Use Synchronized Output sequences

[valpackett]

Describe your feature request

To avoid any possible visual glitches like flickering, many modern terminal emulators (WezTerm, Kitty, iTerm2, foot, mintty, …) support DEC mode 2026 as described in:

https://gist.github.com/christianparpart/d8a62cc1ab659194337d73e399004036

to allow applications like text editors to mark complete frames with begin and end markers.

Helix should ensure these are used.

[pickfire]

I believe this is upstream library dependent, not sure if the upstream libraries support it.

[kirawi]

It looks like termwiz supports it, but there's no available release yet for the commits that implemented it.

[kchibisov]

What kind of upstream library this should go for? I can try to implement it in some way when I have time? It's not like a complicated escape sequence as a whole and more of just a marker that could be sent in a right point of time?

[the-mikedavis]

If it isn't already implemented in crossterm (https://github.com/crossterm-rs/crossterm) it might make a good contribution there. Currently we use crossterm for terminat manipulation. I think in the long run we want to switch to termwiz though which already supports it

[kirawi]

There's #1847, but it looks like it's stalled.

[the-mikedavis]

This was added to crossterm recently in https://github.com/crossterm-rs/crossterm/pull/756 but we will need detection (similar to #4939). I'll post a patch upstream to add the detection function

[k4lizen]

Any progress on this? When I move and resize my windows around in kitty I get flicker even worse than the one in this issue: https://github.com/kovidgoyal/kitty/discussions/4395

[k4lizen]

https://github.com/user-attachments/assets/948f135a-64ea-40e4-8bc8-270f219d5419

[kirawi]

Someone still needs to add detection upstream.

[k4lizen]

Could someone who understands more about this than me open a feature request for the detection upstream so the people working on crossterm at least know it's keeping this issue open