feat(#2948): add custom decorators, :help nvim-tree-decorators (#2996)

* feat(#2948): add UserDecorator, proof of concept

* feat(#2948): add UserDecorator, proof of concept

* feat(#2948): add UserDecorator, proof of concept

* feat(#2948): add UserDecorator

* feat(#2948): add UserDecorator

* feat(#2948): add UserDecorator

* feat(#2948): add Decorator node icon override

* feat(#2948): add nvim_tree.api.* node classes

* feat(#2948): extract _meta following nvim pattern

* feat(#2948): extract _meta following nvim pattern

* feat(#2948): add decorator registry and order

* feat(#2948): add decorator registry and order

* feat(#2948): tidy

* feat(#2948): document API

* feat(#2948): document API

* feat(#2948): document API

* feat(#2948): pass api nodes to user decorators

* feat(#2948): document API

* feat(#2948): use renderer.decorators to define order and register

* feat(#2948): tidy decorator args and complete documentation

* feat(#2948): decorator classes specified by prefix rather than suffix

* feat(#2948): improve doc

* feat(#2948): improve doc

* feat(#2948): improve doc

* feat(#2948): additional user decorator safety

* feat(#2948): create nvim_tree.api.decorator.UserDecorator class in API, add :extend

* feat(#2948): improve doc

Makefile

@@ -13,7 +13,7 @@ check: luals
 # subtasks
 #
 luacheck:
-	luacheck -q lua
+	luacheck --codes --quiet lua --exclude-files "**/_meta/**"
 
 # --diagnosis-as-error does not function for workspace, hence we post-process the output
 style-check:

doc/nvim-tree-lua.txt

@@ -52,14 +52,16 @@ CONTENTS                                                           *nvim-tree*
   8.2  Highlight: Overhaul                      |nvim-tree-highlight-overhaul|
   9. Events                                   |nvim-tree-events|
  10. Prompts                                  |nvim-tree-prompts|
- 11. OS Specific Restrictions                 |nvim-tree-os-specific|
+ 11. Decorators                               |nvim-tree-decorators|
- 12. Netrw                                    |nvim-tree-netrw|
+ 11.1  Decorator Example                        |nvim-tree-decorator-example|
- 13. Legacy                                   |nvim-tree-legacy|
+ 12. OS Specific Restrictions                 |nvim-tree-os-specific|
- 13.1  Legacy: Opts                             |nvim-tree-legacy-opts|
+ 13. Netrw                                    |nvim-tree-netrw|
- 13.2  Legacy: Highlight                        |nvim-tree-legacy-highlight|
+ 14. Legacy                                   |nvim-tree-legacy|
- 14. Index                                    |nvim-tree-index|
+ 14.1  Legacy: Opts                             |nvim-tree-legacy-opts|
- 14.1  Index: Opts                              |nvim-tree-index-opts|
+ 14.2  Legacy: Highlight                        |nvim-tree-legacy-highlight|
- 14.2  Index: API                               |nvim-tree-index-api|
+ 15. Index                                    |nvim-tree-index|
+ 15.1  Index: Opts                              |nvim-tree-index-opts|
+ 15.2  Index: API                               |nvim-tree-index-api|
 
 ==============================================================================
  1. INTRODUCTION                                      *nvim-tree-introduction*
@@ -425,6 +427,7 @@ Following is the default configuration. See |nvim-tree-opts| for details. >lua
         special_files = { "Cargo.toml", "Makefile", "README.md", "readme.md" },
         hidden_display = "none",
         symlink_destination = true,
+        decorators = { "Git", "Open", "Hidden", "Modified", "Bookmark", "Diagnostics", "Copied", "Cut", },
         highlight_git = "none",
         highlight_diagnostics = "none",
         highlight_opened_files = "none",
@@ -842,9 +845,6 @@ Use nvim-tree in a floating window.
 ==============================================================================
  5.3 OPTS: RENDERER                                  *nvim-tree-opts-renderer*
 
-Highlight precedence, additive:
-  git < opened < modified < bookmarked < diagnostics < copied < cut
-
 *nvim-tree.renderer.add_trailing*
 Appends a trailing slash to folder names.
   Type: `boolean`, Default: `false`
@@ -927,6 +927,22 @@ Show a summary of hidden files below the tree using `NvimTreeHiddenDisplay
 Whether to show the destination of the symlink.
   Type: `boolean`, Default: `true`
 
+*nvim-tree.renderer.decorators*
+Highlighting and icons for the nodes, in increasing order of precedence.
+Uses strings to specify builtin decorators otherwise specify your
+`nvim_tree.api.decorator.UserDecorator` class.
+  Type: `nvim_tree.api.decorator.Name[]`, Default: >lua
+    {
+      "Git",
+      "Open",
+      "Hidden",
+      "Modified",
+      "Bookmark",
+      "Diagnostics",
+      "Copied",
+      "Cut",
+    }
+<
 *nvim-tree.renderer.highlight_git*
 Enable highlight for git attributes using `NvimTreeGit*HL` highlight groups.
 Requires |nvim-tree.git.enable|
@@ -996,9 +1012,6 @@ Configuration options for tree indent markers.
 *nvim-tree.renderer.icons*
 Configuration options for icons.
 
-Icon order and sign column precedence:
-  git < hidden < modified < bookmarked < diagnostics
-
 `renderer.icons.*_placement` options may be:
 - `"before"` : before file/folder, after the file/folders icons
 - `"after"` : after file/folder
@@ -2755,7 +2768,90 @@ configurations for different types of prompts.
     send all bookmarked to trash during |nvim-tree-api.marks.bulk.trash()|
 
 ==============================================================================
- 11. OS SPECIFIC RESTRICTIONS                          *nvim-tree-os-specific*
+ 11. DECORATORS                                         *nvim-tree-decorators*
+
+Highlighting and icons for nodes are provided by Decorators. You may provide
+your own in addition to the builtin decorators.
+
+Decorators may:
+- Add icons
+- Set highlight group for the name or icons
+- Override node icon
+
+Specify decorators and their precedence via |nvim-tree.renderer.decorators|
+e.g. defaults with a user decorator class being overridden only by Cut: >lua
+  {
+    "Git",
+    "Open",
+    "Hidden",
+    "Modified",
+    "Bookmark",
+    "Diagnostics",
+    "Copied",
+    MyDecorator,
+    "Cut",
+  }
+
+See `nvim-tree/_meta/api_decorator.lua` for full
+`nvim_tree.api.decorator.UserDecorator` class documentation.
+<
+==============================================================================
+ 11.1. DECORATOR EXAMPLE                         *nvim-tree-decorator-example*
+>lua
+  ---Create your decorator class
+  ---@class (exact) MyDecorator: nvim_tree.api.decorator.UserDecorator
+  ---@field private my_icon nvim_tree.api.HighlightedString
+  local MyDecorator = require("nvim-tree.api").decorator.UserDecorator:extend()
+
+  ---Mandatory constructor  :new()  will be called once per tree render, with no arguments.
+  function MyDecorator:new()
+    self.enabled         = true
+    self.highlight_range = "all"
+    self.icon_placement  = "signcolumn"
+
+    -- create your icon once, for convenience
+    self.my_icon         = { str = "I", hl = { "MyIcon" } }
+
+    -- Define the icon sign only once
+    -- Only needed if you are using icon_placement = "signcolumn"
+    self:define_sign(self.my_icon)
+  end
+
+  ---Override node icon
+  ---@param node nvim_tree.api.Node
+  ---@return nvim_tree.api.HighlightedString? icon_node
+  function MyDecorator:icon_node(node)
+    if node.name == "example" then
+      return self.my_icon
+    else
+      return nil
+    end
+  end
+
+  ---Return one icon for DecoratorIconPlacement
+  ---@param node nvim_tree.api.Node
+  ---@return nvim_tree.api.HighlightedString[]? icons
+  function MyDecorator:icons(node)
+    if node.name == "example" then
+      return { self.my_icon }
+    else
+      return nil
+    end
+  end
+
+  ---Exactly one highlight group for DecoratorHighlightRange
+  ---@param node nvim_tree.api.Node
+  ---@return string? highlight_group
+  function MyDecorator:highlight_group(node)
+    if node.name == "example" then
+      return "MyHighlight"
+    else
+      return nil
+    end
+  end
+<
+==============================================================================
+ 12. OS SPECIFIC RESTRICTIONS                          *nvim-tree-os-specific*
 
 Windows WSL and PowerShell
 - Trash is synchronized
@@ -2767,7 +2863,7 @@ Windows WSL and PowerShell
   issues or disable this feature.
 
