[PATCH 1/1] Make buttons for attachments allow viewing as well as saving

[Mark Walters]

> > I am happy to make that change. My original patch in the summer was more
> > like that:
> > id:"CALUdzSWAto+4mCUOOMk+8vFs+Pog-xUma6u-Aqx2M6-sbyQROg at mail.gmail.com"
> 
> Is this the right id?  I couldn't find it in the list archive.

Sorry I messed up: it should be id:"87mxehqhbl.fsf at r102.config" However
I have included my current draft along these lines. I think it is
working but I am not submitting yet: just asking if this is the right
idea.

Best wishes 

Mark

>From 9e52414b9871369c1cbb5c3e72d833b56bb236d4 Mon Sep 17 00:00:00 2001
From: Mark Walters <markwalters1009 at gmail.com>
Date: Sat, 14 Jan 2012 18:04:22 +0000
Subject: [PATCH] Make buttons for attachments allow viewing as well as saving

Define a keymap for attachment buttons to allow multiple actions.
Define 3 possible actions:
    save attachment: exactly as currently,
    view attachment: uses mailcap entry,
    view attachment with user chosen program

Keymap on a button is: s for save, v for view and o for view with
other program. Default (i.e. enter or mouse button) is save but this
is configurable in notmuch customize.

One implementation detail: the view attachment function forces all
attachments to be "displayed" using mailcap even if emacs could
display them itself. Thus, for example, text/html appears in a browser
and text/plain asks whether to save (on a standard debian setup)
---
 emacs/notmuch-show.el |   87 ++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 79 insertions(+), 8 deletions(-)

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 03c1f6b..2413caa 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -281,10 +281,21 @@ message at DEPTH in the current thread."
 	(run-hooks 'notmuch-show-markup-headers-hook)))))
 
 (define-button-type 'notmuch-show-part-button-type
-  'action 'notmuch-show-part-button-action
+  'action 'notmuch-show-part-button-default
+  'keymap 'notmuch-show-part-button-map
   'follow-link t
   'face 'message-mml)
 
+(defvar notmuch-show-part-button-map
+  (let ((map (make-sparse-keymap)))
+       (set-keymap-parent map button-map)
+       (define-key map "s" 'notmuch-show-part-button-save)
+       (define-key map "v" 'notmuch-show-part-button-view)
+       (define-key map "o" 'notmuch-show-part-button-interactively-view)
+    map)
+  "Submap for button commands")
+(fset 'notmuch-show-part-button-map notmuch-show-part-button-map)
+
 (defun notmuch-show-insert-part-header (nth content-type declared-type &optional name comment)
   (let ((button))
     (setq button
@@ -299,7 +310,8 @@ message at DEPTH in the current thread."
 		   " ]")
 	   :type 'notmuch-show-part-button-type
 	   :notmuch-part nth
-	   :notmuch-filename name))
+	   :notmuch-filename name
+	   :notmuch-content-type content-type))
     (insert "\n")
     ;; return button
     button))
@@ -323,6 +335,28 @@ message at DEPTH in the current thread."
 	;; ange-ftp, which is reasonable to use here.
 	(mm-write-region (point-min) (point-max) file nil nil nil 'no-conversion t)))))
 
+(defun notmuch-show-view-part (message-id nth content-type)
+  (let ((process-crypto notmuch-show-process-crypto))
+    (with-temp-buffer
+      (setq notmuch-show-process-crypto process-crypto)
+      ;; Always acquires the part via `notmuch part', even if it is
+      ;; available in the JSON output.
+      (insert (notmuch-show-get-bodypart-internal message-id nth))
+      ;; set mm-inlined-types to nil to force an external viewer
+      (let ((handle (mm-make-handle (current-buffer) (list content-type)))
+	    (mm-inlined-types nil))
+	(mm-display-part handle t)))))
+
+(defun notmuch-show-interactively-view-part (message-id nth content-type)
+  (let ((process-crypto notmuch-show-process-crypto))
+    (with-temp-buffer
+      (setq notmuch-show-process-crypto process-crypto)
+      ;; Always acquires the part via `notmuch part', even if it is
+      ;; available in the JSON output.
+      (insert (notmuch-show-get-bodypart-internal message-id nth))
+      (let ((handle (mm-make-handle (current-buffer) (list content-type))))
+	(mm-interactively-view-part handle)))))
+
 (defun notmuch-show-mm-display-part-inline (msg part nth content-type)
   "Use the mm-decode/mm-view functions to display a part in the
 current buffer, if possible."
@@ -1502,12 +1536,49 @@ buffer."
 
 ;; Commands typically bound to buttons.
 
-(defun notmuch-show-part-button-action (button)
-  (let ((nth (button-get button :notmuch-part)))
-    (if nth
-	(notmuch-show-save-part (notmuch-show-get-message-id) nth
-				(button-get button :notmuch-filename))
-      (message "Not a valid part (is it a fake part?)."))))
+(defcustom notmuch-show-part-button-default-action 'notmuch-show-part-button-save
+  "Default part header button action (on ENTER or mouse click)."
+  :group 'notmuch
+  :type '(choice (const :tag "Save part"
+			notmuch-show-part-button-save)
+		 (const :tag "View part"
+			notmuch-show-part-button-view)
+		 (const :tag "View interactively"
+			notmuch-show-part-button-interactively-view)))
+
+(defun notmuch-show-part-button-default (&optional button)
+  (interactive)
+  (funcall notmuch-show-part-button-default-action button))
+
+(defun notmuch-show-part-button-save (&optional button)
+  (interactive)
+  (let ((button (or button (button-at (point)))))
+    (if button
+	(let ((nth (button-get button :notmuch-part)))
+	  (if nth
+	      (notmuch-show-save-part (notmuch-show-get-message-id) nth
+				      (button-get button :notmuch-filename))
+	    (message "Not a valid part (is it a fake part?)."))))))
+
+(defun notmuch-show-part-button-view (&optional button)
+  (interactive)
+  (let ((button (or button (button-at (point)))))
+    (if button
+	(let ((nth (button-get button :notmuch-part)))
+	  (if nth
+	      (notmuch-show-view-part (notmuch-show-get-message-id) nth
+				      (button-get button :notmuch-content-type))
+	    (message "Not a valid part (is it a fake part?)."))))))
+
+(defun notmuch-show-part-button-interactively-view (&optional button)
+  (interactive)
+  (let ((button (or button (button-at (point)))))
+    (if button
+	(let ((nth (button-get button :notmuch-part)))
+	  (if nth
+	      (notmuch-show-interactively-view-part (notmuch-show-get-message-id) nth
+						    (button-get button :notmuch-content-type))
+	    (message "Not a valid part (is it a fake part?)."))))))
 
 ;;
 
-- 
1.7.2.3