fix: Preview window position based on outline split position

- preview window can adapt based on position of outline window, and not
  based on config value of `position` left/right
- it can also properly vertically center-align, even when there are
  horizontal splits below the outline
- fixed a few bugs associated with previous rewrite commits in init.lua

config:
- Added min_height for preview window

lua/outline/config.lua

@@ -23,7 +23,7 @@ M.defaults = {
     -- On open, always followed. This is for auto_update_events.follow, whether
     -- to auto update cursor position to reflect code location. If false, can
     -- manually trigger with follow_cursor (API, command, keymap action).
-    auto_follow_cursor = true,
+    auto_set_cursor = true,
     auto_update_events = {
       follow = { 'CursorMoved' },
       items = { 'InsertLeave', 'WinEnter', 'BufEnter', 'BufWinEnter', 'TabEnter', 'BufWritePost' },
@@ -40,7 +40,7 @@ M.defaults = {
     auto_jump = false,
     show_numbers = false,
     show_relative_numbers = false,
-    ---@type boolean?|string?
+    ---@type boolean|string?
     show_cursorline = true,
     hide_cursor = false,
     winhl = 'OutlineDetails:Comment,OutlineLineno:LineNr',
@@ -52,6 +52,7 @@ M.defaults = {
     width = 50,
     min_width = 50,
     relative_width = true,
+    min_height = 10,
     border = 'single',
     open_hover_on_preview = false,
     winhl = '',

lua/outline/init.lua

@@ -50,6 +50,9 @@ local function wipe_state()
   }
 end
 
+---Calls writer.make_outline and then calls M.update_cursor_pos if update_cursor is not false
+---@param update_cursor boolean?
+---@param set_cursor_to_node outline.SymbolNode|outline.FlatSymbolNode?
 local function _update_lines(update_cursor, set_cursor_to_node)
   local current
   M.state.flattened_outline_items, current =
@@ -64,6 +67,35 @@ local function _merge_items(items)
   utils.merge_items_rec({ children = items }, { children = M.state.outline_items })
 end
 
+---Setup autocmds for the buffer that the outline attached to
+---@param code_win integer Must be valid
+---@param code_buf integer Must be valid
+local function setup_attached_buffer_autocmd(code_win, code_buf)
+  local events = cfg.o.outline_items.auto_update_events
+  if
+    cfg.o.outline_items.highlight_hovered_item
+    or cfg.o.symbol_folding.auto_unfold_hover
+  then
+    if M.state.autocmds[code_win] then
+      vim.api.nvim_del_autocmd(M.state.autocmds[code_win])
+      M.state.autocmds[code_win] = nil
+    end
+
+    if utils.str_or_nonempty_table(events.follow) then
+      M.state.autocmds[code_win] =
+        vim.api.nvim_create_autocmd(events.follow, {
+          buffer = code_buf,
+          callback = function()
+            M._highlight_current_item(
+              code_win,
+              cfg.o.outline_items.auto_set_cursor
+            )
+          end,
+        })
+    end
+  end
+end
+
 local function __refresh()
   local current_buffer_is_outline = M.view.bufnr == vim.api.nvim_get_current_buf()
   if M.view:is_open() and not current_buffer_is_outline then
@@ -82,29 +114,16 @@ local function __refresh()
           M.state.autocmds[M.state.code_win] = nil
         end
       end
+
       M.state.code_win = curwin
       M.state.code_buf = curbuf
 
-      if cfg.o.outline_items.highlight_hovered_item or cfg.o.symbol_folding.auto_unfold_hover then
-        if M.state.autocmds[curwin] then
-          vim.api.nvim_del_autocmd(M.state.autocmds[curwin])
-          M.state.autocmds[curwin] = nil
-        end
-        if utils.str_or_nonempty_table(cfg.o.outline_items.auto_update_events.follow) then
-          M.state.autocmds[curwin] =
-            vim.api.nvim_create_autocmd(cfg.o.outline_items.auto_update_events.follow, {
-              buffer = curbuf,
-              callback = function()
-                M._highlight_current_item(nil, cfg.o.outline_items.auto_follow_cursor)
-              end,
-            })
-        end
-      end
+      setup_attached_buffer_autocmd(curwin, curbuf)
 
       local items = parser.parse(response, vim.api.nvim_get_current_buf())
       _merge_items(items)
 
-      local update_cursor = newbuf or cfg.o.outline_items.auto_follow_cursor
+      local update_cursor = newbuf or cfg.o.outline_items.auto_set_cursor
       _update_lines(update_cursor)
     end
 
