[mini.pick] Augment Pick buffers with hotkeys

[abeldekat]

pick_labeled_buffers.mp4

My workflow regarding buffer navigation is centered around grapple.nvim. I do use Pick buffers often. Usually, its query contains more than one character, followed by enter. It would be nice to only type one single "hotkey", in Jump2d fashion.

Trying my hand on this requirement has been on my todo-list for some time. Recently, plugin snipe.nvim was announced on reddit, reminding me on that "todo".

I tried to incorporate Jump2d into Pick in various ways. No cigar unfortunately. The main Pick window disappears before Jump2d has a chance to kick-in.

In my opinion, there exists a sweet spot between the amount of opened buffers and the benefit accomplished by using a "hotkey". When the amount of buffers is considerable, the best approach is to narrow down the list using default Pick buffers. Plugin snipe.nvim uses multiple pages in that situation, a less optimal approach.

I took the code from Pick buffers and implemented Pick labeled_buffers

Algorithm:

If the amount of labels can be used to add "hotkeys" to all buffer items, the labels are highlighted. Otherwise, the labels are dimmed, but they are still available for faster navigation. Pick operates as usual in that case.

The straightforward matching algorithm provided by Pick simplified the implementation.
Just add a unique letter before the text representing the buffer, and done.
For now, I centered the pick window, to more closely resemble the centered grapple window. Also, as the text representing the buffer can be lengthy, I surrounded the text with the labels.

The code:

Pick.registry.labeled_buffers = function(_, _) -- local_opts, opts
  local letters = "abcdefghijklmnopqrstuvwxyz" -- more items than letters: no hotkey
  local buffer_items = (function() -- see Pick.builtin.buffers
    local add_label = function(text, idx)
      local letter = string.sub(letters, idx, idx)
      local label = letter == "" and "[ ]" or ("[" .. letter .. "]")
      return string.format("%s %s %s", label, text, label) -- the first label does the trick!
    end
    local buffers_output = vim.api.nvim_exec2("buffers", { output = true }).output
    local buffer_items, cur_buf_id, include_current = {}, vim.api.nvim_get_current_buf(), false
    for i, l in ipairs(vim.split(buffers_output, "\n")) do
      local buf_str, name = l:match("^%s*%d+"), l:match('"(.*)"')
      local buf_id = tonumber(buf_str)
      local item = { text = add_label(name, i), bufnr = buf_id } -- additionally add label
      if buf_id ~= cur_buf_id or include_current then table.insert(buffer_items, item) end
    end
    return buffer_items
  end)()
  local window = true
      and { -- centered window for consistency with grapple
        config = function() -- copied from :h MiniPick
          local height = math.floor(0.618 * vim.o.lines)
          local width = math.floor(0.618 * vim.o.columns)
          return {
            anchor = "NW",
            height = height,
            width = width,
            row = math.floor(0.5 * (vim.o.lines - height)),
            col = math.floor(0.5 * (vim.o.columns - width)),
          }
        end,
      }
    or nil
  local show_icons = true
  local icon_length = show_icons and 5 or 0
  local use_hotkey = #buffer_items <= string.len(letters)
  local hl = use_hotkey and "MiniPickMatchRanges" or "Comment"

  local show = function(buf_id, items, query)
    local find_label = function(item, find_pos)
      local start, _ = string.find(item.text, "[", find_pos, true)
      start = start and (start - 1) + icon_length or start
      return start
    end
    MiniPick.default_show(buf_id, items, query, { show_icons = show_icons })

    if use_hotkey and query and #query == 1 then
      local submit = vim.api.nvim_replace_termcodes("<cr>", true, false, true)
      vim.api.nvim_feedkeys(submit, "n", false) -- hotkey
    end
    for i = 1, #items do
      local start = find_label(items[i], 1) -- first label occurrence
      if start then vim.api.nvim_buf_add_highlight(buf_id, 0, hl, i - 1, start, start + 3) end
      start = find_label(items[i], 2) -- second label occurrence
      if start then vim.api.nvim_buf_add_highlight(buf_id, 0, hl, i - 1, start, -1) end
    end
  end
  return MiniPick.start({ window = window, source = { name = "Labeled_buffers", items = buffer_items, show = show } })
end

[echasnovski]

That's a nice idea!

To be perfectly honest, I'd say that code look a bit too complex for what it eventually achieves. I especially wouldn't recommend the x = (function() ... end)() approach as it is not as straightforward to read as without it (or with do ... end if absolutely necessary).

My mind immediately went in the direction of making a more general make_labeled_picker(). Which takes a picker source and modifies it to be "labeled":

• Wraps each item (directly or callable's output) in a table with a dedicated label, item, and text fields.
• Overrides match to perform a single (or several until necessary) key match.
• Possibly overrides show to have labels a special highlight (not sure if necessary).

[abeldekat]

Thanks for the feedback! I am working on the changes.

[abeldekat]

See this discussion

[leath-dub]

Good work on this, I do think a hybrid would be interesting to investigate although i personally never really exceed 20 buffers

[abeldekat]

Thanks!