 ==============================================================================
- 12. NETRW                                                   *nvim-tree-netrw*
+ 13. NETRW                                                   *nvim-tree-netrw*
 
 |netrw| is a standard neovim plugin that is enabled by default. It provides,
 amongst other functionality, a file/directory browser.
@@ -2788,14 +2884,14 @@ keep using |netrw| without its browser features please ensure:
 |nvim-tree.hijack_netrw| ` = true`
 
 ==============================================================================
- 13. LEGACY                                                 *nvim-tree-legacy*
+ 14. LEGACY                                                 *nvim-tree-legacy*
 
 Breaking refactors have been made however the legacy versions will be silently
 migrated and used.
 There are no plans to remove this migration.
 
 ==============================================================================
- 13.1 LEGACY: OPTS                                     *nvim-tree-legacy-opts*
+ 14.1 LEGACY: OPTS                                     *nvim-tree-legacy-opts*
 
 Legacy options are translated to the current, making type and value changes as
 needed.
@@ -2813,7 +2909,7 @@ needed.
 `renderer.icons.webdev_colors`       |nvim-tree.renderer.icons.web_devicons.file.color|
 
 ==============================================================================
- 13.2 LEGACY: HIGHLIGHT                           *nvim-tree-legacy-highlight*
+ 14.2 LEGACY: HIGHLIGHT                           *nvim-tree-legacy-highlight*
 
 Legacy highlight group are still obeyed when they are defined and the current
 highlight group is not, hard linking as follows: >
@@ -2862,10 +2958,10 @@ highlight group is not, hard linking as follows: >
     NvimTreeLspDiagnosticsHintFolderText        NvimTreeDiagnosticHintFolderHL
 <
 ==============================================================================
- 14 INDEX                                                    *nvim-tree-index*
+ 15 INDEX                                                    *nvim-tree-index*
 
 ==============================================================================
- 14.1 INDEX: OPTS                                       *nvim-tree-index-opts*
+ 15.1 INDEX: OPTS                                       *nvim-tree-index-opts*
 
 |nvim-tree.actions.change_dir|
 |nvim-tree.actions.change_dir.enable|
@@ -2943,6 +3039,7 @@ highlight group is not, hard linking as follows: >
 |nvim-tree.prefer_startup_root|
 |nvim-tree.reload_on_bufenter|
 |nvim-tree.renderer.add_trailing|
+|nvim-tree.renderer.decorators|
 |nvim-tree.renderer.full_name|
 |nvim-tree.renderer.group_empty|
 |nvim-tree.renderer.hidden_display|
@@ -3033,7 +3130,7 @@ highlight group is not, hard linking as follows: >
 |nvim-tree.view.width.padding|
 
 ==============================================================================
- 14.2 INDEX: API                                         *nvim-tree-index-api*
+ 15.2 INDEX: API                                         *nvim-tree-index-api*
 
 |nvim-tree-api.commands.get()|
 |nvim-tree-api.config.mappings.default_on_attach()|

lua/nvim-tree.lua

@@ -284,6 +284,7 @@ local DEFAULT_OPTS = { -- BEGIN_DEFAULT_OPTS
     special_files = { "Cargo.toml", "Makefile", "README.md", "readme.md" },
     hidden_display = "none",
     symlink_destination = true,
+    decorators = { "Git", "Open", "Hidden", "Modified", "Bookmark", "Diagnostics", "Copied", "Cut", },
     highlight_git = "none",
     highlight_diagnostics = "none",
     highlight_opened_files = "none",

lua/nvim-tree/_meta/api.lua

@@ -0,0 +1,51 @@
+---@meta
+error("Cannot require a meta file")
+
+--
+-- Nodes
+--
+
+---Base Node, Abstract
+---@class (exact) nvim_tree.api.Node
+---@field type "file" | "directory" | "link" uv.fs_stat.result.type
+---@field absolute_path string
+---@field executable boolean
+---@field fs_stat uv.fs_stat.result?
+---@field git_status GitNodeStatus?
+---@field hidden boolean
+---@field name string
+---@field parent nvim_tree.api.DirectoryNode?
+---@field diag_severity lsp.DiagnosticSeverity?
+
+---File
+---@class (exact) nvim_tree.api.FileNode: nvim_tree.api.Node
+---@field extension string
+
+---Directory
+---@class (exact) nvim_tree.api.DirectoryNode: nvim_tree.api.Node
+---@field has_children boolean
+---@field nodes nvim_tree.api.Node[]
+---@field open boolean
+
+---Root Directory
+---@class (exact) nvim_tree.api.RootNode: nvim_tree.api.DirectoryNode
+
+---Link mixin
+---@class (exact) nvim_tree.api.LinkNode
+---@field link_to string
+---@field fs_stat_target uv.fs_stat.result
+
+---File Link
+---@class (exact) nvim_tree.api.FileLinkNode: nvim_tree.api.FileNode, nvim_tree.api.LinkNode
+
+---DirectoryLink
+---@class (exact) nvim_tree.api.DirectoryLinkNode: nvim_tree.api.DirectoryNode, nvim_tree.api.LinkNode
+
+--
+-- Various Types
+--
+
+---A string for rendering, with optional highlight groups to apply to it
+---@class (exact) nvim_tree.api.HighlightedString
+---@field str string
+---@field hl string[]

lua/nvim-tree/_meta/api_decorator.lua

@@ -0,0 +1,54 @@
+---@meta
+error("Cannot require a meta file")
+
+local nvim_tree = { api = { decorator = {} } }
+
+---Highlight group range as per nvim-tree.renderer.highlight_*
+---@alias nvim_tree.api.decorator.HighlightRange "none" | "icon" | "name" | "all"
+
+---Icon position as per renderer.icons.*_placement
+---@alias nvim_tree.api.decorator.IconPlacement "none" | "before" | "after" | "signcolumn" | "right_align"
+
+---Names of builtin decorators or your decorator classes. Builtins are ordered lowest to highest priority.
+---@alias nvim_tree.api.decorator.Name "Git" | "Opened" | "Hidden" | "Modified" | "Bookmarks" | "Diagnostics" | "Copied" | "Cut" | nvim_tree.api.decorator.UserDecorator
+
+---Custom decorator, see :help nvim-tree-decorators
+---
+---@class (exact) nvim_tree.api.decorator.UserDecorator
+---@field protected enabled boolean
+---@field protected highlight_range nvim_tree.api.decorator.HighlightRange
+---@field protected icon_placement nvim_tree.api.decorator.IconPlacement
+nvim_tree.api.decorator.UserDecorator = {}
+
+---Create your decorator class
+---
+function nvim_tree.api.decorator.UserDecorator:extend() end
+
+---Abstract: no-args constructor must be implemented and will be called once per tree render.
+---Must set all fields.
+---
+function nvim_tree.api.decorator.UserDecorator:new() end
+
+---Abstract: optionally implement to set the node's icon
+---
+---@param node nvim_tree.api.Node
+---@return nvim_tree.api.HighlightedString? icon_node
+function nvim_tree.api.decorator.UserDecorator:icon_node(node) end
+
+---Abstract: optionally implement to provide icons and the highlight groups for your icon_placement.
+---
+---@param node nvim_tree.api.Node
+---@return nvim_tree.api.HighlightedString[]? icons
+function nvim_tree.api.decorator.UserDecorator:icons(node) end
+
+---Abstract: optionally implement to provide one highlight group to apply to your highlight_range.
+---
+---@param node nvim_tree.api.Node
+---@return string? highlight_group
+function nvim_tree.api.decorator.UserDecorator:highlight_group(node) end
+
+---Define a sign. This should be called in the constructor.
+---
+---@protected
+---@param icon nvim_tree.api.HighlightedString?
+function nvim_tree.api.decorator.UserDecorator:define_sign(icon) end

