The Wombat now keeps track of which categories are present in the objects

2001-07-31  Federico Mena Quintero  <federico@ximian.com>

	The Wombat now keeps track of which categories are present in the
	objects of a calendar.  It will notify the clients of changes in
	this set.  This is to make the category drop-down menus in the
	calendar/tasks views be always up to date.

	* idl/evolution-calendar.idl (Listener): Added a
	notifyCategoriesChanged() method.  The Wombat now keeps track of
	the categories within a calendar.

	* cal-client/cal-listener.[ch]: Switched it to use BonoboXObject.
	Also added the notifyCategoriesChanged implementation.

	* cal-client/cal-client.[ch]: Added a "categories_changed" signal.

	* pcs/cal-backend-file.c: Maintain a list of the live categories.
	(update_categories_from_comp): New function to maintain the set of
	live categories.
	(add_component): Update the set of categories.
	(remove_component): Likewise.
	(open_cal): Notify about changes in the set of categories.
	(create_cal): Likewise.
	(cal_backend_file_update_objects): Likewise.
	(cal_backend_file_remove_object): Likewise.
	(notify_categories_changed): New function to notify the clients
	about the current set of categories.

	* pcs/cal.c (cal_notify_categories_changed): New function.

svn path=/trunk/; revision=11536

3 files changed, 179 insertions, 1 deletions

diff --git a/calendar/pcs/cal-backend-file.c b/calendar/pcs/cal-backend-file.c
index 219683e4f9..0c87760204 100644
--- a/calendar/pcs/cal-backend-file.c
+++ b/calendar/pcs/cal-backend-file.c
@@ -29,6 +29,15 @@
 
 
 
+/* A category that exists in some of the objects of the calendar */
+typedef struct {
+	/* Category name, also used as the key in the categories hash table */
+	char *name;
+
+	/* Number of objects that have this category */
+	int refcount;
+} Category;
+
 /* Private part of the CalBackendFile structure */
 struct _CalBackendFilePrivate {
 	/* URI where the calendar data is stored */
@@ -56,6 +65,9 @@ struct _CalBackendFilePrivate {
 	GList *todos;
 	GList *journals;
 
+	/* Hash table of live categories */
+	GHashTable *categories;
+
 	/* Idle handler for saving the calendar when it is dirty */
 	guint idle_id;
 };
@@ -181,6 +193,8 @@ cal_backend_file_init (CalBackendFile *cbfile)
 	priv->events = NULL;
 	priv->todos = NULL;
 	priv->journals = NULL;
+
+	priv->categories = g_hash_table_new (g_str_hash, g_str_equal);
 }
 
 /* g_hash_table_foreach() callback to destroy a CalComponent */
@@ -247,6 +261,17 @@ save (CalBackendFile *cbfile)
 	return;
 }
 
+/* Used from g_hash_table_foreach(), frees a Category structure */
+static void
+free_category_cb (gpointer key, gpointer value, gpointer data)
+{
+	Category *c;
+
+	c = value;
+	g_free (c->name);
+	g_free (c);
+}
+
 /* Destroy handler for the file backend */
 static void
 cal_backend_file_destroy (GtkObject *object)
@@ -287,11 +312,14 @@ cal_backend_file_destroy (GtkObject *object)
 	g_list_free (priv->events);
 	g_list_free (priv->todos);
 	g_list_free (priv->journals);
-
 	priv->events = NULL;
 	priv->todos = NULL;
 	priv->journals = NULL;
 
+	g_hash_table_foreach (priv->categories, free_category_cb, NULL);
+	g_hash_table_destroy (priv->categories);
+	priv->categories = NULL;
+
 	if (priv->icalcomp) {
 		icalcomponent_free (priv->icalcomp);
 		priv->icalcomp = NULL;
@@ -465,6 +493,56 @@ check_dup_uid (CalBackendFile *cbfile, CalComponent *comp)
 	mark_dirty (cbfile);
 }
 
+/* Updates the hash table of categories by adding or removing those in the
+ * component.
+ */
+static void
+update_categories_from_comp (CalBackendFile *cbfile, CalComponent *comp, gboolean add)
+{
+	CalBackendFilePrivate *priv;
+	GSList *categories, *l;
+
+	priv = cbfile->priv;
+
+	cal_component_get_categories_list (comp, &categories);
+
+	for (l = categories; l; l = l->next) {
+		const char *name;
+		Category *c;
+
+		name = l->data;
+		c = g_hash_table_lookup (priv->categories, name);
+
+		if (add) {
+			/* Add the category to the set */
+			if (c)
+				c->refcount++;
+			else {
+				c = g_new (Category, 1);
+				c->name = g_strdup (name);
+				c->refcount = 1;
+
+				g_hash_table_insert (priv->categories, c->name, c);
+			}
+		} else {
+			/* Remove the category from the set --- it *must* have existed */
+
+			g_assert (c != NULL);
+			g_assert (c->refcount > 0);
+
+			c->refcount--;
+
+			if (c->refcount == 0) {
+				g_hash_table_remove (priv->categories, c->name);
+				g_free (c->name);
+				g_free (c);
+			}
+		}
+	}
+
+	cal_component_free_categories_list (categories);
+}
+
 /* Tries to add an icalcomponent to the file backend.  We only store the objects
  * of the types we support; all others just remain in the toplevel component so
  * that we don't lose them.
@@ -515,6 +593,10 @@ add_component (CalBackendFile *cbfile, CalComponent *comp, gboolean add_to_tople
 
