Missed this when shipping the pickers. The feature is still planned and
tracked in the tracking issue.
## Self-Review Checklist:
- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content adheres to Zed's UI standards
([UX/UI](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
and
[icon](https://github.com/zed-industries/zed/blob/main/crates/icons/README.md)
guidelines)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable
Release Notes:
- N/A
Candidate fix for #59822.
Adds a live preview pane to the project symbols picker, matching the
file finder and project search pickers. When the selection moves, the
selected symbol's file is shown in the preview with its declaration line
highlighted and vertically centered.
## Changes
- `project_symbols`: construct the picker with
`uniform_list_with_preview`; asynchronously open the buffer for the
selected symbol (cached by candidate id, cleared on each new query) and
implement `try_get_preview_data_for_match` to return the buffer plus the
symbol's anchor range.
- `picker`: add a public `refresh_preview` so a delegate can push
preview data once a buffer finishes opening asynchronously (the symbol
buffer is not available synchronously, unlike text search which already
holds open buffers).
#### Before
<img width="1725" height="712" alt="image"
src="https://github.com/user-attachments/assets/21dcd7d6-7cc4-4de8-ab7d-2f1ce143e814"
/>
##### After
<img width="1725" height="712" alt="image"
src="https://github.com/user-attachments/assets/db981db8-0a61-43bc-9838-c01b7bdbbf78"
/>
Can turn preview pane off by clicking at the bottom button!
## AI disclosure
AI was used for understanding the codebase and formatting this PR.
Release Notes:
- Added a preview pane to the project symbols picker
---------
Co-authored-by: Yara <git@yara.blue>
Yara 🏳️⚧️