lua/nvim-tree/api.lua

@@ -11,6 +11,7 @@ local notify = require("nvim-tree.notify")
 local DirectoryNode = require("nvim-tree.node.directory")
 local FileLinkNode = require("nvim-tree.node.file-link")
 local RootNode = require("nvim-tree.node.root")
+local UserDecorator = require("nvim-tree.renderer.decorator.user")
 
 local Api = {
   tree = {},
@@ -39,6 +40,7 @@ local Api = {
   },
   commands = {},
   diagnostics = {},
+  decorator = {},
 }
 
 ---Print error when setup not called.
@@ -311,4 +313,9 @@ Api.commands.get = wrap(function()
   return require("nvim-tree.commands").get()
 end)
 
+---Create a decorator class by calling :extend()
+---See :help nvim-tree-decorators
+---@type nvim_tree.api.decorator.UserDecorator
+Api.decorator.UserDecorator = UserDecorator --[[@as nvim_tree.api.decorator.UserDecorator]]
+
 return Api

lua/nvim-tree/explorer/init.lua

@@ -530,7 +530,7 @@ function Explorer:place_cursor_on_node()
 end
 
 ---Api.tree.get_nodes
----@return Node
+---@return nvim_tree.api.Node
 function Explorer:get_nodes()
   return self:clone()
 end

lua/nvim-tree/node/directory-link.lua

@@ -73,9 +73,10 @@ function DirectoryLinkNode:highlighted_name()
 end
 
 ---Create a sanitized partial copy of a node, populating children recursively.
----@return DirectoryLinkNode cloned
+---@param api_nodes table<number, nvim_tree.api.Node>? optional map of uids to api node to populate
-function DirectoryLinkNode:clone()
+---@return nvim_tree.api.DirectoryLinkNode cloned
-  local clone = DirectoryNode.clone(self) --[[@as DirectoryLinkNode]]
+function DirectoryLinkNode:clone(api_nodes)
+  local clone = DirectoryNode.clone(self, api_nodes) --[[@as nvim_tree.api.DirectoryLinkNode]]
 
   clone.link_to = self.link_to
   clone.fs_stat_target = self.fs_stat_target

lua/nvim-tree/node/directory.lua

@@ -271,18 +271,20 @@ function DirectoryNode:highlighted_name()
 end
 
 ---Create a sanitized partial copy of a node, populating children recursively.
----@return DirectoryNode cloned
+---@param api_nodes table<number, nvim_tree.api.Node>? optional map of uids to api node to populate
-function DirectoryNode:clone()
+---@return nvim_tree.api.DirectoryNode cloned
-  local clone        = Node.clone(self) --[[@as DirectoryNode]]
+function DirectoryNode:clone(api_nodes)
+  local clone        = Node.clone(self, api_nodes) --[[@as nvim_tree.api.DirectoryNode]]
 
   clone.has_children = self.has_children
-  clone.group_next   = nil
   clone.nodes        = {}
   clone.open         = self.open
-  clone.hidden_stats = nil
 
+  local clone_child
   for _, child in ipairs(self.nodes) do
-    table.insert(clone.nodes, child:clone())
+    clone_child = child:clone(api_nodes)
+    clone_child.parent = clone
+    table.insert(clone.nodes, clone_child)
   end
 
   return clone

lua/nvim-tree/node/file-link.lua

@@ -58,9 +58,10 @@ function FileLinkNode:highlighted_name()
 end
 
 ---Create a sanitized partial copy of a node
----@return FileLinkNode cloned
+---@param api_nodes table<number, nvim_tree.api.Node>? optional map of uids to api node to populate
-function FileLinkNode:clone()
+---@return nvim_tree.api.FileLinkNode cloned
-  local clone = FileNode.clone(self) --[[@as FileLinkNode]]
+function FileLinkNode:clone(api_nodes)
+  local clone = FileNode.clone(self, api_nodes) --[[@as nvim_tree.api.FileLinkNode]]
 
   clone.link_to = self.link_to
   clone.fs_stat_target = self.fs_stat_target

lua/nvim-tree/node/file.lua

@@ -94,9 +94,10 @@ function FileNode:highlighted_name()
 end
 
 ---Create a sanitized partial copy of a node
----@return FileNode cloned
+---@param api_nodes table<number, nvim_tree.api.Node>? optional map of uids to api node to populate
-function FileNode:clone()
+---@return nvim_tree.api.FileNode cloned
-  local clone = Node.clone(self) --[[@as FileNode]]
+function FileNode:clone(api_nodes)
+  local clone = Node.clone(self, api_nodes) --[[@as nvim_tree.api.FileNode]]
 
   clone.extension = self.extension
 

lua/nvim-tree/node/init.lua

@@ -2,6 +2,7 @@ local Class = require("nvim-tree.classic")
 
 ---Abstract Node class.
 ---@class (exact) Node: Class
+---@field uid_node number vim.loop.hrtime() at construction time
 ---@field type "file" | "directory" | "link" uv.fs_stat.result.type
 ---@field explorer Explorer
 ---@field absolute_path string
@@ -25,6 +26,7 @@ local Node = Class:extend()
 ---@protected
 ---@param args NodeArgs
 function Node:new(args)
+  self.uid_node      = vim.loop.hrtime()
   self.explorer      = args.explorer
   self.absolute_path = args.absolute_path
   self.executable    = false
@@ -112,21 +114,19 @@ end
 
 ---Highlighted name for the node
 ---Empty for base Node
----@return HighlightedString icon
+---@return HighlightedString name
 function Node:highlighted_name()
   return self:highlighted_name_empty()
 end
 
 ---Create a sanitized partial copy of a node, populating children recursively.
----@return Node cloned
+---@param api_nodes table<number, nvim_tree.api.Node>? optional map of uids to api node to populate
-function Node:clone()
+---@return nvim_tree.api.Node cloned
-  ---@type Explorer
+function Node:clone(api_nodes)
-  local explorer_placeholder = nil
+  ---@type nvim_tree.api.Node
-
-  ---@type Node
   local clone = {
+    uid_node      = self.uid_node,
     type          = self.type,
-    explorer      = explorer_placeholder,
     absolute_path = self.absolute_path,
     executable    = self.executable,
     fs_stat       = self.fs_stat,
@@ -134,10 +134,13 @@ function Node:clone()
     hidden        = self.hidden,
     name          = self.name,
     parent        = nil,
-    diag_status   = nil,
+    diag_severity = self.diag_status and self.diag_status.value or nil,
-    is_dot        = self.is_dot,
   }
 
