;;; emacspeak-view.el --- Speech enable View mode -- Efficient browsing of read-only content  -*- lexical-binding: t; -*-
;;
;; $Author: tv.raman.tv $ 
;; DescriptionEmacspeak extensions for view
;; Keywords:emacspeak, audio interface to emacs, view-mode
;;{{{  LCD Archive entry: 

;; LCD Archive Entry:
;; emacspeak| T. V. Raman |tv.raman.tv@gmail.com
;; A speech interface to Emacs |
;; 
;;  $Revision: 4532 $ | 
;; Location undetermined
;; 

;;}}}
;;{{{  Copyright:
;; Copyright (C) 1995 -- 2022, T. V. Raman 
;; Copyright (c) 1996 by T. V. Raman 
;; All Rights Reserved. 
;; 
;; This file is not part of GNU Emacs, but the same permissions apply.
;; 
;; 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 2, 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; see the file COPYING.  If not, write to
;; the Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,MA 02110-1301, USA.

;;}}}

;;{{{  Introduction:
;;; Commentary:
;; Provide additional advice to view-mode
;;; Code:
;;}}}
;;{{{ requires
(cl-declaim  (optimize  (safety 0) (speed 3)))
(require 'emacspeak-preamble)

;;}}}
;;{{{  Setup view mode to work with emacspeak

;; restore emacspeak keybindings:
(cl-declaim (special emacspeak-prefix))
(add-hook
 'view-mode-hook
 #'(lambda ()
     (local-unset-key emacspeak-prefix)
     (emacspeak-view-setup-keys)))
;; Generate automatic advise:

;;}}}
;;{{{ additional interactive commands

(defun emacspeak-view-line-to-top ()
  "Moves current line to top of window"
  (interactive)
  (recenter 0)
  (emacspeak-speak-line)
  (emacspeak-auditory-icon 'select-object))

;;}}}
;;{{{ Advise additional interactive commands:
(defadvice view-file (after emacspeak pre act comp)
  "Load directory specific settings"
  (emacspeak-speak-load-directory-settings)
  (outline-minor-mode 1))

(defadvice view-mode (after emacspeak pre act comp)
  "Announce what happened"
  (cl-declare (special view-mode-map))
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'open-object)
    (emacspeak-speak-load-directory-settings)
    (outline-minor-mode 1)
    (if view-mode
        (message "Entered view mode Press %s to exit"
                 (key-description
                  (where-is-internal 'View-exit view-mode-map 'firstonly)))
      (message "Exited view mode"))))

(cl-loop
 for f in
 '(
   View-exit-and-edit View-kill-and-leave
   View-quit-all View-quit)
 do
 (eval
  `(defadvice ,f (after emacspeak pre act comp)
     "speak."
     (when (ems-interactive-p)
       (emacspeak-auditory-icon 'close-object)
       (emacspeak-speak-mode-line)))))

(cl-loop
 for f in
 '(
   view-buffer view-buffer-other-frame view-buffer-other-window
   view-emacs-FAQ
   view-emacs-debugging ^ view-emacs-problems
   view-emacs-todo view-external-packages
   view-file-other-frame view-file-other-window
   view-hello-file view-lossage ) do
 (eval
  `(defadvice ,f (after emacspeak pre act comp)
     "Speech-enabled by Emacspeak."
     (when (ems-interactive-p)
       (emacspeak-auditory-icon 'open-object)
       (emacspeak-speak-mode-line)))))

(defadvice View-exit (after emacspeak pre act comp)
  "speak."
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'close-object)
    (emacspeak-speak-mode-line)))

(defadvice View-leave (after emacspeak pre act comp)
  "speak."
  (when (ems-interactive-p)
    (emacspeak-speak-mode-line)))

(defadvice View-search-regexp-forward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (let ((emacspeak-show-point t))
      (emacspeak-speak-line))
    (emacspeak-auditory-icon 'search-hit)))

(defadvice View-search-regexp-backward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (let ((emacspeak-show-point t))
      (emacspeak-speak-line))
    (emacspeak-auditory-icon 'search-hit)))

(defadvice View-search-last-regexp-forward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (let ((emacspeak-show-point t))
      (emacspeak-speak-line))
    (emacspeak-auditory-icon 'search-hit)))

(defadvice View-search-last-regexp-backward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (let ((emacspeak-show-point t))
      (emacspeak-speak-line))
    (emacspeak-auditory-icon 'search-hit)))

(defadvice view-exit (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'close-object)
    (emacspeak-speak-mode-line)))

(defadvice View-scroll-one-more-line (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'scroll)
    (emacspeak-speak-line)))

(defadvice View-scroll-line-forward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'scroll)
    (emacspeak-speak-line)))

(defadvice View-scroll-line-backward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'scroll)
    (emacspeak-speak-line)))
(defadvice View-scroll-page-forward-set-page-size (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (let ((start (point)))
      (emacspeak-auditory-icon 'scroll)
      (dtk-speak (emacspeak-get-window-contents)))))

(defadvice View-scroll-page-backward-set-page-size (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (let ((start (point)))
      (emacspeak-auditory-icon 'scroll)
      (dtk-speak (emacspeak-get-window-contents)))))

