Add support for tmux control mode (#3656)

[joexue]

Summary of the Pull Request

Let WT supports tmux control mode

References and Relevant Issues

#3656

Detailed Description of the Pull Request / Additional comments

Support:

• Create/attach tmux session

• Split pane vertical/horizontal

• Window/panes size change

• Remove pane/tab if remote pane exit or window exit

Improvements may do:

• Merge the tmux menus/button with existing menu/button
• Add the keyboard accelerators for tmux menus
• Unicode support(the VTParser just pass part of characters in DCS mode
• When attached a session, focus on the same focused tab/pane when detaching(backend is done, need to do some work frontend)
• Test code

Tested by using tmux 3.4:
ssh to a machine has tmux or use wsl, then run
"tmux -CC" or "tmux -CC a"

Validation Steps Performed

PR Checklist

• [x ] Closes Add support for tmux Control Mode #3656
• Tests added/passed
• Documentation updated
  • If checked, please file a pull request on our docs repo and link it here: #xxx
• Schema updated (if necessary)

[joexue]

@microsoft-github-policy-service agree

[DHowett]

whoa

[iDarshan]

This is a long-awaited feature! Thanks @joexue!

[BinaryShrub]

[DHowett]

FYI: I am working with reduced staffing at the moment, so reviews may be slow to come. I apologize for that.

[iDarshan]

Is there a nightly build with this PR to test?

[carlos-zamora]

Is there a nightly build with this PR to test?

Your best bet is to build this locally. Once it merges, it will be available on the Canary channel though.

[iDarshan]

Is there a nightly build with this PR to test?

Your best bet is to build this locally. Once it merges, it will be available on the Canary channel though.

I tried to find the build guide, but couldn't find one. Do you have the link handy?

[joexue]

Is there a nightly build with this PR to test?

Your best bet is to build this locally. Once it merges, it will be available on the Canary channel though.

I tried to find the build guide, but couldn't find one. Do you have the link handy?

README.md ->Developer Guidance @iDarshan

[carlos-zamora]

Hi @joexue! Thanks for doing this! I published a build for the team to test internally and we've got a few notes we want to share with you 😊

• Notes/Reactions:
  • Settings menu item is gone from the dropdown
  • It makes your existing window a special "tmux only" window; it disables the menu, but it doesn't disable the key bindings, so you can still split in non-tmux panes
  • Scrollbars are gone? I guess scrolling is server side
• Requested changes:
  • [Bug] can't type in an older pane after splitting panes
  • tmux tabs should not be draggable into a new window
  • Add a setting to Profile > "Terminal Emulation" page that disables this (it should be disabled by default)
  • Bug: Closing a tab/pane will not kill the instance on the server side
  • Add a feature flag to features.xml (Guidance)
  • [Architectural notes] We should see if we can't just model a tmux pane as a connection so we don't need to pump output into the terminal from the App layer

Overall, this is a really exciting feature and we're excited to see it land! Let us know if you need any guidance or additional comments on any of the thoughts above. 😊

CC @DHowett @lhecker @zadjii-msft

[joexue]

Hi @joexue! Thanks for doing this! I published a build for the team to test internally and we've got a few notes we want to share with you 😊

• Notes/Reactions:

  • Settings menu item is gone from the dropdown
  • It makes your existing window a special "tmux only" window; it disables the menu, but it doesn't disable the key bindings, so you can still split in non-tmux panes
  • Scrollbars are gone? I guess scrolling is server side

Scrollbars are gone is by design, I put the comment in the code, since we want to make local panes size match remote(tmux) panes size, but each split, tmux just lost 1 character to use it as separator, if we have side scrollbars, we cannot make two side's size match. To meet this, the padding size is changed too.

As the menu, it is because I tried to touch as less code as I can to do the job. So give the tmux a separate UI system. I described in the PR, this could be improved and should integrated into the present UI/menu system.
But, I think we can skip this ugly stage, directly change the code to make the tmux control mode work with present UI/menu system. I will address this, those +button/flyout splitting menus specifically for tmux will be gone.

• Requested changes:

  • [Bug] can't type in an older pane after splitting panes

I did not see this bug, to help me to reproduce it here, could you describe your env? how do you connect to tmux server? what is the tmux version?

• tmux tabs should not be draggable into a new window

Sure, let me fix it.

• Add a setting to Profile > "Terminal Emulation" page that disables this (it should be disabled by default)

Sure, let me look it.

• Bug: Closing a tab/pane will not kill the instance on the server side

This is by design, remote pane should close by quit it's app. but this is arguable, if we think close local pane should close remote pane too, it is easy and feasible.

• Add a feature flag to features.xml (Guidance)

Sure. Fair enough.

• [Architectural notes] We should see if we can't just model a tmux pane as a connection so we don't need to pump output into the terminal from the App layer

Please provide the idea, I can try to implement it.

Overall, this is a really exciting feature and we're excited to see it land! Let us know if you need any guidance or additional comments on any of the thoughts above. 😊

CC @DHowett @lhecker @zadjii-msft

Thanks!

Since this PR is a bit big, another option is we split it into two or three parts to make it easy to review and integrate. Such as
part 1: infra libs(parser, TermControl, Terminal, ControlCore)
part 2: TmuxControl
part 3: integrating and UI/Menu

What do you think, split it or just keep as it is?

[joexue]

@carlos-zamora @DHowett @lhecker @zadjii-msft
All comments are addressed, please try again.

Thanks