Doc-view as default viewer for pdf, ps and dvi files (was: Please install: Some improvements to doc-view.el)

[Tassilo Horn]

Hi all,

the attached patch makes doc-view the standard viewer for pdf, ps and
dvi files.  It's done as Juri proposed and image-mode already does.

Whenever you find such a file it will be opened with doc-view-mode in a
text representation.  If emacs was compiled with image (png) support, it
will be switched to the rendered image presentation immediately,
otherwise we stay in the text display mode.

With `C-c C-c' one can toggle between image and source text display.
Both display modes are read-only.  With `C-c C-e' one can switch to an
appropriate editing mode -- ps-mode for ps files and fundamental-mode
for pdf and dvi files.

In the rendered image representation the binding `g' reconverts the
document.

I've tested it briefly and it seems to work well.

Index: lisp/files.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/files.el,v
retrieving revision 1.931
diff -u -r1.931 files.el
--- lisp/files.el       9 Oct 2007 08:52:45 -0000       1.931
+++ lisp/files.el       11 Oct 2007 01:22:06 -0000
@@ -2058,7 +2058,7 @@
      ("\\.\\(as\\|mi\\|sm\\)2\\'" . snmpv2-mode)
      ("\\.\\(diffs?\\|patch\\|rej\\)\\'" . diff-mode)
      ("\\.\\(dif\\|pat\\)\\'" . diff-mode) ; for MSDOG
-     ("\\.[eE]?[pP][sS]\\'" . ps-mode)
+     ("\\.\\(?:DVI\\|P\\(?:DF\\|S\\)\\|dvi\\|p\\(?:df\\|s\\)\\)$" . 
doc-view-mode)
      ("configure\\.\\(ac\\|in\\)\\'" . autoconf-mode)
      ("BROWSE\\'" . ebrowse-tree-mode)
      ("\\.ebrowse\\'" . ebrowse-tree-mode)
Index: lisp/doc-view.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/doc-view.el,v
retrieving revision 1.4
diff -u -r1.4 doc-view.el
--- lisp/doc-view.el    3 Oct 2007 23:39:58 -0000       1.4
+++ lisp/doc-view.el    11 Oct 2007 01:22:06 -0000
@@ -5,7 +5,7 @@
 ;; Author: Tassilo Horn <address@hidden>
 ;; Maintainer: Tassilo Horn <address@hidden>
 ;; Keywords: files, pdf, ps, dvi
-;; Version: <2007-10-02 Tue 18:21>
+;; Version: <2007-10-10 Wed 23:52>
 
 ;; This file is part of GNU Emacs.
 
@@ -37,16 +37,19 @@
 ;; inside an Emacs buffer.  This buffer uses `doc-view-mode' which provides
 ;; convenient key bindings for browsing the document.
 ;;
-;; To use it simply do
+;; To use it simply open a document file with
 ;;
-;;     M-x doc-view RET
+;;     C-x C-f ~/path/to/document RET
 ;;
-;; and you'll be queried for a document to open.
+;; and the document will be converted and displayed, if your emacs supports png
+;; images.  With `C-c C-c' you can toggle between the rendered images
+;; representation and the source text representation of the document.  With
+;; `C-c C-e' you can switch to an appropriate editing mode for the document.
 ;;
 ;; Since conversion may take some time all the PNG images are cached in a
 ;; subdirectory of `doc-view-cache-directory' and reused when you want to view
-;; that file again.  This reusing can be omitted if you provide a prefx
-;; argument to `doc-view'.  To delete all cached files use
+;; that file again.  To reconvert a document hit `g' (`doc-view-reconvert-doc')
+;; when displaying the document.  To delete all cached files use
 ;; `doc-view-clear-cache'.  To open the cache with dired, so that you can tidy
 ;; it out use `doc-view-dired-cache'.
 ;;
@@ -67,8 +70,6 @@
 ;; bottom-right corner of the desired slice.  To reset the slice use
 ;; `doc-view-reset-slice' (bound to `s r').
 ;;
-;; Dired users should have a look at `doc-view-dired'.
-;;
 ;; You can also search within the document.  The command `doc-view-search'
 ;; (bound to `C-s') queries for a search regexp and initializes a list of all
 ;; matching pages and messages how many match-pages were found.  After that you
@@ -80,17 +81,16 @@
 ;; conversion.  When that finishes and you're still viewing the document
 ;; (i.e. you didn't switch to another buffer) you're queried for the regexp
 ;; then.
+;;
+;; Dired users can simply hit `v' on a document file.  If it's a PS, PDF or DVI
+;; it will be opened using `doc-view-mode'.
+;;
 
