branch: elpa/devhelp
commit 2e257e2d1271d88f09fd09661ba4b705febc1b3c
Author: Akib Azmain Turja <a...@disroot.org>
Commit: Akib Azmain Turja <a...@disroot.org>
Add devhelp.el, README.org and COPYING
---
COPYING | 674 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
README.org | 48 +++++
devhelp.el | 597 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1319 insertions(+)
diff --git a/COPYING b/COPYING
new file mode 100644
index 0000000000..f288702d2f
--- /dev/null
+++ b/COPYING
@@ -0,0 +1,674 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
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+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+ 17. Interpretation of Sections 15 and 16.
+
+ If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+
+ 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 <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+ If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+ <program> Copyright (C) <year> <name of author>
+ This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+ You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+ The GNU General Public License does not permit incorporating your program
+into proprietary programs. If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License. But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.
diff --git a/README.org b/README.org
new file mode 100644
index 0000000000..b27390c52c
--- /dev/null
+++ b/README.org
@@ -0,0 +1,48 @@
+#+title: Devhelp - Browse documentation in Devhelp format
+
+In this unfortunate world, many documentations are using various HTML based
+format, instead of using the excellent Texinfo and Info format. This makes
+integrating of these manuals with Emacs hard, although not impossible.
+
+This package make tries to integrate one of those stupid formats, Devhelp,
+with Emacs.
+
+* Usage
+
+=M-x devhelp= and you are good to go. But you use a system that isn't FHS
+(Filesystem Hierarchy Standard) compliant, then you would need to change
+it. For example, you have to put the following in the init file for GNU
+Guix:
+
+#+begin_src emacs-lisp
+(setq devhelp-search-directories
+ '("/run/current-system/profile/share/doc/"
+ "/run/current-system/profile/share/gtk-doc/html/"
+ "~/.guix-profile/share/doc/"
+ "~/.guix-profile/share/gtk-doc/html/"))
+#+end_src
+
+You can also bookmark pages, with the standard ~bookmark-set~ function.
+
+* Installation
+
+Devhelp isn't available on any ELPA right now. So, you have to follow one
+of the following methods:
+
+** Quelpa
+
+#+begin_src emacs-lisp
+(quelpa '(devhelp :fetcher git
+ :url "https://codeberg.org/akib/emacs-devhelp.git";))
+#+end_src
+
+** Straight.el
+
+#+begin_src emacs-lisp
+(straight-use-package
+ '(devhelp :type git :repo "https://codeberg.org/akib/emacs-devhelp.git";))
+#+end_src
+
+** Manual
+
+Download the ~devhelp.el~ file and put it in your ~load-path~.
diff --git a/devhelp.el b/devhelp.el
new file mode 100644
index 0000000000..18433eb97c
--- /dev/null
+++ b/devhelp.el
@@ -0,0 +1,597 @@
+;;; devhelp.el --- Browse documentation in Devhelp format -*-
lexical-binding: t; -*-
+
+;; Copyright (C) 2022 Akib Azmain Turja.
+
+;; Author: Akib Azmain Turja <a...@disroot.org>
+;; Created: 2022-07-26
+;; Version: 0.1
+;; Package-Requires: ((emacs "27.1"))
+;; Keywords: convenience
+;; URL: https://codeberg.org/akib/emacs-devhelp
+
+;; This file is not part of GNU Emacs.
+
+;; This file 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, 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.
+
+;; For a full copy of the GNU General Public License
+;; see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; In this unfortunate world, many documentations are using various HTML
+;; based format, instead of using the excellent Texinfo and Info format.
+;; This makes integrating of these manuals with Emacs hard, although not
+;; impossible.
+
+;; This package make tries to integrate one of those stupid formats,
+;; Devhelp, with Emacs.
