotVixen.Ui.Testing
• AccessibilityTreeSourceVixen.Ui
• AccessibilityTreeTestsVixen.Ui.Tests