Add indentation to imenu in notmuch-show

[notmuch] / emacs / notmuch-show.el

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index e7c22da0f54c35f128b70721128dbe6c87393b26..a4399abb97aa07a4ff08ca125819eb716ac054ae 100644 (file)
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -247,6 +247,19 @@ every user interaction with notmuch."
   :type 'function
   :group 'notmuch-show)
 
+(defcustom notmuch-show-imenu-indent nil
+  "Should Imenu display messages indented.
+
+By default, Imenu (see Info node `(emacs) Imenu') in a
+notmuch-show buffer displays all messages straight.  This is
+because the default Emacs frontend for Imenu makes it difficult
+to select an Imenu entry with spaces in front.  Other imenu
+frontends such as counsel-imenu does not have this limitation.
+In these cases, Imenu entries can be indented to reflect the
+position of the message in the thread."
+  :type 'boolean
+  :group 'notmuch-show)
+
 (defmacro with-current-notmuch-show-message (&rest body)
   "Evaluate body with current buffer set to the text of current message"
   `(save-excursion
@@ -1516,7 +1529,11 @@ All currently available key bindings:
 \\{notmuch-show-mode-map}"
   (setq notmuch-buffer-refresh-function #'notmuch-show-refresh-view)
   (setq buffer-read-only t
-       truncate-lines t))
+       truncate-lines t)
+  (setq imenu-prev-index-position-function
+        #'notmuch-show-imenu-prev-index-position-function)
+  (setq imenu-extract-index-name-function
+        #'notmuch-show-imenu-extract-index-name-function))
 
 (defun notmuch-tree-from-show-current-query ()
   "Call notmuch tree with the current query"
@@ -2465,6 +2482,26 @@ the new buffer."
                          (mailcap-mime-types) nil nil nil nil "text/plain")))
   (notmuch-show-apply-to-current-part-handle #'notmuch-show--mm-display-part mime-type))
 
+(defun notmuch-show-imenu-prev-index-position-function ()
+  "Move point to previous message in notmuch-show buffer.
+This function is used as a value for
+`imenu-prev-index-position-function'."
+  (if (bobp)
+      nil
+    (notmuch-show-previous-message)
+    t))
+
+(defun notmuch-show-imenu-extract-index-name-function ()
+  "Return imenu name for line at point.
+This function is used as a value for
+`imenu-extract-index-name-function'.  Point should be at the
+beginning of the line."
+  (back-to-indentation)
+  (buffer-substring-no-properties (if notmuch-show-imenu-indent
+                                     (line-beginning-position)
+                                   (point))
+                                 (line-end-position)))
+
 (provide 'notmuch-show)
 
 ;;; notmuch-show.el ends here