+
+;; Usage
+;; -----
+
+;; M-x devhelp and you are good to go. But you use a system that isn't FHS
+;; (Filesystem Hierarchy Standard) compliant, then you would need to change
+;; it. For example, you have to put the following in the init file for GNU
+;; Guix:
+
+;; (setq devhelp-search-directories
+;; '("/run/current-system/profile/share/doc/"
+;; "/run/current-system/profile/share/gtk-doc/html/"
+;; "~/.guix-profile/share/doc/"
+;; "~/.guix-profile/share/gtk-doc/html/"))
+
+;; You can also bookmark pages, with the standard `bookmark-set' function.
+
+;;; Code:
+
+(eval-when-compile (require 'cl-lib))
+(require 'dom)
+(require 'shr)
+(require 'bookmark)
+
+(defgroup devhelp nil
+ "Browse documentation in Devhelp format."
+ :group 'convenience
+ :link '(url-link "https://codeberg.org/akib/emacs-devhelp";)
+ :prefix "devhelp-")
+
+(defcustom devhelp-use-variable-pitch-font t
+ "Non-nil means use variable pitch (proportional) font."
+ :type 'boolean)
+
+(defcustom devhelp-text-width nil
+ "Window width to use for HTML rendering.
+
+Integer means use that many columns. Nil means use full window width."
+ :type '(choice (integer :tag "Fixed width in characters")
+ (const :tag "Use the width of the window" nil)))
+
+(defcustom devhelp-toc-group-books-by-language t
+ "Non-nil means group books by language in table of contents."
+ :type 'boolean)
+
+(defcustom devhelp-index-group-keywords-by-type t
+ "Non-nil means group keywords by type in index."
+ :type 'boolean)
+
+(defcustom devhelp-search-directories
+ '("/usr/share/doc/" "/usr/share/gtk-doc/html/" "/usr/local/share/doc/"
+ "/usr/local/share/gtk-doc/html/")
+ "List of directories to search for Devhelp books.
+
+Note that on GNU Guix, Nix or other FHS (Filesystem Hierarchy Standard)
+non-compliant distributions, the default value won't work. For GNU Guix,
+set it to '(\"/run/current-system/profile/share/doc/\"
+\"/run/current-system/profile/share/gtk-doc/html/\"
+\"~/.guix-profile/share/doc/\" \"~/.guix-profile/share/gtk-doc/html/\")."
+ :type '(repeat directory))
+
+(defvar devhelp--books nil
+ "Necessary data extracted from Devhelp file.
+
+Each element is a list returned by `devhelp--parse-devhelp-file'.")
+
+(defvar devhelp--history nil
+ "History of pages visited by the user.
+
+The value is of form (CURRENT . STACK), where STACK is the stack of user
+visited pages, and CURRENT is the index of current page in STACK. Each
+element of STACK is a list of form (TITLE FILE BUFFERPOS), where TITLE is
+the title of the page, FILE is the FILE name followed by optional target
+\(see `url-generic-parse-url') and BUFFERPOS is the position in buffer.
+FILE can also be the symbol `toc', meaning the table of contents page.")
+
+(defun devhelp--parse-devhelp-file (file)
+ "Parse Devhelp file FILE and return book data.
+
+Return a list of form (TITLE NAME LANGUAGE PATH CHAPTERS KEYWORDS), where
+TITLE is the title of book, NAME is the name of the book, LANGUAGE is the
+ programming language name, PATH is the absolute path to it, CHAPTER is a
+list of form (SECTION...) and KEYWORDS is a list of form (KEYWORD...).
+SECTION is a list of form (NAME PATH SUB-SECTIONS...), where NAME is the
+name of the section, PATH is the absolute path to the file and SUB-SECTION
+is a list of form (SECTION...). KEYWORD is a list of (NAME TYPE PATH),
+where NAME the keyword name, TYPE is the type of keyword and PATH is the
+absolute path to it."
