feat: make VirtualIndent react to changes in vim.b.org_indent_mode

Author: PriceHiller

lua/orgmode/org/indent.lua

@@ -311,8 +311,12 @@ end
 local function setup()
   local v = vim.version()
 
-  if config.org_startup_indented and not vim.version.lt({ v.major, v.minor, v.patch }, { 0, 10, 0 }) then
-    VirtualIndent:new():attach()
+  if not vim.version.lt({ v.major, v.minor, v.patch }, { 0, 10, 0 }) then
+    if config.org_startup_indented then
+      VirtualIndent:new():attach()
+    else
+      VirtualIndent:new():start_watch_org_indent()
+    end
   end
 end
 

lua/orgmode/ui/virtual_indent.lua

@@ -1,35 +1,54 @@
 ---@class VirtualIndent
 ---@field private _ns_id number extmarks namespace id
+---@field private _headline_lib any Treesitter headline library
+---@field private _bufnr integer Buffer VirtualIndent is attached to
+---@field private _attached boolean Whether or not VirtualIndent is attached for its buffer
+---@field private _bufnrs {integer: boolean} Buffers with VirtualIndent attached
+---@field private _timer uv_timer_t Timer used for tracking `org_indent_mode`
 local VirtualIndent = {
-  enabled = false,
-  lib = {},
+  _ns_id = vim.api.nvim_create_namespace('orgmode.ui.indent'),
+  _bufnrs = {},
 }
 
-function VirtualIndent:new()
-  if self.enabled then
-    return self
+--- Creates a new instance of VirtualIndent for a given buffer or returns the existing instance if
+--- one exists
+---@param bufnr? integer Buffer to use for VirtualIndent when attached
+---@return VirtualIndent
+function VirtualIndent:new(bufnr)
+  bufnr = bufnr or vim.api.nvim_get_current_buf()
+
+  local curr_instance = VirtualIndent._bufnrs[bufnr]
+  if curr_instance then
+    return curr_instance
   end
-  self._ns_id = vim.api.nvim_create_namespace('orgmode.ui.indent')
-  self.lib.headline = require('orgmode.treesitter.headline')
-  self.enabled = true
-  return self
+
+  local new = {}
+  setmetatable(new, self)
+  self.__index = self
+
+  new._bufnr = bufnr
+  new._headline_lib = require('orgmode.treesitter.headline')
+  new._attached = false
+  VirtualIndent._bufnrs[new._bufnr] = new
+  new._timer = vim.uv.new_timer()
+  return new
 end
 
-function VirtualIndent:_delete_old_extmarks(buffer, start_line, end_line)
+function VirtualIndent:_delete_old_extmarks(start_line, end_line)
   local old_extmarks = vim.api.nvim_buf_get_extmarks(
-    buffer,
+    self._bufnr,
     self._ns_id,
     { start_line, 0 },
     { end_line, 0 },
     { type = 'virt_text' }
   )
   for _, ext in ipairs(old_extmarks) do
-    vim.api.nvim_buf_del_extmark(buffer, self._ns_id, ext[1])
+    vim.api.nvim_buf_del_extmark(self._bufnr, self._ns_id, ext[1])
   end
 end
 
 function VirtualIndent:_get_indent_size(line)
-  local headline = self.lib.headline.from_cursor({ line + 1, 1 })
+  local headline = self._headline_lib.from_cursor({ line + 1, 1 })
 
   if headline then
     local headline_line, _, _ = headline.headline:start()
@@ -42,13 +61,12 @@ function VirtualIndent:_get_indent_size(line)
   return 0
 end
 
