use plugin nvim-ufo for better folding

The settings are copied from https://github.com/kevinhwang91/nvim-ufo/issues/4#issuecomment-1514537245,
with some modification.

README.md

@@ -13,7 +13,7 @@
       <img alt="Latest release" src="https://img.shields.io/github/v/release/jdhao/nvim-config" />
     </a>
     <a href="https://github.com/neovim/neovim/releases/tag/stable">
-      <img src="https://img.shields.io/badge/Neovim-0.9.5-blueviolet.svg?style=flat-square&logo=Neovim&logoColor=green" alt="Neovim minimum version"/>
+      <img src="https://img.shields.io/badge/Neovim-0.10.1-blueviolet.svg?style=flat-square&logo=Neovim&logoColor=green" alt="Neovim minimum version"/>
     </a>
     <a href="https://github.com/jdhao/nvim-config/search?l=vim-script">
       <img src="https://img.shields.io/github/languages/top/jdhao/nvim-config" alt="Top languages"/>
@@ -21,8 +21,8 @@
     <a href="https://github.com/jdhao/nvim-config/graphs/commit-activity">
       <img src="https://img.shields.io/github/commit-activity/m/jdhao/nvim-config?style=flat-square" />
     </a>
-    <a href="https://github.com/jdhao/nvim-config/releases/tag/v0.9.5">
-      <img src="https://img.shields.io/github/commits-since/jdhao/nvim-config/v0.9.5?style=flat-square" />
+    <a href="https://github.com/jdhao/nvim-config/releases/tag/v0.10.0">
+      <img src="https://img.shields.io/github/commits-since/jdhao/nvim-config/v0.10.0?style=flat-square" />
     </a>
     <a href="https://github.com/jdhao/nvim-config/graphs/contributors">
       <img src="https://img.shields.io/github/contributors/jdhao/nvim-config?style=flat-square" />
@@ -169,8 +169,8 @@ Some of the shortcuts I use frequently are listed here. In the following shortcu
 | `<leader>gc`      | Normal        | Linux/macOS/Win | Run git commit                                                           |
 | `<leader>gpl`     | Normal        | Linux/macOS/Win | Run git pull                                                             |
 | `<leader>gpu`     | Normal        | Linux/macOS/Win | Run git push                                                             |
-| `<leader>gl`      | Normal/Visual | Linux/macOS/Win | Get perm link for current/visually-select lines
-| `<leader>gb`      | Normal        | macOS           | Browse current git repo in browser
+| `<leader>gl`      | Normal/Visual | Linux/macOS/Win | Get perm link for current/visually-select lines                          |
+| `<leader>gb`      | Normal        | macOS           | Browse current git repo in browser                                       |
 | `<F9>`            | Normal        | Linux/macOS/Win | Compile&run current source file (for C++, LaTeX, Lua, Python)            |
 | `<F11>`           | Normal        | Linux/macOS/Win | Toggle spell checking                                                    |
 | `<F12>`           | Normal        | Linux/macOS/Win | Toggle paste mode                                                        |

init.lua

@@ -14,11 +14,11 @@ vim.loader.enable()
 local version = vim.version
 
 -- check if we have the latest stable version of nvim
-local expected_ver = "0.10.0"
-local ev = version.parse(expected_ver)
+local expected_ver = "0.10.1"
+local expect_ver = version.parse(expected_ver)
 local actual_ver = version()
 
-local result = version.cmp(ev, {actual_ver.major, actual_ver.minor, actual_ver.patch})
+local result = version.cmp(expect_ver, actual_ver)
 
 if  result ~= 0 then
   local _ver = string.format("%s.%s.%s", actual_ver.major, actual_ver.minor, actual_ver.patch)

lua/colorschemes.lua

@@ -24,9 +24,9 @@ M.colorscheme_conf = {
   end,
   gruvbox_material = function()
     -- foreground option can be material, mix, or original
-    vim.g.gruvbox_material_foreground = "material"
+    vim.g.gruvbox_material_foreground = "original"
     --background option can be hard, medium, soft
-    vim.g.gruvbox_material_background = "soft"
+    vim.g.gruvbox_material_background = "medium"
     vim.g.gruvbox_material_enable_italic = 1
     vim.g.gruvbox_material_better_performance = 1
 

