add: nvim fold config

lua/custom/plugins/nvimufo.lua

@@ -7,10 +7,21 @@ return {
 			config = function()
 				local builtin = require("statuscol.builtin")
 				require("statuscol").setup({
+					-- relculright = true,
+					-- segments = {
+					-- 	{ text = { builtin.foldfunc }, click = "v:lua.ScFa" },
+					-- 	{ text = { "%s" }, click = "v:lua.ScSa" },
+					-- 	{ text = { builtin.lnumfunc, " " }, click = "v:lua.ScLa" },
+					-- },
+					setopt = true,
 					relculright = true,
 					segments = {
-						{ text = { builtin.foldfunc }, click = "v:lua.ScFa" },
 						{ text = { "%s" }, click = "v:lua.ScSa" },
+						{
+							text = { builtin.foldfunc },
+							condition = { builtin.not_empty, true, builtin.not_empty },
+							click = "v:lua.ScFa",
+						},
 						{ text = { builtin.lnumfunc, " " }, click = "v:lua.ScLa" },
 					},
 				})
@@ -24,6 +35,7 @@ return {
 		vim.o.foldlevelstart = 99
 		vim.o.foldenable = true
 		vim.o.fillchars = [[eob: ,fold: ,foldopen:,foldsep: ,foldclose:]]
+		-- vim.o.fillchars = [[eob: ,fold: ,foldopen:▼,foldsep: ,foldclose:⏵]]
 
 		-- these are "extra", change them as you like
 		vim.keymap.set("n", "zR", require("ufo").openAllFolds)
@@ -33,9 +45,43 @@ return {
 		-- Only depend on `nvim-treesitter/queries/filetype/folds.scm`,
 		-- performance and stability are better than `foldmethod=nvim_treesitter#foldexpr()`
 		require("ufo").setup({
-			provider_selector = function(bufnr, filetype, buftype)
+			-- provider_selector = function(bufnr, filetype, buftype)
+			-- 	return { "treesitter", "indent" }
+			-- end,
+			open_fold_hl_timeout = 0,
+			provider_selector = function(_, filetype)
 				return { "treesitter", "indent" }
 			end,
+			fold_virt_text_handler = function(virt_text, lnum, end_lnum, width, truncate)
+				local result = {}
+				local _end = end_lnum - 1
+				local final_text = vim.trim(vim.api.nvim_buf_get_text(0, _end, 0, _end, -1, {})[1])
+				local suffix = final_text:format(end_lnum - lnum)
+				local suffix_width = vim.fn.strdisplaywidth(suffix)
+				local target_width = width - suffix_width
+				local cur_width = 0
+				for _, chunk in ipairs(virt_text) do
+					local chunk_text = chunk[1]
+					local chunk_width = vim.fn.strdisplaywidth(chunk_text)
+					if target_width > cur_width + chunk_width then
+						table.insert(result, chunk)
+					else
+						chunk_text = truncate(chunk_text, target_width - cur_width)
+						local hl_group = chunk[2]
+						table.insert(result, { chunk_text, hl_group })
+						chunk_width = vim.fn.strdisplaywidth(chunk_text)
+						-- str width returned from truncate() may less than 2nd argument, need padding
+						if cur_width + chunk_width < target_width then
+							suffix = suffix .. (" "):rep(target_width - cur_width - chunk_width)
+						end
+						break
+					end
+					cur_width = cur_width + chunk_width
+				end
+				table.insert(result, { " ⋯ ", "NonText" })
+				table.insert(result, { suffix, "TSPunctBracket" })
+				return result
+			end,
 		})
 	end,
 }