+ (unless (fboundp 'libxml-parse-html-region)
+ (error "This function requires Emacs to be compiled with libxml2"))
+ (let* ((dom (with-temp-buffer
+ (insert-file-contents file)
+ (libxml-parse-xml-region (point-min) (point-max))))
+ (version (pcase (if (string= (file-name-extension file) "gz")
+ (file-name-extension
+ (file-name-sans-extension file))
+ (file-name-extension file))
+ ("devhelp" 1)
+ ("devhelp2" 2)
+ (_ (error "Invalid Devhelp file"))))
+ (base (expand-file-name (or (dom-attr dom 'base) "")
+ (file-name-directory file))))
+ (cl-labels ((children-by-tag
+ (tree tag)
+ (mapcan (lambda (node)
+ (when (and (listp node) (eq (dom-tag node) tag))
+ (list node)))
+ (dom-children tree)))
+ (process-section
+ (sec)
+ `(,(dom-attr sec 'name)
+ ,(expand-file-name (dom-attr sec 'link) base)
+ ,(mapcar #'process-section (children-by-tag
+ sec 'sub)))))
+ `(,(or (dom-attr dom 'title) "Untitled")
+ ,(or (dom-attr dom 'name) (file-name-base file))
+ ,(or (dom-attr dom 'language) "any")
+ ,(expand-file-name (dom-attr dom 'link) base)
+ ,(mapcar #'process-section
+ (mapcan (lambda (tree) (children-by-tag tree 'sub))
+ (children-by-tag dom 'chapters)))
+ ,(mapcar
+ (lambda (kw)
+ `(,(dom-attr kw 'name)
+ ,(or (dom-attr kw 'type) "function")
+ ,(expand-file-name (dom-attr kw 'link) base)))
+ (mapcan (lambda (tree)
+ (children-by-tag
+ tree (if (eq version 1) 'function 'keyword)))
+ (children-by-tag dom 'functions)))))))
+
+(defun devhelp--search-for-books ()
+ "Search for Devhelp books in `devhelp-search-directories'.
+
+Return a list of book data returned by `devhelp--parse-devhelp-file' for
+each valid Devhelp books."
+ (unless (fboundp 'libxml-parse-html-region)
+ (error "This function requires Emacs to be compiled with libxml2"))
+ (let ((books nil))
+ (dolist (path devhelp-search-directories)
+ (when (file-directory-p path)
+ (dolist (dir (directory-files path))
+ (when (and (file-directory-p (expand-file-name dir path))
+ (not (member dir '("." ".."))))
+ (catch 'stop
+ (dolist (suffix '(".devhelp2" ".devhelp2.gz"
+ ".devhelp" ".devhelp.gz"))
+ (let ((file (expand-file-name
+ (concat dir suffix)
+ (expand-file-name dir path))))
+ (when (file-regular-p file)
+ (ignore-errors
+ (push (devhelp--parse-devhelp-file file) books)
+ (throw 'stop nil))))))))))
+ (sort books (lambda (a b) (string< (car a) (car b))))))
+
+(defun devhelp--file-to-url (file)
+ "Convert path FILE to URL and return it."
+ (concat "file://" (and (memq system-type '(windows-nt ms-dos)) "/")
+ file))
+
+(defun devhelp-toc ()
+ "Open table of contents, of all books.
+
+If a single file was opened, only show that book's table of contents."
+ (interactive)
+ (when (cdr devhelp--history)
+ (if (eq (nth 1 (nth (car devhelp--history) (cdr devhelp--history)))
+ 'history)
+ (setf (nthcdr (car devhelp--history) (cdr devhelp--history))
+ (nthcdr (1+ (car devhelp--history)) (cdr devhelp--history)))
+ (setf (nth 2 (nth (car devhelp--history) (cdr devhelp--history)))
+ (point))
+ (setf (cdr devhelp--history) (nthcdr (car devhelp--history)
+ (cdr devhelp--history)))))
+ (setf (car devhelp--history) 0)
+ (push (list nil 'toc (point-min)) (cdr devhelp--history))
+ (devhelp--toc-1)
+ (goto-char (point-min)))
+
+(defun devhelp--toc-1 ()
+ "Show table of contents.
+
+See `devhelp-toc' for more details."