----@param bufnr number buffer id
 ---@param start_line number start line number to set the indentation, 0-based inclusive
 ---@param end_line number end line number to set the indentation, 0-based inclusive
 ---@param ignore_ts? boolean whether or not to skip the treesitter start & end lookup
-function VirtualIndent:set_indent(bufnr, start_line, end_line, ignore_ts)
+function VirtualIndent:set_indent(start_line, end_line, ignore_ts)
   ignore_ts = ignore_ts or false
-  local headline = self.lib.headline.from_cursor({ start_line + 1, 1 })
+  local headline = self._headline_lib.from_cursor({ start_line + 1, 1 })
   if headline and not ignore_ts then
     local parent = headline.headline:parent()
     start_line = parent:start()
@@ -57,13 +75,13 @@ function VirtualIndent:set_indent(bufnr, start_line, end_line, ignore_ts)
   if start_line > 0 then
     start_line = start_line - 1
   end
-  self:_delete_old_extmarks(bufnr, start_line, end_line)
+  self:_delete_old_extmarks(start_line, end_line)
   for line = start_line, end_line do
     local indent = self:_get_indent_size(line)
 
     if indent > 0 then
       -- NOTE: `ephemeral = true` is not implemented for `inline` virt_text_pos :(
-      vim.api.nvim_buf_set_extmark(bufnr, self._ns_id, line, 0, {
+      vim.api.nvim_buf_set_extmark(self._bufnr, self._ns_id, line, 0, {
         virt_text = { { string.rep(' ', indent), 'OrgIndent' } },
         virt_text_pos = 'inline',
         right_gravity = false,
@@ -72,22 +90,56 @@ function VirtualIndent:set_indent(bufnr, start_line, end_line, ignore_ts)
   end
 end
 
----@param bufnr? number buffer id
-function VirtualIndent:attach(bufnr)
-  bufnr = bufnr or 0
-  self:set_indent(0, 0, vim.api.nvim_buf_line_count(bufnr) - 1, true)
+--- Begins a timer to check `vim.b.org_indent_mode` and correctly attach or detatch VirtualIndent as
+--- necessary
+function VirtualIndent:start_watch_org_indent()
+  self._timer:start(
+    50,
+    50,
+    vim.schedule_wrap(function()
+      local success, indent_mode_enabled = pcall(vim.api.nvim_buf_get_var, self._bufnr, 'org_indent_mode')
+      if success and indent_mode_enabled then
+        if not self._attached then
+          self:attach()
+        end
+      elseif self._attached then
+        self:detach()
+      end
+    end)
+  )
+end
+
+--- Stops the current VirtualIndent instance from reacting to changes in `vim.b.org_indent_mode`
+function VirtualIndent:stop_watch_org_indent()
+  self._timer:stop()
+end
+
+--- Enables virtual indentation in registered buffer
+function VirtualIndent:attach()
+  self._attached = true
+  self:set_indent(0, vim.api.nvim_buf_line_count(self._bufnr) - 1, true)
+  self:start_watch_org_indent()
 
-  vim.api.nvim_buf_attach(bufnr, false, {
+  vim.api.nvim_buf_attach(self._bufnr, false, {
     on_lines = function(_, _, _, start_line, _, end_line)
+      if not self._attached then
+        return true
+      end
       -- HACK: By calling `set_indent` twice, once synchronously and once in `vim.schedule` we get smooth usage of the
       -- virtual indent in most cases and still properly handle undo redo. Unfortunately this is called *early* when
       -- `undo` or `redo` is used causing the padding to be incorrect for some headlines.
-      self:set_indent(bufnr, start_line, end_line)
+      self:set_indent(self._bufnr, start_line, end_line)
       vim.schedule(function()
-        self:set_indent(bufnr, start_line, end_line)
+        self:set_indent(self._bufnr, start_line, end_line)
       end)
     end,
   })
 end
 
+function VirtualIndent:detach()
+  self._attached = false
+  vim.api.nvim_buf_set_var(self._bufnr, 'org_indent_mode', false)
+  self:_delete_old_extmarks(0, vim.api.nvim_buf_line_count(self._bufnr) - 1)
+end
+
 return VirtualIndent