Alarm trigger queueing for the GUI part.

2000-12-21  Federico Mena Quintero  <federico@helixcode.com>

	Alarm trigger queueing for the GUI part.

	* gui/alarm-notify.[ch]: New files with the high-level alarm
	notification system; mostly moved over from gnome-cal.c.  The
	low-level timer stuff is still in alarm.[ch].

	* gui/alarm-notify.c (alarm_notify_init): New function to
	initialize the alarm notification system.
	(alarm_notify_done): New function to shut down the alarm
	notification system.
	(alarm_notify_add_client): New function to start monitoring a
	calendar client for alarm notification.
	(alarm_notify_remove_client): New function to stop monitoring a
	client.

	* gui/alarm.h (AlarmDestroyNotify): Also pass in the alarm ID so
	the callback may know which ID is being destroyed.

	* gui/alarm.c (clear_itimer): New function.
	(pop_alarm): Use clear_itimer().
	(alarm_done): New function to shut down the timer system.
	(alarm_add): Add some preconditions.  Do not call the destroy
	notification function if we could not create the alarm.
	(alarm_ready): Pass the alarm ID to the destroy notify function.
	(alarm_remove): Likewise.  Also, add some preconditions.

	* gui/gnome-cal.c: Removed the alarm notification functions from
	here since they are now in alarm-notify.c.
	(gnome_calendar_construct): Register the client with
	alarm_notify_add_client().
	(gnome_calendar_destroy): Use alarm_notify_remove_client() to
	unregister the client.
	(obj_updated_cb): Do not do any alarm-related stuff.
	(obj_removed_cb): Likewise.

	* gui/main.c (main): Shut down the alarm timer system.
	(main): Initialize and shut down the alarm notification system.

	* gui/Makefile.am (evolution_calendar_SOURCES): Added
	alarm-notify.[ch] to the list of sources.

	* gui/calendar-model.c (calendar_model_set_cal_client): Only
	connect to the "cal_loaded" signal if the client is not already
	loaded.

	* gui/e-day-view.c (e_day_view_set_cal_client): Likewise.

	* gui/e-week-view.c (e_week_view_set_cal_client): Likewise.

	* gui/e-itip-control.c (update_calendar): Connect to "cal_loaded"
	before issuing the load request.

svn path=/trunk/; revision=7130

17 files changed, 1378 insertions, 255 deletions

diff --git a/calendar/ChangeLog b/calendar/ChangeLog
index 994d22fa2d..74751b91ca 100644
--- a/calendar/ChangeLog
+++ b/calendar/ChangeLog
@@ -1,3 +1,57 @@
+2000-12-21  Federico Mena Quintero  <federico@helixcode.com>
+
+	Alarm trigger queueing for the GUI part.
+
+	* gui/alarm-notify.[ch]: New files with the high-level alarm
+	notification system; mostly moved over from gnome-cal.c.  The
+	low-level timer stuff is still in alarm.[ch].
+
+	* gui/alarm-notify.c (alarm_notify_init): New function to
+	initialize the alarm notification system.
+	(alarm_notify_done): New function to shut down the alarm
+	notification system.
+	(alarm_notify_add_client): New function to start monitoring a
+	calendar client for alarm notification.
+	(alarm_notify_remove_client): New function to stop monitoring a
+	client.
+
+	* gui/alarm.h (AlarmDestroyNotify): Also pass in the alarm ID so
+	the callback may know which ID is being destroyed.
+
+	* gui/alarm.c (clear_itimer): New function.
+	(pop_alarm): Use clear_itimer().
+	(alarm_done): New function to shut down the timer system.
+	(alarm_add): Add some preconditions.  Do not call the destroy
+	notification function if we could not create the alarm.
+	(alarm_ready): Pass the alarm ID to the destroy notify function.
+	(alarm_remove): Likewise.  Also, add some preconditions.
+
+	* gui/gnome-cal.c: Removed the alarm notification functions from
+	here since they are now in alarm-notify.c.
+	(gnome_calendar_construct): Register the client with
+	alarm_notify_add_client().
+	(gnome_calendar_destroy): Use alarm_notify_remove_client() to
+	unregister the client.
+	(obj_updated_cb): Do not do any alarm-related stuff.
+	(obj_removed_cb): Likewise.
+
+	* gui/main.c (main): Shut down the alarm timer system.
+	(main): Initialize and shut down the alarm notification system.
+
+	* gui/Makefile.am (evolution_calendar_SOURCES): Added
+	alarm-notify.[ch] to the list of sources.
+
+	* gui/calendar-model.c (calendar_model_set_cal_client): Only
+	connect to the "cal_loaded" signal if the client is not already
+	loaded.
+
+	* gui/e-day-view.c (e_day_view_set_cal_client): Likewise.
+
+	* gui/e-week-view.c (e_week_view_set_cal_client): Likewise.
+
+	* gui/e-itip-control.c (update_calendar): Connect to "cal_loaded"
+	before issuing the load request.
+
 2000-12-21  Iain Holmes  <iain@helixcode.com>
 