+  if api_nodes then
+    api_nodes[self.uid_node] = clone
+  end
+
   return clone
 end
 

lua/nvim-tree/node/link.lua

@@ -2,7 +2,7 @@ local Class = require("nvim-tree.classic")
 
 ---@class (exact) LinkNode: Class
 ---@field link_to string
----@field protected fs_stat_target uv.fs_stat.result
+---@field fs_stat_target uv.fs_stat.result
 local LinkNode = Class:extend()
 
 ---@class (exact) LinkNodeArgs: NodeArgs

lua/nvim-tree/node/root.lua

@@ -22,4 +22,13 @@ function RootNode:destroy()
   DirectoryNode.destroy(self)
 end
 
+---Create a sanitized partial copy of a node, populating children recursively.
+---@param api_nodes table<number, nvim_tree.api.Node>? optional map of uids to api node to populate
+---@return nvim_tree.api.RootNode cloned
+function RootNode:clone(api_nodes)
+  local clone = DirectoryNode.clone(self, api_nodes) --[[@as nvim_tree.api.RootNode]]
+
+  return clone
+end
+
 return RootNode

lua/nvim-tree/renderer/builder.lua

@@ -3,22 +3,35 @@ local utils = require("nvim-tree.utils")
 local view = require("nvim-tree.view")
 
 local Class = require("nvim-tree.classic")
+
 local DirectoryNode = require("nvim-tree.node.directory")
 
-local DecoratorBookmarks = require("nvim-tree.renderer.decorator.bookmarks")
+local BookmarkDecorator = require("nvim-tree.renderer.decorator.bookmarks")
-local DecoratorCopied = require("nvim-tree.renderer.decorator.copied")
+local CopiedDecorator = require("nvim-tree.renderer.decorator.copied")
-local DecoratorCut = require("nvim-tree.renderer.decorator.cut")
+local CutDecorator = require("nvim-tree.renderer.decorator.cut")
-local DecoratorDiagnostics = require("nvim-tree.renderer.decorator.diagnostics")
+local DiagnosticsDecorator = require("nvim-tree.renderer.decorator.diagnostics")
-local DecoratorGit = require("nvim-tree.renderer.decorator.git")
+local GitDecorator = require("nvim-tree.renderer.decorator.git")
-local DecoratorModified = require("nvim-tree.renderer.decorator.modified")
+local HiddenDecorator = require("nvim-tree.renderer.decorator.hidden")
-local DecoratorHidden = require("nvim-tree.renderer.decorator.hidden")
+local ModifiedDecorator = require("nvim-tree.renderer.decorator.modified")
-local DecoratorOpened = require("nvim-tree.renderer.decorator.opened")
+local OpenDecorator = require("nvim-tree.renderer.decorator.opened")
+local UserDecorator = require("nvim-tree.renderer.decorator.user")
 
 local pad = require("nvim-tree.renderer.components.padding")
 
----@class (exact) HighlightedString
+---@alias HighlightedString nvim_tree.api.HighlightedString
----@field str string
+
----@field hl string[]
+-- Builtin Decorators
+---@type table<nvim_tree.api.decorator.Name, Decorator>
+local BUILTIN_DECORATORS = {
+  Git = GitDecorator,
+  Open = OpenDecorator,
+  Hidden = HiddenDecorator,
+  Modified = ModifiedDecorator,
+  Bookmark = BookmarkDecorator,
+  Diagnostics = DiagnosticsDecorator,
+  Copied = CopiedDecorator,
+  Cut = CutDecorator,
+}
 
 ---@class (exact) AddHighlightArgs
 ---@field group string[]
@@ -39,6 +52,7 @@ local pad = require("nvim-tree.renderer.components.padding")
 ---@field private markers boolean[] indent markers
 ---@field private decorators Decorator[]
 ---@field private hidden_display fun(node: Node): string|nil
+---@field private api_nodes table<number, nvim_tree.api.Node>? optional map of uids to api node for user decorators
 local Builder = Class:extend()
 
 ---@class Builder
@@ -60,18 +74,30 @@ function Builder:new(args)
   self.signs           = {}
   self.extmarks        = {}
   self.virtual_lines   = {}
-  self.decorators      = {
+  self.decorators      = {}
-    -- priority order
-    DecoratorCut({ explorer = args.explorer }),
-    DecoratorCopied({ explorer = args.explorer }),
-    DecoratorDiagnostics({ explorer = args.explorer }),
-    DecoratorBookmarks({ explorer = args.explorer }),
-    DecoratorModified({ explorer = args.explorer }),
-    DecoratorHidden({ explorer = args.explorer }),
-    DecoratorOpened({ explorer = args.explorer }),
-    DecoratorGit({ explorer = args.explorer })
-  }
   self.hidden_display  = Builder:setup_hidden_display_function(self.explorer.opts)
+
+  -- instantiate all the builtin and user decorator instances
+  local builtin, user
+  for _, d in ipairs(self.explorer.opts.renderer.decorators) do
+    ---@type Decorator
+    builtin = BUILTIN_DECORATORS[d]
+
+    ---@type UserDecorator
+    user = type(d) == "table" and type(d.as) == "function" and d:as(UserDecorator)
+
+    if builtin then
+      table.insert(self.decorators, builtin({ explorer = self.explorer }))
+    elseif user then
+      table.insert(self.decorators, user())
+
+      -- clone user nodes once
+      if not self.api_nodes then
+        self.api_nodes = {}
+        self.explorer:clone(self.api_nodes)
+      end
+    end
+  end
 end
 
 ---Insert ranged highlight groups into self.highlights
@@ -131,22 +157,25 @@ function Builder:format_line(indent_markers, arrows, icon, name, node)
     end
   end
 
+  -- use the api node for user decorators
+  local api_node = self.api_nodes and self.api_nodes[node.uid_node] --[[@as Node]]
+
   local line = { indent_markers, arrows }
   add_to_end(line, { icon })
 
-  for i = #self.decorators, 1, -1 do
+  for _, d in ipairs(self.decorators) do
-    add_to_end(line, self.decorators[i]:icons_before(node))
+    add_to_end(line, d:icons_before(not d:is(UserDecorator) and node or api_node))
   end
 
   add_to_end(line, { name })
 
-  for i = #self.decorators, 1, -1 do
+  for _, d in ipairs(self.decorators) do
-    add_to_end(line, self.decorators[i]:icons_after(node))
+    add_to_end(line, d:icons_after(not d:is(UserDecorator) and node or api_node))
   end
 
   local rights = {}
-  for i = #self.decorators, 1, -1 do
+  for _, d in ipairs(self.decorators) do
-    add_to_end(rights, self.decorators[i]:icons_right_align(node))
+    add_to_end(rights, d:icons_right_align(not d:is(UserDecorator) and node or api_node))
   end
   if #rights > 0 then
     self.extmarks[self.index] = rights
@@ -158,10 +187,14 @@ end
 ---@private
 ---@param node Node
 function Builder:build_signs(node)
+  -- use the api node for user decorators
+  local api_node = self.api_nodes and self.api_nodes[node.uid_node] --[[@as Node]]
+
   -- first in priority order
-  local sign_name
+  local d, sign_name
-  for _, d in ipairs(self.decorators) do
+  for i = #self.decorators, 1, -1 do
-    sign_name = d:sign_name(node)
+    d = self.decorators[i]
+    sign_name = d:sign_name(not d:is(UserDecorator) and node or api_node)
     if sign_name then
       self.signs[self.index] = sign_name
       break
@@ -197,43 +230,50 @@ function Builder:create_combined_group(groups)
   return combined_name
 end
 