+ (let ((inhibit-read-only t))
+ (erase-buffer)
+ (insert
+ "<html><head><title>Table of contents</title></head><body><ul>"
+ (let ((book-tocs
+ (mapcar
+ (lambda (book)
+ (cl-labels ((section-to-html
+ (section)
+ (concat
+ "<li>"
+ (format
+ "<a href=%S>%s</a>"
+ (devhelp--file-to-url (nth 1 section))
+ (nth 0 section))
+ (when (nth 2 section)
+ (format
+ "<ul>%s</ul>"
+ (mapconcat #'section-to-html
+ (nth 2 section) "")))
+ "</li>")))
+ (cons
+ (nth 2 book)
+ (concat
+ (format
+ "<b><a href=%S>%s</a></b>"
+ (devhelp--file-to-url (nth 3 book)) (nth 0 book))
+ (when (nth 4 book)
+ (format
+ "<ul>%s</ul>"
+ (mapconcat #'section-to-html (nth 4 book) "")))))))
+ devhelp--books)))
+ (if (not devhelp-toc-group-books-by-language)
+ (mapconcat (lambda (toc) (format "<li>%s</li>" (cdr toc)))
+ book-tocs "")
+ (let ((groups nil))
+ (dolist (toc book-tocs)
+ (if-let ((pair (assoc (car toc) groups)))
+ (setf (cdr pair) (nconc (cdr pair) (list (cdr toc))))
+ (push (cons (car toc) (list (cdr toc))) groups)))
+ (setq groups (sort groups (lambda (a b)
+ (string< (car a) (car b)))))
+ (mapconcat
+ (lambda (group)
+ (when (cdr group)
+ (format
+ "<li><b><u>Language: %s</u></b><ul>%s</ul></li>"
+ (capitalize (car group))
+ (mapconcat (lambda (toc) (format "<li>%s</li>" toc))
+ (cdr group) ""))))
+ groups ""))))
+ "</ul></body></html>")
+ (devhelp--render-html)
+ (goto-char (point-min))))
+
+(defun devhelp-index ()
+ "Show index, of all books.
+
+If a single file was opened, only show that book's index."
+ (interactive)
+ (when (cdr devhelp--history)
+ (if (eq (nth 1 (nth (car devhelp--history) (cdr devhelp--history)))
+ 'history)
+ (setf (nthcdr (car devhelp--history) (cdr devhelp--history))
+ (nthcdr (1+ (car devhelp--history)) (cdr devhelp--history)))
+ (setf (nth 2 (nth (car devhelp--history) (cdr devhelp--history)))
+ (point))
+ (setf (cdr devhelp--history) (nthcdr (car devhelp--history)
+ (cdr devhelp--history)))))
+ (setf (car devhelp--history) 0)
+ (push (list nil 'index (point-min)) (cdr devhelp--history))
+ (devhelp--index-1)
+ (goto-char (point-min)))
+
+(defun devhelp--index-1 ()
+ "Show table of contents.
+
+See `devhelp-index' for more details."
+ (let ((inhibit-read-only t))
+ (erase-buffer)
+ (insert
+ "<html><head><title>Index</title></head><body><ul>"
+ (let ((keywords (mapcan (lambda (book)
+ (copy-sequence (nth 5 book)))
+ devhelp--books)))
+ (sort keywords (lambda (a b) (string< (car a) (car b))))
+ (if (not devhelp-index-group-keywords-by-type)
+ (mapconcat (lambda (keyword)
+ (format "<li>%s <a href=%S>%s</a></li>"
+ (capitalize (nth 1 keyword))
+ (devhelp--file-to-url (nth 2 keyword))
+ (nth 0 keyword)))
+ keywords "")
+ (let ((groups nil))
+ (dolist (keyword keywords)
+ (let ((entry (format "<a href=%S>%s</a>"
+ (devhelp--file-to-url (nth 2 keyword))
+ (nth 0 keyword))))
+ (if-let ((pair (assoc (nth 1 keyword) groups)))
+ (setf (cdr pair) (nconc (cdr pair) (list entry)))
+ (push (cons (nth 1 keyword) (list entry)) groups))))
+ (setq groups (sort groups (lambda (a b)
+ (string< (car a) (car b)))))
+ (mapconcat
+ (lambda (group)
+ (when (cdr group)
+ (format
+ "<li><b><u>Type: %s</u></b><ul>%s</ul></li>"
+ (capitalize (car group))
+ (mapconcat (lambda (entry) (format "<li>%s</li>" entry))
+ (cdr group) ""))))
+ groups ""))))
+ "</ul></body></html>")
+ (devhelp--render-html)
+ (goto-char (point-min))))
+
+(defun devhelp--set-title (title)
+ "Set the title of current page to TITLE."
