feat(bookmarks): add bookmark feature for nodes

Uses the signcolum to display the mark status.
Marks are saved in memory for now, we'll see if we want to implement a
filesystem save for the marks (would not be hard).
Added `m` keybinding to toggle the mark on the node.
Users can call `require "nvim-tree.marks".get_marks()` which returns a
list of absolute paths.

Author: kyazdani42

doc/nvim-tree-lua.txt

@@ -220,6 +220,7 @@ Subsequent calls to setup will replace the previous configuration.
           glyphs = {
             default = "",
             symlink = "",
+            bookmark = "",
             folder = {
               arrow_closed = "",
               arrow_open = "",
@@ -1012,6 +1013,7 @@ DEFAULT MAPPINGS                                     *nvim-tree-default-mappings
 `.`               run_file_command    enter vim command mode with the file the cursor is on
 `<C-k>`           toggle_file_info    toggle a popup with file infos about the file under the cursor
 `g?`              toggle_help         toggle help
+`m`               toggle_mark         Toggle node in bookmarks
 
 >
   view.mappings.list = { -- BEGIN_DEFAULT_MAPPINGS
@@ -1059,6 +1061,7 @@ DEFAULT MAPPINGS                                     *nvim-tree-default-mappings
     { key = ".",                              action = "run_file_command" }
     { key = "<C-k>",                          action = "toggle_file_info" }
     { key = "g?",                             action = "toggle_help" }
+    { key = "m",                              action = "toggle_mark" }
   } -- END_DEFAULT_MAPPINGS
 <
 ==============================================================================
@@ -1130,6 +1133,11 @@ There are 2 highlight groups for the live filter feature
 NvimTreeLiveFilterPrefix
 NvimTreeLiveFilterValue
 
+Color of the bookmark icon
+
+NvimTreeBookmark
+
+
 ==============================================================================
  7. EVENTS                                                  *nvim-tree-events*
 

lua/nvim-tree.lua

@@ -469,6 +469,7 @@ local DEFAULT_OPTS = { -- BEGIN_DEFAULT_OPTS
       glyphs = {
         default = "",
         symlink = "",
+        bookmark = "",
         folder = {
           arrow_closed = "",
           arrow_open = "",
@@ -674,6 +675,7 @@ function M.setup(conf)
   require("nvim-tree.lib").setup(opts)
   require("nvim-tree.renderer").setup(opts)
   require("nvim-tree.live-filter").setup(opts)
+  require("nvim-tree.marks").setup(opts)
   if M.config.renderer.icons.show.file and pcall(require, "nvim-web-devicons") then
     require("nvim-web-devicons").setup()
   end

lua/nvim-tree/actions/dispatch.lua

@@ -45,6 +45,7 @@ local Actions = {
   run_file_command = require("nvim-tree.actions.node.run-command").run_file_command,
   toggle_file_info = require("nvim-tree.actions.node.file-popup").toggle_file_info,
   system_open = require("nvim-tree.actions.node.system-open").fn,
+  toggle_mark = require("nvim-tree.marks").toggle_mark,
 }
 
 local function handle_action_on_help_ui(action)

lua/nvim-tree/actions/init.lua

@@ -227,6 +227,11 @@ local DEFAULT_MAPPINGS = {
     action = "toggle_help",
     desc = "toggle help",
   },
+  {
+    key = "m",
+    action = "toggle_mark",
+    desc = "Toggle node in bookmarks",
+  },
 }
 -- END_DEFAULT_MAPPINGS
 

lua/nvim-tree/colors.lua

@@ -53,6 +53,8 @@ local function get_hl_groups()
     WindowPicker = { gui = "bold", fg = "#ededed", bg = "#4493c8" },
     LiveFilterPrefix = { gui = "bold", fg = colors.purple },
     LiveFilterValue = { gui = "bold", fg = "#fff" },
+
+    Bookmark = { fg = colors.green },
   }
 end
 

lua/nvim-tree/iterators/node-iterator.lua

@@ -38,27 +38,25 @@ function NodeIterator:recursor(f)
 end
 
 function NodeIterator:iterate()
+  local iteration_count = 0
   local function iter(nodes)
-    local i = 1
     for _, node in ipairs(nodes) do
       if self._filter_hidden(node) then
+        iteration_count = iteration_count + 1
         if self._match(node) then
-          return node, i
+          return node, iteration_count
         end
-        self._apply_fn_on_node(node)
+        self._apply_fn_on_node(node, iteration_count)
         local children = self._recurse_with(node)
         if children then
-          local n, idx = iter(children)
-          i = i + idx
+          local n = iter(children)
           if n then
-            return n, i
+            return n, iteration_count
           end
-        else
-          i = i + 1
         end
       end
     end
-    return nil, i
+    return nil, 0
   end
 
   return iter(self.nodes)

lua/nvim-tree/marks.lua

@@ -0,0 +1,70 @@
+local view = require "nvim-tree.view"
+local Iterator = require "nvim-tree.iterators.node-iterator"
+local core = require "nvim-tree.core"
+
+local NvimTreeMarks = {}
+
+local M = {}
+
+local function add_mark(node)
+  NvimTreeMarks[node.absolute_path] = true
+  M.draw()
+end
+
+local function remove_mark(node)
+  NvimTreeMarks[node.absolute_path] = nil
+  M.draw()
+end
+
+function M.toggle_mark(node)
+  if M.get_mark(node) then
+    remove_mark(node)
+  else
+    add_mark(node)
+  end
+end
+
+function M.get_mark(node)
+  return NvimTreeMarks[node.absolute_path]
+end
+
+function M.get_marks()
+  local list = {}
+  for k in pairs(NvimTreeMarks) do
+    table.insert(list, k)
+  end
+  return list
+end
+
+local GROUP = "NvimTreeMarkSigns"
+local SIGN_NAME = "NvimTreeMark"
+
+function M.clear()
+  vim.fn.sign_unplace(GROUP)
+end
+
+function M.draw()
+  if not view.is_visible() then
+    return
+  end
+
+  M.clear()
+
+  local buf = view.get_bufnr()
+  Iterator.builder(core.get_explorer().nodes)
+    :recursor(function(node)
+      return node.open and node.nodes
+    end)
+    :applier(function(node, idx)
+      if M.get_mark(node) then
+        vim.fn.sign_place(0, GROUP, SIGN_NAME, buf, { lnum = idx + 1, priority = 3 })
+      end
+    end)
+    :iterate()
+end
+
+function M.setup(opts)
+  vim.fn.sign_define(SIGN_NAME, { text = opts.renderer.icons.glyphs.bookmark, texthl = "NvimTreeBookmark" })
+end
+
+return M

lua/nvim-tree/renderer/init.lua

@@ -10,6 +10,7 @@ local help = require "nvim-tree.renderer.help"
 local git = require "nvim-tree.renderer.components.git"
 local Builder = require "nvim-tree.renderer.builder"
 local live_filter = require "nvim-tree.live-filter"
+local marks = require "nvim-tree.marks"
 
 local api = vim.api
 
@@ -88,8 +89,10 @@ function M.draw()
 
   if view.is_help_ui() then
     diagnostics.clear()
+    marks.clear()
   else
     diagnostics.update()
+    marks.draw()
   end
 
   view.grow_from_content()