 	* gui/calendar-summary.c: Updated for new executive summary.
diff --git a/calendar/cal-client/cal-client.c b/calendar/cal-client/cal-client.c
index fb4e673ae7..344dd91545 100644
--- a/calendar/cal-client/cal-client.c
+++ b/calendar/cal-client/cal-client.c
@@ -1247,7 +1247,9 @@ build_component_alarms_list (GNOME_Evolution_Calendar_CalComponentAlarmsSeq *seq
  * time.
  *
  * Return value: A list of #CalComponentAlarms structures.  This should be freed
- * using the cal_client_free_alarms() function.
+ * using the cal_client_free_alarms() function, or by freeing each element
+ * separately with cal_component_alarms_free() and then freeing the list with
+ * g_slist_free().
  **/
 GSList *
 cal_client_get_alarms_in_range (CalClient *client, time_t start, time_t end)
diff --git a/calendar/gui/Makefile.am b/calendar/gui/Makefile.am
index ccba4abeeb..48ccd78e95 100644
--- a/calendar/gui/Makefile.am
+++ b/calendar/gui/Makefile.am
@@ -62,6 +62,8 @@ evolution_calendar_SOURCES =			\
 	$(IDL_GENERATED)			\
 	alarm.c					\
 	alarm.h					\
+	alarm-notify.c				\
+	alarm-notify.h				\
 	calendar-config.c			\
 	calendar-config.h			\
 	calendar-commands.c			\
diff --git a/calendar/gui/alarm-notify.c b/calendar/gui/alarm-notify.c
new file mode 100644
index 0000000000..6f0e8e6759
--- /dev/null
+++ b/calendar/gui/alarm-notify.c
@@ -0,0 +1,511 @@
+/* Evolution calendar - Alarm notification engine
+ *
+ * Copyright (C) 2000 Helix Code, Inc.
+ *
+ * Authors: Federico Mena-Quintero <federico@helixcode.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gtk/gtksignal.h>
+#include <cal-util/timeutil.h>
+#include "alarm.h"
+#include "alarm-notify.h"
+
+
+
+/* Whether the notification system has been initialized */
+static gboolean alarm_notify_inited;
+
+/* Clients we are monitoring for alarms */
+static GHashTable *client_alarms_hash = NULL;
+
+/* Structure that stores a client we are monitoring */
+typedef struct {
+	/* Monitored client */
+	CalClient *client;
+
+	/* Number of times this client has been registered */
+	int refcount;
+
+	/* Hash table of component UID -> CompQueuedAlarms.  If an element is
+	 * present here, then it means its cqa->queued_alarms contains at least
+	 * one queued alarm.  When all the alarms for a component have been
+	 * dequeued, the CompQueuedAlarms structure is removed from the hash
+	 * table.  Thus a CQA exists <=> it has queued alarms.
+	 */
+	GHashTable *uid_alarms_hash;
+} ClientAlarms;
+
+/* Pair of a CalComponentAlarms and the mapping from queued alarm IDs to the
+ * actual alarm instance structures.
+ */
+typedef struct {
+	/* The parent client alarms structure */
+	ClientAlarms *parent_client;
+
+	/* The actual component and its alarm instances */
+	CalComponentAlarms *alarms;
+
+	/* List of QueuedAlarm structures */
+	GSList *queued_alarms;
+} CompQueuedAlarms;
+
+/* Pair of a queued alarm ID and the alarm trigger instance it refers to */
+typedef struct {
+	/* Alarm ID from alarm.h */
+	gpointer alarm_id;
+
+	/* Instance from our parent CompAlarms->alarms list */
+	CalAlarmInstance *instance;
+} QueuedAlarm;
+
+/* Alarm ID for the midnight refresh function */
+static gpointer midnight_refresh_id = NULL;
+
+
+
+static void load_alarms (ClientAlarms *ca);
+static void midnight_refresh_cb (gpointer alarm_id, time_t trigger, gpointer data);
+
+/* Queues an alarm trigger for midnight so that we can load the next day's worth
+ * of alarms.
+ */
+static void
+queue_midnight_refresh (void)
+{
+	time_t midnight;
+
+	g_assert (midnight_refresh_id == NULL);
+
+	midnight = time_day_end (time (NULL));
+
+	midnight_refresh_id = alarm_add (midnight, midnight_refresh_cb, NULL, NULL);
+	if (!midnight_refresh_id) {
+		g_message ("alarm_notify_init(): Could not set up the midnight refresh alarm!");
+		/* FIXME: what to do? */
+	}
+}
+
+/* Loads a client's alarms; called from g_hash_table_foreach() */
+static void
+add_client_alarms_cb (gpointer key, gpointer value, gpointer data)
+{
+	ClientAlarms *ca;
+
+	ca = value;
+	load_alarms (ca);
+}
+
+/* Loads the alarms for the new day every midnight */
+static void
+midnight_refresh_cb (gpointer alarm_id, time_t trigger, gpointer data)
+{
+	/* Re-load the alarms for all clients */
+
+	g_hash_table_foreach (client_alarms_hash, add_client_alarms_cb, NULL);
+
+	/* Re-schedule the midnight update */
+
+	midnight_refresh_id = NULL;
+	queue_midnight_refresh ();
+}
+
+/* Looks up a client in the client alarms hash table */
+static ClientAlarms *
+lookup_client (CalClient *client)
+{
+	return g_hash_table_lookup (client_alarms_hash, client);
+}
+
+/* Callback used when an alarm triggers */
+static void
+alarm_trigger_cb (gpointer alarm_id, time_t trigger, gpointer data)
+{
+	CompQueuedAlarms *cqa;
+
+	cqa = data;
+
+	/* FIXME */
+
+	g_message ("alarm_trigger_cb(): Triggered!");
+}
+
+/* Callback used when an alarm must be destroyed */
+static void
+alarm_destroy_cb (gpointer alarm_id, gpointer data)
+{
+	CompQueuedAlarms *cqa;
+	GSList *l;
+	QueuedAlarm *qa;
+	const char *uid;
+
+	cqa = data;
+
+	qa = NULL; /* Keep GCC happy */
+
+	/* Find the alarm in the queued alarms */
+
+	for (l = cqa->queued_alarms; l; l = l->next) {
+		qa = l->data;
+		if (qa->alarm_id == alarm_id)
+			break;
+	}
+
+	g_assert (l != NULL);
+
+	/* Remove it and free it */
+
+	cqa->queued_alarms = g_slist_remove_link (cqa->queued_alarms, l);
+	g_slist_free_1 (l);
+
+	g_free (qa);
+
+	/* If this was the last queued alarm for this component, remove the
+	 * component itself.
+	 */
+
+	if (cqa->queued_alarms != NULL)
+		return;
+
+	cal_component_get_uid (cqa->alarms->comp, &uid);
+	g_hash_table_remove (cqa->parent_client->uid_alarms_hash, uid);
+	cqa->parent_client = NULL;
+
+	cal_component_alarms_free (cqa->alarms);
+	cqa->alarms = NULL;
+
+	g_free (cqa);
+}
+
+/* Adds the alarms in a CalComponentAlarms structure to the alarms queued for a
+ * particular client.  Also puts the triggers in the alarm timer queue.
+ */
+static void
+add_component_alarms (ClientAlarms *ca, CalComponentAlarms *alarms)
+{
+	const char *uid;
+	CompQueuedAlarms *cqa;
+	GSList *l;
+
+	cqa = g_new (CompQueuedAlarms, 1);
+	cqa->parent_client = ca;
+	cqa->alarms = alarms;
+
+	cqa->queued_alarms = NULL;
+
+	for (l = alarms->alarms; l; l = l->next) {
+		CalAlarmInstance *instance;
+		gpointer alarm_id;
+		QueuedAlarm *qa;
+
+		instance = l->data;
+
+		alarm_id = alarm_add (instance->trigger, alarm_trigger_cb, cqa, alarm_destroy_cb);
+		if (!alarm_id) {
+			g_message ("add_component_alarms(): Could not schedule a trigger for "
+				   "%ld, discarding...", (long) instance->trigger);
+			continue;
+		}
+
+		qa = g_new (QueuedAlarm, 1);
+		qa->alarm_id = alarm_id;
+		qa->instance = instance;
+
+		cqa->queued_alarms = g_slist_prepend (cqa->queued_alarms, qa);
+	}
+
+	cal_component_get_uid (alarms->comp, &uid);
+
+	/* If we failed to add all the alarms, then we should get rid of the cqa */
+	if (cqa->queued_alarms == NULL) {
+		g_message ("add_component_alarms(): Could not add any of the alarms "
+			   "for the component `%s'; discarding it...", uid);
+
+		cal_component_alarms_free (cqa->alarms);
+		cqa->alarms = NULL;
+
+		g_free (cqa);
+		return;
+	}
+
+	cqa->queued_alarms = g_slist_reverse (cqa->queued_alarms);
+	g_hash_table_insert (ca->uid_alarms_hash, (char *) uid, cqa);
+}
+
+/* Loads today's remaining alarms for a client */
+static void
+load_alarms (ClientAlarms *ca)
+{
+	time_t now, day_end;
+	GSList *comp_alarms;
+	GSList *l;
+
+	now = time (NULL);
+	day_end = time_day_end (now);
+
+	comp_alarms = cal_client_get_alarms_in_range (ca->client, now, day_end);
+
+	/* All of the last day's alarms should have already triggered and should
+	 * have been removed, so we should have no pending components.
+	 */
+	g_assert (g_hash_table_size (ca->uid_alarms_hash) == 0);
+
+	for (l = comp_alarms; l; l = l->next) {
+		CalComponentAlarms *alarms;
+
+		alarms = l->data;
+		add_component_alarms (ca, alarms);
+	}
+
+	g_slist_free (comp_alarms);
+}
+
+/* Called when a calendar client finished loading; we load its alarms */
+static void
+cal_loaded_cb (CalClient *client, CalClientLoadStatus status, gpointer data)
+{
+	ClientAlarms *ca;
+
+	ca = data;
+
+	if (status != CAL_CLIENT_LOAD_SUCCESS)
+		return;
+
+	load_alarms (ca);
+}
+
+/* Looks up a component's queued alarm structure in a client alarms structure */
+static CompQueuedAlarms *
+lookup_comp_queued_alarms (ClientAlarms *ca, const char *uid)
+{
+	return g_hash_table_lookup (ca->uid_alarms_hash, uid);
+}
+
+/* Removes a component an its alarms */
+static void
+remove_comp (ClientAlarms *ca, const char *uid)
+{
+	CompQueuedAlarms *cqa;
+	GSList *l;
+
+	cqa = lookup_comp_queued_alarms (ca, uid);
+	if (!cqa)
+		return;
+
+	/* If a component is present, then it means we must have alarms queued
+	 * for it.
+	 */
+	g_assert (cqa->queued_alarms != NULL);
+
+	for (l = cqa->queued_alarms; l;) {
+		QueuedAlarm *qa;
+
+		qa = l->data;
+
+		/* Get the next element here because the list element will go
+		 * away.  Also, we do not free the qa here because it will be
+		 * freed by the destroy notification function.
+		 */
+		l = l->next;
+
+		alarm_remove (qa->alarm_id);
+	}
+
+	/* The list should be empty now, and thus the queued component alarms
+	 * structure should have been freed and removed from the hash table.
+	 */
