emacs: show: hide large text attachments by default

notmuch-show can be slow displaying large attachments so hide them by
default. The default maximum size is 10000 bytes/characters but it is
customizable.

Note that notmuch-show-insert-bodypart is also called from the reply
code so we need to be a little careful.

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index f4ad80295d96fa5db7f8f0bc2efb0fbab5a9ec64..2a53461ee64290c2f25f2faee5b4f456003d735e 100644 (file)
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -99,6 +99,13 @@ visible for any given message."
   :group 'notmuch-show
   :group 'notmuch-hooks)
 
+(defcustom notmuch-show-max-text-part-size 10000
+  "Maximum size of a text part to be shown by default in characters.
+
+Set to 0 to show the part regardless of size."
+  :type 'integer
+  :group 'notmuch-show)
+
 ;; Mostly useful for debugging.
 (defcustom notmuch-show-all-multipart/alternative-parts nil
   "Should all parts of multipart/alternative parts be shown?"
@@ -937,14 +944,20 @@ useful for quoting in replies)."
                             "text/x-diff")
                        content-type))
         (nth (plist-get part :id))
+        (long (and (notmuch-match-content-type mime-type "text/*")
+                   (> notmuch-show-max-text-part-size 0)
+                   (> (length (plist-get part :content)) notmuch-show-max-text-part-size)))
         (beg (point))
-        ;; Hide the part initially if HIDE is t.
-        (show-part (not (equal hide t)))
         ;; We omit the part button for the first (or only) part if
         ;; this is text/plain, or HIDE is 'no-buttons.
         (button (unless (or (equal hide 'no-buttons)
                             (and (string= mime-type "text/plain") (<= nth 1)))
                   (notmuch-show-insert-part-header nth mime-type content-type (plist-get part :filename))))
+        ;; Hide the part initially if HIDE is t, or if it is too long
+        ;; and we have a button to allow toggling (thus reply which
+        ;; uses 'no-buttons automatically includes long parts)
+        (show-part (not (or (equal hide t)
+                            (and long button))))
         (content-beg (point)))
 
     ;; Store the computed mime-type for later use (e.g. by attachment handlers).