@@ -326,13 +345,22 @@ function M._highlight_current_item(winnr, update_cursor)
     return
   end
 
-  -- TODO: Find an efficient way to:
-  -- 1) Set highlight for all nodes in range (regardless of visibility)
-  -- 2) Find the line number of the deepest node in range, that is visible (no
-  --    parents folded)
-  -- In one go
+  local valid_code_win = vim.api.nvim_win_is_valid(M.state.code_win)
+  local valid_winnr = winnr and vim.api.nvim_win_is_valid(winnr)
 
-  -- XXX: Could current win ~= M.state.code_win here?
+  if not valid_code_win then
+    -- Definetely don't attempt to update anything if code win is no longer valid
+    return
+  end
+
+  if not valid_winnr then
+    return
+  elseif winnr ~= M.state.code_win then
+    -- Both valid, but given winnr ~= known code_win.
+    -- Best not to handle this situation at all to prevent any unwanted side
+    -- effects
+    return
+  end
 
   _update_lines(update_cursor)
 end
@@ -421,35 +449,16 @@ local function handler(response, opts)
     return
   end
 
+  if not opts then
+    opts = {}
+  end
+
   M.state.code_win = vim.api.nvim_get_current_win()
   M.state.code_buf = vim.api.nvim_get_current_buf()
   M.state.opened_first_outline = true
 
-  if opts and opts.on_symbols then
-    opts.on_symbols()
-  end
-
-  M.view:setup_view()
-
-  if opts and opts.on_outline_setup then
-    opts.on_outline_setup()
-  end
-
-  if cfg.o.outline_items.highlight_hovered_item or cfg.o.symbol_folding.auto_unfold_hover then
-    if M.state.autocmds[M.state.code_win] then
-      vim.api.nvim_del_autocmd(M.state.autocmds[M.state.code_win])
-      M.state.autocmds[M.state.code_win] = nil
-    end
-    if utils.str_or_nonempty_table(cfg.o.outline_items.auto_update_events.follow) then
-      M.state.autocmds[M.state.code_win] =
-        vim.api.nvim_create_autocmd(cfg.o.outline_items.auto_update_events.follow, {
-          buffer = M.state.code_buf,
-          callback = function()
-            M._highlight_current_item(nil, cfg.o.outline_items.auto_follow_cursor)
-          end,
-        })
-    end
-  end
+  local sc = opts.split_command or cfg.get_split_command()
+  M.view:setup_view(sc)
 
   -- clear state when buffer is closed
   vim.api.nvim_buf_attach(M.view.bufnr, false, {
@@ -460,6 +469,7 @@ local function handler(response, opts)
 
   setup_keymaps(M.view.bufnr)
   setup_buffer_autocmd()
+  setup_attached_buffer_autocmd(M.state.code_win, M.state.code_buf)
 
   local items = parser.parse(response, M.state.code_buf)
 
@@ -470,7 +480,7 @@ local function handler(response, opts)
 
   M.update_cursor_pos(current)
 
-  if not cfg.o.outline_window.focus_on_open or (opts and not opts.focus_outline) then
+  if not cfg.o.outline_window.focus_on_open or not opts.focus_outline then
     vim.fn.win_gotoid(M.state.code_win)
   end
 end
@@ -531,26 +541,13 @@ end
 
 local function _cmd_open_with_mods(fn)
   return function(opts)
-    local old_sc, use_old_sc
-    local split = opts.smods.split
-    if split ~= '' then
-      old_sc = cfg.o.outline_window.split_command
-      use_old_sc = true
-      cfg.o.outline_window.split_command = split .. ' vsplit'
+    local fnopts = { focus_outline = not opts.bang }
+    local sc = opts.smods.split
+    if sc ~= '' then
+      fnopts.split_command = sc .. ' vsplit'
     end
 
