feat(view): indicate modified buffers (#1835)

* Outlined new options

* highlight_modified is highlight_opened_files

* prototype with autocmd

* moved modified into glyphs

* show_on_dirs and show_on_open_dirs

* icon placement before & after

* _get_filename_offset

* fixed :wq doesn't update modified indicator

* highlight_modified, signcolumn modified_placement

Refactored to make everything use HighlightedString to remove all the complex `insert_highlight` calculation.
Not tested.

* updated doc to match the reality of no multi char for glyphs.modified

* fixed git signcolumn doesn't show

* fixed highlight_modified gets replaced by highlight_opened_files

* fixed renderer.icons.show.modified = false crash

* updated doc to reflect empty icon not breaking rendering

* removed debounce_delay to implement in a later PR

* doc nit: order placement

* change modified dirs default to be consistent with git

* illegal git & modified placement changed to default

* don't assume icon exist

* nit remove comment

* Noted in doc that glyphs can't have more than 2 characters if in signcolumn

* Don't sign_define if placement isn't signcolumn

Co-authored-by: Alexander Courtis <alex@courtis.org>

lua/nvim-tree/renderer/init.lua

@@ -2,6 +2,7 @@ local core = require "nvim-tree.core"
 local diagnostics = require "nvim-tree.diagnostics"
 local log = require "nvim-tree.log"
 local view = require "nvim-tree.view"
+local modified = require "nvim-tree.renderer.components.modified"
 
 local _padding = require "nvim-tree.renderer.components.padding"
 local icon_component = require "nvim-tree.renderer.components.icons"
@@ -16,6 +17,8 @@ local M = {
   last_highlights = {},
 }
 
+local SIGN_GROUP = "NvimTreeRendererSigns"
+
 local namespace_id = vim.api.nvim_create_namespace "NvimTreeHighlights"
 
 local function _draw(bufnr, lines, hl, signs)
@@ -23,9 +26,9 @@ local function _draw(bufnr, lines, hl, signs)
   vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, lines)
   M.render_hl(bufnr, hl)
   vim.api.nvim_buf_set_option(bufnr, "modifiable", false)
-  vim.fn.sign_unplace(git.SIGN_GROUP)
+  vim.fn.sign_unplace(SIGN_GROUP)
   for _, sign in pairs(signs) do
-    vim.fn.sign_place(0, git.SIGN_GROUP, sign.sign, bufnr, { lnum = sign.lnum, priority = 1 })
+    vim.fn.sign_place(0, SIGN_GROUP, sign.sign, bufnr, { lnum = sign.lnum, priority = sign.priority })
   end
 end
 
@@ -68,8 +71,10 @@ function M.draw(unloaded_bufnr)
       :configure_special_files(M.config.special_files)
       :configure_picture_map(picture_map)
       :configure_opened_file_highlighting(M.config.highlight_opened_files)
-      :configure_git_icons_padding(M.config.icons.padding)
+      :configure_modified_highlighting(M.config.highlight_modified)
+      :configure_icon_padding(M.config.icons.padding)
       :configure_git_icons_placement(M.config.icons.git_placement)
+      :configure_modified_placement(M.config.icons.modified_placement)
       :configure_symlink_destination(M.config.symlink_destination)
       :configure_filter(live_filter.filter, live_filter.prefix)
       :build_header(view.is_root_folder_visible(core.get_cwd()))
@@ -100,10 +105,12 @@ end
 
 function M.setup(opts)
   M.config = opts.renderer
+  M.config.modified = opts.modified
 
   _padding.setup(opts)
   full_name.setup(opts)
   git.setup(opts)
+  modified.setup(opts)
   icon_component.setup(opts)
 end