feat: new highlight_on_hover option (#65)

lua/aerial/autocommands.lua

@@ -79,8 +79,16 @@ M.on_buf_delete = function(bufnr)
   data[tonumber(bufnr)] = nil
 end
 
-M.on_cursor_move = function()
-  window.update_position(0, true)
+M.on_cursor_move = function(is_aerial_buf)
+  if is_aerial_buf then
+    render.update_highlights(util.get_source_buffer())
+  else
+    window.update_position(0, true)
+  end
+end
+
+M.on_leave_aerial_buf = function()
+  render.clear_highlights(util.get_source_buffer())
 end
 
 M.attach_autocommands = function(bufnr)

lua/aerial/config.lua

@@ -55,6 +55,9 @@ local default_options = {
   -- Highlight the closest symbol if the cursor is not exactly on one.
   highlight_closest = true,
 
+  -- Highlight the symbol in the source buffer when cursor is in the aerial win
+  highlight_on_hover = false,
+
   -- When jumping to a symbol, highlight the line for this many ms.
   -- Set to false to disable
   highlight_on_jump = 300,

lua/aerial/render.lua

@@ -179,8 +179,7 @@ M.update_highlights = function(buf)
   winids = vim.tbl_filter(function(wid)
     return bufdata.positions[wid]
   end, winids)
-  local ns = vim.api.nvim_create_namespace("aerial-line")
-  vim.api.nvim_buf_clear_namespace(aer_bufnr, ns, 0, -1)
+  local ns = M.clear_highlights(aer_bufnr)
   if vim.tbl_isempty(winids) then
     return
   end
@@ -212,6 +211,20 @@ M.update_highlights = function(buf)
       end_hl = end_hl + hl_width
     end
   end
+
+  -- If we're in the aerial buffer, update highlight line in the source buffer
+  if config.highlight_on_hover and aer_bufnr == vim.api.nvim_get_current_buf() then
+    M.clear_highlights(bufnr)
+    local cursor = vim.api.nvim_win_get_cursor(0)
+    local item = data[0]:item(cursor[1])
+    vim.api.nvim_buf_add_highlight(bufnr, ns, "AerialLine", item.lnum - 1, 0, -1)
+  end
+end
+
+M.clear_highlights = function(buf)
+  local ns = vim.api.nvim_create_namespace("aerial-line")
+  vim.api.nvim_buf_clear_namespace(buf, ns, 0, -1)
+  return ns
 end
 
 return M

lua/aerial/window.lua

@@ -34,6 +34,14 @@ local function create_aerial_buffer(bufnr)
   api.nvim_buf_set_option(aer_bufnr, "buflisted", false)
   api.nvim_buf_set_option(aer_bufnr, "swapfile", false)
   api.nvim_buf_set_option(aer_bufnr, "modifiable", false)
+  vim.cmd(string.format(
+    [[
+    au CursorMoved <buffer=%d> lua require('aerial.autocommands').on_cursor_move(true)
+    au BufLeave <buffer=%d> lua require('aerial.autocommands').on_leave_aerial_buf()
+  ]],
+    aer_bufnr,
+    aer_bufnr
+  ))
   return aer_bufnr
 end