+ (setq header-line-format
+ (when title (replace-regexp-in-string "%" "%%" title)))
+ (setf (car (nth (car devhelp--history) (cdr devhelp--history))) title))
+
+(defun devhelp-browse-url (&optional event)
+ "Follow link under point/mouse.
+
+EVENT is a mouse event, if any."
+ (interactive (list last-nonmenu-event))
+ (mouse-set-point event)
+ (let ((link (get-text-property (point) 'shr-url)))
+ (devhelp--browse-url-1 link)))
+
+(defun devhelp--browse-url-1 (link)
+ "Goto url specified in LINK."
+ (if (not (stringp link))
+ (user-error "No link under point")
+ (if-let ((url (url-generic-parse-url link))
+ ((string= (url-type url) "file"))
+ (file (url-filename url)))
+ (progn
+ (when (cdr devhelp--history)
+ (setf (nth 2 (nth (car devhelp--history)
+ (cdr devhelp--history)))
+ (point))
+ (setf (cdr devhelp--history)
+ (nthcdr (car devhelp--history)
+ (cdr devhelp--history))))
+ (setf (car devhelp--history) 0)
+ (push (list nil (url-recreate-url (url-parse-make-urlobj
+ nil nil nil nil nil file
+ (url-target url)))
+ (point-min))
+ (cdr devhelp--history))
+ (devhelp--set-title "Untitled")
+ (devhelp--render-html-file
+ (if (memq system-type '(windows-nt ms-dos))
+ (substring file 1)
+ file))
+ (goto-char (point-min))
+ (when (and (url-target url)
+ (not (string-empty-p (url-target url))))
+ (text-property-search-forward 'shr-target-id (url-target url)))
+ (recenter 0)
+ (setf (nth 2 (nth 0 (cdr devhelp--history))) (point)))
+ (browse-url url))))
+
+(defun devhelp--render-html (&optional base)
+ "Render HTML in current buffer.
+
+When BASE is given, use it to make relative URLs absolute."
+ (let ((shr-map
+ (let ((map (make-sparse-keymap)))
+ (set-keymap-parent map shr-map)
+ (let ((fn (if (eq (nth 1 (nth (car devhelp--history)
+ (cdr devhelp--history)))
+ 'history)
+ #'devhelp-history-goto #'devhelp-browse-url)))
+ (define-key map (kbd "RET") fn)
+ (define-key map [mouse-2] fn))
+ map))
+ (shr-external-rendering-functions
+ (append `((title
+ . ,(lambda (dom)
+ (devhelp--set-title (car (dom-children dom))))))
+ shr-external-rendering-functions))
+ (shr-use-fonts devhelp-use-variable-pitch-font)
+ (shr-width devhelp-text-width)
+ (dom (libxml-parse-html-region (point-min) (point-max))))
+ (erase-buffer)
+ (shr-insert-document (if base `(base ((href . ,base)) (,dom)) dom))
+ (goto-char (point-min))))
+
+(defun devhelp--render-html-file (file)
+ "Load and render HTML file FILE in current buffer."
+ (let ((inhibit-read-only t))
+ (erase-buffer)
+ (insert-file-contents file)
+ (devhelp--render-html (devhelp--file-to-url file))))
+
+(defun devhelp--history-goto (n)
+ "Goto Nth page in `devhelp--history'."
