Add djvu layer

Update layers/+readers/djvu/packages.el

Co-authored-by: Lucius Hu <1222865+lebensterben@users.noreply.github.com>

CHANGELOG.develop

@@ -445,6 +445,7 @@ In org-agenda-mode
 - outshine (thanks to Langston Barrett)
 **** Readers
 - epub (thanks to Jeremy Dormitzer and André Peric Tavares)
+- djvu (thanks to Daniel Nicolai)
 **** Spacemacs
 - spacemacs-defaults
 - spacemacs-modeline
@@ -477,6 +478,7 @@ In org-agenda-mode
 - xclipboard (thanks to Charles Weill, Sylvain Benner, and Alex Palaistras)
 **** WEB services
 - confluence
+- eww (thanks to Colton Kopsa, Maximilian Wolff and Daniel Nicolai)
 *** Renamed layers
 - =extra-langs= renamed to =major-modes= (thanks to Eivind Fonn)
 - =pdf-tools= renamed to =pdf=

layers/+readers/djvu/README.org

@@ -0,0 +1,87 @@
+#+TITLE: djvu layer
+#+TAGS: layer|reader
+
+# The maximum height of the logo should be 200 pixels.
+[[img/djvu-logo.svg]]
+
+# TOC links should be GitHub style anchors.
+* Table of Contents                                        :TOC_4_gh:noexport:
+- [[#description][Description]]
+  - [[#features][Features:]]
+- [[#install][Install]]
+  - [[#prerequisites][Prerequisites]]
+  - [[#dotfile][Dotfile]]
+- [[#key-bindings][Key bindings]]
+
+* Description
+This layer adds support for reading djvu files with spacemacs.
+
+Because of some difficulties, the layer does not lazy load the =djvu.el= and
+=djvu3.el= packages.
+
+** Features:
+This layer provides a full featured djvu editor by implementing the [[https://github.com/dalanicolai/djvu2.el][djvu.el
+package]] along with the [[https://github.com/dalanicolai/djvu3][djvu3]] extension (a newer alternative to [[https://github.com/dalanicolai/djvu2.el][djvu2.el]]).
+
+- flexible annotation editing and rendering, covering most (but not all) of
+  [[https://linux.die.net/man/1/djvused][djvused]] annotation definitions
+- fast navigation with imenu
+- fast search with djvu-occur
+- remember last view with djvu-restore
+- dark mode
+
+* Install
+** Prerequisites
+  The =djvu= package requires the =djvused= command (from [[http://djvu.sourceforge.net/][djvulibre]]) to be
+  available in =exec-path=.
+
+  Additionally, for =dark-mode= availability of the command =pnminvert= (from
+  [[http://netpbm.sourceforge.net/][netpbm]]) is required.
+
+** Dotfile
+    After installing the dependencies, add this to your ~/.spacemacs.
+
+#+BEGIN_SRC emacs-lisp
+(setq-default dotspacemacs-configuration-layers '(djvu))
+#+END_SRC
+
+After that, syncronize your configuration with SPC f e R.
+
+* Key bindings
+
+*djvu-read-mode*
+| Key Binding | Description                                                                      |
+|-------------+----------------------------------------------------------------------------------|
+| ~i~         | djvu-image-toggle                                                                |
+| ~j~         | scroll up                                                                        |
+| ~k~         | scroll down                                                                      |
+| ~J~         | next page                                                                        |
+| ~K~         | previous page                                                                    |
+| ~g~         | goto page                                                                        |
+|             |                                                                                  |
+| ~d~         | djvu-toggle-invert (dark-mode)                                                   |
+| ~c~         | djvu-toggle-semi-continuous-scrolling (works only when image larger than window) |
+| ~+/-~       | zoom-in/out                                                                      |
+| ~, s~       | djvu-occur                                                                       |
+| ~/~         | djvu fast search                                                                 |
+| ~n~         | djvu search continue                                                             |
+|             |                                                                                  |
+| ~SPC j i~   | imenu navigation                                                                 |
+| ~o~         | outline                                                                          |
+
+*Annotations*
+| ~SPC m h~          | keyboard highlight                                     |
+| ~mouse-1-drag~     | highlight                                              |
+| ~S-mouse-1-drag~   | text annotation ([[https://github.com/dalanicolai/djvu3#comments][comment]])                              |
+| ~C-mouse-1-drag~   | text pushpin (rendering pushpin not, yet, implemented) |
+| ~mouse-2-drag~     | line                                                   |
+| ~S-mouse-2-drag~   | horizontal line                                        |
+| ~C-mouse-2-drag~   | vertical line                                          |
+| ~C-S-mouse-2-drag~ | arrow                                                  |
+
+*djvu-image-minor-mode*
+| ~s~ | save-image |
+
+*djvu-occur-mode*
+| ~C-j~ | next entry and follow     |
+| ~C-k~ | prevoius entry and follow |