(defadvice View-scroll-half-page-forward (around emacspeak pre act comp)
  "Read newly scrolled contents"
  (cond
   ((ems-interactive-p)
    (let ((start (point)))
      ad-do-it
      (emacspeak-auditory-icon 'scroll)
      (save-excursion
        (end-of-line)
        (dtk-speak
         (buffer-substring
          start (point))))))
   (t ad-do-it))
  ad-return-value)
(defadvice View-scroll-half-page-backward (around emacspeak pre act comp)
  "Read newly scrolled contents"
  (cond
   ((ems-interactive-p)
    (let ((start (point)))
      ad-do-it
      (emacspeak-auditory-icon 'scroll)
      (save-excursion
        (end-of-line)
        (dtk-speak
         (buffer-substring
          start (point))))))
   (t ad-do-it))
  ad-return-value)

(defadvice View-scroll-lines-forward-set-scroll-size (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (let ((start (point)))
      (emacspeak-auditory-icon 'scroll)
      (save-excursion
        (forward-line (window-height))
        (emacspeak-speak-region start (point))))))

(defadvice View-scroll-lines-forward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'scroll)
    (dtk-speak (emacspeak-get-window-contents))))

(defadvice View-scroll-lines-backward (around  emacspeak pre act comp)
  "provide auditory feedback"
  (cond
   ((ems-interactive-p)
    (let ((buffer (current-buffer)))
      ad-do-it
      (cond
       ((not (eq buffer (current-buffer))) ;we exitted view mode 
        (emacspeak-auditory-icon 'close-object)
        (emacspeak-speak-mode-line))
       (t (emacspeak-auditory-icon 'scroll)
          (dtk-speak (emacspeak-get-window-contents))))))
   (t ad-do-it))
  ad-return-value)

(defadvice View-back-to-mark (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'large-movement)
    (let ((emacspeak-show-point t))
      (emacspeak-speak-line))))

(defadvice View-goto-line (after emacspeak pre act comp)
  "Speak"
  (when (ems-interactive-p)
    (let ((line-number
           (format "line %s"
                   (ad-get-arg 0))))
      (put-text-property 0 (length line-number)
                         'personality voice-annotate line-number)
      (emacspeak-auditory-icon 'large-movement)
      (dtk-speak
       (concat line-number (ems--this-line))))))
(defadvice View-scroll-to-buffer-end (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-speak-line)
    (emacspeak-auditory-icon 'large-movement)))

(defadvice View-goto-percent (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'scroll)
    (dtk-speak (emacspeak-get-window-contents))))

(defadvice View-revert-buffer-scroll-page-forward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'scroll)
    (dtk-speak (emacspeak-get-window-contents))))

(defadvice View-scroll-page-forward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'scroll)
    (dtk-speak (emacspeak-get-window-contents))))

(defadvice View-scroll-page-backward (after emacspeak pre act comp)
  "speak"
  (when (ems-interactive-p)
    (emacspeak-auditory-icon 'scroll)
    (dtk-speak (emacspeak-get-window-contents))))

;;}}}
;;{{{ bind convenience keys
(defvar emacspeak-view-keys-optimized nil
  "Records if we have already optimized Emacspeak
keybindings for view mode")

(defvar emacspeak-view-edit-commands
  (list ''completion-separator-self-insert-autofilling
        'completion-separator-self-insert-command
        'delete-char
        'completion-kill-region
        )
  "Editing commands that emacspeak should rebind in view mode")

(defun emacspeak-view-optimize-view-keys()
  "optimize keybindings for emacspeak in view mode"
  (cl-declare (special emacspeak-view-edit-commands
                       emacspeak-view-keys-optimized
                       view-mode-map emacspeak-keymap))
  (unless emacspeak-view-keys-optimized
    (setq emacspeak-view-keys-optimized t)
    (cl-loop for edit-command in emacspeak-view-edit-commands
             do
             (let ((edit-keys (where-is-internal edit-command (list view-mode-map))))
               (cl-loop for key in edit-keys 
                        do
                        (let ((command (lookup-key emacspeak-keymap key)))
                          (when command
                            (define-key view-mode-map key command))))))
    (cl-loop for k in
             '(
               ("[" backward-paragraph)
               ("]" forward-paragraph)
               )
             do
             (define-key view-mode-map (cl-first k) (cl-second k)))))

(defun emacspeak-view-setup-keys()
  "Setup emacspeak convenience keys"
  (cl-declare (special view-mode-map))
  (cl-loop for i from 0 to 9
           do
           (define-key view-mode-map
                       (format "%s" i)
                       'emacspeak-speak-predefined-window))
  ;; convenience keys
  (define-key view-mode-map "\C-j" 'emacspeak-hide-speak-block-sans-prefix)
  (define-key view-mode-map "\M- " 'emacspeak-outline-speak-this-heading)
  (define-key view-mode-map "\M-n" 'outline-next-visible-heading)
  (define-key view-mode-map "\M-p" 'outline-previous-visible-heading)
  (define-key view-mode-map " " 'scroll-up)
  (define-key view-mode-map "\d" 'scroll-down)
  (define-key view-mode-map "[" 'backward-page)
  (define-key view-mode-map "]" 'forward-page)
  (define-key view-mode-map "S" 'dtk-stop)
  (define-key view-mode-map "t" 'emacspeak-view-line-to-top)
  (define-key view-mode-map "," 'emacspeak-speak-current-window)
  (define-key view-mode-map "\M-d" 'emacspeak-pronounce-dispatch)
  (define-key view-mode-map "c" 'emacspeak-speak-char)
  (define-key view-mode-map "w" 'emacspeak-speak-word)
  (emacspeak-view-optimize-view-keys))

;;}}}
(provide  'emacspeak-view)
;;{{{  emacs local variables 

;; local variables:
;; folded-file: t
;; end: 

;;}}}