lua/config/lsp.lua

@@ -231,11 +231,12 @@ if utils.executable("lua-language-server") then
         },
         workspace = {
           -- Make the server aware of Neovim runtime files,
-          -- see also https://github.com/LuaLS/lua-language-server/wiki/Libraries#link-to-workspace .
-          -- Lua-dev.nvim also has similar settings for lua ls, https://github.com/folke/neodev.nvim/blob/main/lua/neodev/luals.lua .
+          -- see also https://luals.github.io/wiki/settings/#workspacelibrary
           library = {
             vim.env.VIMRUNTIME,
             fn.stdpath("config"),
+            -- make lua_ls aware of functions under vim.uv
+            "${3rd}/luv/library"
           },
           maxPreload = 2000,
           preloadFileSize = 50000,

lua/config/nvim_ufo.lua

@@ -0,0 +1,48 @@
+local handler = function(virtText, lnum, endLnum, width, truncate)
+  local newVirtText = {}
+  local totalLines = vim.api.nvim_buf_line_count(0)
+  local foldedLines = endLnum - lnum
+  local suffix = (" 󰁂  %d"):format(foldedLines)
+  local sufWidth = vim.fn.strdisplaywidth(suffix)
+  local targetWidth = width - sufWidth
+  local curWidth = 0
+
+  for _, chunk in ipairs(virtText) do
+    local chunkText = chunk[1]
+    local chunkWidth = vim.fn.strdisplaywidth(chunkText)
+    if targetWidth > curWidth + chunkWidth then
+      table.insert(newVirtText, chunk)
+    else
+      chunkText = truncate(chunkText, targetWidth - curWidth)
+      local hlGroup = chunk[2]
+      table.insert(newVirtText, { chunkText, hlGroup })
+      chunkWidth = vim.fn.strdisplaywidth(chunkText)
+      -- str width returned from truncate() may less than 2nd argument, need padding
+      if curWidth + chunkWidth < targetWidth then
+        suffix = suffix .. (" "):rep(targetWidth - curWidth - chunkWidth)
+      end
+      break
+    end
+    curWidth = curWidth + chunkWidth
+  end
+  local rAlignAppndx = math.max(math.min(vim.opt.textwidth["_value"], width - 1) - curWidth - sufWidth, 0)
+  suffix = (" "):rep(rAlignAppndx) .. suffix
+  table.insert(newVirtText, { suffix, "MoreMsg" })
+  return newVirtText
+end
+
+local opts = {}
+opts["fold_virt_text_handler"] = handler
+
+require("ufo").setup(opts)
+
+vim.keymap.set("n", "zR", require("ufo").openAllFolds)
+vim.keymap.set("n", "zM", require("ufo").closeAllFolds)
+vim.keymap.set("n", "zr", require("ufo").openFoldsExceptKinds)
+vim.keymap.set("n", "<leader>K", function()
+  local winid = require("ufo").peekFoldedLinesUnderCursor()
+  if not winid then
+    -- vim.lsp.buf.hover()
+    vim.cmd([[ Lspsaga hover_doc ]])
+  end
+end)

lua/config/statusline.lua

@@ -99,12 +99,12 @@ end
 
 local virtual_env = function()
   -- only show virtual env for Python
-  if vim.bo.filetype ~= 'python' then
+  if vim.bo.filetype ~= "python" then
     return ""
   end
 
-  local conda_env = os.getenv('CONDA_DEFAULT_ENV')
-  local venv_path = os.getenv('VIRTUAL_ENV')
+  local conda_env = os.getenv("CONDA_DEFAULT_ENV")
+  local venv_path = os.getenv("VIRTUAL_ENV")
 
   if venv_path == nil then
     if conda_env == nil then
@@ -113,17 +113,32 @@ local virtual_env = function()
       return string.format("  %s (conda)", conda_env)
     end
   else
-    local venv_name = vim.fn.fnamemodify(venv_path, ':t')
+    local venv_name = vim.fn.fnamemodify(venv_path, ":t")
     return string.format("  %s (venv)", venv_name)
   end
 end
 
