From 8ccfe9440363569d6624153177d724bbcf2a122f Mon Sep 17 00:00:00 2001 From: Visuwesh Date: Sat, 28 Sep 2024 20:37:50 +0530 Subject: [PATCH] Add imenu index function for Djvu files in doc-view * lisp/doc-view.el (doc-view-imenu-enabled): Tweak the default value to check for 'djvused', and make it obsolete. (doc-view--djvu-outline, doc-view--parse-djvu-outline): Add new functions to return imenu index for a Djvu file. (doc-view--outline): Add new function to create the imenu index depending on the file type. (doc-view--outline): Document new possible variable value. (doc-view-imenu-index): Use the above function instead. (doc-view-imenu-setup): Try to create the imenu index unconditionally. * doc/emacs/misc.texi (DocView Navigation): Mention index creation using 'djvused' too. * etc/NEWS: Announce the change. (Bug#73530) --- doc/emacs/misc.texi | 15 +++---- etc/NEWS | 7 ++++ lisp/doc-view.el | 99 ++++++++++++++++++++++++++++++++++++++------- 3 files changed, 98 insertions(+), 23 deletions(-) diff --git a/doc/emacs/misc.texi b/doc/emacs/misc.texi index e19e554fb26..332d5b1468f 100644 --- a/doc/emacs/misc.texi +++ b/doc/emacs/misc.texi @@ -581,17 +581,14 @@ DocView Navigation default size for DocView, customize the variable @code{doc-view-resolution}. -@vindex doc-view-imenu-enabled @vindex doc-view-imenu-flatten @vindex doc-view-imenu-format - When the @command{mutool} program is available, DocView will use it -to generate entries for an outline menu, making it accessible via the -@code{imenu} facility (@pxref{Imenu}). To disable this functionality -even when @command{mutool} can be found on your system, customize the -variable @code{doc-view-imenu-enabled} to the @code{nil} value. You -can further customize how @code{imenu} items are formatted and -displayed using the variables @code{doc-view-imenu-format} and -@code{doc-view-imenu-flatten}. + DocView can generate an outline menu for PDF and Djvu documents using +the @command{mutool} and the @command{djvused} programs respectively +when they are available. This is made accessible via the @code{imenu} +facility (@pxref{Imenu}). You can customize how @code{imenu} items are +formatted and displayed using the variables @code{doc-view-imenu-format} +and @code{doc-view-imenu-flatten}. @findex doc-view-page-to-register @findex doc-view-jump-to-register diff --git a/etc/NEWS b/etc/NEWS index 607665a71bb..b6035e13639 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -268,6 +268,13 @@ Docview can store current page to buffer local registers with the new command 'doc-view-page-to-register' (bound to 'm'), and later can be restored with 'doc-view-jump-to-register' (bound to '''). ++++ +*** Docview can generate imenu index for Djvu files. +When the 'djvused' program is available, Docview can now generate imenu +index for Djvu files from its outline. +The name of the 'djvused' program can be customized by changing the user +option 'doc-view-djvused-program'. + ** Tramp +++ diff --git a/lisp/doc-view.el b/lisp/doc-view.el index 395993e6263..1c8bcaee2f1 100644 --- a/lisp/doc-view.el +++ b/lisp/doc-view.el @@ -29,6 +29,8 @@ ;; and OXPS documents require `mutool' which comes with mupdf ;; (https://mupdf.com/index.html). Djvu documents require `ddjvu' ;; (from DjVuLibre). ODF files require `soffice' (from LibreOffice). +;; `djvused' (from DjVuLibre) can be optionally used to generate imenu +;; outline for Djvu files when available. ;;; Commentary: @@ -216,10 +218,23 @@ doc-view-mupdf-use-svg :type 'boolean :version "30.1") -(defcustom doc-view-imenu-enabled (and (executable-find "mutool") t) - "Whether to generate an imenu outline when \"mutool\" is available." +(defcustom doc-view-djvused-program (and (executable-find "djvused") + "djvused") + "Name of \"djvused\" program to generate imenu outline for Djvu files. +This is part of DjVuLibre." + :type 'file + :version "31.1") + +(defcustom doc-view-imenu-enabled (and (or (executable-find "mutool") + (executable-find "djvused")) + t) + "Whether to generate imenu outline for PDF and Djvu files. +This uses \"mutool\" for PDF files and \"djvused\" for Djvu files." :type 'boolean - :version "29.1") + :version "31.1") +(make-obsolete-variable 'doc-view-imenu-enabled + "Imenu index is generated unconditionally, when available" + "31.1") (defcustom doc-view-imenu-title-format "%t (%p)" "Format spec for imenu's display of section titles from docview documents. @@ -1953,7 +1968,9 @@ doc-view--outline-rx "[^\t]+\\(\t+\\)\"\\(.