feat: added highlight for open but unloaded files (#856)

Author: nhat-vo

lua/neo-tree/defaults.lua

@@ -213,7 +213,10 @@ local config = {
     },
     name = {
       trailing_slash = false,
-      highlight_opened_files = false, -- Requires `enable_opened_markers = true`
+      highlight_opened_files = false, -- Requires `enable_opened_markers = true`. 
+                                      -- Take values in { false (no highlight), true (only loaded), 
+                                      -- "all" (both loaded and unloaded)}. For more information,
+                                      -- see the `show_unloaded` config of the `buffers` source.
       use_git_status_colors = true,
       highlight = "NeoTreeFileName",
     },
@@ -473,7 +476,9 @@ local config = {
     bind_to_cwd = true,
     follow_current_file = true, -- This will find and focus the file in the active buffer every time
                                 -- the current file is changed while the tree is open.
-    group_empty_dirs = true, -- when true, empty directories will be grouped together
+    group_empty_dirs = true,  -- when true, empty directories will be grouped together
+    show_unloaded = false,    -- When working with sessions, for example, restored but unfocused buffers
+                              -- are mark as "unloaded". Turn this on to view these unloaded buffer.
     window = {
       mappings = {
         ["<bs>"] = "navigate_up",

lua/neo-tree/sources/common/components.lua

@@ -328,9 +328,13 @@ M.name = function(config, node, state)
     end
   end
 
-  if config.highlight_opened_files then
+  local hl_opened = config.highlight_opened_files
+  if hl_opened then
     local opened_buffers = state.opened_buffers or {}
-    if opened_buffers[node.path] ~= nil then
+    if
+      (hl_opened == "all" and opened_buffers[node.path])
+      or (opened_buffers[node.path] and opened_buffers[node.path].loaded)
+    then
       highlight = highlights.FILE_NAME_OPENED
     end
   end

lua/neo-tree/utils.lua

@@ -257,13 +257,14 @@ end
 M.get_opened_buffers = function()
   local opened_buffers = {}
   for _, buffer in ipairs(vim.api.nvim_list_bufs()) do
-    if vim.api.nvim_buf_is_loaded(buffer) and vim.fn.buflisted(buffer) then
+    if vim.fn.buflisted(buffer) ~= 0 then
       local buffer_name = vim.api.nvim_buf_get_name(buffer)
       if buffer_name == nil or buffer_name == "" then
         buffer_name = "[No Name]#" .. buffer
       end
       opened_buffers[buffer_name] = {
         ["modified"] = vim.api.nvim_buf_get_option(buffer, "modified"),
+        ["loaded"] = vim.api.nvim_buf_is_loaded(buffer),
       }
     end
   end