+local get_active_lsp = function()
+  local msg = "No Active Lsp"
+  local buf_ft = vim.api.nvim_get_option_value("filetype", {})
+  local clients = vim.lsp.get_clients { bufnr = 0 }
+  if next(clients) == nil then
+    return msg
+  end
+
+  for _, client in ipairs(clients) do
+    local filetypes = client.config.filetypes
+    if filetypes and vim.fn.index(filetypes, buf_ft) ~= -1 then
+      return client.name
+    end
+  end
+  return msg
+end
+
 require("lualine").setup {
   options = {
     icons_enabled = true,
     theme = "auto",
-    -- component_separators = { left = "", right = "" },
-    -- section_separators = { left = "", right = "" },
     section_separators = "",
     component_separators = "",
     disabled_filetypes = {},
@@ -132,18 +147,29 @@ require("lualine").setup {
   sections = {
     lualine_a = { "mode" },
     lualine_b = {
-      "branch",
+      {
+        "branch",
+        fmt = function(name, context)
+          -- truncate branch name in case the name is too long
+          return string.sub(name, 1, 20)
+        end,
+      },
+      {
+        virtual_env,
+        color = { fg = "black", bg = "#F1CA81" },
+      },
+    },
+    lualine_c = {
+      {
+        "filename",
+        symbols = {
+          readonly = "[🔒]",
+        },
+      },
       {
         "diff",
         source = diff,
       },
-      {
-        virtual_env,
-        color = { fg = 'black', bg = "#F1CA81" }
-      }
-    },
-    lualine_c = {
-      "filename",
       {
         ime_state,
         color = { fg = "black", bg = "#f46868" },
@@ -152,13 +178,19 @@ require("lualine").setup {
         spell,
         color = { fg = "black", bg = "#a7c080" },
       },
+    },
+    lualine_x = {
+      {
+        get_active_lsp,
+        icon = " LSP:",
+      },
       {
         "diagnostics",
         sources = { "nvim_diagnostic" },
-        symbols = {error = '🆇 ', warn = '⚠️ ', info = 'ℹ️ ', hint = ' '},
+        symbols = { error = "🆇 ", warn = "⚠️ ", info = "ℹ️ ", hint = " " },
       },
     },
-    lualine_x = {
+    lualine_y = {
       "encoding",
       {
         "fileformat",
@@ -170,9 +202,6 @@ require("lualine").setup {
       },
       "filetype",
     },
-    lualine_y = {
-      "location",
-    },
     lualine_z = {
       {
         trailing_space,
@@ -182,6 +211,7 @@ require("lualine").setup {
         mixed_indent,
         color = "WarningMsg",
       },
+      "progress"
     },
   },
   inactive_sections = {

lua/plugin_specs.lua

@@ -1,6 +1,7 @@
 local utils = require("utils")
 
-local lazypath = vim.fn.stdpath("data") .. "/lazy/lazy.nvim"
+local plugin_dir = vim.fn.stdpath("data") .. "/lazy"
+local lazypath = plugin_dir .. "/lazy.nvim"
 
 if not vim.uv.fs_stat(lazypath) then
   vim.fn.system {
@@ -108,8 +109,12 @@ local plugin_specs = {
     "Yggdroot/LeaderF",
     cmd = "Leaderf",
     build = function()
+      local leaderf_path = plugin_dir .. "/LeaderF"
+      vim.opt.runtimepath:append(leaderf_path)
+      vim.cmd("runtime! plugin/leaderf.vim")
+
       if not vim.g.is_win then
-        vim.cmd(":LeaderfInstallCExtension")
+        vim.cmd("LeaderfInstallCExtension")
       end
     end,
   },
@@ -122,9 +127,10 @@ local plugin_specs = {
     },
   },
   {
-    "lukas-reineke/headlines.nvim",
-    dependencies = "nvim-treesitter/nvim-treesitter",
-    config = true, -- or `opts = {}`
+    "MeanderingProgrammer/markdown.nvim",
+    main = "render-markdown",
+    opts = {},
+    dependencies = { "nvim-treesitter/nvim-treesitter", "nvim-tree/nvim-web-devicons" },
   },
   -- A list of colorscheme plugin you may want to try. Find what suits you.
   { "navarasu/onedark.nvim", lazy = true },
@@ -169,12 +175,41 @@ local plugin_specs = {
   {
     "lukas-reineke/indent-blankline.nvim",
     event = "VeryLazy",
-    main = 'ibl',
+    main = "ibl",
     config = function()
       require("config.indent-blankline")
     end,
   },
-
+  {
+    "luukvbaal/statuscol.nvim",
+    opts = {},
+    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" },
+        },
+      }
+    end,
+  },
+  {
+    "kevinhwang91/nvim-ufo",
+    dependencies = "kevinhwang91/promise-async",
+    event = "VeryLazy",
+    opts = {},
+    init = function()
+      vim.o.foldcolumn = "1" -- '0' is not bad
+      vim.o.foldlevel = 99 -- Using ufo provider need a large value, feel free to decrease the value
+      vim.o.foldlevelstart = 99
+      vim.o.foldenable = true
+    end,
+    config = function()
+      require("config.nvim_ufo")
+    end,
+  },
   -- Highlight URLs inside vim
   { "itchyny/vim-highlighturl", event = "VeryLazy" },
 