----Calculate highlight group for icon and name. A combined highlight group will be created
+---Calculate decorated icon and name for a node.
----when there is more than one highlight.
+---A combined highlight group will be created when there is more than one highlight.
 ---A highlight group is always calculated and upserted for the case of highlights changing.
 ---@private
 ---@param node Node
----@return string|nil icon_hl_group
+---@return HighlightedString icon
----@return string|nil name_hl_group
+---@return HighlightedString name
-function Builder:add_highlights(node)
+function Builder:icon_name_decorated(node)
-  -- result
+  -- use the api node for user decorators
-  local icon_hl_group, name_hl_group
+  local api_node = self.api_nodes and self.api_nodes[node.uid_node] --[[@as Node]]
 
-  -- calculate all groups
+  -- base case
+  local icon = node:highlighted_icon()
+  local name = node:highlighted_name()
+
+  -- calculate node icon and all decorated highlight groups
   local icon_groups = {}
   local name_groups = {}
-  local d, icon, name
+  local hl_icon, hl_name
-  for i = #self.decorators, 1, -1 do
+  for _, d in ipairs(self.decorators) do
-    d = self.decorators[i]
+    -- maybe overridde icon
-    icon, name = d:groups_icon_name(node)
+    icon = d:icon_node((not d:is(UserDecorator) and node or api_node)) or icon
-    table.insert(icon_groups, icon)
+
-    table.insert(name_groups, name)
+    hl_icon, hl_name = d:highlight_group_icon_name((not d:is(UserDecorator) and node or api_node))
+
+    table.insert(icon_groups, hl_icon)
+    table.insert(name_groups, hl_name)
   end
 
-  -- one or many icon groups
+  -- add one or many icon groups
   if #icon_groups > 1 then
-    icon_hl_group = self:create_combined_group(icon_groups)
+    table.insert(icon.hl, self:create_combined_group(icon_groups))
   else
-    icon_hl_group = icon_groups[1]
+    table.insert(icon.hl, icon_groups[1])
   end
 
-  -- one or many name groups
+  -- add one or many name groups
   if #name_groups > 1 then
-    name_hl_group = self:create_combined_group(name_groups)
+    table.insert(name.hl, self:create_combined_group(name_groups))
   else
-    name_hl_group = name_groups[1]
+    table.insert(name.hl, name_groups[1])
   end
 
-  return icon_hl_group, name_hl_group
+  return icon, name
 end
 
 ---Insert node line into self.lines, calling Builder:build_lines for each directory
@@ -246,13 +286,8 @@ function Builder:build_line(node, idx, num_children)
   local indent_markers = pad.get_indent_markers(self.depth, idx, num_children, node, self.markers)
   local arrows = pad.get_arrows(node)
 
-  -- main components
+  -- decorated node icon and name
-  local icon, name = node:highlighted_icon(), node:highlighted_name()
+  local icon, name = self:icon_name_decorated(node)
-
-  -- highighting
-  local icon_hl_group, name_hl_group = self:add_highlights(node)
-  table.insert(icon.hl, icon_hl_group)
-  table.insert(name.hl, name_hl_group)
 
   local line = self:format_line(indent_markers, arrows, icon, name, node)
   table.insert(self.lines, self:unwrap_highlighted_strings(line))

lua/nvim-tree/renderer/decorator/bookmarks.lua

@@ -1,21 +1,21 @@
 local Decorator = require("nvim-tree.renderer.decorator")
 
----@class (exact) DecoratorBookmarks: Decorator
+---@class (exact) BookmarkDecorator: Decorator
----@field icon HighlightedString?
+---@field private explorer Explorer
-local DecoratorBookmarks = Decorator:extend()
+---@field private icon HighlightedString?
+local BookmarkDecorator = Decorator:extend()
 
----@class DecoratorBookmarks
+---@class BookmarkDecorator
----@overload fun(explorer: DecoratorArgs): DecoratorBookmarks
+---@overload fun(args: DecoratorArgs): BookmarkDecorator
 
 ---@protected
 ---@param args DecoratorArgs
-function DecoratorBookmarks:new(args)
+function BookmarkDecorator:new(args)
-  Decorator.new(self, {
+  self.explorer        = args.explorer
-    explorer       = args.explorer,
+
-    enabled        = true,
+  self.enabled         = true
-    hl_pos         = args.explorer.opts.renderer.highlight_bookmarks or "none",
+  self.highlight_range = self.explorer.opts.renderer.highlight_bookmarks or "none"
-    icon_placement = args.explorer.opts.renderer.icons.bookmarks_placement or "none",
+  self.icon_placement  = self.explorer.opts.renderer.icons.bookmarks_placement or "none"
-  })
 
   if self.explorer.opts.renderer.icons.show.bookmarks then
     self.icon = {
@@ -28,8 +28,8 @@ end
 
 ---Bookmark icon: renderer.icons.show.bookmarks and node is marked
 ---@param node Node
----@return HighlightedString[]|nil icons
+---@return HighlightedString[]? icons
-function DecoratorBookmarks:calculate_icons(node)
+function BookmarkDecorator:icons(node)
   if self.explorer.marks:get(node) then
     return { self.icon }
   end
@@ -37,11 +37,11 @@ end
 
 ---Bookmark highlight: renderer.highlight_bookmarks and node is marked
 ---@param node Node
----@return string|nil group
+---@return string? highlight_group
-function DecoratorBookmarks:calculate_highlight(node)
+function BookmarkDecorator:highlight_group(node)
-  if self.range ~= "none" and self.explorer.marks:get(node) then
+  if self.highlight_range ~= "none" and self.explorer.marks:get(node) then
     return "NvimTreeBookmarkHL"
   end
 end
 
-return DecoratorBookmarks
+return BookmarkDecorator

lua/nvim-tree/renderer/decorator/copied.lua

@@ -1,29 +1,29 @@
 local Decorator = require("nvim-tree.renderer.decorator")
 
----@class (exact) DecoratorCopied: Decorator
+---@class (exact) CopiedDecorator: Decorator
-local DecoratorCopied = Decorator:extend()
+---@field private explorer Explorer
+local CopiedDecorator = Decorator:extend()
 
----@class DecoratorCopied
+---@class CopiedDecorator
----@overload fun(explorer: DecoratorArgs): DecoratorCopied
+---@overload fun(args: DecoratorArgs): CopiedDecorator
 
 ---@protected
 ---@param args DecoratorArgs
-function DecoratorCopied:new(args)
+function CopiedDecorator:new(args)
-  Decorator.new(self, {
+  self.explorer   = args.explorer
-    explorer       = args.explorer,
+
-    enabled        = true,
+  self.enabled         = true
-    hl_pos         = args.explorer.opts.renderer.highlight_clipboard or "none",
+  self.highlight_range = self.explorer.opts.renderer.highlight_clipboard or "none"
-    icon_placement = "none",
+  self.icon_placement  = "none"
-  })
 end
 
 ---Copied highlight: renderer.highlight_clipboard and node is copied
 ---@param node Node
----@return string|nil group
+---@return string? highlight_group
-function DecoratorCopied:calculate_highlight(node)
+function CopiedDecorator:highlight_group(node)
-  if self.range ~= "none" and self.explorer.clipboard:is_copied(node) then
+  if self.highlight_range ~= "none" and self.explorer.clipboard:is_copied(node) then
     return "NvimTreeCopiedHL"
   end
 end
 
-return DecoratorCopied
+return CopiedDecorator

lua/nvim-tree/renderer/decorator/cut.lua

@@ -1,29 +1,29 @@
 local Decorator = require("nvim-tree.renderer.decorator")
 
