So, I am building the "GPUI re-render devtools" in [this
branch](https://github.com/zed-industries/zed/pull/55825)
And while running the new devtools I found a few low-risk
over-invalidation sources and included the easy fixes here:
- Avoid notifying for sticky headers when the computed sticky header
result has not changed.
- Avoid repeated `cx.notify()` calls while overscrolling at the top of
the editor when the scroll position is clamped.
- Give `Button::loading` a keyed animation id so repeat animation frame
requests can be attributed to the concrete loading button instance.
The attached video shows the workflow I used to find these with the new
devtools.
https://github.com/user-attachments/assets/852c64a9-ae91-4878-bbf8-21cc23763c42
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 is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [ ] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable
Release Notes:
- N/A
cc @SomeoneToIgnore
## Summary
Follow-up to [this
comment](https://github.com/zed-industries/zed/discussions/55352#discussioncomment-16961889).
This extracts the buffer header and breadcrumb rendering helpers out of
`element.rs` into a `header.rs` and mouse related things to `mouse.rs`
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 is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable
Release Notes:
- N/A
Mikhail Pertsev