A very minimal emacs configuration

nano.el

;; nano.el -- A very minimal emacs
;; Usage: emacs -q -l nano.el
;; 
;; Copyright (C) 2020 Nicolas .P Rougier
;;
;; Author: Nicolas P. Rougier <nicolas.rougier@inria.fr>
;;
;; This program 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.

;; This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

(setq default-frame-alist
      (append (list
               '(font . "Roboto Mono Light 14")
               ;; '(unsplittable . t)
               ;; '(buffer-predicate . (lambda (x) nil))
	           '(min-height . 1)
               '(height     . 42)
	           '(min-width  . 40)
	           '(width      . 74)
	           '(foreground-color . "#333333")
               '(background-color . "#ffffff")
               '(cursor-color . "black")
               '(internal-border-width . 1)
               '(vertical-scroll-bars . nil)
               '(left-fringe . 32)
               '(right-fringe . 32)
               '(tool-bar-lines . 0)
               '(menu-bar-lines . 0))))

(setq inhibit-startup-screen t
      inhibit-startup-message t
      inhibit-startup-echo-area-message t
      initial-scratch-message nil)
(tool-bar-mode 0)
(menu-bar-mode t)
(tooltip-mode 0)
(setq org-hide-emphasis-markers t)


(set-face-attribute 'mode-line nil
                    :height 0.5
                    :foreground "#999977"
                    :background "#ffffff"
                    :overline nil
		            :underline nil
		            :box nil)
(set-face-attribute 'mode-line-inactive nil
                    :height 0.5
                    :foreground "#999977"
                    :background "#ffffff"
                    :overline nil 
                    :underline nil
		            :inherit nil
                    :box nil)
(set-face-attribute 'header-line nil
		            :weight 'light
                    :foreground "#000000"
                    :background "#f0f0f0"
                    :overline nil
                    :underline nil
                    :box nil
                    :box `(:line-width 1 :color "#ffffff" :style nil)
		            :inherit nil)

(set-face-attribute 'internal-border nil
                    :background "#777777")
(set-face-attribute 'fringe nil
                    :foreground "#cccccc"
                    :background "#ffffff")
(set-face-attribute 'bold nil
                    :weight 'medium)


(defun header-line-render (left right)
   (let* ((available-width (- (window-total-width) (length left) )))
     (format (format "%%s%%%ds" available-width) left right)))

(setq-default header-line-format
    '((:eval
        (header-line-render
         (format-mode-line
	  (list
	   (cond ((and buffer-file-name (buffer-modified-p)) " [M] ")
		 (buffer-read-only                           " [RO] ")
		 (t                                          " "))
	   (propertize "%b" 'face '(:weight regular))
	   " (%m)"
	   (propertize " " 'display '(raise +0.25))
	   (propertize " " 'display '(raise -0.30))))
         (format-mode-line
	  (list "%l:%c "))))))

(setq-default mode-line-format "%-")


(defun update-buffers-mode-line ()
  (dolist (window (window-list))
    (with-selected-window window
      (if (or (one-window-p t)
	      (eq (window-in-direction 'below) (minibuffer-window))
	      (not (window-in-direction 'below)))
	  (with-current-buffer (window-buffer window)
	    (setq mode-line-format "%-"))
	(with-current-buffer (window-buffer window)
 	  (setq mode-line-format nil)))
      (if (window-in-direction 'above)
	  (face-remap-add-relative 'header-line '(:overline "#777777"))
	(face-remap-add-relative 'header-line '(:overline nil))))))
(add-hook 'window-configuration-change-hook 'update-buffers-mode-line)


(dolist (buffer (list " *Minibuf-0*" " *Echo Area 0*"
                      " *Minibuf-1*" " *Echo Area 1*"))
  (when (get-buffer buffer)
    (with-current-buffer buffer
      (face-remap-add-relative 'default '(:foreground "#999999")))))


;; (define-key global-map (kbd "M-q") 'kill-emacs)
(define-key global-map (kbd "M-n") 'make-frame)
;; (define-key global-map (kbd "M-w") 'delete-frame)


;; See https://200ok.ch/posts/...
;;   ... 2020-09-29_comprehensive_guide_on_handling_long_lines_in_emacs.html
(setq bidi-paragraph-direction 'left-to-right)
(if (version<= "27.1" emacs-version)
    (setq bidi-inhibit-bpa t))
(if (version<= "27.1" emacs-version)
    (global-so-long-mode 1))


(defun help-message ()
  (interactive)
  (let ((message-log-max nil))
    (message
     (concat
      "[C-x C-f] Open  [M-w] Copy   [C-w] Cut   [C-s] Search   ——  "
      (propertize "[C-g]   Cancel" 'face '(:foreground "black"))
      "\n"
      "[C-x C-s] Save  [C-y] Paste  [C-/] Undo  [M-x] Command  ——  "
      (propertize "[C-x C-c] Quit" 'face '(:foreground "black"))))
    ;; (message
    ;;  (concat
    ;;   "[⌘-O] Open [⌘-C] Copy  [⌘-X] Cut  [⌘-F] Search  [⌘-H] Help  "
    ;;   (propertize "[Esc] Cancel" 'face '(:foreground "black"))
    ;;   "\n"
    ;;   "[⌘-S] Save [⌘-V] Paste [⌘-Z] Undo [⌘-R] Replace [⌘-P] Command "
    ;;   (propertize "[⌘-Q] Quit" 'face '(:foreground "black"))))
    (sit-for 30)))

(help-message)
(define-key global-map (kbd "C-h") 'help-message)




(setq minibuffer-prompt-properties
      (quote (read-only nil
	      cursor-intangible t
 	      face minibuffer-prompt)))

(defun nano-minibuffer-hook ()
  (if (active-minibuffer-window)
      (with-current-buffer
	  (window-buffer (active-minibuffer-window))
	(add-text-properties (point-min) (point-max)
			     `(display '(raise +0.25))))))

(defun nano-minibuffer-setup-hook ()
  (add-hook 'post-command-hook 'nano-minibuffer-hook))

(defun nano-minibuffer-exit-hook ()
  (remove-hook 'post-command-hook 'nano-minibuffer-hook))

(defun my-command-error-function (data context caller)
  "Ignore some minor warnings."
  (when (not (memq (car data) '(quit
				beginning-of-line    end-of-line
				beginning-of-buffer  end-of-buffer
				end-of-file          buffer-read-only)))
    (command-error-default-function data context caller)))
(setq command-error-function #'nano-command-error-function)

(defun nano-message (orig-fun &rest args)
  (let* ((msg (if (car args) (apply 'format-message args) ""))
	 (split (string-match "\n.*\\'" msg)))
    (if split
	(let ((part-1 (substring msg 0 split))
	      (part-2 (propertize (substring msg split)
				  'display '(raise +0.25))))
	  (apply orig-fun (list (concat part-1 part-2))))
      (apply orig-fun (list (propertize msg 'display '(raise +0.25)))))))
    
(add-hook 'minibuffer-setup-hook 'nano-minibuffer-setup-hook)
(add-hook 'minibuffer-exit-hook 'nano-minibuffer-exit-hook)
(advice-add 'message :around #'nano-message)