feat: highlight_closest config option (#52)

lua/aerial/config.lua

@@ -41,7 +41,7 @@ local default_options = {
   },
 
   -- Enum: split_width, full_width, last, none
-  -- Determines line highlighting mode when multiple splits are visible
+  -- Determines line highlighting mode when multiple splits are visible.
   -- split_width   Each open window will have its cursor location marked in the
   --               aerial buffer. Each line will only be partially highlighted
   --               to indicate which window is at that location.
@@ -52,6 +52,9 @@ local default_options = {
   -- none          Do not show the cursor locations in the aerial window.
   highlight_mode = "split_width",
 
+  -- Highlight the closest symbol if the cursor is not exactly on one.
+  highlight_closest = true,
+
   -- When jumping to a symbol, highlight the line for this many ms.
   -- Set to false to disable
   highlight_on_jump = 300,

lua/aerial/data.lua

@@ -6,7 +6,7 @@ local BufData = {
     local new = {
       items = {},
       positions = {},
-      last_position = 1,
+      last_win = -1,
       collapsed = {},
     }
     setmetatable(new, { __index = t })

lua/aerial/init.lua

@@ -118,28 +118,19 @@ M.get_location = function(exact)
   if not pos then
     return {}
   end
-  local item = bufdata:item(pos.lnum)
-  local cur = vim.api.nvim_win_get_cursor(0)
+  local item
+  if exact then
+    item = pos.exact_symbol
+  else
+    item = pos.closest_symbol
+  end
   local ret = {}
   while item do
-    if exact then
-      if not item.end_lnum or not item.end_col then
-        -- end_lnum/end_col isn't supported by all backends yet
-      elseif
-        item.lnum > cur[1]
-        or item.end_lnum < cur[1]
-        or (item.lnum == cur[1] and item.col > cur[2])
-        or (item.end_lnum == cur[1] and item.end_col < cur[2])
-      then
-        goto continue
-      end
-    end
     table.insert(ret, 1, {
       kind = item.kind,
       icon = config.get_icon(item.kind),
       name = item.name,
     })
-    ::continue::
     item = item.parent
   end
   return ret
@@ -204,14 +195,20 @@ M.tree_cmd = function(action, opts)
     fold = true,
   })
   local index
+  local item
   if opts.index then
     index = opts.index
   elseif util.is_aerial_buffer() then
     index = vim.api.nvim_win_get_cursor(0)[1]
   else
-    index = window.get_position_in_win().lnum
+    local pos = window.get_position_in_win()
+    index = pos.lnum
+    item = pos.closest_symbol
+  end
+  if item == nil then
+    item = data[0]:item(index)
   end
-  local lnum = data[0]:item(index).lnum
+  local lnum = item.lnum
   local did_update, new_cursor_pos = tree.edit_tree_node(data[0], action, index, opts)
   if did_update then
     if config.link_tree_to_folds and opts.fold then

lua/aerial/navigation.lua

@@ -180,7 +180,7 @@ M.select = function(opts)
       opts.index = vim.api.nvim_win_get_cursor(0)[1]
     else
       local bufdata = data[0]
-      opts.index = bufdata.positions[winid]
+      opts.index = bufdata.positions[winid].lnum
     end
     opts.index = opts.index or 1
   end

lua/aerial/render.lua

@@ -131,8 +131,10 @@ M.update_highlights = function(buf)
   local hl_width = math.floor(util.get_width(aer_bufnr) / #winids)
 
   if hl_mode == "last" then
-    local row = bufdata.last_position
-    vim.api.nvim_buf_add_highlight(aer_bufnr, ns, "AerialLine", row - 1, 0, -1)
+    local pos = bufdata.positions[bufdata.last_win]
+    if pos and (config.highlight_closest or pos.exact_symbol) then
+      vim.api.nvim_buf_add_highlight(aer_bufnr, ns, "AerialLine", pos.lnum - 1, 0, -1)
+    end
     return
   end
 