layers/+readers/djvu/config.el

@@ -0,0 +1,2 @@
+(defvar djvu-semi-continuous-scrolling nil
+  "If non-nil, scroll using visual lines.")

layers/+readers/djvu/funcs.el

@@ -0,0 +1,90 @@
+;;; funcs.el --- DjVu Layer functions File for Spacemacs
+;;
+;; Copyright (c) 2021 Sylvain Benner & Contributors
+;;
+;; Author: Daniel Nicolai <dalanicolai@gmail.com>
+;; URL: https://github.com/syl20bnr/spacemacs
+;;
+;; This file is not part of GNU Emacs.
+;;
+;; 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/>.
+
+
+(defun djvu-toggle-semi-continuous-scrolling ()
+  (interactive)
+  (setq djvu-semi-continuous-scrolling (not djvu-semi-continuous-scrolling))
+  (message "Djvu alternative scrolling %s" (if djvu-semi-continuous-scrolling
+                                               "enabled"
+                                             "disabled")))
+
+(defun spacemacs/djvu-advise-image-toggle (_file &rest args)
+  (djvu-image-toggle))
+
+;; djvu-continuous of djvu.el does not work with djvu3.el
+(defun spacemacs/djvu-scroll-up-or-next-page ()
+  (interactive)
+  (if (not djvu-semi-continuous-scrolling)
+      (if djvu-image-mode
+          (djvu-image-scroll-up)
+        (evil-next-visual-line))
+    (scroll-up-line 5)
+    (when (= (window-vscroll) 0)
+      (djvu-next-page 1))))
+
+(defun spacemacs/djvu-scroll-down-or-previous-page ()
+  (interactive)
+  (if (not djvu-semi-continuous-scrolling)
+      (if djvu-image-mode
+          (djvu-image-scroll-down)
+        (evil-previous-visual-line))
+    (if (/= (window-vscroll) 0)
+        (scroll-down-line 5)
+      (djvu-prev-page 1)
+      (scroll-up-command))))
+
+(defun spacemacs/djvu-fast-search (regexp)
+  (interactive "sSearch (regexp): ")
+  (when djvu-image-mode
+    (djvu-image-toggle))
+  (spacemacs/djvu-search-forward regexp))
+
+(defun spacemacs/djvu-search-forward (query)
+  "Search forward for match for REGEXP.
+Search case-sensitivity is determined by the value of the variable
+`case-fold-search', see Info node `(elisp)Searching and Case'.
+Use the command `djvu-search-forward-continue' to continue the search."
+  (interactive "sQuery: ")
+  (setq djvu-last-search-re query)
+  (while (not (or (search-forward query nil t)
+                  (eq (djvu-ref page) (djvu-ref pagemax))))
+    (djvu-goto-page (let ((page (djvu-ref page))
+                          (return 1))
+                      (while (and (/= return 0) (< page (+ (djvu-ref pagemax) 1)))
+                        (setq return (call-process-shell-command
+                                      (format "djvused %s -e 'select %s; print-pure-txt' | grep -i '%s'"
+                                              (shell-quote-argument buffer-file-name)
+                                              page
+                                              query)))
+                        (setq page (1+ page)))
+                      (print page)))))
+
+(defun djvu-occur-next-entry-and-follow ()
+  (interactive)
+  (evil-next-visual-line)
+  (call-interactively 'djvu-occur-show-entry))
+
+(defun djvu-occur-previous-entry-and-follow ()
+  (interactive)
+  (evil-previous-visual-line)
+  (call-interactively 'djvu-occur-show-entry))

layers/+readers/djvu/layers.el

@@ -0,0 +1 @@
+(configuration-layer/declare-layer 'spacemacs-evil)