+	g_assert (lookup_comp_queued_alarms (ca, uid) == NULL);
+}
+
+/* Called when a calendar component changes; we must reload its corresponding
+ * alarms.
+ */
+static void
+obj_updated_cb (CalClient *client, const char *uid, gpointer data)
+{
+	ClientAlarms *ca;
+	time_t now, day_end;
+	CalComponentAlarms *alarms;
+	gboolean found;
+
+	ca = data;
+
+	remove_comp (ca, uid);
+
+	now = time (NULL);
+	day_end = time_day_end (now);
+
+	found = cal_client_get_alarms_for_object (ca->client, uid, now, day_end, &alarms);
+
+	if (!found)
+		return;
+
+	add_component_alarms (ca, alarms);
+}
+
+/* Called when a calendar component is removed; we must delete its corresponding
+ * alarms.
+ */
+static void
+obj_removed_cb (CalClient *client, const char *uid, gpointer data)
+{
+	ClientAlarms *ca;
+
+	ca = data;
+
+	remove_comp (ca, uid);
+}
+
+
+
+/**
+ * alarm_notify_init:
+ *
+ * Initializes the alarm notification system.  This should be called near the
+ * beginning of the program, after calling alarm_init().
+ **/
+void
+alarm_notify_init (void)
+{
+	g_return_if_fail (alarm_notify_inited == FALSE);
+
+	client_alarms_hash = g_hash_table_new (g_direct_hash, g_direct_equal);
+	queue_midnight_refresh ();
+
+	alarm_notify_inited = TRUE;
+}
+
+/**
+ * alarm_notify_done:
+ *
+ * Shuts down the alarm notification system.  This should be called near the end
+ * of the program.  All the monitored calendar clients should already have been
+ * unregistered with alarm_notify_remove_client().
+ **/
+void
+alarm_notify_done (void)
+{
+	g_return_if_fail (alarm_notify_inited);
+
+	/* All clients must be unregistered by now */
+	g_return_if_fail (g_hash_table_size (client_alarms_hash) == 0);
+
+	g_hash_table_destroy (client_alarms_hash);
+	client_alarms_hash = NULL;
+
+	g_assert (midnight_refresh_id != NULL);
+	alarm_remove (midnight_refresh_id);
+	midnight_refresh_id = NULL;
+
+	alarm_notify_inited = FALSE;
+}
+
+/**
+ * alarm_notify_add_client:
+ * @client: A calendar client.
+ *
+ * Adds a calendar client to the alarm notification system.  Alarm trigger
+ * notifications will be presented at the appropriate times.  The client should
+ * be removed with alarm_notify_remove_client() when receiving notifications
+ * from it is no longer desired.
+ *
+ * A client can be added any number of times to the alarm notification system,
+ * but any single alarm trigger will only be presented once for a particular
+ * client.  The client must still be removed the same number of times from the
+ * notification system when it is no longer wanted.
+ **/
+void
+alarm_notify_add_client (CalClient *client)
+{
+	ClientAlarms *ca;
+
+	g_return_if_fail (alarm_notify_inited);
+	g_return_if_fail (client != NULL);
+	g_return_if_fail (IS_CAL_CLIENT (client));
+
+	ca = lookup_client (client);
+	if (ca) {
+		ca->refcount++;
+		return;
+	}
+
+	ca = g_new (ClientAlarms, 1);
+
+	ca->client = client;
+	gtk_object_ref (GTK_OBJECT (ca->client));
+
+	ca->refcount = 1;
+	g_hash_table_insert (client_alarms_hash, client, ca);
+
+	ca->uid_alarms_hash = g_hash_table_new (g_str_hash, g_str_equal);
+
+	if (!cal_client_is_loaded (client))
+		gtk_signal_connect (GTK_OBJECT (client), "cal_loaded",
+				    GTK_SIGNAL_FUNC (cal_loaded_cb), ca);
+
+	gtk_signal_connect (GTK_OBJECT (client), "obj_updated",
+			    GTK_SIGNAL_FUNC (obj_updated_cb), ca);
+	gtk_signal_connect (GTK_OBJECT (client), "obj_removed",
+			    GTK_SIGNAL_FUNC (obj_removed_cb), ca);
+
+	if (cal_client_is_loaded (client))
+		load_alarms (ca);
+}
+
+/**
+ * alarm_notify_remove_client:
+ * @client: A calendar client.
+ *
+ * Removes a calendar client from the alarm notification system.
+ **/
+void
+alarm_notify_remove_client (CalClient *client)
+{
+	ClientAlarms *ca;
+
+	g_return_if_fail (alarm_notify_inited);
+	g_return_if_fail (client != NULL);
+	g_return_if_fail (IS_CAL_CLIENT (client));
+
+	ca = lookup_client (client);
+	g_return_if_fail (ca != NULL);
+
+	g_assert (ca->refcount > 0);
+	ca->refcount--;
+
+	if (ca->refcount > 0)
+		return;
+
+	/* FIXME: remove alarms */
+
+	/* Clean up */
+
+	gtk_signal_disconnect_by_data (GTK_OBJECT (ca->client), ca);
+
+	gtk_object_unref (GTK_OBJECT (ca->client));
+	ca->client = NULL;
+
+	g_hash_table_destroy (ca->uid_alarms_hash);
+	ca->uid_alarms_hash = NULL;
+
+	g_free (ca);
+
+	g_hash_table_remove (client_alarms_hash, client);
+}
diff --git a/calendar/gui/alarm-notify.h b/calendar/gui/alarm-notify.h
new file mode 100644
index 0000000000..f386a56ae4
--- /dev/null
+++ b/calendar/gui/alarm-notify.h
@@ -0,0 +1,35 @@
+/* Evolution calendar - Alarm notification engine
+ *
+ * Copyright (C) 2000 Helix Code, Inc.
+ *
+ * Authors: Federico Mena-Quintero <federico@helixcode.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef ALARM_NOTIFY_H
+#define ALARM_NOTIFY_H
+
+#include <cal-client/cal-client.h>
+
+
+void alarm_notify_init (void);
+void alarm_notify_done (void);
+
+void alarm_notify_add_client (CalClient *client);
+void alarm_notify_remove_client (CalClient *client);
+
+
+#endif
diff --git a/calendar/gui/alarm-notify/alarm-queue.c b/calendar/gui/alarm-notify/alarm-queue.c
new file mode 100644
index 0000000000..6f0e8e6759
--- /dev/null
+++ b/calendar/gui/alarm-notify/alarm-queue.c
@@ -0,0 +1,511 @@
+/* Evolution calendar - Alarm notification engine
+ *
+ * Copyright (C) 2000 Helix Code, Inc.
+ *
+ * Authors: Federico Mena-Quintero <federico@helixcode.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gtk/gtksignal.h>
+#include <cal-util/timeutil.h>
+#include "alarm.h"
+#include "alarm-notify.h"
+
+
+
+/* Whether the notification system has been initialized */
+static gboolean alarm_notify_inited;
+
+/* Clients we are monitoring for alarms */
+static GHashTable *client_alarms_hash = NULL;
+
+/* Structure that stores a client we are monitoring */
+typedef struct {
+	/* Monitored client */
+	CalClient *client;
+
+	/* Number of times this client has been registered */
+	int refcount;
+
+	/* Hash table of component UID -> CompQueuedAlarms.  If an element is
+	 * present here, then it means its cqa->queued_alarms contains at least
+	 * one queued alarm.  When all the alarms for a component have been
+	 * dequeued, the CompQueuedAlarms structure is removed from the hash
+	 * table.  Thus a CQA exists <=> it has queued alarms.
+	 */
+	GHashTable *uid_alarms_hash;
+} ClientAlarms;
+
+/* Pair of a CalComponentAlarms and the mapping from queued alarm IDs to the
+ * actual alarm instance structures.
+ */
+typedef struct {
+	/* The parent client alarms structure */
+	ClientAlarms *parent_client;
+
+	/* The actual component and its alarm instances */
+	CalComponentAlarms *alarms;
+
+	/* List of QueuedAlarm structures */
+	GSList *queued_alarms;
+} CompQueuedAlarms;
+
+/* Pair of a queued alarm ID and the alarm trigger instance it refers to */
+typedef struct {
+	/* Alarm ID from alarm.h */
+	gpointer alarm_id;
+
+	/* Instance from our parent CompAlarms->alarms list */
+	CalAlarmInstance *instance;
+} QueuedAlarm;
+
+/* Alarm ID for the midnight refresh function */
+static gpointer midnight_refresh_id = NULL;
+
+
+
+static void load_alarms (ClientAlarms *ca);
+static void midnight_refresh_cb (gpointer alarm_id, time_t trigger, gpointer data);
+
+/* Queues an alarm trigger for midnight so that we can load the next day's worth
+ * of alarms.
+ */
+static void
+queue_midnight_refresh (void)
+{
+	time_t midnight;
+
+	g_assert (midnight_refresh_id == NULL);
+
+	midnight = time_day_end (time (NULL));
+
+	midnight_refresh_id = alarm_add (midnight, midnight_refresh_cb, NULL, NULL);
+	if (!midnight_refresh_id) {
+		g_message ("alarm_notify_init(): Could not set up the midnight refresh alarm!");
+		/* FIXME: what to do? */
+	}
+}
+
+/* Loads a client's alarms; called from g_hash_table_foreach() */
+static void
+add_client_alarms_cb (gpointer key, gpointer value, gpointer data)
+{
+	ClientAlarms *ca;
+
+	ca = value;
+	load_alarms (ca);
+}
+
+/* Loads the alarms for the new day every midnight */
+static void
+midnight_refresh_cb (gpointer alarm_id, time_t trigger, gpointer data)
+{
+	/* Re-load the alarms for all clients */
+
+	g_hash_table_foreach (client_alarms_hash, add_client_alarms_cb, NULL);
+
+	/* Re-schedule the midnight update */
+
+	midnight_refresh_id = NULL;
+	queue_midnight_refresh ();
+}
+
+/* Looks up a client in the client alarms hash table */
+static ClientAlarms *
+lookup_client (CalClient *client)
+{
+	return g_hash_table_lookup (client_alarms_hash, client);
+}
+
+/* Callback used when an alarm triggers */
+static void
+alarm_trigger_cb (gpointer alarm_id, time_t trigger, gpointer data)
+{
+	CompQueuedAlarms *cqa;
+
+	cqa = data;
+
+	/* FIXME */
+
+	g_message ("alarm_trigger_cb(): Triggered!");
+}
+
+/* Callback used when an alarm must be destroyed */
+static void
+alarm_destroy_cb (gpointer alarm_id, gpointer data)
+{
+	CompQueuedAlarms *cqa;
+	GSList *l;
+	QueuedAlarm *qa;
+	const char *uid;
+
+	cqa = data;
+
+	qa = NULL; /* Keep GCC happy */
+
+	/* Find the alarm in the queued alarms */
+
+	for (l = cqa->queued_alarms; l; l = l->next) {
+		qa = l->data;
+		if (qa->alarm_id == alarm_id)
+			break;
+	}
+
+	g_assert (l != NULL);
+
+	/* Remove it and free it */
+
+	cqa->queued_alarms = g_slist_remove_link (cqa->queued_alarms, l);
+	g_slist_free_1 (l);
+
+	g_free (qa);
+
+	/* If this was the last queued alarm for this component, remove the
