feat: add tmux support

[tummetott]

tmux support

[!IMPORTANT]\ 🧪 tmux support is currently experimental This issue is used to track all tmux related issues or questions. Please comment on this issue instead of created a new issue while tmux support is considered experimental.

The following checklist is planned to be completed before moving these feature to stable.

• [x] add tests checking env var and kitty_data.tmux
• [ ] add multipane test
• [ ] check positioning of paste window
  • [x] status line impacts this, look into tmux set-option status on tmux set-option status 3 etc . check with tmux show-options status
  • [ ] adjust cursor pos for split panes (tmux display-message -p '#{cursor_x} #{cursor_y} #{pane_width} #{pane_height} #{window_visible_layout}')
  • [ ] idea, check if zoomed, if not toggle zoom before hand. tmux resize-pane -Z need to figure out command to check if already zoomed ( try #{window_zoomed_flag} )
• [ ] check positioning for scrolled window
• [x] add command to generate config
• [ ] copy to clipboard, add/modify option to copy to tmux buffer with set-buffer command
• [ ] look into history-limit configuration and document preferred settings
• [ ] doc differences between tmux copy mode, e.g., one pane full screen instead of split panes
• [x] if get-extent all, -S - -E -, if screen remove -S and -E options. see tmux capture-pane help

• [x] review all options in capture-pane https://man7.org/linux/man-pages/man1/tmux.1.html

     capture-pane [-aAepPqCJN] [-b buffer-name] [-E end-line] [-S
             start-line] [-t target-pane]
                   (alias: capturep)
             Capture the contents of a pane.  If -p is given, the
             output goes to stdout, otherwise to the buffer specified
             with -b or a new buffer if omitted.  If -a is given, the
             alternate screen is used, and the history is not
             accessible.  If no alternate screen exists, an error will
             be returned unless -q is given.  If -e is given, the
             output includes escape sequences for text and background
             attributes.  -C also escapes non-printable characters as
             octal \xxx.  -T ignores trailing positions that do not
             contain a character.  -N preserves trailing spaces at
             each line's end and -J preserves trailing spaces and
             joins any wrapped lines; -J implies -T.  -P captures only
             any output that the pane has received that is the
             beginning of an as-yet incomplete escape sequence.
  
             -S and -E specify the starting and ending line numbers,
             zero is the first line of the visible pane and negative
             numbers are lines in the history.  ‘-’ to -S is the start
             of the history and to -E the end of the visible pane.
             The default is to capture only the visible contents of
             the pane.

• [ ] doc required tmux version
• [ ] nice to have? maybe? add tmux nerd font icon to status when in tmux mode
• [ ] doc doesn't work over ssh
• [ ] investigate if tmux_capture_last_command_output or alternatives are a viable option for getting the last command output. or create a follow up issue for this

This issue has been modified. See details on the original issue below.

Original issue below

Hello, First of all, I wanted to express my admiration for your plugin, which I had the pleasure of discovering after attending your talk at the nvim conference.

While experimenting with your plugin, I encountered a specific issue related to its compatibility with tmux. It appears that the kitty_get_text.extent setting do not seem to function as expected when used in conjunction with tmux. It has come to my attention that this setting, regardless of the value chosen—be it (all, first_cmd_output_on_screen, last_cmd_output, last_non_empty_output, last_visited_cmd_output, selection), —seems to consistently yield the same result. In essence, it consistently displays only the content visible on the screen, akin to the behavior one would expect when setting the setting to screen.

The root cause of this behavior lies in the fact that the kitty @ get-text command consistently retrieves only the content visible on the current screen. Unfortunately, tmux retains all text within its internal buffer, which remains inaccessible to the kitty scrollback history.

I understand that some of these modes, such as last_visited_cmd_output, are inherently dependent on kitty-specific features that tmux lacks. However, I wonder if there might be a way to at least make the full mode compatible with tmux.

I'd like to offer a couple of suggestions that might help in achieving this compatibility:

• Detecting tmux: You could consider checking if tmux is running, which can be accomplished by checking if the $TMUX environment variable is set. This step would allow the plugin to identify when it is operating within a tmux session.
• Accessing the buffer content: To access the buffer content in tmux, the following command could be utilized:

tmux capture-pane -p -S - -E -

The -p flag directs the output to stdout.

The -S and -E options specify the starting and ending line numbers for the capture. For instance, '0' represents the first line of the visible pane, and negative numbers refer to lines in the history. The use of '-' with -S denotes the start of the history, and '-' with -E indicates the end of the visible pane.