+ (if (not (< -1 n (if (eq (nth 1 (nth (car devhelp--history)
+ (cdr devhelp--history)))
+ 'history)
+ (1- (length (cdr devhelp--history)))
+ (length (cdr devhelp--history)))))
+ (user-error (concat (if (< n 0) "Beginning" "End") " of history"))
+ (when (eq (nth 1 (nth (car devhelp--history) (cdr devhelp--history)))
+ 'history)
+ (setf (nthcdr (car devhelp--history) (cdr devhelp--history))
+ (nthcdr (1+ (car devhelp--history)) (cdr devhelp--history))))
+ (setf (nth 2 (nth (car devhelp--history)
+ (cdr devhelp--history)))
+ (point))
+ (setf (car devhelp--history) n)
+ (if (symbolp (nth 1 (nth n (cdr devhelp--history))))
+ (pcase (nth 1 (nth n (cdr devhelp--history)))
+ ('toc (devhelp--toc-1))
+ ('index (devhelp--index-1)))
+ (let* ((url (url-generic-parse-url
+ (devhelp--file-to-url
+ (nth 1 (nth n (cdr devhelp--history))))))
+ (file (url-filename url)))
+ (devhelp--render-html-file
+ (if (memq system-type '(windows-nt ms-dos))
+ (substring file 1)
+ file))))
+ (goto-char (nth 2 (nth n (cdr devhelp--history))))
+ (recenter)))
+
+(defun devhelp-history-back (&optional n)
+ "Go to the previous page.
+
+When prefix argument N is given, go to Nth previous page."
+ (interactive "p")
+ (devhelp--history-goto (+ (car devhelp--history) n)))
+
+(defun devhelp-history-forward (&optional n)
+ "Go to the next page.
+
+When prefix argument N is given, go to Nth next page."
+ (interactive "p")
+ (devhelp--history-goto (- (car devhelp--history) n)))
+
+(defun devhelp-history-goto (&optional event)
+ "Go to history link under point.
+
+This only works in history page.
+
+EVENT is a mouse event, if any."
+ (interactive (list last-nonmenu-event))
+ (mouse-set-point event)
+ (unless (eq (nth 1 (nth (car devhelp--history)
+ (cdr devhelp--history)))
+ 'history)
+ (user-error "Not in history page"))
+ (devhelp--history-goto
+ (string-to-number (get-text-property (point) 'shr-url))))
+
+(defun devhelp-history ()
+ "Show history."
+ (interactive)
+ (setf (nth 2 (nth (car devhelp--history) (cdr devhelp--history)))
+ (point))
+ (let ((inhibit-read-only t))
+ (erase-buffer)
+ (insert "<html><head><title>History of visited pages</title></head>"
+ "<body><h1>History of visited pages</h1><ul>")
+ (dolist (i (number-sequence 0 (1- (length (cdr devhelp--history)))))
+ (insert (format "<li><a href=\"%i\">%s</a></li>" i
+ (let ((title (car (nth i (cdr devhelp--history)))))
+ (if (eq i (car devhelp--history))
+ (format "<i>%s</i>" title)
+ title)))))
+ (insert "</ul></body></html>")
+ (push (list nil 'history (point-min)) (nthcdr (car devhelp--history)
+ (cdr devhelp--history)))
+ (devhelp--render-html)))
+
+(defun devhelp--directory ()
+ "List all available Devhelp books."
+ (message "Composing Devhelp directory...")
+ (setq devhelp--books (devhelp--search-for-books))
+ (devhelp-toc)
+ (message "Composing Devhelp directory...done"))
+
+(defun devhelp--open-file (file)
+ "Open FILE in current buffer."
+ (setq devhelp--books (list (devhelp--parse-devhelp-file file)))
+ (devhelp--browse-url-1 (devhelp--file-to-url
+ (nth 3 (car devhelp--books)))))
+
+;;;###autoload
+(defun devhelp (file buffer)
+ "Browse documentation in Devhelp format.
