Can we add a gap between stacked notifier popups?

[kaihocd]

The notifier popups are packed tightly together. This makes the layout look quite crowded with the solid border style, and it also doesn’t look good with floating window shadows in Neovide.

This has been bothering me for quite a while, so if anyone knows how to make this work, please help me out — I’d be really grateful!

Currently, the default layout of the notifier popups is very compact, like this:

Is there a way to add some spacing (e.g., 1 line) between them when they are stacked?

For example, in the illustration below, the four red boxes represent the original four notifier popups, but with an extra gap between each:

[drowning-cat]

Now built into snacks.nvim! See #2331.

Previous message

I think it can be done better. I’m not sure how to hook up before the layout changes.

notifier = {
  ---@param buf integer
  ---@param notif snacks.notifier.Notif
  ---@param ctx snacks.notifier.ctx
  style = function(buf, notif, ctx)
    local render = ctx.notifier:get_render 'compact'
    render(buf, notif, ctx)
    vim.schedule(function()
      notif.layout.top = notif.layout.top + 1
      ctx.notifier:process()
    end)
  end,
},

[kaihocd]

You are absolutely awesome! I had considered writing a hook to intercept the source code of snacks.notifier, but that approach simply didn't work. In contrast, your solution is so simple and yet works perfectly for my case!

Thank you so much!

[kaihocd]

After testing, this code still has issues.
For example, when the LSP is loading, the notifier that displays the LSP progress keeps scrolling on the screen continuously until Neovim freezes.

I worked around this issue by filtering notifications with the same buffer to avoid this LSP progress notifier bug:

local function notifier_style()
	local last_buf

	---@param buf integer
	---@param notif snacks.notifier.Notif
	---@param ctx snacks.notifier.ctx
	return function(buf, notif, ctx)
		local render = ctx.notifier:get_render('compact')
		render(buf, notif, ctx)
		vim.schedule(function()
			if not notif.layout or buf == last_buf then
				return
			end
			notif.layout.top = (notif.layout.top or 0) + 1
			ctx.notifier:process()
			last_buf = buf
		end)
	end
end

notifier = {
	style = notifier_style(),
}

Another problem is that when too many notifiers are stacked, the ones that appear later are temporarily hidden.
When the earlier notifiers disappear, several hidden notifiers get rendered all at once — and in this case, there’s still no gap between them.
I haven’t been able to solve this issue yet 😵.

[drowning-cat]

Hide

Basically, we only override one line.

---@param self snacks.notifier.Class
---@param gap integer
local gap_layout = function(self, gap)
  local uv = vim.uv or vim.loop
  -- https://github.com/folke/snacks.nvim/blob/5d9dacd09876eed33bde204d224fa7596ac850e8/lua/snacks/notifier.lua#L261-L268
  local function ts()
    if uv.clock_gettime then
      local ret = assert(uv.clock_gettime 'realtime')
      return ret.sec + ret.nsec / 1e9
    end
    local sec, usec = uv.gettimeofday()
    return sec + usec / 1e6
  end
  -- https://github.com/folke/snacks.nvim/blob/5d9dacd09876eed33bde204d224fa7596ac850e8/lua/snacks/notifier.lua#L671-L724
  local layout = self:new_layout()
  local wins_updated = 0
  local wins_created = 0
  local update = {} ---@type snacks.win[]
  for _, notif in ipairs(assert(self.sorted)) do
    if layout.free < (self.opts.height.min + 2) then -- not enough space
      if notif.win then
        notif.shown = nil
        notif.win:hide()
      end
    else
      local prev_layout = notif.layout and { top = notif.layout.top, height = notif.layout.height, width = notif.layout.width }
      if not notif.win or notif.dirty or not notif.win:buf_valid() or type(notif.opts) == 'function' then
        notif.dirty = true
        self:render(notif)
        notif.dirty = false
        notif.layout = notif.win:size()
        notif.layout.top = prev_layout and prev_layout.top
        prev_layout = nil -- always re-render since opts might've changed
      end
      notif.layout.top = layout.find(notif.layout.height, notif.layout.top)
      if notif.layout.top then
        -- NOTE: Changed from
        -- layout.mark(notif.layout.top, notif.layout.height, false)
        layout.mark(notif.layout.top + gap, notif.layout.height, false)
        if not vim.deep_equal(prev_layout, notif.layout) then
          if notif.win:win_valid() then
            wins_updated = wins_updated + 1
          else
            wins_created = wins_created + 1
          end
          update[#update + 1] = notif.win
          notif.win.opts.row = notif.layout.top - 1
          notif.win.opts.col = vim.o.columns - notif.layout.width - self.opts.margin.right
          notif.shown = notif.shown or ts()
          notif.win:show()
        end
      elseif notif.win then
        notif.shown = nil
        notif.win:hide()
      end
    end
  end
  if #update > 0 and not self.in_search() then
    if vim.api.nvim__redraw then
      for _, win in ipairs(update) do
        win:redraw()
      end
    else
      vim.cmd.redraw()
    end
  end
end

opts = {
  notifier = {
    ---@param buf integer
    ---@param notif snacks.notifier.Notif
    ---@param ctx snacks.notifier.ctx
    style = function(buf, notif, ctx)
      local render = ctx.notifier:get_render 'compact'
      ctx.notifier.layout = function(self)
        gap_layout(self, 1)
      end
      render(buf, notif, ctx)
    end,
  },
},