Cursor highlighting lost in highlighted blocks

[jay-aye-see-kay]

First of all thanks sharing this plugin, I've used it to replace a buggy implementation in my config built using signs instead of extmarks. In my implementation I had this same issue, but I think with extmarks it can be fixed.

Here's an video of the issue, you can see when the CursorLine enters the highlighted area it disappears. I'd guess this is due to the extmarks colour getting a higher priority.

I briefly looked into it and found this thread about that behaviour neovim/neovim#15485 . This suggests it's possible to call nvim_buf_set_extmark with opts.hl_mode to resolve this issue...

Would you be open to changing the default behaviour, or perhaps exposing this an option? If you're busy I should have time to look into this later in the week.

Screen.Recording.2023-02-28.at.4.30.56.pm.mov

---

Here's my tsnode-marker config (h.autocmd is an internal helper function that autmattically sets augroup)

h.autocmd({ "ColorScheme" }, {
	callback = function()
		-- add hl group for markdown codeblock backgrounds
		vim.api.nvim_set_hl(0, "CodeBlockBackground", { bg = require("zenbones").Normal.bg.li(70).hex })
		-- darken cursorline so it's more visible
		vim.api.nvim_set_hl(0, "CursorLine", { bg = require("zenbones").CursorLine.bg.darken(7).hex })
	end,
})


h.autocmd({ "FileType" }, {
	pattern = { "markdown", "md" },
	callback = function(ctx)
		require("tsnode-marker").set_automark(ctx.buf, {
			target = { "code_fence_content" },
			hl_group = "CodeBlockBackground",
		})
	end,
})

[atusy]

Thank you for the report.

I have been aware of this problem, but it seems none of the hl_mode fixes the problem...
I tried replace, combine, and blend.

I have an idea to use CursorMoved event to disable or add extmark for the cursor position.
This should be better than nothing, but not yet implemented because of difficulty to leave CursorLine highlight on other windows with the same buffer.
I also have a concern about conflicts with other plugins (maybe I'm too pessimistic)

You can try my idea with the following code.

vim.api.nvim_create_autocmd({"CursorMoved", "CursorMovedI"}, {
  callback = function(ctx)
    local ns = vim.api.nvim_create_namespace("tsnode-marker-cursorline")
    local winid = vim.api.nvim_get_current_win()
    local winbuf = vim.api.nvim_win_get_buf(winid)
    vim.api.nvim_buf_clear_namespace(ctx.buf, ns, 0, -1)
    if ctx.buf == winbuf and vim.wo[winid].cursorline then
      local pos = vim.api.nvim_win_get_cursor(winid)
      vim.api.nvim_buf_set_extmark(ctx.buf, ns, pos[1] - 1, 0, {
        end_row = pos[1],
        end_col = 0,
        hl_group = "CursorLine",
        hl_eol = true,
        priority = 10,
      })
    end
  end,
})

[atusy]

I have considered more without no good conclusions...
Any suggestions are welcome.

Here are my notes.

Some concerns I found by trying above idea:

• Undesired appearance when buffer appears on multiple windows.
  In the image below, the current window is on the right.

  
  • Real-cursorline on the inactive window still looks ugly
  • Pseudo-cursorline appears on windows sharing the same buffer

• virt_text-based pseudo indent has higher priority regardless of hl_mode

  

The second solution is to temporary remove extmarks from the current cursor position.
However, this is tricky because we have to deal with extmark's id...
Also, this solution is still buffer-local, not window-local.
'cursorline' is a window-local option.

The third solution is to use semi-transparent floating windows, but I think this is further complex...

• a floating window on a current window have to move along with cursor
• floating windows have to resize on WinResize event
• underlying characters will be dimmed because of the semi-transparent floating window

[jay-aye-see-kay]

Thanks for looking into it, it seem like a more complicated problem than I expected.

Looking at the docs a bit better now I see why the hl_mode option doesn't work, it's only supposed to affect the text color, not background color. But I also see cursorline_hl_group is an option we can pass to nvim_buf_set_extmark, it doesn't work (even when the extmark is single line) but it seems like it should. I wonder if this is a bug in nvim?

---

I tried your solution above adding a new cursor line hl group, this doesn't work for me as I only have the cursorline active on the current buffer. And then there are the issues you mention above too.

I like the idea of disabling the highlighting under the current cursor rather than adding a new one over the top. It would be difficult to implement as you say, but feels like it could be the best way.

Anyway no stress if you don't feel like implementing it. It would be nice to have, but the plugin works well now. If you end up implementing something tag me here and I'm happy to help beta test.