add emacs tip about custom keybindings

diff --git a/emacstips.mdwn b/emacstips.mdwn
index 20b671f1c5fa6dd3ecc94ed1082e66a25615510b..94b09ff9fcbc54fb730917ba4b201a570c202c2c 100644 (file)
--- a/emacstips.mdwn
+++ b/emacstips.mdwn
@@ -70,6 +70,33 @@ As its name implies, notmuch isn't really doing that much (which is part of its
 -----
 
 <h2 id="advanced_tips">Advanced tips and tweaks</h2>
+
+* <span id="custom_keybinding">**Add a keybinding to add/remove/toggle a tag.**</span>
+
+  Here's an example of how to add a key binding to notmuch-show-mode
+  to toggle a "deleted" tag:
+
+               (define-key notmuch-show-mode-map "d"
+                 (lambda ()
+                   "toggle deleted tag for message"
+                   (interactive)
+                   (if (member "deleted" (notmuch-show-get-tags))
+                       (notmuch-show-remove-tag "deleted")
+                     (notmuch-show-add-tag "deleted"))))
+
+  You can do the same for threads in notmuch-search-mode by just
+  replacing "show" with "search" in the called functions.  This
+  definition makes use of a lambda function, but you could just as
+  easily defined a separate function first:
+
+               (defun notmuch-show-toggle-deleted-tag()
+                 "toggle deleted tag for message"
+                 (interactive)
+                 (if (member "deleted" (notmuch-show-get-tags))
+                     (notmuch-show-remove-tag "deleted")
+                   (notmuch-show-add-tag "deleted")))
+               (define-key notmuch-show-mode-map "d" 'notmuch-show-toggle-deleted-tag)
+
 * <span id="fcc">**How to do FCC/BCC...**</span>
 
   Any notmuch reply will automatically include your primary email
@@ -234,4 +261,4 @@ As its name implies, notmuch isn't really doing that much (which is part of its
   This inserts the blurb `<#part sign=pgpmime>` into the beginning of
   my mail text body and will be converted into a pgp signature when
   sending (so I can just manually delete that line if I do not want a
-  mail to be signed).
\ No newline at end of file
+  mail to be signed).