 ;;; Configuration:
 
-;; Basically doc-view should be quite usable with its standard settings, so
-;; putting
-;;
-;;     (require 'doc-view)
-;;
-;; into your `user-init-file' should be enough.  If the images are too small or
-;; too big you should set the "-rXXX" option in `doc-view-ghostscript-options'
-;; to another value.  (The bigger your screen, the higher the value.)
+;; If the images are too small or too big you should set the "-rXXX" option in
+;; `doc-view-ghostscript-options' to another value.  (The bigger your screen,
+;; the higher the value.)
 ;;
 ;; This and all other options can be set with the customization interface.
 ;; Simply do
@@ -201,7 +201,10 @@
 (defvar doc-view-current-info nil
   "Only used internally.")
 
-;;;; DocView Keymap
+(defvar doc-view-current-display nil
+  "Only used internally.")
+
+;;;; DocView Keymaps
 
 (defvar doc-view-mode-map
   (let ((map (make-sparse-keymap)))
@@ -235,9 +238,21 @@
     (define-key map (kbd "M-v")       'scroll-down)
     ;; Show the tooltip
     (define-key map (kbd "C-t")       'doc-view-show-tooltip)
+    ;; Toggle between text and image display or editing
+    (define-key map (kbd "C-c C-c")   'doc-view-toggle-display)
+    (define-key map (kbd "C-c C-e") 'doc-view-edit-doc)
+    ;; Reconvert the current document
+    (define-key map (kbd "g")         'doc-view-reconvert-doc)
     (suppress-keymap map)
     map)
-  "Keymap used by `doc-view-mode'.")
+  "Keymap used by `doc-view-mode' when displaying a doc as a set of images.")
+
+(defvar doc-view-mode-text-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map (kbd "C-c C-c") 'doc-view-toggle-display)
+    (define-key map (kbd "C-c C-e") 'doc-view-edit-doc)
+    map)
+  "Keymap used by `doc-view-mode' when displaying a document as text.")
 
 ;;;; Navigation Commands
 
@@ -271,16 +286,16 @@
                         (setq contexts (concat contexts "  - \"" m "\"\n")))
                       contexts)))))
     ;; Update the buffer
-    (setq inhibit-read-only t)
-    (erase-buffer)
-    (let ((beg (point)))
-      (doc-view-insert-image (nth (1- page) doc-view-current-files)
-                            :pointer 'arrow)
-      (put-text-property beg (point) 'help-echo doc-view-current-info))
-    (insert "\n" doc-view-current-info)
-    (goto-char (point-min))
-    (forward-char)
-    (setq inhibit-read-only nil)))
+    (let ((inhibit-read-only t))
+      (erase-buffer)
+      (let ((beg (point)))
+       (doc-view-insert-image (nth (1- page) doc-view-current-files)
+                              :pointer 'arrow)
+       (put-text-property beg (point) 'help-echo doc-view-current-info))
+      (insert "\n" doc-view-current-info)
+      (goto-char (point-min))
+      (forward-char))
+    (set-buffer-modified-p nil)))
 
 (defun doc-view-next-page (&optional arg)
   "Browse ARG pages forward."
@@ -330,10 +345,21 @@
 