----@class (exact) DecoratorCut: Decorator
+---@class (exact) CutDecorator: Decorator
-local DecoratorCut = Decorator:extend()
+---@field private explorer Explorer
+local CutDecorator = Decorator:extend()
 
----@class DecoratorCut
+---@class CutDecorator
----@overload fun(explorer: DecoratorArgs): DecoratorCut
+---@overload fun(args: DecoratorArgs): CutDecorator
 
 ---@protected
 ---@param args DecoratorArgs
-function DecoratorCut:new(args)
+function CutDecorator:new(args)
-  Decorator.new(self, {
+  self.explorer        = args.explorer
-    explorer       = args.explorer,
+
-    enabled        = true,
+  self.enabled         = true
-    hl_pos         = args.explorer.opts.renderer.highlight_clipboard or "none",
+  self.highlight_range = self.explorer.opts.renderer.highlight_clipboard or "none"
-    icon_placement = "none",
+  self.icon_placement  = "none"
-  })
 end
 
 ---Cut highlight: renderer.highlight_clipboard and node is cut
 ---@param node Node
----@return string|nil group
+---@return string? highlight_group
-function DecoratorCut:calculate_highlight(node)
+function CutDecorator:highlight_group(node)
-  if self.range ~= "none" and self.explorer.clipboard:is_cut(node) then
+  if self.highlight_range ~= "none" and self.explorer.clipboard:is_cut(node) then
     return "NvimTreeCutHL"
   end
 end
 
-return DecoratorCut
+return CutDecorator

lua/nvim-tree/renderer/decorator/diagnostics.lua

@@ -30,58 +30,54 @@ local ICON_KEYS = {
   ["hint"] = vim.diagnostic.severity.HINT,
 }
 
----@class (exact) DecoratorDiagnostics: Decorator
+---@class (exact) DiagnosticsDecorator: Decorator
----@field icons HighlightedString[]?
+---@field private explorer Explorer
-local DecoratorDiagnostics = Decorator:extend()
+---@field private diag_icons HighlightedString[]?
+local DiagnosticsDecorator = Decorator:extend()
 
----@class DecoratorDiagnostics
+---@class DiagnosticsDecorator
----@overload fun(explorer: DecoratorArgs): DecoratorDiagnostics
+---@overload fun(args: DecoratorArgs): DiagnosticsDecorator
 
 ---@protected
 ---@param args DecoratorArgs
-function DecoratorDiagnostics:new(args)
+function DiagnosticsDecorator:new(args)
-  Decorator.new(self, {
+  self.explorer        = args.explorer
-    explorer       = args.explorer,
-    enabled        = true,
-    hl_pos         = args.explorer.opts.renderer.highlight_diagnostics or "none",
-    icon_placement = args.explorer.opts.renderer.icons.diagnostics_placement or "none",
-  })
 
-  if not self.enabled then
+  self.enabled         = true
-    return
+  self.highlight_range = self.explorer.opts.renderer.highlight_diagnostics or "none"
-  end
+  self.icon_placement  = self.explorer.opts.renderer.icons.diagnostics_placement or "none"
 
   if self.explorer.opts.renderer.icons.show.diagnostics then
-    self.icons = {}
+    self.diag_icons = {}
     for name, sev in pairs(ICON_KEYS) do
-      self.icons[sev] = {
+      self.diag_icons[sev] = {
         str = self.explorer.opts.diagnostics.icons[name],
         hl = { HG_ICON[sev] },
       }
-      self:define_sign(self.icons[sev])
+      self:define_sign(self.diag_icons[sev])
     end
   end
 end
 
 ---Diagnostic icon: diagnostics.enable, renderer.icons.show.diagnostics and node has status
 ---@param node Node
----@return HighlightedString[]|nil icons
+---@return HighlightedString[]? icons
-function DecoratorDiagnostics:calculate_icons(node)
+function DiagnosticsDecorator:icons(node)
-  if node and self.enabled and self.icons then
+  if node and self.diag_icons then
     local diag_status = diagnostics.get_diag_status(node)
     local diag_value = diag_status and diag_status.value
 
     if diag_value then
-      return { self.icons[diag_value] }
+      return { self.diag_icons[diag_value] }
     end
   end
 end
 
 ---Diagnostic highlight: diagnostics.enable, renderer.highlight_diagnostics and node has status
 ---@param node Node
----@return string|nil group
+---@return string? highlight_group
-function DecoratorDiagnostics:calculate_highlight(node)
+function DiagnosticsDecorator:highlight_group(node)
-  if not node or not self.enabled or self.range == "none" then
+  if self.highlight_range == "none" then
     return nil
   end
 
@@ -106,4 +102,4 @@ function DecoratorDiagnostics:calculate_highlight(node)
   end
 end
 
-return DecoratorDiagnostics
+return DiagnosticsDecorator

lua/nvim-tree/renderer/decorator/git.lua

@@ -3,7 +3,7 @@ local notify = require("nvim-tree.notify")
 local Decorator = require("nvim-tree.renderer.decorator")
 local DirectoryNode = require("nvim-tree.node.directory")
 
----@class (exact) GitHighlightedString: HighlightedString
+---@class (exact) GitHighlightedString: nvim_tree.api.HighlightedString
 ---@field ord number decreasing priority
 
 ---@alias GitStatusStrings "deleted" | "ignored" | "renamed" | "staged" | "unmerged" | "unstaged" | "untracked"
@@ -12,31 +12,31 @@ local DirectoryNode = require("nvim-tree.node.directory")
 ---@alias GitIconsByXY table<GitXY, GitHighlightedString[]> porcelain status
 ---@alias GitGlyphsByStatus table<GitStatusStrings, string> from opts
 
----@class (exact) DecoratorGit: Decorator
+---@class (exact) GitDecorator: Decorator
----@field file_hl_by_xy table<GitXY, string>?
+---@field private explorer Explorer
----@field folder_hl_by_xy table<GitXY, string>?
+---@field private file_hl_by_xy table<GitXY, string>?
----@field icons_by_status GitIconsByStatus?
+---@field private folder_hl_by_xy table<GitXY, string>?
----@field icons_by_xy GitIconsByXY?
+---@field private icons_by_status GitIconsByStatus?
-local DecoratorGit = Decorator:extend()
+---@field private icons_by_xy GitIconsByXY?
+local GitDecorator = Decorator:extend()
 
----@class DecoratorGit
+---@class GitDecorator
----@overload fun(explorer: DecoratorArgs): DecoratorGit
+---@overload fun(args: DecoratorArgs): GitDecorator
 
 ---@protected
 ---@param args DecoratorArgs
-function DecoratorGit:new(args)
+function GitDecorator:new(args)
-  Decorator.new(self, {
+  self.explorer        = args.explorer
-    explorer       = args.explorer,
+
-    enabled        = args.explorer.opts.git.enable,
+  self.enabled         = self.explorer.opts.git.enable
-    hl_pos         = args.explorer.opts.renderer.highlight_git or "none",
+  self.highlight_range = self.explorer.opts.renderer.highlight_git or "none"
-    icon_placement = args.explorer.opts.renderer.icons.git_placement or "none",
+  self.icon_placement  = self.explorer.opts.renderer.icons.git_placement or "none"
-  })
 
   if not self.enabled then
     return
   end
 
-  if self.range ~= "none" then
+  if self.highlight_range ~= "none" then
     self:build_file_folder_hl_by_xy()
   end
 
