Oleksiy Syvokon
4c555e5765
This change allows using simple navigation keys (PageDown / PageUp / Ctrl-Home / Ctrl-End) when the message editor is focused, but only if the cursor is at the beginning/end of the message, where pressing these keys would normally result in no-op. One important corollary is that when the cursor is in an empty message, navigation keys scroll the thread. We already have this behavior for Up/Down and this change just expands it for other navigation keys. Demo: [Demo](https://github.com/user-attachments/assets/ff540c8c-a223-417b-b16a-b0d08599b1ae) 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