@@ -144,14 +146,10 @@ M.update_highlights = function(buf)
     if i == #winids then
       end_hl = -1
     end
-    vim.api.nvim_buf_add_highlight(
-      aer_bufnr,
-      ns,
-      "AerialLine",
-      bufdata.positions[winid].lnum - 1,
-      start_hl,
-      end_hl
-    )
+    local pos = bufdata.positions[winid]
+    if config.highlight_closest or pos.exact_symbol then
+      vim.api.nvim_buf_add_highlight(aer_bufnr, ns, "AerialLine", pos.lnum - 1, start_hl, end_hl)
+    end
     if hl_mode ~= "full_width" then
       start_hl = end_hl
       end_hl = end_hl + hl_width

lua/aerial/window.lua

@@ -209,36 +209,61 @@ M.get_position_in_win = function(bufnr, winid)
   local bufdata = data[bufnr]
   local selected = 0
   local relative = "above"
-  bufdata:visit(function(item)
+  local prev = nil
+  local symbol = bufdata:visit(function(item)
     if item.lnum > lnum then
-      return true
+      return prev or item
     elseif item.lnum == lnum then
       if item.col > col then
-        return true
+        return prev or item
       elseif item.col == col then
         selected = selected + 1
         relative = "exact"
-        return true
+        return item
       else
         relative = "below"
       end
     else
       relative = "below"
     end
+    prev = item
     selected = selected + 1
   end)
+  -- Check if we're on the last symbol
+  if symbol == nil then
+    symbol = prev
+  end
+  local exact_symbol = symbol
+  while
+    exact_symbol
+    -- TODO: end_lnum/end_col isn't supported by all backends yet
+    and exact_symbol.end_lnum
+    and exact_symbol.end_col
+    and (
+      exact_symbol.lnum > lnum
+      or exact_symbol.end_lnum < lnum
+      or (exact_symbol.lnum == lnum and exact_symbol.col > col)
+      or (exact_symbol.end_lnum == lnum and exact_symbol.end_col < col)
+    )
+  do
+    exact_symbol = exact_symbol.parent
+  end
   return {
     lnum = math.max(1, selected),
+    closest_symbol = symbol,
+    exact_symbol = exact_symbol,
     relative = relative,
   }
 end
 
+-- Updates all cursor positions for a given source buffer
 M.update_all_positions = function(bufnr, last_focused_win)
   local source_buffer = util.get_buffers(bufnr)
   local all_source_wins = util.get_fixed_wins(source_buffer)
   M.update_position(all_source_wins, last_focused_win)
 end
 
+-- Update the cursor position for one or more windows
 -- winids can be nil, a winid, or a list of winids
 M.update_position = function(winids, last_focused_win)
   if not config.highlight_mode or config.highlight_mode == "none" then
@@ -267,7 +292,7 @@ M.update_position = function(winids, last_focused_win)
     if pos ~= nil then
       bufdata.positions[target_win] = pos
       if last_focused_win and (last_focused_win == true or last_focused_win == target_win) then
-        bufdata.last_position = pos.lnum
+        bufdata.last_win = target_win
       end
     end
   end
@@ -276,14 +301,14 @@ M.update_position = function(winids, last_focused_win)
   if last_focused_win then
     local aer_winid = util.buf_first_win_in_tabpage(aer_bufnr)
     if aer_winid then
-      local last_position = bufdata.last_position
+      local last_position = bufdata.positions[bufdata.last_win]
       local lines = api.nvim_buf_line_count(aer_bufnr)
 
       -- When aerial window is global, the items can change and cursor will move
       -- before the symbols are published, which causes the line number to be
       -- invalid.
-      if lines >= last_position then
-        api.nvim_win_set_cursor(aer_winid, { bufdata.last_position, 0 })
+      if last_position and lines >= last_position.lnum then
+        api.nvim_win_set_cursor(aer_winid, { last_position.lnum, 0 })
       end
     end
   end