layers/+readers/djvu/packages.el

@@ -0,0 +1,111 @@
+;;; packages.el --- djvu layer packages file for Spacemacs.
+;;
+;; Copyright (c) 2021 Sylvain Benner & Contributors
+;;
+;; Author: Daniel Laurens Nicolai <dalanicolai@gmail.com>
+;; URL: https://github.com/syl20bnr/spacemacs
+;;
+;; This file is not part of GNU Emacs.
+;;
+;; 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/>.
+
+;;; Code:
+
+(defconst djvu-packages
+  '(djvu
+    tablist
+    (djvu3 :location (recipe
+                      :fetcher github
+                      :repo "dalanicolai/djvu3"))))
+
+(defun djvu/init-djvu ()
+  (use-package djvu
+    :defer t
+    :magic ("%DJVU" . djvu-read-mode)))
+
+(defun djvu/init-tablist ()
+  (use-package tablist
+    :defer t))
+
+(defun djvu/init-djvu3 ()
+  (use-package djvu3
+    :after djvu
+    :init
+    (add-to-list 'spacemacs-large-file-modes-list 'djvu-read-mode t)
+    (add-hook 'djvu-read-mode-hook (lambda () (setq imenu-create-index-function #'djvu-imenu-create-index)))
+    (add-hook 'djvu-read-mode-hook (lambda ()
+                                     (setq imenu-default-goto-function (lambda (title page)
+                                                                         (djvu-goto-page page djvu-doc)))))
+
+    :config
+    (advice-add 'djvu-find-file :after #'spacemacs/djvu-advise-image-toggle)
+
+    (evilified-state-evilify-map djvu-read-mode-map
+      :mode  djvu-read-mode
+      :bindings
+      "j" 'spacemacs/djvu-scroll-up-or-next-page
+      "k" 'spacemacs/djvu-scroll-down-or-previous-page
+      "J" 'djvu-next-page
+      "K" 'djvu-prev-page
+      "g" 'djvu-goto-page
+      "/" 'spacemacs/djvu-fast-search
+      "n" 'djvu-re-search-forward-continue
+      "H" 'djvu-history-backward
+      "L" 'djvu-history-forward
+      "c" 'djvu-toggle-semi-continuous-scrolling
+      "d" 'djvu-toggle-invert
+      "r" 'djvu-revert-buffer
+      "q" 'djvu-kill-doc)
+
+    (define-key djvu-image-mode-map "s" 'image-save)
+
+    (spacemacs/declare-prefix-for-mode 'djvu-read-mode "mb" "buffers")
+    (spacemacs/set-leader-keys-for-major-mode 'djvu-read-mode
+      "s" 'djvu-occur
+      "h" 'djvu-keyboard-annot
+      "d" 'djvu-toggle-invert
+      "i" 'djvu-image-toggle
+      "bs" 'djvu-switch-shared
+      "bo" 'djvu-switch-outline
+      "bt" 'djvu-switch-text
+      "ba" 'djvu-switch-annot
+      "bb" 'djvu-switch-bookmarks)
+
+    ;; for some reason can not use dolist here
+    (define-key djvu-read-mode-map [remap save-buffer] 'djvu-save)
+    (define-key djvu-script-mode-map [remap save-buffer] 'djvu-save)
+    (define-key djvu-outline-mode-map [remap save-buffer] 'djvu-save)
+
+    (spacemacs/set-leader-keys-for-major-mode 'djvu-script-mode
+      "r" 'djvu-switch-read
+      "s" 'djvu-switch-shared
+      "o" 'djvu-switch-outline
+      "t" 'djvu-switch-text
+      "a" 'djvu-switch-annot
+      "b" 'djvu-switch-bookmarks)
+
+    (evilified-state-evilify-map djvu-outline-mode-map
+      :mode  djvu-outline-mode
+      :bindings
+      "r" 'djvu-revert-buffer
+      "q" 'djvu-quit-window)
+
+    (evilified-state-evilify-map djvu-occur-mode-map
+      :mode djvu-occur-mode
+      :bindings
+      (kbd "C-j") 'djvu-occur-next-entry-and-follow
+      (kbd "C-k") 'djvu-occur-previous-entry-and-follow
+      "r" 'tablist-revert)))
+
+;;; packages.el ends here