Upstream Jackdaw tab widget for bevy UI

[jbuehler23]

Objective

Implement the "Tab Deck" item from the widgets roadmap (#19236).

This is the first PR in an effort to upstream the tab and docking functionality built for jackdaw, following the layered design
from the tab panes and docking specification written by @viridia here: https://hackmd.io/@dreamertalin/HkA2okNSzx. This starts with the first PR: headless tab behavior, with no styling.

Solution

• Headless tab list and tab components in bevy_ui_widgets.
• Selection is externally owned, matching the crate's controlled-widget convention: interaction emits a selection request, and the app either applies it itself or attaches the provided self-update observer.
• Keyboard navigation with a roving tab index, in both orientations, with manual or automatic activation.
• Accessibility roles, and disabled handling for individual tabs or whole strips.
• A headless_tabs example and a release note.

Dragging tabs, reodering tabs, styling, and dock layout are all planned for follow-ups

Testing

• cargo test -p bevy_ui_widgets tabs
• cargo run --example headless_tabs:

Showcase

2026-08-22.21-18-58.mp4

AI Disclaimer

I used an LLM (claude code) to help with the transfer of code from jackdaw to bevy, and to post-check/review before committing/submitting the PR

[github-actions]

The generated examples/README.md is out of sync with the example metadata in Cargo.toml or the example readme template. Please run cargo run -p build-templated-pages -- update examples to update it, and commit the file change.

[viridia]

This looks great!

[viridia]

I'd like to see a comment describing the theory of operation here.

[jbuehler23]

Yep will update!

[jbuehler23]

updated @viridia