defaults: restore cursor position when opening a file

[clason]

Feature already in Vim?

Yes, Vim 7.4.2111

Feature description

What it says on the tin. Vim uses an autocommand in defaults.vim for this: https://github.com/vim/vim/blob/728104da6cd561b8cb2c7142769f7526d725958e/runtime/defaults.vim#L103-L110

(Note: This is the last open item transferred from #6289 so that that issue could be put out of its misery.)

[gpanders]

Drive by note: this is complicated by the fact that Neovim enables filetype autocommands later than Vim does in defaults.vim. The "restore cursor position" autocommand needs to be defined after the FileType autocommands to allow blacklisting specific filetypes (e.g. gitcommit).

[mjlbach]

I personally don't think this should be a default, I think the segmentation for default statefulness should end at undo/jumplist/command history (but that is ofc just my opinion :) )

[lewis6991]

Agree with @mjlbach .

Also I've always used https://github.com/farmergreg/vim-lastplace to achieve this which handles more edge cases.

[hermitmaster]

Dropping this here for anybody looking for this functionality: https://github.com/ethanholz/nvim-lastplace

[lewis6991]

@hermitmaster cool! Wasn't aware someone ported this to Lua. I've taken a look and been able to reduce it down <50LOC which people can drop into the $XDG_CONFIG/nvim/plugin/*:

-- adapted from https://github.com/ethanholz/nvim-lastplace/blob/main/lua/nvim-lastplace/init.lua
local ignore_buftype = { "quickfix", "nofile", "help" }
local ignore_filetype = { "gitcommit", "gitrebase", "svn", "hgcommit" }

local function run()
  if vim.tbl_contains(ignore_buftype, vim.bo.buftype) then
    return
  end

  if vim.tbl_contains(ignore_filetype, vim.bo.filetype) then
    -- reset cursor to first line
    vim.cmd[[normal! gg]]
    return
  end

  -- If a line has already been specified on the command line, we are done
  --   nvim file +num
  if vim.fn.line(".") > 1 then
    return
  end

  local last_line = vim.fn.line([['"]])
  local buff_last_line = vim.fn.line("$")

  -- If the last line is set and the less than the last line in the buffer
  if last_line > 0 and last_line <= buff_last_line then
    local win_last_line = vim.fn.line("w$")
    local win_first_line = vim.fn.line("w0")
    -- Check if the last line of the buffer is the same as the win
    if win_last_line == buff_last_line then
      -- Set line to last line edited
      vim.cmd[[normal! g`"]]
      -- Try to center
    elseif buff_last_line - last_line > ((win_last_line - win_first_line) / 2) - 1 then
      vim.cmd[[normal! g`"zz]]
    else
      vim.cmd[[normal! G'"<c-e>]]
    end
  end
end

vim.api.nvim_create_autocmd({'BufWinEnter', 'FileType'}, {
  group    = vim.api.nvim_create_augroup('nvim-lastplace', {}),
  callback = run
})

Note: by using BufWinEnter, 'foldopen' is respected (unlike BufReadPost).

[bew]

Small re-implementation of the suggested autocmd in :h restore-cursor:

vim.api.nvim_create_autocmd('BufRead', {
  callback = function(opts)
    vim.api.nvim_create_autocmd('BufWinEnter', {
      once = true,
      buffer = opts.buf,
      callback = function()
        local ft = vim.bo[opts.buf].filetype
        local last_known_line = vim.api.nvim_buf_get_mark(opts.buf, '"')[1]
        if
          not (ft:match('commit') and ft:match('rebase'))
          and last_known_line > 1
          and last_known_line <= vim.api.nvim_buf_line_count(opts.buf)
        then
          vim.api.nvim_feedkeys([[g`"]], 'nx', false)
        end
      end,
    })
  end,
})

Copied from farmergreg/vim-lastplace#28 (comment) by @musjj, but using BufWinEnter instead of FileType
Updated as per #16339 (comment) to feed keys through the builtin key meaning, never through user mappings

[bew]

Testing that snippet a bit more, something isn't working as I'd expect:
Starting nvim using the same file in multiple splits/tabs will restore cursor ONLY in the first window, not the others.
(and annoyingly, an immediate :qa will loose the last known position as the other (non-restored) windows are closed last)

So doing:

nvim foo.txt foo.txt -p

Will open the file foo.txt in 2 tabs, but only the first tab will have its cursor restored to last known position :/
(note: removing once = true in the 'nested' autocmd to test this doesn't help)

This seems to be because BufWinEnter is purposefully not triggered if the buffer is already displayed in another window (as per its documentation).

I'd expect BufWinEnter with once=true to trigger once for each (buf, win) tuple. (WDYT?)

👉 Any idea what we could do to make this work?

Aside: I'm not fond of the name BufWinEnter for that kind of specific use case, I think I'd like to suggest to rename it to something like BufFirstWinEnter. WDYT?

---

Suggested a new autocmd idea at #22597