While I lack the confidence to submit a pull request myself, I sincerely hope that these suggestions prove useful in enhancing the compatibility of your plugin with tmux. I believe that such compatibility would greatly benefit users like me who rely on both tools in their development workflow.

[tummetott]

However, I'm not sure about how altering the input source from kitty @ get-text to tmux capture-pane -p -S - -E - might impact the handling of ANSI escape sequences. Upon examining your code, I've noticed that you employ sed for filtering out a number of these escape sequences. However, I lack clarity regarding the specific ANSI sequences that tmux generates, as they might differ from those produced by kitty?

[mikesmithgh]

@tummetott thanks! It looks like there is an -e flag that will keep the ANSI escape sequences.

tmux capture-pane -e -p -S - -E -

     capture-pane [-aepPqCJN] [-b buffer-name] [-E end-line] [-S start-line] [-t target-pane]
                   (alias: capturep)
             Capture the contents of a pane.  If -p is given, the output goes to stdout, otherwise to the buffer specified with -b or a new buffer if
             omitted.  If -a is given, the alternate screen is used, and the history is not accessible.  If no alternate screen exists, an error will be
             returned unless -q is given.  If -e is given, the output includes escape sequences for text and background attributes.  -C also escapes non-
             printable characters as octal \xxx.  -N preserves trailing spaces at each line's end and -J preserves trailing spaces and joins any wrapped
             lines.  -P captures only any output that the pane has received that is the beginning of an as-yet incomplete escape sequence.

             -S and -E specify the starting and ending line numbers, zero is the first line of the visible pane and negative numbers are lines in the
             history.  ‘-’ to -S is the start of the history and to -E the end of the visible pane.  The default is to capture only the visible contents of
             the pane.

I'd have to look into this a bit, but this seems like a good idea to me 😸.

Since kitty-scrollback.nvim runs in a kitten (separate process) it does not have access to the TMUX environment variable. I played around a bit and may be able to determine if tmux is running in kitty_scrollback_nvim.py with the code:

        print(w.child.foreground_processes)
        fg_process_entrypoints = list(
            map(
                lambda pd: next(
                    iter(pd.get(
                        'cmdline',
                        [],
                    )),
                    None,
                ),
                w.child.foreground_processes,
            ))
        print(fg_process_entrypoints)
        if 'tmux' in fg_process_entrypoints:
            print('perform alternative logic')
        else:
            print('perform normal logic')

output

[{'pid': 83576, 'cmdline': ['tmux'], 'cwd': '/Users/mike'}]
['tmux']
perform alternative logic

if this logic holds, I should be able to use tmux capture-pane instead of kitty @ get-text.

[mikesmithgh]

Reference: https://github.com/roosta/tmux-fuzzback

[milch]

I don't remember if GH sends out notifications when an issue is mentioned, but I added a PoC over at #151

[mikesmithgh]

        print(w.child.foreground_processes)
        fg_process_entrypoints = list(
            map(
                lambda pd: next(
                    iter(pd.get(
                        'cmdline',
                        [],
                    )),
                    None,
                ),
                w.child.foreground_processes,
            ))
        print(fg_process_entrypoints)
        if 'tmux' in fg_process_entrypoints:
            print('perform alternative logic')
        else:
            print('perform normal logic')

this approach does not work since the TMUX_PANE env variable is needed

[mikesmithgh]

Current plan:

Setup .tmux.conf with a command similar to

bind h run-shell 'kitty @ kitten /Users/mike/gitrepos/kitty-scrollback.nvim/python/kitty_scrollback_nvim.py --env "TMUX=$TMUX" --env "TMUX_PANE=%#{pane_id}"'

kitty-scrollback.nvim logic:

• if TMUX env var is present, use an implementation similar to https://github.com/mikesmithgh/kitty-scrollback.nvim/pull/151 (thanks @milch !)

  tmux capture-pane -t$TMUX_PANE -e -p -S - -E -

• else continue with normal flow kitty @ get-text

[mikesmithgh]

🎉 I have added experimental tmux support to the latest release 4.1.0 🎉

See the README section tmux (🧪 experimental ) for setup instructions.

I have also added a checklist to this issue to include what I consider needs to be completed to make this feature stable.

If you have any questions or issues please comment on this PR. Thanks!

[tummetott]

AMAZING. I'll look into this soon. thanks you in advance

[mikesmithgh]

🎉 I have added cursor position fixes to take into account the tmux status line and added some basic test coverage in the latest release 4.2.1 🎉