Provide accessible names for tree items

Tree widgets represent hierarchical data (file explorers, nested navigation, organization charts). Screen readers announce each focused treeitem's name, level, and position, e.g., 'src, collapsed, level 1, 1 of 3'. If the name is empty or generic ('folder', 'item'), blind users cannot distinguish between nodes and cannot navigate the hierarchy with confidence. VoiceOver on macOS uses the name to populate the rotor, and NVDA reads it as the user moves through the tree with arrow keys.

Quick Reference

• Every element with role='treeitem' must have a non-empty accessible name
• Text content of the element is used as the name by default, ensure it is descriptive
• Use aria-label to override or supplement the visible text (e.g., adding file type context)
• Use aria-labelledby to compose a name from multiple visible elements within the item
• A treeitem with aria-expanded must also convey its expanded/collapsed state, this is separate from its name

Check

Find all elements with role='treeitem'. For each, determine its accessible name via the accname computation: check aria-labelledby first, then aria-label, then visible text content. Flag any treeitem with an empty or whitespace-only accessible name. Also check whether treeitems with children have aria-expanded set to 'true' or 'false' (not just absent).

Fix

For each unnamed treeitem: (1) If the element has visible text content that is descriptive, no change is needed, the text content becomes the accessible name. (2) If the visible text is ambiguous (e.g., an icon with no text), add aria-label='Descriptive name'. (3) If the item has multiple text parts (e.g., filename + file size), use aria-labelledby referencing the most descriptive element's id. (4) For expandable treeitems, ensure aria-expanded='true' or aria-expanded='false' is present and toggled on expand/collapse.

Explain