[PATCH] emacs: Improved printing support.

[David Edmondson]

Add various functions to print notmuch messages and tie them together
with a simple frontend.

Add a binding ('#') in `notmuch-show-mode' to print the current
message.
---

Updates based on Aaron's review - the comments were very useful in
improving things - thanks!

Add a keybinding to `notmuch-show-mode'.

 emacs/Makefile.local   |    3 +-
 emacs/notmuch-print.el |   85 ++++++++++++++++++++++++++++++++++++++++++++++++
 emacs/notmuch-show.el  |   53 ++++++++++++++++++++++++++++++
 3 files changed, 140 insertions(+), 1 deletions(-)
 create mode 100644 emacs/notmuch-print.el

diff --git a/emacs/Makefile.local b/emacs/Makefile.local
index 0c58b82..4fee0e8 100644
--- a/emacs/Makefile.local
+++ b/emacs/Makefile.local
@@ -13,7 +13,8 @@ emacs_sources := \
 	$(dir)/notmuch-maildir-fcc.el \
 	$(dir)/notmuch-message.el \
 	$(dir)/notmuch-crypto.el \
-	$(dir)/coolj.el
+	$(dir)/coolj.el \
+	$(dir)/notmuch-print.el
 
 emacs_images := \
 	$(srcdir)/$(dir)/notmuch-logo.png
diff --git a/emacs/notmuch-print.el b/emacs/notmuch-print.el
new file mode 100644
index 0000000..77f10bb
--- /dev/null
+++ b/emacs/notmuch-print.el
@@ -0,0 +1,85 @@
+;; notmuch-print.el --- printing messages from notmuch.
+;;
+;; Copyright © David Edmondson
+;;
+;; This file is part of Notmuch.
+;;
+;; Notmuch 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.
+;;
+;; Notmuch 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 Notmuch.  If not, see <http://www.gnu.org/licenses/>.
+;;
+;; Authors: David Edmondson <dme at dme.org>
+
+(defcustom notmuch-print-mechanism 'notmuch-print-lpr
+  "How should printing be done?"
+  :group 'notmuch
+  :type '(choice
+	  (function :tag "Use lpr" notmuch-print-lpr)
+	  (function :tag "Use ps-print" notmuch-print-ps-print)
+	  (function :tag "Use ps-print then evince" notmuch-print-ps-print/evince)
+	  (function :tag "Use muttprint" notmuch-print-muttprint)
+	  (function :tag "Use muttprint then evince" notmuch-print-muttprint/evince)
+	  (function :tag "Using a custom function")))
+
+;; Utility functions:
+
+(defun notmuch-print-run-evince (file)
+  "View FILE using 'evince'."
+  (start-process "evince" nil "evince" file))
+
+(defun notmuch-print-run-muttprint (&optional output)
+  "Pass the contents of the current buffer to 'muttprint'.
+
+Optional OUTPUT allows passing a list of flags to muttprint."
+  (apply #'call-process-region (point-min) (point-max)
+	 ;; Reads from stdin.
+	 "muttprint"
+	 nil nil nil
+	 ;; Show the tags.
+	 "--printed-headers" "Date_To_From_CC_Newsgroups_*Subject*_/Tags/"
+	 output))
+
+;; User-visible functions:
+
+(defun notmuch-print-lpr (msg)
+  "Print a message buffer using lpr."
+  (lpr-buffer))
+
+(defun notmuch-print-ps-print (msg)
+  "Print a message buffer using the ps-print package."
+  (let ((subject (plist-get (notmuch-show-get-prop :headers msg) :Subject)))
+    (rename-buffer subject t)
+    (ps-print-buffer)))
+
+(defun notmuch-print-ps-print/evince (msg)
+  "Preview a message buffer using ps-print and evince."
+  (let ((ps-file (make-temp-file "notmuch"))
+	(subject (plist-get (notmuch-show-get-prop :headers msg) :Subject)))
+    (rename-buffer subject t)
+    (ps-print-buffer ps-file)
+    (notmuch-print-run-evince ps-file)))
+
+(defun notmuch-print-muttprint (msg)
+  "Print a message using muttprint."
+  (notmuch-print-run-muttprint))
+ 
+(defun notmuch-print-muttprint/evince (msg)
+  "Preview a message buffer using muttprint and evince."
+  (let ((ps-file (make-temp-file "notmuch")))
+    (notmuch-print-run-muttprint (list "--printer" (concat "TO_FILE:" ps-file)))
+    (notmuch-print-run-evince ps-file)))
+
+(defun notmuch-print-message (msg)
+  "Print a message using the user-selected mechanism."
+  (funcall notmuch-print-mechanism msg))
+
+(provide 'notmuch-print)
diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 797f94b..db25565 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -34,6 +34,7 @@
 (require 'notmuch-wash)
 (require 'notmuch-mua)
 (require 'notmuch-crypto)
+(require 'notmuch-print)
 