 ;;;; Conversion Functions
 
+(defun doc-view-reconvert-doc ()
+  "Reconvert the current document.
+Should be invoked when the cached images aren't up-to-date."
+  (interactive)
+  (let ((inhibit-read-only t)
+       (doc doc-view-current-doc))
+    ;; Clear the old cached files
+    (when (file-exists-p doc-view-current-cache-dir)
+      (dired-delete-file doc-view-current-cache-dir 'always))
+    (doc-view-kill-proc-and-buffer)
+    (find-file doc)))
+
 (defun doc-view-file-name-to-directory-name (file)
   "Return the directory where the png files of FILE should be saved.
-
-It'a a subdirectory of `doc-view-cache-directory'."
+It's a subdirectory of `doc-view-cache-directory'."
   (if doc-view-current-cache-dir
       doc-view-current-cache-dir
     (file-name-as-directory
@@ -398,7 +424,7 @@
   (when doc-view-conversion-refresh-interval
     (setq doc-view-current-timer
          (run-at-time "1 secs" doc-view-conversion-refresh-interval
-                      'doc-view-display
+                      'doc-view-display-maybe
                       doc-view-current-doc))))
 
 (defun doc-view-pdf->txt-sentinel (proc event)
@@ -449,45 +475,26 @@
   (process-put doc-view-current-converter-process 'buffer   (current-buffer))
   (process-put doc-view-current-converter-process 'pdf-file pdf))
 
-(defun doc-view-convert-doc (doc)
-  "Convert DOC to a set of png files, one file per page.
-
+(defun doc-view-convert-current-doc ()
+  "Convert `doc-view-current-doc' to a set of png files, one file per page.
 Those files are saved in the directory given by
 `doc-view-file-name-to-directory-name'."
   (clear-image-cache)
-  (let* ((dir (doc-view-file-name-to-directory-name doc))
-        (png-file (concat (file-name-as-directory dir) "page-%d.png")))
-    (when (file-exists-p dir)
-      (dired-delete-file dir 'always))
-    (make-directory dir t)
-    (if (not (string= (file-name-extension doc) "dvi"))
+  ;; Calculate the cache dir
+  (setq doc-view-current-cache-dir
+       (doc-view-file-name-to-directory-name doc-view-current-doc))
+  (let ((png-file (concat (file-name-as-directory doc-view-current-cache-dir)
+                         "page-%d.png")))
+    (make-directory doc-view-current-cache-dir t)
+    (if (not (string= (file-name-extension doc-view-current-doc) "dvi"))
        ;; Convert to PNG images.
-       (doc-view-pdf/ps->png doc png-file)
+       (doc-view-pdf/ps->png doc-view-current-doc png-file)
       ;; DVI files have to be converted to PDF before GhostScript can process
       ;; it.
-      (doc-view-dvi->pdf doc
-                        (concat (file-name-as-directory dir)
+      (doc-view-dvi->pdf doc-view-current-doc
+                        (concat (file-name-as-directory 
doc-view-current-cache-dir)
                                 "doc.pdf")))))
 
-;;;; DocView Mode
-
-(define-derived-mode doc-view-mode nil "DocView"
-  "Major mode in DocView buffers.
-
-\\{doc-view-mode-map}"
-  :group 'doc-view
-  (setq buffer-read-only t)
-  (make-local-variable 'doc-view-current-files)
-  (make-local-variable 'doc-view-current-doc)
-  (make-local-variable 'doc-view-current-image)
-  (make-local-variable 'doc-view-current-page)
-  (make-local-variable 'doc-view-current-converter-process)
-  (make-local-variable 'doc-view-current-timer)
-  (make-local-variable 'doc-view-current-slice)
-  (make-local-variable 'doc-view-current-cache-dir)
-  (make-local-variable 'doc-view-current-info)
-  (make-local-variable 'doc-view-current-search-matches))
-
 ;;;; Slicing
 
 (defun doc-view-set-slice (x y width height)
@@ -555,10 +562,15 @@
        nil
       (string< a b))))
 
+(defun doc-view-display-maybe (doc)
+  "Call `doc-view-display' iff we're in the image display."
+  (when (eq doc-view-current-display 'image)
+    (doc-view-display doc)))
+
 (defun doc-view-display (doc)
   "Start viewing the document DOC."
   (let ((dir (doc-view-file-name-to-directory-name doc)))
-    (set-buffer (format "*DocView: %s*" doc))
+    (set-buffer (get-file-buffer doc))
     (setq doc-view-current-files
          (sort (directory-files dir t "page-[0-9]+\\.png" t)
                'doc-view-sort))
@@ -566,8 +578,6 @@
       (doc-view-goto-page doc-view-current-page))))
 