+	 * component itself.
+	 */
+
+	if (cqa->queued_alarms != NULL)
+		return;
+
+	cal_component_get_uid (cqa->alarms->comp, &uid);
+	g_hash_table_remove (cqa->parent_client->uid_alarms_hash, uid);
+	cqa->parent_client = NULL;
+
+	cal_component_alarms_free (cqa->alarms);
+	cqa->alarms = NULL;
+
+	g_free (cqa);
+}
+
+/* Adds the alarms in a CalComponentAlarms structure to the alarms queued for a
+ * particular client.  Also puts the triggers in the alarm timer queue.
+ */
+static void
+add_component_alarms (ClientAlarms *ca, CalComponentAlarms *alarms)
+{
+	const char *uid;
+	CompQueuedAlarms *cqa;
+	GSList *l;
+
+	cqa = g_new (CompQueuedAlarms, 1);
+	cqa->parent_client = ca;
+	cqa->alarms = alarms;
+
+	cqa->queued_alarms = NULL;
+
+	for (l = alarms->alarms; l; l = l->next) {
+		CalAlarmInstance *instance;
+		gpointer alarm_id;
+		QueuedAlarm *qa;
+
+		instance = l->data;
+
+		alarm_id = alarm_add (instance->trigger, alarm_trigger_cb, cqa, alarm_destroy_cb);
+		if (!alarm_id) {
+			g_message ("add_component_alarms(): Could not schedule a trigger for "
+				   "%ld, discarding...", (long) instance->trigger);
+			continue;
+		}
+
+		qa = g_new (QueuedAlarm, 1);
+		qa->alarm_id = alarm_id;
+		qa->instance = instance;
+
+		cqa->queued_alarms = g_slist_prepend (cqa->queued_alarms, qa);
+	}
+
+	cal_component_get_uid (alarms->comp, &uid);
+
+	/* If we failed to add all the alarms, then we should get rid of the cqa */
+	if (cqa->queued_alarms == NULL) {
+		g_message ("add_component_alarms(): Could not add any of the alarms "
+			   "for the component `%s'; discarding it...", uid);
+
+		cal_component_alarms_free (cqa->alarms);
+		cqa->alarms = NULL;
+
+		g_free (cqa);
+		return;
+	}
+
+	cqa->queued_alarms = g_slist_reverse (cqa->queued_alarms);
+	g_hash_table_insert (ca->uid_alarms_hash, (char *) uid, cqa);
+}
+
+/* Loads today's remaining alarms for a client */
+static void
+load_alarms (ClientAlarms *ca)
+{
+	time_t now, day_end;
+	GSList *comp_alarms;
+	GSList *l;
+
+	now = time (NULL);
+	day_end = time_day_end (now);
+
+	comp_alarms = cal_client_get_alarms_in_range (ca->client, now, day_end);
+
+	/* All of the last day's alarms should have already triggered and should
+	 * have been removed, so we should have no pending components.
+	 */
+	g_assert (g_hash_table_size (ca->uid_alarms_hash) == 0);
+
+	for (l = comp_alarms; l; l = l->next) {
+		CalComponentAlarms *alarms;
+
+		alarms = l->data;
+		add_component_alarms (ca, alarms);
+	}
+
+	g_slist_free (comp_alarms);
+}
+
+/* Called when a calendar client finished loading; we load its alarms */
+static void
+cal_loaded_cb (CalClient *client, CalClientLoadStatus status, gpointer data)
+{
+	ClientAlarms *ca;
+
+	ca = data;
+
+	if (status != CAL_CLIENT_LOAD_SUCCESS)
+		return;
+
+	load_alarms (ca);
+}
+
+/* Looks up a component's queued alarm structure in a client alarms structure */
+static CompQueuedAlarms *
+lookup_comp_queued_alarms (ClientAlarms *ca, const char *uid)
+{
+	return g_hash_table_lookup (ca->uid_alarms_hash, uid);
+}
+
+/* Removes a component an its alarms */
+static void
+remove_comp (ClientAlarms *ca, const char *uid)
+{
+	CompQueuedAlarms *cqa;
+	GSList *l;
+
+	cqa = lookup_comp_queued_alarms (ca, uid);
+	if (!cqa)
+		return;
+
+	/* If a component is present, then it means we must have alarms queued
+	 * for it.
+	 */
+	g_assert (cqa->queued_alarms != NULL);
+
+	for (l = cqa->queued_alarms; l;) {
+		QueuedAlarm *qa;
+
+		qa = l->data;
+
+		/* Get the next element here because the list element will go
+		 * away.  Also, we do not free the qa here because it will be
+		 * freed by the destroy notification function.
+		 */
+		l = l->next;
+
+		alarm_remove (qa->alarm_id);
+	}
+
+	/* The list should be empty now, and thus the queued component alarms
+	 * structure should have been freed and removed from the hash table.
+	 */
+	g_assert (lookup_comp_queued_alarms (ca, uid) == NULL);
+}
+
+/* Called when a calendar component changes; we must reload its corresponding
+ * alarms.
+ */
+static void
+obj_updated_cb (CalClient *client, const char *uid, gpointer data)
+{
+	ClientAlarms *ca;
+	time_t now, day_end;
+	CalComponentAlarms *alarms;
+	gboolean found;
+
+	ca = data;
+
+	remove_comp (ca, uid);
+
+	now = time (NULL);
+	day_end = time_day_end (now);
+
+	found = cal_client_get_alarms_for_object (ca->client, uid, now, day_end, &alarms);
+
+	if (!found)
+		return;
+
+	add_component_alarms (ca, alarms);
+}
+
+/* Called when a calendar component is removed; we must delete its corresponding
+ * alarms.
+ */
+static void
+obj_removed_cb (CalClient *client, const char *uid, gpointer data)
+{
+	ClientAlarms *ca;
+
+	ca = data;
+
+	remove_comp (ca, uid);
+}
+
+
+
+/**
+ * alarm_notify_init:
+ *
+ * Initializes the alarm notification system.  This should be called near the
+ * beginning of the program, after calling alarm_init().
+ **/
+void
+alarm_notify_init (void)
+{
+	g_return_if_fail (alarm_notify_inited == FALSE);
+
+	client_alarms_hash = g_hash_table_new (g_direct_hash, g_direct_equal);
+	queue_midnight_refresh ();
+
+	alarm_notify_inited = TRUE;
+}
+
+/**
+ * alarm_notify_done:
+ *
+ * Shuts down the alarm notification system.  This should be called near the end
+ * of the program.  All the monitored calendar clients should already have been
+ * unregistered with alarm_notify_remove_client().
+ **/
+void
+alarm_notify_done (void)
+{
+	g_return_if_fail (alarm_notify_inited);
+
+	/* All clients must be unregistered by now */
+	g_return_if_fail (g_hash_table_size (client_alarms_hash) == 0);
+
+	g_hash_table_destroy (client_alarms_hash);
+	client_alarms_hash = NULL;
+
+	g_assert (midnight_refresh_id != NULL);
+	alarm_remove (midnight_refresh_id);
+	midnight_refresh_id = NULL;
+
+	alarm_notify_inited = FALSE;
+}
+
+/**
+ * alarm_notify_add_client:
+ * @client: A calendar client.
+ *
+ * Adds a calendar client to the alarm notification system.  Alarm trigger
+ * notifications will be presented at the appropriate times.  The client should
+ * be removed with alarm_notify_remove_client() when receiving notifications
+ * from it is no longer desired.
+ *
+ * A client can be added any number of times to the alarm notification system,
+ * but any single alarm trigger will only be presented once for a particular
+ * client.  The client must still be removed the same number of times from the
+ * notification system when it is no longer wanted.
+ **/
+void
+alarm_notify_add_client (CalClient *client)
+{
+	ClientAlarms *ca;
+
+	g_return_if_fail (alarm_notify_inited);
+	g_return_if_fail (client != NULL);
+	g_return_if_fail (IS_CAL_CLIENT (client));
+
+	ca = lookup_client (client);
+	if (ca) {
+		ca->refcount++;
+		return;
+	}
+
+	ca = g_new (ClientAlarms, 1);
+
+	ca->client = client;
+	gtk_object_ref (GTK_OBJECT (ca->client));
+
+	ca->refcount = 1;
+	g_hash_table_insert (client_alarms_hash, client, ca);
+
+	ca->uid_alarms_hash = g_hash_table_new (g_str_hash, g_str_equal);
+
+	if (!cal_client_is_loaded (client))
+		gtk_signal_connect (GTK_OBJECT (client), "cal_loaded",
+				    GTK_SIGNAL_FUNC (cal_loaded_cb), ca);
+
+	gtk_signal_connect (GTK_OBJECT (client), "obj_updated",
+			    GTK_SIGNAL_FUNC (obj_updated_cb), ca);
+	gtk_signal_connect (GTK_OBJECT (client), "obj_removed",
+			    GTK_SIGNAL_FUNC (obj_removed_cb), ca);
+
+	if (cal_client_is_loaded (client))
+		load_alarms (ca);
+}
+
+/**
+ * alarm_notify_remove_client:
+ * @client: A calendar client.
+ *
+ * Removes a calendar client from the alarm notification system.
+ **/
+void
+alarm_notify_remove_client (CalClient *client)
+{
+	ClientAlarms *ca;
+
+	g_return_if_fail (alarm_notify_inited);
+	g_return_if_fail (client != NULL);
+	g_return_if_fail (IS_CAL_CLIENT (client));
+
+	ca = lookup_client (client);
+	g_return_if_fail (ca != NULL);
+
+	g_assert (ca->refcount > 0);
+	ca->refcount--;
+
+	if (ca->refcount > 0)
+		return;
+
+	/* FIXME: remove alarms */
+
+	/* Clean up */
+
+	gtk_signal_disconnect_by_data (GTK_OBJECT (ca->client), ca);
+
+	gtk_object_unref (GTK_OBJECT (ca->client));
+	ca->client = NULL;
+
+	g_hash_table_destroy (ca->uid_alarms_hash);
+	ca->uid_alarms_hash = NULL;
+
+	g_free (ca);
+
+	g_hash_table_remove (client_alarms_hash, client);
+}
diff --git a/calendar/gui/alarm-notify/alarm-queue.h b/calendar/gui/alarm-notify/alarm-queue.h
new file mode 100644
index 0000000000..f386a56ae4
--- /dev/null
+++ b/calendar/gui/alarm-notify/alarm-queue.h
@@ -0,0 +1,35 @@
+/* Evolution calendar - Alarm notification engine
+ *
+ * Copyright (C) 2000 Helix Code, Inc.
+ *
+ * Authors: Federico Mena-Quintero <federico@helixcode.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef ALARM_NOTIFY_H
+#define ALARM_NOTIFY_H
+
+#include <cal-client/cal-client.h>
+
+
+void alarm_notify_init (void);
+void alarm_notify_done (void);
+
+void alarm_notify_add_client (CalClient *client);
+void alarm_notify_remove_client (CalClient *client);
+
+
+#endif
diff --git a/calendar/gui/alarm-notify/alarm.c b/calendar/gui/alarm-notify/alarm.c
index 087ec518bc..a0fe90f337 100644
--- a/calendar/gui/alarm-notify/alarm.c
+++ b/calendar/gui/alarm-notify/alarm.c
@@ -1,4 +1,4 @@
-/* Evolution calendar - alarm notification support
+/* Evolution calendar - Low-level alarm timer mechanism
  *
  * Copyright (C) 2000 Helix Code, Inc.
  *
@@ -21,15 +21,19 @@
  */
 