+\\)\"\t#\\(?:page=\\)?\\([0-9]+\\)") (defvar-local doc-view--outline nil - "Cached PDF outline, so that it is only computed once per document.") + "Cached PDF outline, so that it is only computed once per document. +It can be the symbol `unavailable' to indicate that outline is +unavailable for the document.") (defun doc-view--pdf-outline (&optional file-name) "Return a list describing the outline of FILE-NAME. @@ -1968,6 +1985,7 @@ doc-view--pdf-outline (fn (expand-file-name fn))) (with-temp-buffer (unless (eql 0 (call-process "mutool" nil (current-buffer) nil "show" fn "outline")) + (setq doc-view--outline 'unavailable) (imenu-unavailable-error "Unable to create imenu index using `mutool'")) (goto-char (point-min)) (while (re-search-forward doc-view--outline-rx nil t) @@ -1978,6 +1996,42 @@ doc-view--pdf-outline outline))) (nreverse outline))))) +(defun doc-view--djvu-outline (&optional file-name) + "Return a list describing the outline of FILE-NAME. +If FILE-NAME is nil or omitted, it defaults to the current buffer's file +name. + +For the format, see `doc-view--pdf-outline'." + (unless file-name (setq file-name (buffer-file-name))) + (with-temp-buffer + (call-process doc-view-djvused-program nil (current-buffer) nil + "-e" "print-outline" file-name) + (goto-char (point-min)) + (when (eobp) + (setq doc-view--outline 'unavailable) + (imenu-unavailable-error "Unable to create imenu index using `djvused'")) + (nreverse (doc-view--parse-djvu-outline (read (current-buffer)))))) + +(defun doc-view--parse-djvu-outline (bookmark &optional level) + "Return a list describing the djvu outline from BOOKMARK. +Optional argument LEVEL is the current heading level, which defaults to 1." + (unless level (setq level 1)) + (let ((res)) + (unless (eq (car bookmark) 'bookmarks) + (user-error "Unknown outline type: %S" (car bookmark))) + (pcase-dolist (`(,title ,page . ,rest) (cdr bookmark)) + (push `((level . ,level) + (title . ,title) + (page . ,(string-to-number (string-remove-prefix "#" page)))) + res) + (when (and rest (listp (car rest))) + (setq res (append + (doc-view--parse-djvu-outline + (cons 'bookmarks rest) + (+ level 1)) + res)))) + res)) + (defun doc-view--imenu-subtree (outline act) "Construct a tree of imenu items for the given outline list and action. @@ -2010,19 +2064,36 @@ doc-view-imenu-index For extensibility, callers can specify a FILE-NAME to indicate the buffer other than the current buffer, and a jumping function GOTO-PAGE-FN other than `doc-view-goto-page'." - (let* ((goto (or goto-page-fn 'doc-view-goto-page)) - (act (lambda (_name _pos page) (funcall goto page))) - (outline (or doc-view--outline (doc-view--pdf-outline file-name)))) - (car (doc-view--imenu-subtree outline act)))) + (unless doc-view--outline + (setq doc-view--outline (doc-view--outline file-name))) + (unless (eq doc-view--outline 'unavailable) + (let* ((goto (or goto-page-fn #'doc-view-goto-page)) + (act (lambda (_name _pos page) (funcall goto page))) + (outline doc-view--outline)) + (car (doc-view--imenu-subtree outline act))))) + +(defun doc-view--outline (&optional file-name) + "Return the outline for the file FILE-NAME. +If FILE-NAME is nil, use the current file instead." + (unless file-name (setq file-name (buffer-file-name))) + (let ((outline + (pcase doc-view-doc-type + ('djvu + (when doc-view-djvused-program + (doc-view--djvu-outline file-name))) + (_ + (doc-view--pdf-outline file-name))))) + (when outline (imenu-add-to-menubar "Outline")) + ;; When the outline could not be made due to unavailability of the + ;; required program, or its absency from the document, return + ;; 'unavailable'. + (or outline 'unavailable))) (defun doc-view-imenu-setup () "Set up local state in the current buffer for imenu, if needed." - (when doc-view-imenu-enabled - (setq-local imenu-create-index-function #'doc-view-imenu-index - imenu-submenus-on-top nil - imenu-sort-function nil - doc-view--outline (doc-view--pdf-outline)) - (when doc-view--outline (imenu-add-to-menubar "Outline")))) + (setq-local imenu-create-index-function #'doc-view-imenu-index + imenu-submenus-on-top nil + imenu-sort-function nil)) ;;;; User interface commands and the mode -- 2.45.2