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|
- 12. Netrw                                    |nvim-tree-netrw|
- 13. Legacy                                   |nvim-tree-legacy|
- 13.1  Legacy: Opts                             |nvim-tree-legacy-opts|
- 13.2  Legacy: Highlight                        |nvim-tree-legacy-highlight|
- 14. Index                                    |nvim-tree-index|
- 14.1  Index: Opts                              |nvim-tree-index-opts|
- 14.2  Index: API                               |nvim-tree-index-api|
+ 11. Decorators                               |nvim-tree-decorators|
+ 11.1  Decorator Example                        |nvim-tree-decorator-example|
+ 12. OS Specific Restrictions                 |nvim-tree-os-specific|
+ 13. Netrw                                    |nvim-tree-netrw|
+ 14. Legacy                                   |nvim-tree-legacy|
+ 14.1  Legacy: Opts                             |nvim-tree-legacy-opts|
+ 14.2  Legacy: Highlight                        |nvim-tree-legacy-highlight|
+ 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