Avoid superfluous registering of signals. (Bug#10807)

* notifications.el (notifications-on-action-object)
(notifications-on-close-object): New defvars.
(notifications-on-action-signal, notifications-on-closed-signal):
Unregister the signal if not needed any longer.
(notifications-notify): Register `notifications-action-signal' or
`notifications-closed-signal', if :on-action or :on-close has been
passed as argument.

2 files changed, 49 insertions, 22 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index da2783ede46..d8342df4da5 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,15 @@
+2012-03-07  Michael Albinus  <Michael.Albinus@alcatel-lucent.com>
+
+        Avoid superfluous registering of signals.  (Bug#10807)
+
+        * notifications.el (notifications-on-action-object)
+        (notifications-on-close-object): New defvars.
+        (notifications-on-action-signal, notifications-on-closed-signal):
+        Unregister the signal if not needed any longer.
+        (notifications-notify): Register `notifications-action-signal' or
+        `notifications-closed-signal', if :on-action or :on-close has been
+        passed as argument.
+
 2012-03-07  Chong Yidong  <cyd@gnu.org>
 
         * cus-start.el: Avoid x-select-enable-clipboard-manager warning on
diff --git a/lisp/notifications.el b/lisp/notifications.el
index 1b75c2c5702..908cbcaabab 100644
--- a/lisp/notifications.el
+++ b/lisp/notifications.el
@@ -88,25 +88,26 @@
 (defvar notifications-on-action-map nil
   "Mapping between notification and action callback functions.")
 
+(defvar notifications-on-action-object nil
+  "Object for registered on-action signal.")
+
 (defvar notifications-on-close-map nil
   "Mapping between notification and close callback functions.")
 
+(defvar notifications-on-close-object nil
+  "Object for registered on-close signal.")
+
 (defun notifications-on-action-signal (id action)
   "Dispatch signals to callback functions from `notifications-on-action-map'."
   (let* ((unique-name (dbus-event-service-name last-input-event))
          (entry (assoc (cons unique-name id) notifications-on-action-map)))
     (when entry
       (funcall (cadr entry) id action)
-      (remove entry notifications-on-action-map))))
-
-(when (fboundp 'dbus-register-signal)
-  (dbus-register-signal
-   :session
-   nil
-   notifications-path
-   notifications-interface
-   notifications-action-signal
-   'notifications-on-action-signal))
+      (when (and (not (setq notifications-on-action-map
+                            (remove entry notifications-on-action-map)))
+                 notifications-on-action-object)
+        (dbus-unregister-object notifications-on-action-object)
+        (setq notifications-on-action-object nil)))))
 
 (defun notifications-on-closed-signal (id &optional reason)
   "Dispatch signals to callback functions from `notifications-on-closed-map'."
@@ -118,16 +119,11 @@
     (when entry
       (funcall (cadr entry)
                id (cadr (assoc reason notifications-closed-reason)))
-      (remove entry notifications-on-close-map))))
-
-(when (fboundp 'dbus-register-signal)
-  (dbus-register-signal
-   :session
-   nil
-   notifications-path
-   notifications-interface
-   notifications-closed-signal
-   'notifications-on-closed-signal))
+      (when (and (not (setq notifications-on-close-map
+                            (remove entry notifications-on-close-map)))
+                 notifications-on-close-object)
+        (dbus-unregister-object notifications-on-close-object)
+        (setq notifications-on-close-object nil)))))
 
 (defun notifications-notify (&rest params)
   "Send notification via D-Bus using the Freedesktop notification protocol.
@@ -287,10 +283,29 @@ used to manipulate the notification item with
           (unique-name (dbus-get-name-owner :session notifications-service)))
       (when on-action
         (add-to-list 'notifications-on-action-map
-                     (list (cons unique-name id) on-action)))
+                     (list (cons unique-name id) on-action))
+        (unless notifications-on-action-object
+          (setq notifications-on-action-object
+                (dbus-register-signal
+                 :session
+                 nil
+                 notifications-path
+                 notifications-interface
+                 notifications-action-signal
+                 'notifications-on-action-signal))))
+
       (when on-close
         (add-to-list 'notifications-on-close-map
-                     (list (cons unique-name id) on-close))))
+                     (list (cons unique-name id) on-close))
+        (unless notifications-on-close-object
+          (setq notifications-on-close-object
+                (dbus-register-signal
+                 :session
+                 nil
+                 notifications-path
+                 notifications-interface
+                 notifications-closed-signal
+                 'notifications-on-closed-signal)))))
 
     ;; Return notification id
     id))