Feature request: support tailwind-fold conceallevels

[MuntasirSZN]

Describe the bug
A description of what the bug is.

Nothing/

To Reproduce
Provide your config and steps to reproduce.
You can use test/minimal.lua to produce a minimal config.

Install tailwind-fold.nvim and open a file where is does folding.

Expected behavior
A description of what you expected to happen.

Colorizer should not show the virtual text unless my cursor is in that folded line

Screenshots
If applicable, add screenshots to help explain your problem.

Lemme clear it:

When my cursor is not on a line that is folded, colorizer should not colorize that line (virtual text). Thats all.

Operating System:
Archlinux

Neovim Version:
0.11

[catgoose]

So I believe this has to do with conceallevel. Setting concealevel = 0 after loading a tailwind file:

:help conceallevel:

						*'conceallevel'* *'cole'*
'conceallevel' 'cole'	number	(default 0)
			local to window
	Determine how text with the "conceal" syntax attribute |:syn-conceal|
	is shown:

	Value		Effect ~
	0		Text is shown normally
	1		Each block of concealed text is replaced with one
			character.  If the syntax item does not have a custom
			replacement character defined (see |:syn-cchar|) the
			character defined in 'listchars' is used.
			It is highlighted with the "Conceal" highlight group.
	2		Concealed text is completely hidden unless it has a
			custom replacement character defined (see
			|:syn-cchar|).
	3		Concealed text is completely hidden.

tailwind-fold.nvim sets the highlight group TailwindConceal so initially I thought we could do something like

    hooks = {
      disable_line_highlight = function(line, bufnr, line_num)
        for _, ns_id in pairs(vim.api.nvim_get_namespaces()) do
          local extmarks = vim.api.nvim_buf_get_extmarks(
            bufnr,
            ns_id,
            { line_num, 0 },
            { line_num, -1 },
            { details = true }
          )
          for _, mark in ipairs(extmarks) do
            local details = mark[4]
            if details and details.hl_group == "TailwindConceal" then
              return true
            end
          end
        end
        return false
      end,
    },

But this is quite slow and it doesn't really work because tailwind-fold.nvim doesn't seem to update it's highlight groups very well after editing:

I am not very familiar with conceallevel, so I am sorry I cannot be of better help.

[catgoose]

Do you still want to me to support this? You can do something like:

  hooks = {
    should_highlight_line = function(line, bufnr, line_nr)
      -- Skip lines where text is concealed (e.g. by tailwind-fold.nvim)
      -- unless cursor is on this line (conceal reveals at cursor)
      local win = vim.fn.bufwinid(bufnr)
      if win == -1 then return true end
      local conceallevel = vim.wo[win].conceallevel
      if conceallevel < 2 then return true end
      local cursor_line = vim.api.nvim_win_get_cursor(win)[1] - 1
      if line_nr == cursor_line then return true end
      -- Check if first non-blank char is concealed
      local col = line:find("%S")
      if col and vim.fn.synconcealed(line_nr + 1, col)[1] == 1 then
        return false
      end
      return true
    end,
  }

But I would need to add an option to re-highlight on CursorMoved, which has performance implications. Let me know if this is something you still want.

[MuntasirSZN]

Practically yes @catgoose

[catgoose]

Can you try with feat/rehighlight_events branch?

Try something like this:

require("colorizer").setup({
  options = {
    rehighlight_events = { "CursorMoved", "CursorMovedI" },
    parsers = { css = true },
    hooks = {
      should_highlight_line = function(line, bufnr, line_nr)
        -- Skip concealed lines unless cursor is on them
        local win = vim.fn.bufwinid(bufnr)
        if win == -1 then return true end
        if vim.wo[win].conceallevel < 2 then return true end
        local cursor_line = vim.api.nvim_win_get_cursor(win)[1] - 1
        if line_nr == cursor_line then return true end
        local col = line:find("%S")
        if col and vim.fn.synconcealed(line_nr + 1, col)[1] == 1 then
          return false
        end
        return true
      end,
    },
  },
})

Per-filetype overrides work too — only add events for filetypes that need them:

require("colorizer").setup({
  filetypes = {
    "*",
    typescript = { rehighlight_events = { "CursorHold" } },
    typescriptreact = { rehighlight_events = { "CursorHold" } },
  },
  options = {
    parsers = { css = true },
  },
})

Note: Adding high-frequency events like CursorMoved has a performance
cost. Only add events you actually need.

[MuntasirSZN]

Sorry but I cannot test as my computer is away. Though I still want thism