Fix support for hide leading stars option.

README.md

@@ -193,7 +193,6 @@ Highlights are partially supported.
 #### Known highlighting issues and limitations
 * Performance issues. This is generally an issue in Neovim that should be resolved before 0.6 release (https://github.com/neovim/neovim/issues/14762, https://github.com/neovim/neovim/issues/14762)
 * Anything that requires concealing ([org_hide_emphasis_markers](/DOCS.md#org_hide_emphasis_markers), links concealing) is not (yet) supported in TS highlighter
-* Option [org_hide_leading_stars](/DOCS.md#org_hide_leading_stars) does not work due to limitations with grammar and Neovim.
 * LaTex is still highlighted through syntax file
 
 #### Improvements over Vim's syntax highlighting

lua/orgmode/colors/hide_leading_stars.lua

@@ -0,0 +1,44 @@
+local config = require('orgmode.config')
+local namespace = vim.api.nvim_create_namespace('org_hide_leading_stars')
+local valid_bufnrs = {}
+
+local function update_line_highlight(bufnr, line_index, line)
+  local stars = line:match('^%*+')
+  if stars then
+    vim.api.nvim_buf_set_extmark(bufnr, namespace, line_index, 0, {
+      end_line = line_index,
+      end_col = stars:len() - 1,
+      hl_group = 'OrgHideLeadingStars',
+      ephemeral = true,
+    })
+  end
+end
+
+local function update_range_highlight(bufnr, first_line, last_line)
+  local changed_lines = vim.api.nvim_buf_get_lines(bufnr, first_line, last_line, false)
+  for i, line in ipairs(changed_lines) do
+    update_line_highlight(bufnr, first_line + i - 1, line)
+  end
+end
+
+local function setup_hide_leading_stars()
+  if not config.org_hide_leading_stars then
+    return
+  end
+  vim.api.nvim_set_decoration_provider(namespace, {
+    on_win = function(_, _, bufnr, topline, botline)
+      if valid_bufnrs[bufnr] then
+        return update_range_highlight(bufnr, topline, botline)
+      end
+      local ft = vim.api.nvim_buf_get_option(bufnr, 'filetype')
+      if ft == 'org' then
+        valid_bufnrs[bufnr] = true
+        return update_range_highlight(bufnr, topline, botline)
+      end
+    end,
+  })
+end
+
+return {
+  setup = setup_hide_leading_stars,
+}

lua/orgmode/colors/highlights.lua

@@ -60,10 +60,10 @@ function M.define_org_headline_colors(faces)
     table.insert(contains, face)
   end
   if config.org_hide_leading_stars then
-    vim.cmd([[
-         syn match OrgHideLeadingStars /^\*\{2,\}/me=e-1 contained
-         hi def link OrgHideLeadingStars org_hide_leading_stars
-      ]])
+    if not ts_highlights_enabled then
+      vim.cmd([[syn match OrgHideLeadingStars /^\*\{2,\}/me=e-1 contained]])
+    end
+    vim.cmd([[hi def link OrgHideLeadingStars org_hide_leading_stars]])
     table.insert(contains, 'OrgHideLeadingStars')
   end
   contains = table.concat(contains, ',')

lua/orgmode/init.lua

@@ -23,6 +23,7 @@ function Org:init()
     return
   end
   require('orgmode.colors.todo_highlighter').add_todo_keyword_highlights()
+  require('orgmode.colors.hide_leading_stars').setup()
   self.files = require('orgmode.parser.files').new()
   self.agenda = require('orgmode.agenda'):new()
   self.capture = require('orgmode.capture'):new()