[PATCH v4 3/3] emacs: colorize buttonized 'id:' links depending on the target message's state

[Pieter Praet <pieter@praet.org>]

* emacs/notmuch-show.el

  (notmuch-show-buttonized-link-colors):
    - new defcustom, allows toggling colorization of buttonized links.

  (notmuch-show-buttonized-link-available),
  (notmuch-show-buttonized-link-available-and-unread),
  (notmuch-show-buttonized-link-missing):
    - new faces for buttonized id: links.

  (notmuch-show-found-target-p):
    - add optional arg SUBQUERY to allow addition filtering,
      eg. with "tag:unread".

  (notmuch-show-buttonize-links):
    - tweak `Message-Id' regexp: less greedy matching.
    - use different face property depending on the result of
      `notmuch-show-found-target-p', causing buttons to available,
      available-and-unread and missing messages to be displayed in
      different colors.
---

Updated regexp.

 emacs/notmuch-show.el |   47 +++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 972ac79..c04fc28 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -899,6 +899,38 @@ current buffer, if possible."
 (defvar notmuch-show-buffer-name nil)
 (make-variable-buffer-local 'notmuch-show-buffer-name)
 
+(defcustom notmuch-show-buttonized-link-colors t
+  "Colorize buttonized links depending on their target's state.
+
+Also see `notmuch-show-buttonized-link-available',
+         `notmuch-show-buttonized-link-available-and-unread',
+         `notmuch-show-buttonized-link-missing'.
+
+Might impact performance."
+  :type 'boolean
+  :group 'notmuch-show)
+
+(defface notmuch-show-buttonized-link-available
+  '((t (:inherit goto-address-mail-face :foreground "blue")))
+  "Face used for buttonized links to messages which are present
+in the mail store."
+  :group 'notmuch-show
+  :group 'notmuch-faces)
+
+(defface notmuch-show-buttonized-link-available-and-unread
+  '((t (:inherit goto-address-mail-face :foreground "green")))
+  "Face used for buttonized links to messages which are present
+in the mail store, and are tagged `unread'."
+  :group 'notmuch-show
+  :group 'notmuch-faces)
+
+(defface notmuch-show-buttonized-link-missing
+  '((t (:inherit goto-address-mail-face :foreground "red")))
+  "Face used for buttonized links to messages which are NOT
+present in in the mail store."
+  :group 'notmuch-show
+  :group 'notmuch-faces)
+
 (defun notmuch-show-buttonize-links (start end)
   "Buttonize URLs and mail addresses between START and END.
 
@@ -907,7 +939,7 @@ a corresponding notmuch search."
   (goto-address-fontify-region start end)
   (save-excursion
     (goto-char start)
-    (while (re-search-forward "id:\\(\"?\\)[^[:space:]\"]+\\1" end t)
+    (while (re-search-forward "id:\\(\"?\\)[^[:space:]\"]+@[^[:space:]\"]\\{3,\\}\\1" end t)
       (let ((message-id (match-string-no-properties 0))
 	    (string-start (match-beginning 0))
 	    (string-end (match-end 0)))
@@ -918,7 +950,14 @@ a corresponding notmuch search."
 				     (notmuch-show-if-found ,message-id))
 			  'follow-link t
 			  'help-echo "Mouse-1, RET: search for this message"
-			  'face goto-address-mail-face)))))
+			  'face (if notmuch-show-buttonized-link-colors
+				    (cond
+				     ((notmuch-show-found-target-p message-id "and tag:unread")
+				      'notmuch-show-buttonized-link-available-and-unread)
+				     ((notmuch-show-found-target-p message-id nil)
+				      'notmuch-show-buttonized-link-available)
+				     (t 'notmuch-show-buttonized-link-missing))
+				  'goto-address-mail-face))))))
 
 ;;;###autoload
 (defun notmuch-show (thread-id &optional parent-buffer query-context buffer-name crypto-switch)
@@ -1008,8 +1047,8 @@ thread id.  If a prefix is given, crypto processing is toggled."
     (notmuch-kill-this-buffer)
     (notmuch-show-worker thread-id parent-buffer query-context buffer-name process-crypto)))
 
-(defun notmuch-show-found-target-p (target)
-  (let ((args `("count" ,target)))
+(defun notmuch-show-found-target-p (target &optional subquery)
+  (let ((args `("count" ,target ,(or subquery ""))))
     (> (string-to-number
 	(with-output-to-string
 	  (apply 'call-process notmuch-command nil standard-output nil args)))
-- 
1.7.8.1