@@ -51,7 +51,7 @@ function DecoratorGit:new(args)
 end
 
 ---@param glyphs GitGlyphsByStatus
-function DecoratorGit:build_icons_by_status(glyphs)
+function GitDecorator:build_icons_by_status(glyphs)
   self.icons_by_status           = {}
   self.icons_by_status.staged    = { str = glyphs.staged, hl = { "NvimTreeGitStagedIcon" }, ord = 1 }
   self.icons_by_status.unstaged  = { str = glyphs.unstaged, hl = { "NvimTreeGitDirtyIcon" }, ord = 2 }
@@ -63,7 +63,7 @@ function DecoratorGit:build_icons_by_status(glyphs)
 end
 
 ---@param icons GitIconsByXY
-function DecoratorGit:build_icons_by_xy(icons)
+function GitDecorator:build_icons_by_xy(icons)
   self.icons_by_xy = {
     ["M "] = { icons.staged },
     [" M"] = { icons.unstaged },
@@ -100,7 +100,7 @@ function DecoratorGit:build_icons_by_xy(icons)
   }
 end
 
-function DecoratorGit:build_file_folder_hl_by_xy()
+function GitDecorator:build_file_folder_hl_by_xy()
   self.file_hl_by_xy = {
     ["M "] = "NvimTreeGitFileStagedHL",
     ["C "] = "NvimTreeGitFileStagedHL",
@@ -142,9 +142,9 @@ end
 
 ---Git icons: git.enable, renderer.icons.show.git and node has status
 ---@param node Node
----@return HighlightedString[]|nil modified icon
+---@return HighlightedString[]? icons
-function DecoratorGit:calculate_icons(node)
+function GitDecorator:icons(node)
-  if not node or not self.enabled or not self.icons_by_xy then
+  if not self.icons_by_xy then
     return nil
   end
 
@@ -159,7 +159,7 @@ function DecoratorGit:calculate_icons(node)
   for _, s in pairs(git_xy) do
     local icons = self.icons_by_xy[s]
     if not icons then
-      if self.range == "none" then
+      if self.highlight_range == "none" then
         notify.warn(string.format("Unrecognized git state '%s'", git_xy))
       end
       return nil
@@ -190,12 +190,12 @@ end
 ---Get the first icon as the sign if appropriate
 ---@param node Node
 ---@return string|nil name
-function DecoratorGit:sign_name(node)
+function GitDecorator:sign_name(node)
   if self.icon_placement ~= "signcolumn" then
     return
   end
 
-  local icons = self:calculate_icons(node)
+  local icons = self:icons(node)
   if icons and #icons > 0 then
     return icons[1].hl[1]
   end
@@ -203,9 +203,9 @@ end
 
 ---Git highlight: git.enable, renderer.highlight_git and node has status
 ---@param node Node
----@return string|nil group
+---@return string? highlight_group
-function DecoratorGit:calculate_highlight(node)
+function GitDecorator:highlight_group(node)
-  if not node or not self.enabled or self.range == "none" then
+  if self.highlight_range == "none" then
     return nil
   end
 
@@ -221,4 +221,4 @@ function DecoratorGit:calculate_highlight(node)
   end
 end
 
-return DecoratorGit
+return GitDecorator

lua/nvim-tree/renderer/decorator/hidden.lua

@@ -1,22 +1,22 @@
 local Decorator = require("nvim-tree.renderer.decorator")
 local DirectoryNode = require("nvim-tree.node.directory")
 
----@class (exact) DecoratorHidden: Decorator
+---@class (exact) HiddenDecorator: Decorator
----@field icon HighlightedString?
+---@field private explorer Explorer
-local DecoratorHidden = Decorator:extend()
+---@field private icon HighlightedString?
+local HiddenDecorator = Decorator:extend()
 
----@class DecoratorHidden
+---@class HiddenDecorator
----@overload fun(explorer: DecoratorArgs): DecoratorHidden
+---@overload fun(args: DecoratorArgs): HiddenDecorator
 
 ---@protected
 ---@param args DecoratorArgs
-function DecoratorHidden:new(args)
+function HiddenDecorator:new(args)
-  Decorator.new(self, {
+  self.explorer        = args.explorer
-    explorer       = args.explorer,
+
-    enabled        = true,
+  self.enabled         = true
-    hl_pos         = args.explorer.opts.renderer.highlight_hidden or "none",
+  self.highlight_range = self.explorer.opts.renderer.highlight_hidden or "none"
-    icon_placement = args.explorer.opts.renderer.icons.hidden_placement or "none",
+  self.icon_placement  = self.explorer.opts.renderer.icons.hidden_placement or "none"
-  })
 
   if self.explorer.opts.renderer.icons.show.hidden then
     self.icon = {
@@ -29,18 +29,18 @@ end
 
 ---Hidden icon: renderer.icons.show.hidden and node starts with `.` (dotfile).
 ---@param node Node
----@return HighlightedString[]|nil icons
+---@return HighlightedString[]? icons
-function DecoratorHidden:calculate_icons(node)
+function HiddenDecorator:icons(node)
-  if self.enabled and node:is_dotfile() then
+  if node:is_dotfile() then
     return { self.icon }
   end
 end
 
 ---Hidden highlight: renderer.highlight_hidden and node starts with `.` (dotfile).
 ---@param node Node
----@return string|nil group
+---@return string? highlight_group
-function DecoratorHidden:calculate_highlight(node)
+function HiddenDecorator:highlight_group(node)
-  if not self.enabled or self.range == "none" or not node:is_dotfile() then
+  if self.highlight_range == "none" or not node:is_dotfile() then
     return nil
   end
 
@@ -51,4 +51,4 @@ function DecoratorHidden:calculate_highlight(node)
   end
 end
 
-return DecoratorHidden
+return HiddenDecorator

lua/nvim-tree/renderer/decorator/init.lua

@@ -1,48 +1,52 @@
 local Class = require("nvim-tree.classic")
 
----@alias DecoratorRange "none" | "icon" | "name" | "all"
----@alias DecoratorIconPlacement "none" | "before" | "after" | "signcolumn" | "right_align"
-
 ---Abstract Decorator
----Uses the factory pattern to instantiate child instances.
 ---@class (exact) Decorator: Class
----@field protected explorer Explorer
 ---@field protected enabled boolean
----@field protected range DecoratorRange
+---@field protected highlight_range nvim_tree.api.decorator.HighlightRange
----@field protected icon_placement DecoratorIconPlacement
+---@field protected icon_placement nvim_tree.api.decorator.IconPlacement
 local Decorator = Class:extend()
 
 ---@class (exact) DecoratorArgs
 ---@field explorer Explorer
 
----@class (exact) AbstractDecoratorArgs: DecoratorArgs
+---Abstract icon override, optionally implemented
----@field enabled boolean
+---@param node Node
----@field hl_pos DecoratorRange
+---@return HighlightedString? icon_node
----@field icon_placement DecoratorIconPlacement
+function Decorator:icon_node(node)
-
+  return self:nop(node)
----@protected
----@param args AbstractDecoratorArgs
-function Decorator:new(args)
-  self.explorer       = args.explorer
-  self.enabled        = args.enabled
-  self.range          = args.hl_pos
-  self.icon_placement = args.icon_placement
 end
 
----Maybe highlight groups
+---Abstract icons, optionally implemented
+---@protected
 ---@param node Node
----@return string|nil icon highlight group
+---@return HighlightedString[]? icons
----@return string|nil name highlight group
+function Decorator:icons(node)
-function Decorator:groups_icon_name(node)
+  self:nop(node)
+end
+
+---Abstract highlight group, optionally implemented
+---@protected
+---@param node Node
+---@return string? highlight_group
+function Decorator:highlight_group(node)
+  self:nop(node)
+end
+
+---Maybe highlight groups for icon and name
+---@param node Node
+---@return string? icon highlight group
+---@return string? name highlight group
+function Decorator:highlight_group_icon_name(node)
   local icon_hl, name_hl
 