 #include <config.h>
+#include <unistd.h>
 #include <time.h>
-#include <gnome.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <sys/time.h>
+#include <gdk/gdk.h>
 #include "alarm.h"
 
 
 
+/* Whether the timer system has been initialized */
+static gboolean alarm_inited;
+
 /* The pipes used to notify about an alarm */
 static int alarm_pipes [2];
 
@@ -72,6 +76,13 @@ setup_itimer (time_t diff)
 	return (v == 0) ? TRUE : FALSE;
 }
 
+/* Clears the itimer we have pending */
+static gboolean
+clear_itimer (void)
+{
+	return setup_itimer (0);
+}
+
 /* Removes the head alarm, returns it, and schedules the next alarm in the
  * queue.
  */
@@ -106,20 +117,10 @@ pop_alarm (void)
 			 * will fail?
 			 */
 		}
-	} else {
-		struct itimerval itimer;
-		int v;
-
-		itimer.it_interval.tv_sec = 0;
-		itimer.it_interval.tv_usec = 0;
-		itimer.it_value.tv_sec = 0;
-		itimer.it_value.tv_usec = 0;
-
-		v = setitimer (ITIMER_REAL, &itimer, NULL);
-		if (v != 0)
+	} else
+		if (!clear_itimer ())
 			g_message ("pop_alarm(): Could not clear the timer!  "
 				   "Weird things may happen.");
-	}
 
 	return ar;
 }
@@ -144,7 +145,7 @@ alarm_ready (gpointer data, gint fd, GdkInputCondition cond)
 	(* ar->alarm_fn) (ar, ar->trigger, ar->data);
 
 	if (ar->destroy_notify_fn)
-		(* ar->destroy_notify_fn) (ar->data);
+		(* ar->destroy_notify_fn) (ar, ar->data);
 
 	g_free (ar);
 }
@@ -216,6 +217,10 @@ alarm_add (time_t trigger, AlarmFunction alarm_fn, gpointer data,
 	time_t now;
 	AlarmRecord *ar;
 
+	g_return_val_if_fail (alarm_inited, NULL);
+	g_return_val_if_fail (trigger != -1, NULL);
+	g_return_val_if_fail (alarm_fn != NULL, NULL);
+
 	now = time (NULL);
 	if (trigger < now)
 		return NULL;
@@ -229,9 +234,6 @@ alarm_add (time_t trigger, AlarmFunction alarm_fn, gpointer data,
 	g_print ("alarm_add(): Adding alarm for %s\n", ctime (&trigger));
 
 	if (!queue_alarm (now, ar)) {
-		if (ar->destroy_notify_fn)
-			(* ar->destroy_notify_fn) (ar->data);
-
 		g_free (ar);
 		ar = NULL;
 	}
@@ -252,6 +254,7 @@ alarm_remove (gpointer alarm)
 	AlarmRecord *old_head;
 	GList *l;
 
+	g_return_if_fail (alarm_inited);
 	g_return_if_fail (alarm != NULL);
 
 	ar = alarm;
@@ -272,7 +275,7 @@ alarm_remove (gpointer alarm)
 	}
 
 	if (ar->destroy_notify_fn)
-		(* ar->destroy_notify_fn) (ar->data);
+		(* ar->destroy_notify_fn) (ar, ar->data);
 
 	g_free (ar);
 }
@@ -280,7 +283,7 @@ alarm_remove (gpointer alarm)
 /**
  * alarm_init:
  *
- * Initializes the alarm notification system.  This must be called near the
+ * Initializes the alarm timer mechanism.  This must be called near the
  * beginning of the program.
  **/
 void
@@ -289,6 +292,8 @@ alarm_init (void)
 	struct sigaction sa;
 	int flags;
 
+	g_return_if_fail (alarm_inited == FALSE);
+
 	pipe (alarm_pipes);
 
