Helix overrides Kitty Terminal's `cursor_trail` configuration

[genskyff]

I'm using Helix on macOS through the Kitty terminal emulator with the cursor_trail feature enabled. My kitty.conf is configured as follows:

cursor_trail 10
cursor_trail_decay 0.1 0.3

This configuration allows the cursor to have a trail effect similar to that of Neovide.

When I use Neovim within Kitty, the cursor trail effect works as expected because Neovim does not override Kitty's cursor settings.

However, when I use Helix, the cursor trail effect does not take effect. It appears that Helix's internal mechanisms override Kitty's cursor configurations.

Expected Behavior

Helix should respect the terminal emulator's cursor settings, allowing the cursor trail effect to function as configured.

Possible Solutions

Is there a way to prevent Helix from overriding the terminal emulator's cursor effects, or can this be configured through existing settings? If not, could this feature be added in a future update?

Environment

Operating System: macOS 14.7.2
Terminal Emulator: Kitty 0.39.0
Helix Version: 25.01.1 (e7ac2fc)

[pascalkuthe]

this is not possible, we always overwrite the terimnals cursor because we support multiple cursor and the terminal only supports a single cursor

[lavafroth]

kitty.conf

cursor_shape block
cursor_trail 1
cursor_trail_decay 0.1 0.3
cursor_trail_start_threshold 0
shell_integration no-cursor

.config/helix/config.toml

[editor.cursor-shape]
insert = "bar"
normal = "underline"
select = "underline"

Edit: switched normal and select mode to underline for easier distinction. Thank me later.

[sommerper]

@lavafroth Interesting, for some reason only the block shape doesn't work.

[lavafroth]

I believe this is because the block shape does not use the same block character as a shell. Helix simply inverts the background of what is under the cursor. For the other shapes like underline, helix has to print the underline character and kitty can latch on.

[sommerper]

Maybe Helix could render the main cursor as a real cursor and the rest as is. That would be awesome. I’m starting to like the kitty trail.

[EmrysMyrddin]

A bit disappointed to see this being closed without any discussion for possible solutions. Using an actual cursor for the main cursor would indeed be a pretty good fix for this, and improve usability for people that are struggle with following the cursor across huge jumps.

[luccahuguet]

a good candidate for a plugin

correction: what @EmrysMyrddin said below is more correct

[EmrysMyrddin]

Not sure how much a plugin will be able to override the way the cursor is rendered.
It's way simpler to add a cursor type in addition to the exiting block, beam and underline. Something like native_block, to make the distinction with the default emulated block cursor.

This way, the default remain the same, with hight level of customization with theme, but with a possibility for those that needs it (for accessibility reason for example) to use a less themable but terminal compatible cursor.

For those interested, someone made this PR that is doing it: #13821

You can see that it is very small change. While doing it in a plugin will probably be way more complex.

[genskyff]

kitty support the multiple cursors protocol

• https://sw.kovidgoyal.net/kitty/multiple-cursors-protocol/

[MunsMan]

Apologies for commenting on an unplanned issue, but I've implemented a draft solution that I'll be testing over the coming days.
I added a use_terminal_cursor config option that uses the terminal's native cursor instead of Helix's software-rendered cursor (when only a single cursor is active). The changes are relatively small and it works well with Ghostty shaders.

Note: In my current draft, the default is set to true for easier testing. This should be changed to false before any potential merge to maintain backward compatibility.

Happy to open a PR if there's interest once I've finished testing.

[sommerper]

@MunsMan You certainly have my interest. I’d also like to test it for you.

[MunsMan]

I published my changes on this branch. @sommerper feel free to check it out and test it.