Tip: tty mode-line popup menus

[Gerd Möllmann]

Just a tip I wanted to share. Maybe some tty Emacs user finds it useful.
Couldn't find anything mentioned on the internet.

When clicking on, say, the major mode indicator in the mode-line
different things happen, depending on whether I'm using a GUI or tty
Emacs (-nw):

- GUI (NS In may case): a popup menu opens on down-mpuse-1 and stays
  open when I release the mouse button.

- Tty: a popup menu opens on down-mouse-1 and is closed as soon as I
  release the mouse button. If the mouse is over a menu item[B releasing
  the button also selects the menu item.

I don't like the tty behavior. It is fiddly with a track pad, which I
normally use, leading to inadvertent menu selections. Furthermore,
keyboard operation of the menu seems impossible.

To fix this, I've added this in my init.el:

  (defun my-fix-mode-line-map (map)
    (let* ((down-mouse (kbd "<mode-line> <down-mouse-1>"))
           (mouse (kbd "<mode-line> <mouse-1>"))
           (def (lookup-key map down-mouse)))
      (when def
        (define-key map down-mouse nil)
        (define-key map mouse def))))

  (my-fix-mode-line-map mode-line-major-mode-keymap)
  (my-fix-mode-line-map mode-line-minor-mode-keymap)

Have fun!