 	/* set non blocking mode */
@@ -302,4 +307,50 @@ alarm_init (void)
 	sigemptyset (&sa.sa_mask);
 	sa.sa_flags = SA_RESTART;
 	sigaction (SIGALRM, &sa, NULL);
+
+	alarm_inited = TRUE;
+}
+
+/**
+ * alarm_done:
+ * 
+ * Terminates the alarm timer mechanism.  This should be called at the end of
+ * the program.
+ **/
+void
+alarm_done (void)
+{
+	GList *l;
+
+	g_return_if_fail (alarm_inited);
+
+	if (!clear_itimer ())
+		g_message ("alarm_done(): Could not clear the timer!  "
+			   "Weird things may happen.");
+
+	for (l = alarms; l; l = l->next) {
+		AlarmRecord *ar;
+
+		ar = l->data;
+
+		if (ar->destroy_notify_fn)
+			(* ar->destroy_notify_fn) (ar, ar->data);
+
+		g_free (ar);
+	}
+
+	g_list_free (alarms);
+	alarms = NULL;
+
+	if (close (alarm_pipes[0]) != 0)
+		g_message ("alarm_done(): Could not close the input pipe for notification");
+
+	alarm_pipes[0] = -1;
+
+	if (close (alarm_pipes[1]) != 0)
+		g_message ("alarm_done(): Could not close the output pipe for notification");
+
+	alarm_pipes[1] = -1;
+
+	alarm_inited = FALSE;
 }
diff --git a/calendar/gui/alarm-notify/alarm.h b/calendar/gui/alarm-notify/alarm.h
index 2394d28024..afa79edfd8 100644
--- a/calendar/gui/alarm-notify/alarm.h
+++ b/calendar/gui/alarm-notify/alarm.h
@@ -1,4 +1,4 @@
-/* Evolution calendar - alarm notification support
+/* Evolution calendar - Low-level alarm timer mechanism
  *
  * Copyright (C) 2000 Helix Code, Inc.
  *
@@ -24,16 +24,19 @@
 #define ALARM_H
 
 #include <time.h>
+#include <glib.h>
 
 
 
 typedef void (* AlarmFunction) (gpointer alarm_id, time_t trigger, gpointer data);
-typedef void (* AlarmDestroyNotify) (gpointer data);
+typedef void (* AlarmDestroyNotify) (gpointer alarm_id, gpointer data);
 
-void     alarm_init   (void);
-gpointer alarm_add    (time_t trigger, AlarmFunction alarm_fn, gpointer data,
-		       AlarmDestroyNotify destroy_notify_fn);
-void     alarm_remove (gpointer alarm);
+void alarm_init (void);
+void alarm_done (void);
+
+gpointer alarm_add (time_t trigger, AlarmFunction alarm_fn, gpointer data,
+		    AlarmDestroyNotify destroy_notify_fn);
+void alarm_remove (gpointer alarm);
 
 
 
diff --git a/calendar/gui/alarm.c b/calendar/gui/alarm.c
index 087ec518bc..a0fe90f337 100644
--- a/calendar/gui/alarm.c
+++ b/calendar/gui/alarm.c
@@ -1,4 +1,4 @@
-/* Evolution calendar - alarm notification support
+/* Evolution calendar - Low-level alarm timer mechanism
  *
  * Copyright (C) 2000 Helix Code, Inc.
  *
@@ -21,15 +21,19 @@
  */
 
 #include <config.h>
+#include <unistd.h>
 #include <time.h>
-#include <gnome.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <sys/time.h>
+#include <gdk/gdk.h>
 #include "alarm.h"
 
 
 
+/* Whether the timer system has been initialized */
+static gboolean alarm_inited;
+
 /* The pipes used to notify about an alarm */
 static int alarm_pipes [2];
 
@@ -72,6 +76,13 @@ setup_itimer (time_t diff)
 	return (v == 0) ? TRUE : FALSE;
 }
 
+/* Clears the itimer we have pending */
+static gboolean
+clear_itimer (void)
+{
+	return setup_itimer (0);
+}
+
 /* Removes the head alarm, returns it, and schedules the next alarm in the
  * queue.
  */
@@ -106,20 +117,10 @@ pop_alarm (void)
 			 * will fail?
 			 */
 		}
-	} else {
-		struct itimerval itimer;
-		int v;
-
-		itimer.it_interval.tv_sec = 0;
-		itimer.it_interval.tv_usec = 0;
-		itimer.it_value.tv_sec = 0;
-		itimer.it_value.tv_usec = 0;
-
-		v = setitimer (ITIMER_REAL, &itimer, NULL);
-		if (v != 0)
+	} else
+		if (!clear_itimer ())
 			g_message ("pop_alarm(): Could not clear the timer!  "
 				   "Weird things may happen.");
-	}
 
 	return ar;
 }
@@ -144,7 +145,7 @@ alarm_ready (gpointer data, gint fd, GdkInputCondition cond)
 	(* ar->alarm_fn) (ar, ar->trigger, ar->data);
 
 	if (ar->destroy_notify_fn)
-		(* ar->destroy_notify_fn) (ar->data);
+		(* ar->destroy_notify_fn) (ar, ar->data);
 
 	g_free (ar);
 }
@@ -216,6 +217,10 @@ alarm_add (time_t trigger, AlarmFunction alarm_fn, gpointer data,
 	time_t now;
 	AlarmRecord *ar;
 
+	g_return_val_if_fail (alarm_inited, NULL);
+	g_return_val_if_fail (trigger != -1, NULL);
+	g_return_val_if_fail (alarm_fn != NULL, NULL);
+
 	now = time (NULL);
 	if (trigger < now)
 		return NULL;
@@ -229,9 +234,6 @@ alarm_add (time_t trigger, AlarmFunction alarm_fn, gpointer data,
 	g_print ("alarm_add(): Adding alarm for %s\n", ctime (&trigger));
 
 	if (!queue_alarm (now, ar)) {
-		if (ar->destroy_notify_fn)
-			(* ar->destroy_notify_fn) (ar->data);
-
 		g_free (ar);
 		ar = NULL;
 	}
@@ -252,6 +254,7 @@ alarm_remove (gpointer alarm)
 	AlarmRecord *old_head;
 	GList *l;
 
+	g_return_if_fail (alarm_inited);
 	g_return_if_fail (alarm != NULL);
 
 	ar = alarm;
@@ -272,7 +275,7 @@ alarm_remove (gpointer alarm)
 	}
 
 	if (ar->destroy_notify_fn)
-		(* ar->destroy_notify_fn) (ar->data);
+		(* ar->destroy_notify_fn) (ar, ar->data);
 
 	g_free (ar);
 }
@@ -280,7 +283,7 @@ alarm_remove (gpointer alarm)
 /**
  * alarm_init:
  *
- * Initializes the alarm notification system.  This must be called near the
+ * Initializes the alarm timer mechanism.  This must be called near the
  * beginning of the program.
  **/
 void
@@ -289,6 +292,8 @@ alarm_init (void)
 	struct sigaction sa;
 	int flags;
 
+	g_return_if_fail (alarm_inited == FALSE);
+
 	pipe (alarm_pipes);
 
 	/* set non blocking mode */
@@ -302,4 +307,50 @@ alarm_init (void)
 	sigemptyset (&sa.sa_mask);
 	sa.sa_flags = SA_RESTART;
 	sigaction (SIGALRM, &sa, NULL);
+
+	alarm_inited = TRUE;
+}
+
+/**
+ * alarm_done:
+ * 
+ * Terminates the alarm timer mechanism.  This should be called at the end of
+ * the program.
+ **/
+void
+alarm_done (void)
+{
+	GList *l;
+
+	g_return_if_fail (alarm_inited);
+
+	if (!clear_itimer ())
+		g_message ("alarm_done(): Could not clear the timer!  "
+			   "Weird things may happen.");
+
+	for (l = alarms; l; l = l->next) {
+		AlarmRecord *ar;
+
+		ar = l->data;
+
+		if (ar->destroy_notify_fn)
+			(* ar->destroy_notify_fn) (ar, ar->data);
+
+		g_free (ar);
+	}
+
+	g_list_free (alarms);
+	alarms = NULL;
+
+	if (close (alarm_pipes[0]) != 0)
+		g_message ("alarm_done(): Could not close the input pipe for notification");
+
+	alarm_pipes[0] = -1;
+
+	if (close (alarm_pipes[1]) != 0)
+		g_message ("alarm_done(): Could not close the output pipe for notification");
+
+	alarm_pipes[1] = -1;
+
+	alarm_inited = FALSE;
 }
diff --git a/calendar/gui/alarm.h b/calendar/gui/alarm.h
index 2394d28024..afa79edfd8 100644
--- a/calendar/gui/alarm.h
+++ b/calendar/gui/alarm.h
@@ -1,4 +1,4 @@
-/* Evolution calendar - alarm notification support
+/* Evolution calendar - Low-level alarm timer mechanism
  *
  * Copyright (C) 2000 Helix Code, Inc.
  *
@@ -24,16 +24,19 @@
 #define ALARM_H
 
