Debug symbol doesn't disappear when switching tabs

[nnra6864]

Summary

When hovering over the left side of the screen where the debug symbol appears, switch the tab, move the mouse away, and switch back to the tab we hovered, the symbol doesn't go away.

Steps to reproduce:

1. Hover for the debug symbol to appear

2. Switch to another tab

3. Move the mouse away

4. Switch back to the original tab

Expected Behavior: The debug symbol should've disappeared
Actual Behavior: The debug symbol doesn't disappear

This is a very minor bug and doesn't affect my workflow in any way, just thought I'd report it so you are aware.

Zed Version and System Specs

Zed: v0.210.4 (Zed)
OS: Linux Wayland arch unknown
Memory: 23.4 GiB
Architecture: x86_64
GPU: NVIDIA GeForce RTX 3060 || NVIDIA || 580.95.05

[dinocosta]

Thank you for reporting @nnra6864 ! I was able to reproduce this issue on macOS too, and it seems to impact any UI elements that we show depending on the mouse location. For example, the same happens with the fold indicators.

Will add it to the correct board so the team can take a look and see if it makes sense to try and fix this 🙂

[MrSubidubi]

I think this is a good issue for someone looking to pick this up: What basically happens is that upon re-rendering after the editor was switched away from, we do not re-check which mouse position is the current one and basically re-use everything based upon the last reported position (as reported above).

Optimally, upon re-painting the editor, we should then invoke EditorElement::mouse_moved with an artificial mouse move event to properly update the state for this. This should happen iff the editor was hidden and then shown again. That way, what is shown is actually up to date and does not reuse the state from the last mouse move during the last render.

This should not be too difficult (should be possible in only editor.rs and element.rs), but might require some tweaking to get right. Ultimately, though, the change for this to work should be pretty minor (and include even less text than what I wrote up here right now).

[amustaque97]

I would like to work on this @MrSubidubi

[MrSubidubi]

@amustaque97 As mentioned in #39515 (comment), we usually do not assign issues (the current lets-git-together project being an exception), so feel free to pick this up and open a PR for it!
That said, anyone else is still welcome to look at this as well, if they'd like to