 (declare-function notmuch-call-notmuch-process "notmuch" (&rest args))
 (declare-function notmuch-fontify-headers "notmuch" nil)
@@ -186,6 +187,52 @@ indentation."
       mm-handle (> (notmuch-count-attachments mm-handle) 1))))
   (message "Done"))
 
+(defun notmuch-show-with-message-as-text (fn)
+  "Apply FN to a text representation of the current message.
+
+FN is called with one argument, the message properties. It should
+operation on the contents of the current buffer."
+
+  ;; Remake the header to ensure that all information is available.
+  (let* ((to (notmuch-show-get-to))
+	 (cc (notmuch-show-get-cc))
+	 (from (notmuch-show-get-from))
+	 (subject (notmuch-show-get-subject))
+	 (date (notmuch-show-get-date))
+	 (tags (notmuch-show-get-tags))
+	 (depth (notmuch-show-get-depth))
+
+	 (header (concat
+		  "Subject: " subject "\n"
+		  "To: " to "\n"
+		  (if (not (string= cc ""))
+		      (concat "Cc: " cc "\n")
+		    "")
+		  "From: " from "\n"
+		  "Date: " date "\n"
+		  (if tags
+		      (concat "Tags: "
+			      (mapconcat #'identity tags ", ") "\n")
+		    "")))
+	 (all (buffer-substring (notmuch-show-message-top)
+				(notmuch-show-message-bottom)))
+
+	 (props (notmuch-show-get-message-properties)))
+    (with-temp-buffer
+      (insert all)
+      (indent-rigidly (point-min) (point-max) (- depth))
+      ;; Remove the original header.
+      (goto-char (point-min))
+      (re-search-forward "^$" (point-max) nil)
+      (delete-region (point-min) (point))
+      (insert header)
+      (funcall fn props))))
+
+(defun notmuch-show-print-message ()
+  "Print the current message."
+  (interactive)
+  (notmuch-show-with-message-as-text 'notmuch-print-message))
+
 (defun notmuch-show-fontify-header ()
   (let ((face (cond
 	       ((looking-at "[Tt]o:")
@@ -757,6 +804,8 @@ current buffer, if possible."
       (overlay-put headers-overlay 'priority 10))
     (overlay-put (make-overlay body-start body-end) 'invisible message-invis-spec)
 
+    (plist-put msg :depth depth)
+
     ;; Save the properties for this message. Currently this saves the
     ;; entire message (augmented it with other stuff), which seems
     ;; like overkill. We might save a reduced subset (for example, not
@@ -947,6 +996,7 @@ thread id.  If a prefix is given, crypto processing is toggled."
 	(define-key map " " 'notmuch-show-advance-and-archive)
 	(define-key map (kbd "M-RET") 'notmuch-show-open-or-close-all)
 	(define-key map (kbd "RET") 'notmuch-show-toggle-message)
+	(define-key map "#" 'notmuch-show-print-message)
 	map)
       "Keymap for \"notmuch show\" buffers.")
 (fset 'notmuch-show-mode-map notmuch-show-mode-map)
@@ -1107,6 +1157,9 @@ Some useful entries are:
 (defun notmuch-show-get-to ()
   (notmuch-show-get-header :To))
 
+(defun notmuch-show-get-depth ()
+  (notmuch-show-get-prop :depth))
+
 (defun notmuch-show-set-tags (tags)
   "Set the tags of the current message."
   (notmuch-show-set-prop :tags tags)
-- 
1.7.7.3