 #include <time.h>
+#include <glib.h>
 
 
 
 typedef void (* AlarmFunction) (gpointer alarm_id, time_t trigger, gpointer data);
-typedef void (* AlarmDestroyNotify) (gpointer data);
+typedef void (* AlarmDestroyNotify) (gpointer alarm_id, gpointer data);
 
-void     alarm_init   (void);
-gpointer alarm_add    (time_t trigger, AlarmFunction alarm_fn, gpointer data,
-		       AlarmDestroyNotify destroy_notify_fn);
-void     alarm_remove (gpointer alarm);
+void alarm_init (void);
+void alarm_done (void);
+
+gpointer alarm_add (time_t trigger, AlarmFunction alarm_fn, gpointer data,
+		    AlarmDestroyNotify destroy_notify_fn);
+void alarm_remove (gpointer alarm);
 
 
 
diff --git a/calendar/gui/calendar-model.c b/calendar/gui/calendar-model.c
index beb9f338c8..67904b451a 100644
--- a/calendar/gui/calendar-model.c
+++ b/calendar/gui/calendar-model.c
@@ -1840,8 +1840,10 @@ calendar_model_set_cal_client (CalendarModel *model, CalClient *client, CalObjTy
 	priv->type = type;
 
 	if (priv->client) {
-		gtk_signal_connect (GTK_OBJECT (priv->client), "cal_loaded",
-				    GTK_SIGNAL_FUNC (cal_loaded_cb), model);
+		if (!cal_client_is_loaded (priv->client))
+			gtk_signal_connect (GTK_OBJECT (priv->client), "cal_loaded",
+					    GTK_SIGNAL_FUNC (cal_loaded_cb), model);
+
 		gtk_signal_connect (GTK_OBJECT (priv->client), "obj_updated",
 				    GTK_SIGNAL_FUNC (obj_updated_cb), model);
 		gtk_signal_connect (GTK_OBJECT (priv->client), "obj_removed",
diff --git a/calendar/gui/e-day-view.c b/calendar/gui/e-day-view.c
index 861b2e04ad..9a2bd82732 100644
--- a/calendar/gui/e-day-view.c
+++ b/calendar/gui/e-day-view.c
@@ -1449,8 +1449,10 @@ e_day_view_set_cal_client	(EDayView	*day_view,
 	day_view->client = client;
 
 	if (day_view->client) {
-		gtk_signal_connect (GTK_OBJECT (day_view->client), "cal_loaded",
-				    GTK_SIGNAL_FUNC (cal_loaded_cb), day_view);
+		if (!cal_client_is_loaded (day_view->client))
+			gtk_signal_connect (GTK_OBJECT (day_view->client), "cal_loaded",
+					    GTK_SIGNAL_FUNC (cal_loaded_cb), day_view);
+
 		gtk_signal_connect (GTK_OBJECT (day_view->client), "obj_updated",
 				    GTK_SIGNAL_FUNC (obj_updated_cb), day_view);
 		gtk_signal_connect (GTK_OBJECT (day_view->client), "obj_removed",
diff --git a/calendar/gui/e-itip-control.c b/calendar/gui/e-itip-control.c
index 8e1ee0df22..4292878c9b 100644
--- a/calendar/gui/e-itip-control.c
+++ b/calendar/gui/e-itip-control.c
@@ -168,6 +168,10 @@ update_calendar (EItipControlPrivate *priv)
 	snprintf (cal_uri, 250, "%s/local/Calendar/calendar.ics", evolution_dir);
 	
 	client = cal_client_new ();
+
+	gtk_signal_connect (GTK_OBJECT (client), "cal_loaded",
+	    	   	    GTK_SIGNAL_FUNC (cal_loaded_cb), priv);
+	
 	if (cal_client_load_calendar (client, cal_uri) == FALSE) {
 		GtkWidget *dialog;
 
@@ -178,9 +182,6 @@ update_calendar (EItipControlPrivate *priv)
 		return;
 	}
 
-	gtk_signal_connect (GTK_OBJECT (client), "cal_loaded",
-	    	   	    GTK_SIGNAL_FUNC (cal_loaded_cb), priv);
-	
 	gtk_progress_bar_update (GTK_PROGRESS_BAR (priv->loading_progress), 0.5);
 	gtk_widget_show (priv->loading_progress);
 
diff --git a/calendar/gui/e-week-view.c b/calendar/gui/e-week-view.c
index 916034991b..d5d5520105 100644
--- a/calendar/gui/e-week-view.c
+++ b/calendar/gui/e-week-view.c
@@ -976,8 +976,10 @@ e_week_view_set_cal_client	(EWeekView	*week_view,
 	week_view->client = client;
 
 	if (week_view->client) {
-		gtk_signal_connect (GTK_OBJECT (week_view->client), "cal_loaded",
-				    GTK_SIGNAL_FUNC (cal_loaded_cb), week_view);
+		if (!cal_client_is_loaded (week_view->client))
+			gtk_signal_connect (GTK_OBJECT (week_view->client), "cal_loaded",
+					    GTK_SIGNAL_FUNC (cal_loaded_cb), week_view);
+
 		gtk_signal_connect (GTK_OBJECT (week_view->client), "obj_updated",
 				    GTK_SIGNAL_FUNC (obj_updated_cb), week_view);
 		gtk_signal_connect (GTK_OBJECT (week_view->client), "obj_removed",
diff --git a/calendar/gui/gnome-cal.c b/calendar/gui/gnome-cal.c
index 3177912695..e3dae90a4d 100644
--- a/calendar/gui/gnome-cal.c
+++ b/calendar/gui/gnome-cal.c
@@ -18,7 +18,7 @@
 #include <gal/e-paned/e-vpaned.h>
 #include <cal-util/timeutil.h>
 #include "dialogs/alarm-notify-dialog.h"
-#include "alarm.h"
+#include "alarm-notify.h"
 #include "e-calendar-table.h"
 #include "e-day-view.h"
 #include "e-week-view.h"
@@ -109,7 +109,7 @@ struct _GnomeCalendarPrivate {
 	/* Alarm ID for the midnight refresh function */
 	gpointer midnight_alarm_refresh_id;
 
-	/* UID->alarms hash */
+	/* UID->ObjectAlarms hash */
 	GHashTable *alarms;
 
 	/* Whether we are being destroyed and should not mess with the object
@@ -120,12 +120,24 @@ struct _GnomeCalendarPrivate {
 
 
 
-/* An entry in the UID->alarms hash table.  The UID key *is* the uid field in
- * this structure, so don't free it separately.
- */
+/* A queued alarm for a component */
 typedef struct {
-	char *uid;
-	GList *alarm_ids;
+	/* Alarm ID from alarm.h */
+	gpointer alarm_id;
+
+	/* Trigger instance this queued alarm refers to */
+	CalAlarmInstance *instance;
+} QueuedAlarm;
+
+/* An entry in the UID->alarms hash table */
+typedef struct {
+	/* The actual component we keep around; its UID *is* the key in the hash
+         * table.
+	 */
+	CalComponentAlarms *alarms;
+
+	/* List of QueuedAlarm structures */
+	GList *queued_alarms;
 } ObjectAlarms;
 
 
@@ -323,16 +335,30 @@ static void
 free_object_alarms (gpointer key, gpointer value, gpointer data)
 {
 	ObjectAlarms *oa;
+	GList *l;
 
 	oa = value;
 
-	g_assert (oa->uid != NULL);
-	g_free (oa->uid);
-	oa->uid = NULL;
+	g_assert (oa->alarms != NULL);
+	cal_component_alarms_free (oa->alarms);
+	oa->alarms = NULL;
 
-	g_assert (oa->alarm_ids != NULL);
-	g_list_free (oa->alarm_ids);
-	oa->alarm_ids = NULL;
+	g_assert (oa->queued_alarms != NULL);
+
+	for (l = oa->queued_alarms; l; l = l->next) {
+		QueuedAlarm *qa;
+
+		qa = l->data;
+
+		/* The instance structures were already freed by the call to
+		 * cal_component_alarms_free().
+		 */
+
+		g_free (qa);
+	}
+
+	g_list_free (oa->queued_alarms);
+	oa->queued_alarms = NULL;
 
 	g_free (oa);
 }
@@ -373,6 +399,9 @@ gnome_calendar_destroy (GtkObject *object)
 	}
 
 	if (priv->client) {
+		if (cal_client_is_loaded (priv->client))
+			alarm_notify_remove_client (priv->client);
+
 		gtk_object_unref (GTK_OBJECT (priv->client));
 		priv->client = NULL;
 	}
@@ -880,13 +909,6 @@ audio_notification (time_t trigger, time_t occur, CalComponent *comp, GnomeCalen
 	/* FIXME */
 }
 
