feat(nvim): improve ufo

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" },
+  },
+})