@@ -222,9 +257,9 @@ local plugin_specs = {
 
   -- Automatic insertion and deletion of a pair of characters
   {
-      'windwp/nvim-autopairs',
-      event = "InsertEnter",
-      config = true
+    "windwp/nvim-autopairs",
+    event = "InsertEnter",
+    config = true,
   },
 
   -- Comment plugin
@@ -316,7 +351,7 @@ local plugin_specs = {
   { "rhysd/committia.vim", lazy = true },
 
   {
-    "sindrets/diffview.nvim"
+    "sindrets/diffview.nvim",
   },
 
   {
@@ -418,17 +453,26 @@ local plugin_specs = {
   {
     "glacambre/firenvim",
     enabled = function()
-      if vim.g.is_win or vim.g.is_mac then
-        return true
-      end
-      return false
+      local result = vim.g.is_win or vim.g.is_mac
+      return result
     end,
+    -- it seems that we can only call the firenvim function directly.
+    -- Using vim.fn or vim.cmd to call this function will fail.
     build = function()
-      vim.fn["firenvim#install"](0)
-    end,
-    lazy = true,
-  },
+      local firenvim_path = plugin_dir .. "/firenvim"
+      vim.opt.runtimepath:append(firenvim_path)
+      vim.cmd("runtime! firenvim.vim")
 
+      -- macOS will reset the PATH when firenvim starts a nvim process, causing the PATH variable to change unexpectedly.
+      -- Here we are trying to get the correct PATH and use it for firenvim.
+      -- See also https://github.com/glacambre/firenvim/blob/master/TROUBLESHOOTING.md#make-sure-firenvims-path-is-the-same-as-neovims
+      local path_env = vim.env.PATH
+      local prologue = string.format('export PATH="%s"', path_env)
+      -- local prologue = "echo"
+      local cmd_str = string.format(":call firenvim#install(0, '%s')", prologue)
+      vim.cmd(cmd_str)
+    end,
+  },
   -- Debugger plugin
   {
     "sakhnik/nvim-gdb",
@@ -494,13 +538,14 @@ local plugin_specs = {
   },
 }
 
--- configuration for lazy itself.
-local lazy_opts = {
+require("lazy").setup {
+  spec = plugin_specs,
   ui = {
     border = "rounded",
     title = "Plugin Manager",
     title_pos = "center",
   },
+  rocks = {
+    enabled = false,
+  },
 }
-
-require("lazy").setup(plugin_specs, lazy_opts)

viml_conf/options.vim

@@ -1,11 +1,14 @@
 scriptencoding utf-8
 
 " change fillchars for folding, vertical split, end of buffer, and message separator
-set fillchars=fold:\ ,vert:\│,eob:\ ,msgsep:‾,diff:╱
+set fillchars=fold:\ ,foldsep:\ ,foldopen:,foldclose:,vert:\│,eob:\ ,msgsep:‾,diff:╱
 
 " Split window below/right when creating horizontal/vertical windows
 set splitbelow splitright
 
+" avoid the flickering when splitting window horizontal
+set splitkeep=screen
+
 " Time in milliseconds to wait for a mapped sequence to complete,
 " see https://unix.stackexchange.com/q/36882/221410 for more info
 set timeoutlen=500

viml_conf/plugins.vim

@@ -58,16 +58,6 @@ endif
 " Only fuzzy-search files names
 let g:Lf_DefaultMode = 'FullPath'
 
-" Popup window settings
-let w = float2nr(&columns * 0.8)
-if w > 140
-  let g:Lf_PopupWidth = 140
-else
-  let g:Lf_PopupWidth = w
-endif
-
-let g:Lf_PopupPosition = [0, float2nr((&columns - g:Lf_PopupWidth)/2)]
-
 " Do not use version control tool to list files under a directory since
 " submodules are not searched by default.
 let g:Lf_UseVersionControlTool = 0