-struct trigger_alarm_closure {
-	GnomeCalendar *gcal;
-	char *uid;
-	CalComponentAlarmAction type;
-	time_t occur;
-};
-
 /* Callback function used when an alarm is triggered */
 static void
 trigger_alarm_cb (gpointer alarm_id, time_t trigger, gpointer data)
@@ -973,108 +995,7 @@ trigger_alarm_cb (gpointer alarm_id, time_t trigger, gpointer data)
 	gtk_object_unref (GTK_OBJECT (comp));
 }
 
-/* Frees a struct trigger_alarm_closure */
-static void
-free_trigger_alarm_closure (gpointer data)
-{
-	struct trigger_alarm_closure *c;
-
-	c = data;
-	g_free (c->uid);
-	g_free (c);
-}
-
-/* Queues the specified alarm */
-static void
-setup_alarm (GnomeCalendar *gcal, CalAlarmInstance *ai)
-{
-	GnomeCalendarPrivate *priv;
-	struct trigger_alarm_closure *c;
-	gpointer alarm;
-	ObjectAlarms *oa;
-
-	priv = gcal->priv;
-
-	c = g_new (struct trigger_alarm_closure, 1);
-	c->gcal = gcal;
-	c->uid = g_strdup (ai->uid);
-#if 0
-	c->type = ai->type;
 #endif
-	c->occur = ai->occur;
-
-	alarm = alarm_add (ai->trigger, trigger_alarm_cb, c, free_trigger_alarm_closure);
-	if (!alarm) {
-		g_message ("setup_alarm(): Could not set up alarm");
-		g_free (c->uid);
-		g_free (c);
-		return;
-	}
-
-	oa = g_hash_table_lookup (priv->alarms, ai->uid);
-	if (oa)
-		oa->alarm_ids = g_list_prepend (oa->alarm_ids, alarm);
-	else {
-		oa = g_new (ObjectAlarms, 1);
-		oa->uid = g_strdup (ai->uid);
-		oa->alarm_ids = g_list_prepend (NULL, alarm);
-
-		g_hash_table_insert (priv->alarms, oa->uid, oa);
-	}
-}
-
-static void load_alarms (GnomeCalendar *cal);
-
-/* Called nightly to refresh the day's alarms */
-static void
-midnight_refresh_cb (gpointer alarm_id, time_t trigger, gpointer data)
-{
-	GnomeCalendar *cal;
-	GnomeCalendarPrivate *priv;
-
-	cal = GNOME_CALENDAR (data);
-	priv = cal->priv;
-
-	priv->midnight_alarm_refresh_id = NULL;
-
-	load_alarms (cal);
-}
-
-#endif
-
-/* Loads and queues the alarms from the current time up to midnight. */
-static void
-load_alarms (GnomeCalendar *gcal)
-{
-#if 0
-	GnomeCalendarPrivate *priv;
-	time_t now;
-	time_t end_of_day;
-	GList *alarms, *l;
-
-	priv = gcal->priv;
-
-	now = time (NULL);
-	end_of_day = time_day_end (now);
-
-	/* Queue alarms */
-
-	alarms = cal_client_get_alarms_in_range (priv->client, now, end_of_day);
-
-	for (l = alarms; l; l = l->next)
-		setup_alarm (gcal, l->data);
-
-	cal_alarm_instance_list_free (alarms);
-
-	/* Queue the midnight alarm refresh */
-
-	priv->midnight_alarm_refresh_id = alarm_add (end_of_day, midnight_refresh_cb, gcal, NULL);
-	if (!priv->midnight_alarm_refresh_id) {
-		g_message ("load_alarms(): Could not set up the midnight refresh alarm!");
-		/* FIXME: what to do? */
-	}
-#endif
-}
 
 /* Loads the initial data into the calendar; this should be called right after
  * the cal_loaded signal from the client is invoked.
@@ -1086,69 +1007,9 @@ initial_load (GnomeCalendar *gcal)
 
 	priv = gcal->priv;
 
-	load_alarms (gcal);
 	tag_calendar_by_client (priv->date_navigator, priv->client);
 }
 
-#if 0
-/* Removes any queued alarms for the specified UID */
-static void
-remove_alarms_for_object (GnomeCalendar *gcal, const char *uid)
-{
-	GnomeCalendarPrivate *priv;
-	ObjectAlarms *oa;
-	GList *l;
-
-	priv = gcal->priv;
-
-	oa = g_hash_table_lookup (priv->alarms, uid);
-	if (!oa)
-		return;
-
-	for (l = oa->alarm_ids; l; l = l->next) {
-		gpointer alarm_id;
-
-		alarm_id = l->data;
-		alarm_remove (alarm_id);
-	}
-
-	g_hash_table_remove (priv->alarms, uid);
-
-	g_free (oa->uid);
-	g_list_free (oa->alarm_ids);
-	g_free (oa);
-}
-
-/* Adds today's alarms for the specified object */
-static void
-add_alarms_for_object (GnomeCalendar *gcal, const char *uid)
-{
-	GnomeCalendarPrivate *priv;
-	GList *alarms;
-	gboolean result;
-	time_t now, end_of_day;
-	GList *l;
-
-	priv = gcal->priv;
-
-	now = time (NULL);
-	end_of_day = time_day_end (now);
-
-	result = cal_client_get_alarms_for_object (priv->client, uid, now, end_of_day, &alarms);
-	if (!result) {
-		/* FIXME: should we warn here, or is it OK if the object
-		 * disappeared in the meantime?
-		 */
-		return;
-	}
-
-	for (l = alarms; l; l = l->next)
-		setup_alarm (gcal, l->data);
-
-	cal_alarm_instance_list_free (alarms);
-}
-#endif
-
 /* Displays an error to indicate that loading a calendar failed */
 static void
 load_error (GnomeCalendar *gcal, const char *uri)
@@ -1282,11 +1143,6 @@ obj_updated_cb (CalClient *client, const char *uid, gpointer data)
 	gcal = GNOME_CALENDAR (data);
 	priv = gcal->priv;
 
-#if 0
-	remove_alarms_for_object (gcal, uid);
-	add_alarms_for_object (gcal, uid);
-#endif
-
 	tag_calendar_by_client (priv->date_navigator, priv->client);
 }
 
@@ -1300,10 +1156,6 @@ obj_removed_cb (CalClient *client, const char *uid, gpointer data)
 	gcal = GNOME_CALENDAR (data);
 	priv = gcal->priv;
 
-#if 0
-	remove_alarms_for_object (gcal, uid);
-#endif
-
 	tag_calendar_by_client (priv->date_navigator, priv->client);
 }
 
@@ -1331,6 +1183,8 @@ gnome_calendar_construct (GnomeCalendar *gcal)
 	gtk_signal_connect (GTK_OBJECT (priv->client), "obj_removed",
 			    GTK_SIGNAL_FUNC (obj_removed_cb), gcal);
 
+	alarm_notify_add_client (priv->client);
+
 	e_calendar_table_set_cal_client (E_CALENDAR_TABLE (priv->todo), priv->client);
 
 	e_day_view_set_cal_client (E_DAY_VIEW (priv->day_view), priv->client);
@@ -1378,9 +1232,9 @@ gnome_calendar_new (void)
 /**
  * gnome_calendar_get_cal_client:
  * @gcal: A calendar view.
- * 
+ *
  * Queries the calendar client interface object that a calendar view is using.
- * 
+ *
  * Return value: A calendar client interface object.
  **/
 CalClient *
@@ -1689,7 +1543,7 @@ gnome_calendar_set_selected_time_range (GnomeCalendar *gcal,
  * @gcal: A calendar view.
  * @start_time: Return value for the start of the time selection.
  * @end_time: Return value for the end of the time selection.
- * 
+ *
  * Queries the time selection range on the calendar view.
  **/
 void
diff --git a/calendar/gui/main.c b/calendar/gui/main.c
index 4f28031201..183d7bfd90 100644
--- a/calendar/gui/main.c
+++ b/calendar/gui/main.c
@@ -34,6 +34,7 @@
 
 #include <gal/widgets/e-cursors.h>
 #include "alarm.h"
+#include "alarm-notify.h"
 #include "calendar-commands.h"
 #include "calendar-config.h"
 #include "component-factory.h"
@@ -63,6 +64,7 @@ main (int argc, char **argv)
 	init_bonobo (argc, argv);
 	glade_gnome_init ();
 	alarm_init ();
+	alarm_notify_init ();
 	e_cursors_init ();
 
 	init_calendar ();
@@ -81,6 +83,8 @@ main (int argc, char **argv)
 	bonobo_main ();
 
 	calendar_config_write_on_exit ();
+	alarm_notify_done ();
+	alarm_done ();
 
 	return 0;
 }