feat: highlight groups for hidden files (#459)

* feat: hidden highlights

* feat: OilHidden for hidden highlights instead of Comment

* fix: add the new combinatoric highlight groups

* perf: get rid of a call to is_hidden_file

* fix: tweak the default highlight group links

* fix: update function call in unit tests

---------

Co-authored-by: Steven Arcangeli <stevearc@stevearc.com>

doc/oil.txt

@@ -607,30 +607,54 @@ yank_entry                                                    *actions.yank_entr
 --------------------------------------------------------------------------------
 HIGHLIGHTS                                                        *oil-highlights*
 
+OilHidden                                                           *hl-OilHidden*
+    Hidden entry in an oil buffer
+
 OilDir                                                                 *hl-OilDir*
     Directory names in an oil buffer
 
+OilDirHidden                                                     *hl-OilDirHidden*
+    Hidden directory names in an oil buffer
+
 OilDirIcon                                                         *hl-OilDirIcon*
     Icon for directories
 
 OilSocket                                                           *hl-OilSocket*
     Socket files in an oil buffer
 
+OilSocketHidden                                               *hl-OilSocketHidden*
+    Hidden socket files in an oil buffer
+
 OilLink                                                               *hl-OilLink*
     Soft links in an oil buffer
 
 OilOrphanLink                                                   *hl-OilOrphanLink*
     Orphaned soft links in an oil buffer
 
+OilLinkHidden                                                   *hl-OilLinkHidden*
+    Hidden soft links in an oil buffer
+
+OilOrphanLinkHidden                                       *hl-OilOrphanLinkHidden*
+    Hidden orphaned soft links in an oil buffer
+
 OilLinkTarget                                                   *hl-OilLinkTarget*
     The target of a soft link
 
 OilOrphanLinkTarget                                       *hl-OilOrphanLinkTarget*
     The target of an orphaned soft link
 
+OilLinkTargetHidden                                       *hl-OilLinkTargetHidden*
+    The target of a hidden soft link
+
+OilOrphanLinkTargetHidden                           *hl-OilOrphanLinkTargetHidden*
+    The target of an hidden orphaned soft link
+
 OilFile                                                               *hl-OilFile*
     Normal files in an oil buffer
 
+OilFileHidden                                                   *hl-OilFileHidden*
+    Hidden normal files in an oil buffer
+
 OilCreate                                                           *hl-OilCreate*
     Create action in the oil preview window
 

lua/oil/init.lua

@@ -796,11 +796,21 @@ end
 ---@private
 M._get_highlights = function()
   return {
+    {
+      name = "OilHidden",
+      link = "Comment",
+      desc = "Hidden entry in an oil buffer",
+    },
     {
       name = "OilDir",
       link = "Directory",
       desc = "Directory names in an oil buffer",
     },
+    {
+      name = "OilDirHidden",
+      link = "OilHidden",
+      desc = "Hidden directory names in an oil buffer",
+    },
     {
       name = "OilDirIcon",
       link = "OilDir",
@@ -811,6 +821,11 @@ M._get_highlights = function()
       link = "Keyword",
       desc = "Socket files in an oil buffer",
     },
+    {
+      name = "OilSocketHidden",
+      link = "OilHidden",
+      desc = "Hidden socket files in an oil buffer",
+    },
     {
       name = "OilLink",
       link = nil,
@@ -821,6 +836,16 @@ M._get_highlights = function()
       link = nil,
       desc = "Orphaned soft links in an oil buffer",
     },
+    {
+      name = "OilLinkHidden",
+      link = "OilHidden",
+      desc = "Hidden soft links in an oil buffer",
+    },
+    {
+      name = "OilOrphanLinkHidden",
+      link = "OilLinkHidden",
+      desc = "Hidden orphaned soft links in an oil buffer",
+    },
     {
       name = "OilLinkTarget",
       link = "Comment",
@@ -831,11 +856,26 @@ M._get_highlights = function()
       link = "DiagnosticError",
       desc = "The target of an orphaned soft link",
     },
+    {
+      name = "OilLinkTargetHidden",
+      link = "OilHidden",
+      desc = "The target of a hidden soft link",
+    },
+    {
+      name = "OilOrphanLinkTargetHidden",
+      link = "OilOrphanLinkTarget",
+      desc = "The target of an hidden orphaned soft link",
+    },
     {
       name = "OilFile",
       link = nil,
       desc = "Normal files in an oil buffer",
     },
+    {
+      name = "OilFileHidden",
+      link = "OilHidden",
+      desc = "Hidden normal files in an oil buffer",
+    },
     {
       name = "OilCreate",
       link = "DiagnosticInfo",

lua/oil/view.lua

@@ -19,10 +19,16 @@ local last_cursor_entry = {}
 
 ---@param name string
 ---@param bufnr integer
----@return boolean
+---@return boolean display
+---@return boolean is_hidden Whether the file is classified as a hidden file
 M.should_display = function(name, bufnr)
-  return not config.view_options.is_always_hidden(name, bufnr)
+  if config.view_options.is_always_hidden(name, bufnr) then
-    and (config.view_options.show_hidden or not config.view_options.is_hidden_file(name, bufnr))
+    return false, true
+  else
+    local is_hidden = config.view_options.is_hidden_file(name, bufnr)
+    local display = config.view_options.show_hidden or not is_hidden
+    return display, is_hidden
+  end
 end
 
