feat(nvim): improve ufo

modules/programs/nvim/plugins/default.nix

@@ -111,7 +111,7 @@ with builtins;
     }
     {
       plugin = nvim-lspconfig;
-      event = [ "BufReadPre" "BufNewFile" ];
+      event = [ "BufRead" "BufNewFile" ];
       conf = readFile ./nvim-lspconfig.lua;
       dependencies = [
         {
@@ -126,6 +126,7 @@ with builtins;
         { plugin = lsp_lines-nvim; }
         {
           plugin = nvim-ufo;
+          conf = readFile ./nvim-ufo.lua;
           dependencies = [
             { plugin = promise-async; }
           ];

modules/programs/nvim/plugins/nvim-lspconfig.lua

@@ -5,58 +5,27 @@ vim.diagnostic.config({
   virtual_text = false,
 })
 
-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
-vim.o.fillchars = [[eob: ,fold: ,foldopen:,foldsep: ,foldclose:]]
-vim.o.statuscolumn = "%= "
-  -- FIXME: figure out how to put on the other side without having to do a lot of shifting
-  .. "%s" -- sign column
-  .. "%{%" -- evaluate this, and then evaluate what it returns
-  .. "&number ?"
-  .. "(v:relnum ?"
-  -- when showing relative numbers, make sure to pad so things don't shift as you move the cursor
-  .. 'printf("%"..len(line("$")).."s", v:relnum)'
-  .. ":"
-  .. "v:lnum"
-  .. ")"
-  .. ":"
-  .. '""'
-  .. " " -- space between lines and fold
-  .. "%}"
-  .. "%= "
-  .. "%#FoldColumn#" -- highlight group for fold
-  .. "%{" -- expression for showing fold expand/colapse
-  .. "foldlevel(v:lnum) > foldlevel(v:lnum - 1)" -- any folds?
-  .. "? (foldclosed(v:lnum) == -1" -- currently open?
-  .. '? ""' -- point down
-  .. ':  ""' -- point to right
-  .. ")"
-  .. ': " "' -- blank for no fold, or inside fold
-  .. "}"
-  .. "%= " -- spacing between end of column and start of text
-
--- Using ufo provider need remap `zR` and `zM`. If Neovim is 0.6.1, remap yourself
-require("which-key").register({
-  z = {
-    R = { require("ufo").openAllFolds, "Open all folds" },
-    M = { require("ufo").closeAllFolds, "Close all folds" },
-  },
-})
 local capabilities = vim.lsp.protocol.make_client_capabilities()
+-- NOTE for nvim-ufo
 -- Tell the server the capability of foldingRange,
 -- Neovim hasn't added foldingRange to default capabilities, users must add it manually
 capabilities.textDocument.foldingRange = {
   dynamicRegistration = false,
   lineFoldingOnly = true,
 }
-require("ufo").setup()
 
 local lspconfig = require("lspconfig")
 local on_attach_def = function(client, bufnr)
   require("which-key").register({
-    K = { vim.lsp.buf.hover, "Hover" },
+    K = {
+      function()
+        local winid = require("ufo").peekFoldedLinesUnderCursor()
+        if not winid then
+          vim.lsp.buf.hover()
+        end
+      end,
+      "Hover",
+    },
     ["<leader>"] = {
       l = {
         d = { vim.diagnostic.open_float, "Open diagnostic window" },

modules/programs/nvim/plugins/nvim-ufo.lua

@@ -0,0 +1,98 @@
+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
+vim.o.fillchars = [[eob: ,fold: ,foldopen:,foldsep: ,foldclose:]]
+vim.o.statuscolumn = "%s" -- sign column
+  .. "%="
+  .. "%{%" -- evaluate this, and then evaluate what it returns
+  .. "&number ?"
+  .. "(v:relnum ?"
+  -- when showing relative numbers, make sure to pad so things don't shift as you move the cursor
+  .. 'printf("%"..len(line("$")).."s", v:relnum)'
+  .. ":"
+  .. "v:lnum"
+  .. ")"
+  .. ":"
+  .. '""'
+  .. "%}"
+  .. "%#FoldColumn#" -- highlight group for fold
+  .. "%{" -- expression for showing fold expand/colapse
+  .. "foldlevel(v:lnum) > foldlevel(v:lnum - 1)" -- any folds?
+  .. "? (foldclosed(v:lnum) == -1" -- currently open?
+  .. '? ""' -- point down
+  .. ': ""' -- point to right
+  .. ")"
+  .. ': " "' -- blank for no fold, or inside fold
+  .. "}"
+  .. " "
+
+local ftMap = {
+  vim = "indent",
+  python = { "indent" },
+  git = "",
+}
+
+---@param bufnr number
+---@return Promise
+local function customizeSelector(bufnr)
+  local function handleFallbackException(err, providerName)
+    if type(err) == "string" and err:match("UfoFallbackException") then
+      return require("ufo").getFolds(bufnr, providerName)
+    else
+      return require("promise").reject(err)
+    end
+  end
+
+  return require("ufo")
+    .getFolds(bufnr, "lsp")
+    :catch(function(err)
+      return handleFallbackException(err, "treesitter")
+    end)
+    :catch(function(err)
+      return handleFallbackException(err, "indent")
+    end)
+end
+
+local handler = function(virtText, lnum, endLnum, width, truncate)
+  local newVirtText = {}
+  local suffix = ("  %d "):format(endLnum - lnum)
+  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
+  table.insert(newVirtText, { suffix, "MoreMsg" })
+  return newVirtText
+end
+
+require("ufo").setup({
+  provider_selector = function(_, filetype, _)
+    return ftMap[filetype] or customizeSelector
+  end,
+  fold_virt_text_handler = handler,
+})
+
+-- Using ufo provider need remap `zR` and `zM`. If Neovim is 0.6.1, remap yourself
+require("which-key").register({
+  z = {
+    R = { require("ufo").openAllFolds, "Open all folds" },
+    M = { require("ufo").closeAllFolds, "Close all folds" },
+  },
+})