[PATCH v3 2/9] emacs/show: Allow the user to decide when part headers should be inserted

[David Edmondson]

Make the function that determines whether a part header should be
inserted a user controlled, with some example functions.
---
 emacs/notmuch-show.el | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index ec99141..f78a0ab 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -135,6 +135,17 @@ indentation."
   :type 'boolean
   :group 'notmuch-show)
 
+(defcustom notmuch-show-insert-header-p-function 'notmuch-show-insert-header-p-smart
+  "A function to call to determine whether a MIME part should have a header button.
+
+The function is passed one argument, PART - the MIME part in
+question."
+  :type 'function
+  :group 'notmuch-show
+  :options '(notmuch-show-insert-header-p-smart
+	     notmuch-show-insert-header-p-always
+	     notmuch-show-insert-header-p-never))
+
 (defvar notmuch-show-thread-id nil)
 (make-variable-buffer-local 'notmuch-show-thread-id)
 (put 'notmuch-show-thread-id 'permanent-local t)
@@ -880,12 +891,18 @@ message at DEPTH in the current thread."
 	     "text/x-diff")
 	content-type)))
 
-(defun notmuch-show-insert-header-p (part)
+(defun notmuch-show-insert-header-p-smart (part)
   "Return non-NIL if a header button should be inserted for this part."
   (let ((mime-type (notmuch-show-mime-type part)))
     (not (and (string= mime-type "text/plain")
 	      (<= (plist-get part :id) 1)))))
 
+(defun notmuch-show-insert-header-p-always (part)
+  t)
+
+(defun notmuch-show-insert-header-p-never (part)
+  nil)
+
 (defun notmuch-show-insert-bodypart (msg part depth &optional hide)
   "Insert the body part PART at depth DEPTH in the current thread.
 
@@ -904,7 +921,7 @@ useful for quoting in replies)."
 	 ;; We omit the part button for the first (or only) part if
 	 ;; this is text/plain, or HIDE is 'no-buttons.
 	 (button (when (and (not (equal hide 'no-buttons))
-			    (notmuch-show-insert-header-p part))
+			    (funcall notmuch-show-insert-header-p-function part))
 		   (notmuch-show-insert-part-header nth mime-type content-type (plist-get part :filename))))
 	 (content-beg (point)))
 
-- 
2.0.0.rc0