feat: Synchronized output

[nervo]

This is an attempt to implement synchronized output in bubbletea. At this time, this is so naive, that you can see it as a proof-of-concept :)

Anyway, this does not break on my machine 👍

Some interesting reading:

• https://gitlab.com/gnachman/iterm2/-/wikis/synchronized-updates-spec
• https://gist.github.com/christianparpart/d8a62cc1ab659194337d73e399004036
• https://hugotunius.se/2019/12/29/efficient-terminal-drawing-in-rust.html#going-faster
• Support for Synchronized Output (Mode 2026) #850

Feel free to comment ❤️

[vito]

Friendly poke to whoever can keep this moving, could really use this for my TUI as it flickers pretty heavily on certain terminals. Cool to see a PR up for it already! 😄

[nervo]

@vito do you think you can give a try ?

Dear maintainners, are you ok with the way the feature is implemented (wording of methods and variables) ?

For the feature itself, i'm not an ansi guru, i just need to know:

1. if i made the terminal query the good way
2. If i understood the protocol correctly (the event.Value 2 or 4)
3. if i'm doing the right things: sending the enable code just before, and the disable code right after writing the buffer, both independently from the buffer itself.

[vito]

Tried it out and went looking for how to enable it, and noticed it just enables itself if the terminal supports it, which makes sense to me. 👍

I think I found a typo along the way though - left a suggestion.

[meowgorithm]

Hey @nervo! Thanks for looking into this one, it's something we've very much been wanting to get in.

API aside, the big thing that will need to happen for this feature to work is an implementation at the renderer level so that Bubble Tea can repaint in-step with the terminal. We're currently working on an overhaul to the renderer, so we should hold off on this until we've made that update.

[nervo]

@meowgorithm ok, good to hear 👍