 ---@param bufname string
@@ -633,13 +639,15 @@ local function render_buffer(bufnr, opts)
   end
 
   if M.should_display("..", bufnr) then
-    local cols = M.format_entry_cols({ 0, "..", "directory" }, column_defs, col_width, adapter)
+    local cols =
+      M.format_entry_cols({ 0, "..", "directory" }, column_defs, col_width, adapter, true)
     table.insert(line_table, cols)
   end
 
   for _, entry in ipairs(entry_list) do
-    if M.should_display(entry[FIELD_NAME], bufnr) then
+    local should_display, is_hidden = M.should_display(entry[FIELD_NAME], bufnr)
-      local cols = M.format_entry_cols(entry, column_defs, col_width, adapter)
+    if should_display then
+      local cols = M.format_entry_cols(entry, column_defs, col_width, adapter, is_hidden)
       table.insert(line_table, cols)
 
       local name = entry[FIELD_NAME]
@@ -688,10 +696,15 @@ end
 ---@param column_defs table[]
 ---@param col_width integer[]
 ---@param adapter oil.Adapter
+---@param is_hidden boolean
 ---@return oil.TextChunk[]
-M.format_entry_cols = function(entry, column_defs, col_width, adapter)
+M.format_entry_cols = function(entry, column_defs, col_width, adapter, is_hidden)
   local name = entry[FIELD_NAME]
   local meta = entry[FIELD_META]
+  local hl_suffix = ""
+  if is_hidden then
+    hl_suffix = "Hidden"
+  end
   if meta and meta.display_name then
     name = meta.display_name
   end
@@ -711,9 +724,9 @@ M.format_entry_cols = function(entry, column_defs, col_width, adapter)
   -- Always add the entry name at the end
   local entry_type = entry[FIELD_TYPE]
   if entry_type == "directory" then
-    table.insert(cols, { name .. "/", "OilDir" })
+    table.insert(cols, { name .. "/", "OilDir" .. hl_suffix })
   elseif entry_type == "socket" then
-    table.insert(cols, { name, "OilSocket" })
+    table.insert(cols, { name, "OilSocket" .. hl_suffix })
   elseif entry_type == "link" then
     local link_text
     if meta then
@@ -722,7 +735,7 @@ M.format_entry_cols = function(entry, column_defs, col_width, adapter)
       end
 
       if meta.link then
-        link_text = "->" .. " " .. meta.link
+        link_text = "-> " .. meta.link
         if meta.link_stat and meta.link_stat.type == "directory" then
           link_text = util.addslash(link_text)
         end
@@ -730,12 +743,13 @@ M.format_entry_cols = function(entry, column_defs, col_width, adapter)
     end
     local is_orphan = not (meta and meta.link_stat)
 
-    table.insert(cols, { name, is_orphan and "OilOrphanLink" or "OilLink" })
+    table.insert(cols, { name, (is_orphan and "OilOrphanLink" or "OilLink") .. hl_suffix })
     if link_text then
-      table.insert(cols, { link_text, is_orphan and "OilOrphanLinkTarget" or "OilLinkTarget" })
+      local target_hl = (is_orphan and "OilOrphanLinkTarget" or "OilLinkTarget") .. hl_suffix
+      table.insert(cols, { link_text, target_hl })
     end
   else
-    table.insert(cols, { name, "OilFile" })
+    table.insert(cols, { name, "OilFile" .. hl_suffix })
   end
   return cols
 end

tests/parser_spec.lua

@@ -90,7 +90,7 @@ describe("parser", function()
     local file = test_adapter.test_set("/foo/a.txt", "file")
     vim.cmd.edit({ args = { "oil-test:///foo/" } })
     local bufnr = vim.api.nvim_get_current_buf()
-    local cols = view.format_entry_cols(file, {}, {}, test_adapter)
+    local cols = view.format_entry_cols(file, {}, {}, test_adapter, false)
     local lines = util.render_table({ cols }, {})
     table.insert(lines, "")
     table.insert(lines, "     ")