-  if self.enabled and self.range ~= "none" then
+  if self.enabled and self.highlight_range ~= "none" then
-    local hl = self:calculate_highlight(node)
+    local hl = self:highlight_group(node)
 
-    if self.range == "all" or self.range == "icon" then
+    if self.highlight_range == "all" or self.highlight_range == "icon" then
       icon_hl = hl
     end
-    if self.range == "all" or self.range == "name" then
+    if self.highlight_range == "all" or self.highlight_range == "name" then
       name_hl = hl
     end
   end
@@ -52,13 +56,13 @@ end
 
 ---Maybe icon sign
 ---@param node Node
----@return string|nil name
+---@return string? name
 function Decorator:sign_name(node)
   if not self.enabled or self.icon_placement ~= "signcolumn" then
     return
   end
 
-  local icons = self:calculate_icons(node)
+  local icons = self:icons(node)
   if icons and #icons > 0 then
     return icons[1].hl[1]
   end
@@ -66,56 +70,40 @@ end
 
 ---Icons when "before"
 ---@param node Node
----@return HighlightedString[]|nil icons
+---@return HighlightedString[]? icons
 function Decorator:icons_before(node)
   if not self.enabled or self.icon_placement ~= "before" then
     return
   end
 
-  return self:calculate_icons(node)
+  return self:icons(node)
 end
 
 ---Icons when "after"
 ---@param node Node
----@return HighlightedString[]|nil icons
+---@return HighlightedString[]? icons
 function Decorator:icons_after(node)
   if not self.enabled or self.icon_placement ~= "after" then
     return
   end
 
-  return self:calculate_icons(node)
+  return self:icons(node)
 end
 
 ---Icons when "right_align"
 ---@param node Node
----@return HighlightedString[]|nil icons
+---@return HighlightedString[]? icons
 function Decorator:icons_right_align(node)
   if not self.enabled or self.icon_placement ~= "right_align" then
     return
   end
 
-  return self:calculate_icons(node)
+  return self:icons(node)
-end
-
----Maybe icons, optionally implemented
----@protected
----@param _ Node
----@return HighlightedString[]|nil icons
-function Decorator:calculate_icons(_)
-  return nil
-end
-
----Maybe highlight group, optionally implemented
----@protected
----@param _ Node
----@return string|nil group
-function Decorator:calculate_highlight(_)
-  return nil
 end
 
 ---Define a sign
 ---@protected
----@param icon HighlightedString|nil
+---@param icon HighlightedString?
 function Decorator:define_sign(icon)
   if icon and #icon.hl > 0 then
     local name = icon.hl[1]

lua/nvim-tree/renderer/decorator/modified.lua

@@ -3,26 +3,22 @@ local buffers = require("nvim-tree.buffers")
 local Decorator = require("nvim-tree.renderer.decorator")
 local DirectoryNode = require("nvim-tree.node.directory")
 
----@class (exact) DecoratorModified: Decorator
+---@class (exact) ModifiedDecorator: Decorator
----@field icon HighlightedString?
+---@field private explorer Explorer
-local DecoratorModified = Decorator:extend()
+---@field private icon HighlightedString?
+local ModifiedDecorator = Decorator:extend()
 
----@class DecoratorModified
+---@class ModifiedDecorator
----@overload fun(explorer: DecoratorArgs): DecoratorModified
+---@overload fun(args: DecoratorArgs): ModifiedDecorator
 
 ---@protected
 ---@param args DecoratorArgs
-function DecoratorModified:new(args)
+function ModifiedDecorator:new(args)
-  Decorator.new(self, {
+  self.explorer        = args.explorer
-    explorer       = args.explorer,
-    enabled        = true,
-    hl_pos         = args.explorer.opts.renderer.highlight_modified or "none",
-    icon_placement = args.explorer.opts.renderer.icons.modified_placement or "none",
-  })
 
-  if not self.enabled then
+  self.enabled         = true
-    return
+  self.highlight_range = self.explorer.opts.renderer.highlight_modified or "none"
-  end
+  self.icon_placement  = self.explorer.opts.renderer.icons.modified_placement or "none"
 
   if self.explorer.opts.renderer.icons.show.modified then
     self.icon = {
@@ -35,18 +31,18 @@ end
 
 ---Modified icon: modified.enable, renderer.icons.show.modified and node is modified
 ---@param node Node
----@return HighlightedString[]|nil icons
+---@return HighlightedString[]? icons
-function DecoratorModified:calculate_icons(node)
+function ModifiedDecorator:icons(node)
-  if self.enabled and buffers.is_modified(node) then
+  if buffers.is_modified(node) then
     return { self.icon }
   end
 end
 
 ---Modified highlight: modified.enable, renderer.highlight_modified and node is modified
 ---@param node Node
----@return string|nil group
+---@return string? highlight_group
-function DecoratorModified:calculate_highlight(node)
+function ModifiedDecorator:highlight_group(node)
-  if not self.enabled or self.range == "none" or not buffers.is_modified(node) then
+  if self.highlight_range == "none" or not buffers.is_modified(node) then
     return nil
   end
 
@@ -57,4 +53,4 @@ function DecoratorModified:calculate_highlight(node)
   end
 end
 
-return DecoratorModified
+return ModifiedDecorator

lua/nvim-tree/renderer/decorator/opened.lua

@@ -2,31 +2,31 @@ local buffers = require("nvim-tree.buffers")
 
 local Decorator = require("nvim-tree.renderer.decorator")
 
----@class (exact) DecoratorOpened: Decorator
+---@class (exact) OpenDecorator: Decorator
----@field icon HighlightedString|nil
+---@field private explorer Explorer
-local DecoratorOpened = Decorator:extend()
+---@field private icon HighlightedString|nil
+local OpenDecorator = Decorator:extend()
 
----@class DecoratorOpened
+---@class OpenDecorator
----@overload fun(explorer: DecoratorArgs): DecoratorOpened
+---@overload fun(args: DecoratorArgs): OpenDecorator
 
 ---@protected
 ---@param args DecoratorArgs
-function DecoratorOpened:new(args)
+function OpenDecorator:new(args)
-  Decorator.new(self, {
+  self.explorer        = args.explorer
-    explorer       = args.explorer,
+
-    enabled        = true,
+  self.enabled         = true
-    hl_pos         = args.explorer.opts.renderer.highlight_opened_files or "none",
+  self.highlight_range = self.explorer.opts.renderer.highlight_opened_files or "none"
-    icon_placement = "none",
+  self.icon_placement  = "none"
-  })
 end
 
 ---Opened highlight: renderer.highlight_opened_files and node has an open buffer
 ---@param node Node
----@return string|nil group
+---@return string? highlight_group
-function DecoratorOpened:calculate_highlight(node)
+function OpenDecorator:highlight_group(node)
-  if self.range ~= "none" and buffers.is_opened(node) then
+  if self.highlight_range ~= "none" and buffers.is_opened(node) then
     return "NvimTreeOpenedHL"
   end
 end
 
-return DecoratorOpened
+return OpenDecorator

lua/nvim-tree/renderer/decorator/user.lua

@@ -0,0 +1,7 @@
+local Decorator = require("nvim-tree.renderer.decorator")
+
+---Exposed as nvim_tree.api.decorator.UserDecorator
+---@class (exact) UserDecorator: Decorator
+local UserDecorator = Decorator:extend()
+
+return UserDecorator