 (defun doc-view-buffer-message ()
-  (setq inhibit-read-only t)
-  (erase-buffer)
   (insert (propertize "Welcome to DocView!" 'face 'bold)
          "\n"
          "
@@ -580,12 +590,60 @@
 
 `q' : Bury this buffer.  Conversion will go on in background.
 `k' : Kill the conversion process and this buffer.\n")
-  (setq inhibit-read-only nil))
+  (set-buffer-modified-p nil))
 
 (defun doc-view-show-tooltip ()
   (interactive)
   (tooltip-show doc-view-current-info))
 
+;;;;; Toggle between text and image display
+
+(defun doc-view-toggle-display ()
+  "Start or stop displaying a document file as a set of images.
+This command toggles between showing the text of the document
+file and showing the document as a set of images."
+  (interactive)
+  (if (get-text-property (point-min) 'display)
+      ;; Switch to text display
+      (let ((inhibit-read-only t))
+       (erase-buffer)
+       (insert-file-contents doc-view-current-doc)
+       (use-local-map doc-view-mode-text-map)
+       (setq mode-name "DocView[text]"
+             doc-view-current-display 'text)
+       (if (called-interactively-p)
+           (message "Repeat this command to go back to displaying the file as 
images")))
+    ;; Switch to image display
+    (let ((filename (buffer-file-name))
+         (inhibit-read-only t))
+      (erase-buffer)
+      (doc-view-buffer-message)
+      (setq doc-view-current-page (or doc-view-current-page 1)
+           doc-view-current-cache-dir (doc-view-file-name-to-directory-name 
filename))
+      (if (file-exists-p doc-view-current-cache-dir)
+         (progn
+           (message "DocView: using cached files!")
+           (doc-view-display doc-view-current-doc))
+       (doc-view-convert-current-doc))
+      (use-local-map doc-view-mode-map)
+      (setq mode-name (format "DocView")
+           doc-view-current-display 'image)
+      (if (called-interactively-p)
+         (message "Repeat this command to go back to displaying the file as 
text"))))
+  (set-buffer-modified-p nil))
+
+;;;;; Leave doc-view-mode and open the file for edit
+
+(defun doc-view-edit-doc ()
+  "Leave `doc-view-mode' and open the current doc with an appropriate editing 
mode."
+  (interactive)
+  (let ((filename doc-view-current-doc)
+       (auto-mode-alist (append '(("\\.[eE]?[pP][sS]\\'" . ps-mode)
+                                  ("\\.\\(pdf\\|PDF\\|dvi\\|DVI\\)$" . 
fundamental-mode))
+                                auto-mode-alist)))
+    (kill-buffer (current-buffer))
+    (find-file filename)))
+
 ;;;; Searching
 
 (defun doc-view-search-internal (regexp file)
@@ -698,52 +756,41 @@
             (y-or-n-p "No more matches before current page.  Wrap to last 
match? "))
        (doc-view-goto-page (caar (last doc-view-current-search-matches)))))))
 
-;;;; User Interface Commands
+;;;; User interface commands and the mode
+
+(put 'doc-view-mode 'mode-class 'special)
 
