Add a custom function in mini.tabline

[Dupond]

Contributing guidelines

• I have read CODE_OF_CONDUCT.md

Module(s)

mini.tabline

Question

Hello!

In diff mode, I use a function to display the number of differences between the buffers being compared:

function! DiffCount()
    let winview = winsaveview()
    let num_diffs = 0
    if &diff
        let pos = getpos(".")
        keepj sil exe 'normal! G'
        let lnum = 1
        let moved = 1
        while moved
            let startl = line(".")
            keepj sil exe 'normal! [c'
            let moved = line(".") - startl
            if moved
                let num_diffs += 1
            endif
        endwhile
        call winrestview(winview)
        call setpos(".",pos)
    endif
    if num_diffs > 0 | echo '['.num_diffs.' diff]' | else | echo '' | endif
endfunction
augroup diffMode
    autocmd DiffUpdated * call DiffCount()
augroup END

As you can see, the function returns a simple echo, so the number of differences is displayed below the statusline. This is far from ideal, and leads to a number of problems (including misalignments between buffers).

It would be much better if I could display the result of the function inside of my mini.tabline (for example, on the far right of the window). Is it possible to do this?

Many thanks for your help!

[echasnovski]

It would be much better if I could display the result of the function inside of my mini.tabline (for example, on the far right of the window). Is it possible to do this?

I am afraid the answer to this particular question is no. The 'mini.tabline' specifically is reserved to only show listed buffers and possibly tabpage section. Anything beyond that is out of scope.

Here are some alternatives:

• Use config.format to add this information to buffer's tab (either all or only current). That would require writing a Lua function that computes the necessary data as a string.
• Show the same information in the statusline. For example, 'mini.statusline' allows customization via config.content.active.
• Use own tabline locally to the window when inside diff mode.

[Dupond]

Thank you very much for taking the time to answer.

Using config.format is a great idea, and rewriting my function in Lua shouldn't be that hard. The tricky part might be to integrate the autocmd (that is: autocmd DiffUpdated * call DiffCount()) into config.format; is this even possible?

[echasnovski]

The tricky part might be to integrate the autocmd (that is: autocmd DiffUpdated * call DiffCount()) into config.format; is this even possible?

There should be no need for that. I'd suggest something along these lines:

• Store a diff data (probably per-buffer, but not sure) in a specific table, for example local diff_count = {}. The DiffCount() then transforms into update_diff_count() and should still be called inside DiffUpdated event.
• Write config.format to use data from the table based on the current buffer identifier.

[Dupond]

Once again, thank you for taking the time to reply!

Thanks to your answer, I've replaced the echo in my function with return, and simply added the following lines to the format function:

    if buf_id == vim.api.nvim_get_current_buf() then
        local diff_count = vim.fn.DiffCount()
        suffix = suffix .. diff_count
    end

And it seems to work just fine! Thank you for your help!

Is it normal however that in diff mode both buffer names are underlined in the tabline, instead of only the active one?

[echasnovski]

Is it normal however that in diff mode both buffer names are underlined in the tabline, instead of only the active one?

I am not sure why that happens. If the 'mini.tabline' is active, only these highlight groups should be used and that should not depend on whether there is a diff mode or not.

[Dupond]

I've found it: it's because by default, you've linked the MiniTablineVisible highlight to TabLineSel, which has cterm=underline in my theme.

Anyway, I think I'll give up on this function: I've been searching for hours, but the buffers in diff mode keep moving (I mean creating misalignments between the 2 or 3 difff buffers) when I move to another tmux pane. So my function doesn't seem to work properly. Strangely enough, the buffer that moves is not the active buffer... so I don't even know if my condition if buf_id == vim.api.nvim_get_current_buf() works correctly.

Anyway! Unfortunately, I don't have any more time to spend on it. So I thank you one last time for your help, and wish you a good week (here in France, many people are on vacation ;))! Your plugins are great, thank you for them!

[echasnovski]

Anyway, I think I'll give up on this function: I've been searching for hours, but the buffers in diff mode keep moving (I mean creating misalignments between the 2 or 3 difff buffers) when I move to another tmux pane. So my function doesn't seem to work properly. Strangely enough, the buffer that moves is not the active buffer... so I don't even know if my condition if buf_id == vim.api.nvim_get_current_buf() works correctly.

I am sorry I can't help further, as I don't have enough experience with diff mode. If you can come up with some small example of how I can reproduce the behavior locally (with or without the DiffCount function), I might take a closer look.

[Dupond]

I might take a closer look.

Once again, that's very kind of you, but I don't want to waste your time. I can live with this (tiny) problem :) Thanks again and have a nice evening!