-    local function on_outline_setup()
-      if use_old_sc then
-        cfg.o.outline_window.split_command = old_sc
-        -- the old option should already have been resolved during set up
-      end
-    end
-
-    if opts.bang then
-      fn({ focus_outline = false, on_outline_setup = on_outline_setup })
-    else
-      fn({ focus_outline = true, on_outline_setup = on_outline_setup })
-    end
+    fn(fnopts)
   end
 end
 

lua/outline/preview.lua

@@ -26,29 +26,37 @@ end
 
 M.has_code_win = has_code_win
 
-local function get_width_offset()
+---Get the correct column to place the floating window based on
+-- Relative positions of the outline and the code window.
+---@param preview_width integer
+local function get_col(preview_width)
   ---@type integer
   local outline_winnr = outline.view.winnr
-  local width = cfg.get_preview_width() + 3
-  local has_numbers = vim.api.nvim_win_get_option(outline_winnr, 'number')
-  has_numbers = has_numbers or vim.api.nvim_win_get_option(outline_winnr, 'relativenumber')
+  local outline_col = vim.api.nvim_win_get_position(outline_winnr)[2]
+  local outline_width = vim.api.nvim_win_get_width(outline_winnr)
+  local code_col = vim.api.nvim_win_get_position(outline.state.code_win)[2]
 
-  if has_numbers then
-    width = width + 4
-  end
+  -- TODO: What if code win is below/above outline instead?
 
-  -- FIXME: use actual window position based on view rather than config
-  if cfg.o.outline_window.position == 'right' then
-    width = 0 - width
+  local col = outline_col
+  if outline_col > code_col then
+    col = col - preview_width - 3
   else
-    width = vim.api.nvim_win_get_width(outline_winnr) + 1
+    col = col + outline_width + 1
   end
 
-  return width
+  return col
+end
+
+---@param preview_height integer
+---@param outline_height integer
+local function get_row(preview_height, outline_height)
+  local offset = math.floor((outline_height - preview_height) / 2) - 1
+  return vim.api.nvim_win_get_position(outline.view.winnr)[1] + offset
 end
 
 local function get_height()
-  return vim.api.nvim_list_uis()[1].height
+  return vim.api.nvim_win_get_height(outline.view.winnr)
 end
 
 local function get_hovered_node()
@@ -106,15 +114,16 @@ local function show_preview()
       end,
     })
     local height = get_height()
-    local winheight = math.ceil(height / 2)
+    local width = cfg.get_preview_width()
+    local winheight = math.max(math.ceil(height / 2), cfg.o.preview_window.min_height)
     state.preview_win = vim.api.nvim_open_win(state.preview_buf, false, {
-      relative = 'win',
+      relative = 'editor',
       height = winheight,
-      width = cfg.get_preview_width(),
+      width = width,
       bufpos = { 0, 0 },
-      col = get_width_offset(),
+      col = get_col(width),
       -- Position preview window middle-aligned vertically
-      row = math.floor((height - winheight) / 2) - 1,
+      row = get_row(winheight, height),
       border = cfg.o.preview_window.border,
     })
     setup_preview_buf()

lua/outline/types/outline.lua

@@ -42,7 +42,7 @@
 ---@class outline.FlatSymbolNode
 ---@field name string
 ---@field depth integer
----@field parent outline.SymbolNode
+---@field parent outline.FlatSymbolNode
 ---@field deprecated boolean
 ---@field kind integer|string
 ---@field icon string
@@ -53,7 +53,7 @@
 ---@field range_end integer
 ---@field isLast boolean
 ---@field hierarchy boolean
----@field children? outline.SymbolNode[]
+---@field children? outline.FlatSymbolNode[]
 ---@field traversal_child integer
 ---@field line_in_outline integer
 ---@field prefix_length integer
@@ -64,5 +64,4 @@
 
 ---@class outline.OutlineOpts
 ---@field focus_outline boolean?  Whether to focus on outline of after some operation. If nil, defaults to true
----@field on_symbols function?  After symbols have been received, before sidebar window is setup
----@field on_outline_setup function?   After sidebar window is setup
+---@field split_command string?

lua/outline/view.lua

@@ -6,15 +6,17 @@ function View:new()
   return setmetatable({ bufnr = nil, winnr = nil }, { __index = View })
 end
 
----creates the outline window and sets it up
-function View:setup_view()
+---Creates the outline window and sets it up
+---@param split_command string A valid split command that is to be executed in order to create the view.
+function View:setup_view(split_command)
   -- create a scratch unlisted buffer
   self.bufnr = vim.api.nvim_create_buf(false, true)
 
   -- delete buffer when window is closed / buffer is hidden
   vim.api.nvim_buf_set_option(self.bufnr, 'bufhidden', 'delete')
   -- create a split
-  vim.cmd(cfg.get_split_command())
+  vim.cmd(split_command)
+
   -- resize to a % of the current window size
   vim.cmd('vertical resize ' .. cfg.get_window_width())