bug#47690: 28.0.50; repeat-mode: Introduce a defmacro for chaining commands ???

[Ramesh Nedunchezian <rameshnedunchezian@outlook.com>]

Think of this email not as a bug, but as a note ... So, feel free to
close it after digesting the contents.

Context:

   When I look at the documentation of many of the MELPA packages,
   they have long long long lines i.e., one line per-paragraph.  It
   always bothers me when I run across such files.  I always hated
   reaching out to menu to fix the wrap.  Now that there is
   `repeat-mode', I can mindlessly keep pressing a key--F12 in the
   present case--to cycle through various wraps until I land in the
   one that is agreeable.

;; Pressing F12 repeatedly is equivalent to cycling through the
;; following 3 radio buttons
;;
;; 1. Wrap at Window Edge
;; 2. Truncate Long Lines
;; 3. Word Wrap (Visual Line Mode)
;;
;; in Menu->Options->Line Wrapping in this Buffer.
;;
;; This is implemented through the all new `repeat-mode' feature.
;;
;; Much like how `C-l' (= `recenter-top-bottom') cycles the cursor
;; though different positions, pressing F12 will take the buffer
;; through different wrap settings.
;;
;; This is what I see in *Messages* buffer when I press F12
;; repeatedly.
;;
;; Visual-Line mode enabled
;; Visual-Line mode enabled [Repeat with <f12>]
;; Truncate long lines enabled
;; Truncate long lines enabled [Repeat with <f12>]
;; Truncate long lines disabled
;; Truncate long lines disabled [Repeat with <f12>]
;; Visual-Line mode enabled
;; Visual-Line mode enabled [Repeat with <f12>]

;; Note: Instead of wrapping at window edge, a better idea would be to
;; use `visual-fill-mode'.  See
;; https://elpa.gnu.org/packages/visual-fill.html.

;; It may be a good idea (?) to provide a macro, say, `chaincmds',
;; which can generate the below code when invoked with
;;
;; (chain-cmds (kbd "<f12>")
;; 		'(menu-bar--visual-line-mode-enable
;; 		  menu-bar--toggle-truncate-long-lines 
;; 		  menu-bar--wrap-long-lines-window-edge))

(define-key global-map (kbd "<f12>") 'menu-bar--visual-line-mode-enable)
(let ((key [f12]))
  (defvar menu-bar--visual-line-mode-enable--repeat-map
    (let ((map (make-sparse-keymap))) map))
  (define-key menu-bar--visual-line-mode-enable--repeat-map key 'menu-bar--toggle-truncate-long-lines)

  (put 'menu-bar--visual-line-mode-enable 'repeat-map 'menu-bar--visual-line-mode-enable--repeat-map)
  

  (defvar menu-bar--toggle-truncate-long-lines--repeat-map
    (let ((map (make-sparse-keymap))) map))
  (define-key menu-bar--toggle-truncate-long-lines--repeat-map key 'menu-bar--wrap-long-lines-window-edge)

  (put 'menu-bar--toggle-truncate-long-lines 'repeat-map 'menu-bar--toggle-truncate-long-lines--repeat-map)

  (defvar menu-bar--wrap-long-lines-window-edge--repeat-map
    (let ((map (make-sparse-keymap))) map))
  (define-key menu-bar--wrap-long-lines-window-edge--repeat-map key 'menu-bar--visual-line-mode-enable)

  (put 'menu-bar--wrap-long-lines-window-edge 'repeat-map 'menu-bar--wrap-long-lines-window-edge--repeat-map))


--------------------------------


In GNU Emacs 28.0.50 (build 5, x86_64-pc-linux-gnu, GTK+ Version 3.24.24, cairo version 1.16.0)
 of 2021-04-10 built on debian
Repository revision: 0db2126d7176b0bd1b13d4b0d1cd958c8cf55714
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12010000
System Description: Debian GNU/Linux bullseye/sid

Configured using:
 'configure -with-imagemagick --with-json --with-xwidgets'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ
IMAGEMAGICK JPEG JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2
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