 ;;;###autoload
-(defun doc-view (no-cache &optional file)
-  "Convert FILE to png and start viewing it.
-If no FILE is given, query for on.
-If this FILE is still in the cache, don't convert and use the
-existing page files.  With prefix arg NO-CACHE, don't use the
-cached files and convert anew."
-  (interactive "P")
-  (if (not (and (image-type-available-p 'png)
-               (display-images-p)))
-      (message "DocView: your emacs or display doesn't support png images.")
-    (let* ((doc (or file
-                   (expand-file-name
-                    (let ((completion-ignored-extensions
-                           ;; Don't hide files doc-view can display
-                           (remove-if (lambda (str)
-                                        (string-match 
"\\.\\(ps\\|pdf\\|dvi\\)$"
-                                                      str))
-                                      completion-ignored-extensions)))
-                      (read-file-name "File: " nil nil t)))))
-          (buffer (get-buffer-create (format "*DocView: %s*" doc)))
-          (dir (doc-view-file-name-to-directory-name doc)))
-      (switch-to-buffer buffer)
-      (doc-view-buffer-message)
-      (doc-view-mode)
-      (setq doc-view-current-doc doc)
-      (setq doc-view-current-page 1)
-      (if (not (and (file-exists-p dir)
-                   (not no-cache)))
-         (progn
-           (setq doc-view-current-cache-dir nil)
-           (doc-view-convert-doc doc-view-current-doc))
-       (message "DocView: using cached files!")
-       (doc-view-display doc-view-current-doc)))))
-
-(defun doc-view-dired (no-cache)
-  "View the current dired file with doc-view.
-NO-CACHE is the same as in `doc-view'.
-
-You might want to bind this command to a dired key, e.g.
-
-    (define-key dired-mode-map (kbd \"C-c d\") 'doc-view-dired)"
-  (interactive "P")
-  (doc-view no-cache (dired-get-file-for-visit)))
+(define-derived-mode doc-view-mode nil "DocView"
+  "Major mode in DocView buffers.
+You can use \\<doc-view-mode-map>\\[doc-view-toggle-display] to
+toggle between display as a set of images and display as text."
+  :group 'doc-view
+  (make-local-variable 'doc-view-current-files)
+  (make-local-variable 'doc-view-current-doc)
+  (make-local-variable 'doc-view-current-image)
+  (make-local-variable 'doc-view-current-page)
+  (make-local-variable 'doc-view-current-converter-process)
+  (make-local-variable 'doc-view-current-timer)
+  (make-local-variable 'doc-view-current-slice)
+  (make-local-variable 'doc-view-current-cache-dir)
+  (make-local-variable 'doc-view-current-info)
+  (make-local-variable 'doc-view-current-search-matches)
+  (setq doc-view-current-doc buffer-file-name)
+  (insert-file-contents doc-view-current-doc)
+  (use-local-map doc-view-mode-text-map)
+  (setq mode-name "DocView[text]"
+       doc-view-current-display 'text
+       buffer-read-only t)
+  ;; Switch to image display if possible
+  (if (and (display-images-p)
+          (image-type-available-p 'png)
+          (not (get-text-property (point-min) 'display)))
+      (doc-view-toggle-display))
+  (message
+   "%s"
+   (substitute-command-keys
+    "Type \\[doc-view-toggle-display] to toggle between image and text 
display.")))
 
 (defun doc-view-clear-cache ()
   "Delete the whole cache (`doc-view-cache-directory')."
Index: lisp/bindings.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/bindings.el,v
retrieving revision 1.185
diff -u -r1.185 bindings.el
--- lisp/bindings.el    6 Oct 2007 22:15:43 -0000       1.185
+++ lisp/bindings.el    11 Oct 2007 01:22:07 -0000
@@ -536,7 +536,7 @@
        '(".elc" ".lof"
         ".glo" ".idx" ".lot"
         ;; TeX-related
-        ".dvi" ".fmt" ".tfm" ".pdf"
+        ".fmt" ".tfm"
         ;; Java compiled
         ".class"
         ;; CLISP
Index: lisp/ChangeLog
===================================================================
RCS file: /sources/emacs/emacs/lisp/ChangeLog,v
retrieving revision 1.11892
diff -u -r1.11892 ChangeLog
--- lisp/ChangeLog      10 Oct 2007 23:57:32 -0000      1.11892
+++ lisp/ChangeLog      11 Oct 2007 01:22:14 -0000
@@ -1,3 +1,16 @@
+2007-10-10  Tassilo Horn  <address@hidden>
+
+       * bindings.el (completion-ignored-extensions): Remove pdf and dvi
+       extensions since they can be viewed with doc-view.
+
+       * files.el (auto-mode-alist): Make doc-view-mode the default mode
+       for pdf, ps and dvi files.
+
+       * doc-view.el: Make doc-view-mode the standard mode for viewing
+       pdf, ps and dvi files and add binding C-c C-c to toggle between
+       text and image display.  Add binding C-c C-e to switch to an
+       editing mode.
+
 2007-10-10  Carsten Dominik  <address@hidden>
 
        * org.el (org-additional-option-like-keywords): New constant.

What do you think?

Bye,
Tassilo