+
+Interactively, when a non-numeric prefix argument is given, the Devhelp
+file name is read interactively from the minibuffer. When a numeric
+argument N is given, a buffer named \"*devhelp*<N>\" is selected.
+
+Optional argument BUFFER specifies the BUFFER to use, it can be a live
+buffer or a buffer name. If BUFFER is a buffer name and the buffer doesn't
+exist, it is created.
+
+Optional argument FILE specifies the file to open, the default is to open
+the conbined table of contents of all available Devhelp books."
+ (interactive
+ (list (when (and current-prefix-arg (not (numberp current-prefix-arg)))
+ (read-file-name "Devhelp file name: " nil nil t))
+ (when (numberp current-prefix-arg)
+ (format "*devhelp*<%s>" current-prefix-arg))))
+ (unless (fboundp 'libxml-parse-html-region)
+ (error "This function requires Emacs to be compiled with libxml2"))
+ (with-current-buffer (get-buffer-create (or buffer "*devhelp*"))
+ (devhelp-mode)
+ (display-buffer (current-buffer))
+ (if (not file)
+ (devhelp--directory)
+ (devhelp--open-file file))))
+
+(defun devhelp--make-bookmark-record ()
+ "Make a bookmark record."
+ (let ((entry (nth (car devhelp--history) (cdr devhelp--history))))
+ `(,(nth 0 entry)
+ (filename . ,(when (stringp (nth 1 entry)) (nth 1 entry)))
+ (file . ,(nth 1 entry))
+ (position . ,(nth 2 entry))
+ (handler . devhelp-bookmake-jump))))
+
+;;;###autoload
+(defun devhelp-bookmake-jump (bookmark)
+ "Jump to BOOKMARK."
+ (unless (fboundp 'libxml-parse-html-region)
+ (error "This function requires Emacs to be compiled with libxml2"))
+ (with-current-buffer (generate-new-buffer "*devhelp*")
+ (devhelp-mode)
+ (display-buffer (current-buffer))
+ (setq devhelp--books (devhelp--search-for-books))
+ (setq devhelp--history
+ `(0 . ((nil ,(bookmark-prop-get bookmark 'file)
+ ,(bookmark-prop-get bookmark 'position)))))
+ (if (symbolp (bookmark-prop-get bookmark 'file))
+ (pcase (bookmark-prop-get bookmark 'file)
+ ('toc (devhelp--toc-1))
+ ('index (devhelp--index-1)))
+ (let ((file (url-filename
+ (url-generic-parse-url
+ (devhelp--file-to-url
+ (bookmark-prop-get bookmark 'file))))))
+ (devhelp--set-title "Untitled")
+ (devhelp--render-html-file
+ (if (memq system-type '(windows-nt ms-dos))
+ (substring file 1)
+ file))
+ (goto-char (min (max (bookmark-prop-get bookmark 'position)
+ (point-min))
+ (point-max)))
+ (recenter 0)
+ (setf (nth 2 (nth 0 (cdr devhelp--history))) (point))))))
+
+(defvar devhelp-mode-map
+ (let ((map (make-sparse-keymap)))
+ (define-key map (kbd "i") #'devhelp-index)
+ (define-key map (kbd "d") #'devhelp-toc)
+ (define-key map (kbd "l") #'devhelp-history-back)
+ (define-key map (kbd "r") #'devhelp-history-forward)
+ (define-key map (kbd "L") #'devhelp-history)
+ map)
+ "Keymap for Devhelp mode.")
+
+(define-derived-mode devhelp-mode special-mode "Devhelp"
+ "Major mode for browsing Devhelp books."
+ (setq-local devhelp--books nil)
+ (setq-local devhelp--history '(nil . nil))
+ (setq-local bookmark-make-record-function
+ #'devhelp--make-bookmark-record))
+
+(provide 'devhelp)
+;;; devhelp.el ends here
