Add 'modern-mode' command line option

* src/emacs.c (standard_args): Add: '-m' '-modern' '--modern'
	cmd line option.

	* lisp/startup.el (command-line-1): Handle modern-mode cmd line
	option.

lisp/modern-mode.el

@@ -0,0 +1,54 @@
+;;; modern-mode.el --- collection of non invasive modern settings -*- lexical-binding: t -*-
+
+;; Copyright (C) 2020 Free Software Foundation, Inc.
+
+;; Author: Andrea Corallo <akrl@sdf.org>
+;; Version: 0.1
+;; Created: 2020-09-15
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;; A minimal collection of non invasive 'modern' settings trying to
+;; make Emacs more appealing/easy to new comers.
+
+;;; Code:
+
+(defgroup modern-mode nil
+  "A conservative collection of modern settings."
+  :group 'convenience)
+
+;;;###autoload
+(define-minor-mode modern-mode
+  "Toggle modern mode in all buffers."
+  :global t :group 'modern-mode
+  (let ((arg (if modern-mode 1 -1)))
+    (column-number-mode arg)
+    (delete-selection-mode arg)
+    (fido-mode arg)
+    (global-auto-revert-mode arg)
+    (show-paren-mode arg)
+    (winner-mode arg))
+  (if modern-mode
+      (progn
+	(windmove-default-keybindings '(shift))
+	(global-set-key (kbd "C-x C-b") 'ibuffer))
+    (windmove-remove-keybindings)
+    (global-set-key (kbd "C-x C-b") 'list-all-buffers)))
+
+(provide 'modern-mode)
+
+;;; modern-mode.el ends here

lisp/startup.el

@@ -2363,7 +2363,8 @@ A fancy display is used on graphic displays, normal otherwise."
                (longopts
                 (append '("--funcall" "--load" "--insert" "--kill"
                           "--directory" "--eval" "--execute" "--no-splash"
-                          "--find-file" "--visit" "--file" "--no-desktop")
+                          "--find-file" "--visit" "--file" "--no-desktop"
+                          "--modern")
                         (mapcar (lambda (elt) (concat "-" (car elt)))
                                 command-switch-alist)))
                (line 0)
@@ -2514,6 +2515,9 @@ nil default-directory" name)
                          (error "File name omitted from `-insert' option"))
                      (insert-file-contents (command-line-normalize-file-name tem)))
 
+                    ((member argi '("-m" "-modern"))
+                     (modern-mode 1))
+
                     ((equal argi "-kill")
                      (kill-emacs t))
 

lisp/windmove.el

@@ -440,6 +440,15 @@ Default value of MODIFIERS is `shift'."
   (global-set-key (vector (append modifiers '(up)))    'windmove-up)
   (global-set-key (vector (append modifiers '(down)))  'windmove-down))
 
+;;;###autoload
+(defun windmove-remove-keybindings ()
+  "Restore default keybindings touched by `windmove-default-keybindings'."
+  (interactive)
+  (global-set-key (kbd "S-<right>") 'right-char)
+  (global-set-key (kbd "S-<left>") 'left-char)
+  (global-set-key (kbd "S-<up>") 'previous-line)
+  (global-set-key (kbd "S-<down>") 'next-line))
+
 
 ;;; Directional window display and selection
 

src/emacs.c

@@ -2130,6 +2130,8 @@ static const struct standard_args standard_args[] =
   { "-color", "--color", 5, 0},
   { "-no-splash", "--no-splash", 3, 0 },
   { "-no-desktop", "--no-desktop", 3, 0 },
+  { "-m", "--modern", 0, 0 },
+  { "-modern", 0, 0, 0 },
   /* The following two must be just above the file-name args, to get
      them out of our way, but without mixing them with file names.  */
   { "-temacs", "--temacs", 1, 1 },