I was inspecting how Zed did the layout in the editor, specifically for
the gutter, and noticed that `em_width * X` is being used as the 'width
of X consecutive characters'. Howevever, that math didn't work for me,
because em_width doesn't account for the space between characters, so
you can't just multiply it by a character count.
One place this is actually noticeable is in the logic for
`min_width_for_number_on_gutter`, where we try to reserve 4 characters
of line number space. However, once you actually hit 4 characters, the
actual width is bigger, causing things to resize. This seems clearly
counter to the intent of the code.
It seems the more correct logic is to use `em_advance` which accounts
for the space between the characters. I am leaving the rest of the uses
of `em_width` for generic padding. It is also possible that
`column_pixels()` would be the more correct fix here, but it wasn't
straightforward to use that due to it residing EditorElement source
file.
On my MacBook this increases the width of the gutter by 6 pixels when
there are <999 lines in the file, otherwise it's identical.
It might be worth doing some more general audit of some of the other
uses of em_width as a concept. (e.g. `git_blame_entries_width`)
https://github.com/user-attachments/assets/f2a28cd5-9bb6-4109-bf41-1838e56a75f9
Release Notes:
- Fix a slight gutter flicker when going over 999 lines
Appologies if this PR is off base, I'm still not super familiar with the
Zed codebase.
I was trying to integrate with
https://github.com/zed-industries/zed/pull/12940
and found it awkward to hook up global bindings to adjust the UI font
size due to the fact it takes a WindowContext. Looking at the API, it
seemed odd that it took a WindowContext, yet the editor font methods
take an AppContext.
I couldn't find a compelling reason for this to be tied to a
WindowContext, so I personally think it makes sense to switch it.
This does have a behavior change, which hopefully is actually desirable:
Currently, if you have two open and visible Zed windows, and trigger a
UI font adjustment in one, the non-active windows won't update. However,
once you switch focus to the second one it will snap to the new UI font
size. This is inconsistent with adjusting the editor font size, which
applies to all open windows immediately.
Release Notes:
- N/A
Galen Elias