 		icalcomponent_add_component (priv->icalcomp, icalcomp);
 	}
+
+	/* Update the set of categories */
+
+	update_categories_from_comp (cbfile, comp, TRUE);
 }
 
 /* Removes a component from the backend's hash and lists.  Does not perform
@@ -568,6 +650,10 @@ remove_component (CalBackendFile *cbfile, CalComponent *comp)
 	*list = g_list_remove_link (*list, l);
 	g_list_free_1 (l);
 
+	/* Update the set of categories */
+
+	update_categories_from_comp (cbfile, comp, FALSE);
+
 	gtk_object_unref (GTK_OBJECT (comp));
 }
 
@@ -607,6 +693,53 @@ scan_vcalendar (CalBackendFile *cbfile)
 	}
 }
 
+/* Used from g_hash_table_foreach(), adds a category name to the sequence */
+static void
+add_category_cb (gpointer key, gpointer value, gpointer data)
+{
+	Category *c;
+	GNOME_Evolution_Calendar_StringSeq *seq;
+
+	c = value;
+	seq = data;
+
+	seq->_buffer[seq->_length] = CORBA_string_dup (c->name);
+	seq->_length++;
+}
+
+/* Notifies the clients with the current list of categories */
+static void
+notify_categories_changed (CalBackendFile *cbfile)
+{
+	CalBackendFilePrivate *priv;
+	GNOME_Evolution_Calendar_StringSeq *seq;
+	GList *l;
+
+	priv = cbfile->priv;
+
+	/* Build the sequence of category names */
+
+	seq = GNOME_Evolution_Calendar_StringSeq__alloc ();
+	seq->_length = 0;
+	seq->_maximum = g_hash_table_size (priv->categories);
+	seq->_buffer = CORBA_sequence_CORBA_string_allocbuf (seq->_maximum);
+	CORBA_sequence_set_release (seq, TRUE);
+
+	g_hash_table_foreach (priv->categories, add_category_cb, seq);
+	g_assert (seq->_length == seq->_maximum);
+
+	/* Notify the clients */
+
+	for (l = priv->clients; l; l = l->next) {
+		Cal *cal;
+
+		cal = CAL (l->data);
+		cal_notify_categories_changed (cal, seq);
+	}
+
+	CORBA_free (seq);
+}
+
 /* Callback used from icalparser_parse() */
 static char *
 get_line_fn (char *s, size_t size, void *data)
@@ -671,6 +804,8 @@ open_cal (CalBackendFile *cbfile, GnomeVFSURI *uri, FILE *file)
 	gnome_vfs_uri_ref (uri);
 	priv->uri = uri;
 
+	notify_categories_changed (cbfile);
+
 	return CAL_BACKEND_OPEN_SUCCESS;
 }
 
@@ -692,6 +827,8 @@ create_cal (CalBackendFile *cbfile, GnomeVFSURI *uri)
 
 	mark_dirty (cbfile);
 
+	notify_categories_changed (cbfile);
+
 	return CAL_BACKEND_OPEN_SUCCESS;
 }
 
@@ -1786,6 +1923,7 @@ cal_backend_file_update_objects (CalBackend *backend, const char *calobj)
 
 	/* FIXME: do the notification asynchronously */
 	notify_update (cbfile, comp_uid);
+	notify_categories_changed (cbfile);
 
 	return TRUE;
 }
@@ -1797,6 +1935,7 @@ cal_backend_file_remove_object (CalBackend *backend, const char *uid)
 	CalBackendFile *cbfile;
 	CalBackendFilePrivate *priv;
 	CalComponent *comp;
+	int old_n_categories, new_n_categories;
 
 	cbfile = CAL_BACKEND_FILE (backend);
 	priv = cbfile->priv;
@@ -1809,12 +1948,18 @@ cal_backend_file_remove_object (CalBackend *backend, const char *uid)
 	if (!comp)
 		return FALSE;
 
+	old_n_categories = g_hash_table_size (priv->categories);
 	remove_component (cbfile, comp);
+	new_n_categories = g_hash_table_size (priv->categories);
+
 	mark_dirty (cbfile);
 
 	/* FIXME: do the notification asynchronously */
 	notify_remove (cbfile, uid);
 
+	if (old_n_categories != new_n_categories)
+		notify_categories_changed (cbfile);
+
 	return TRUE;
 }
 
diff --git a/calendar/pcs/cal.c b/calendar/pcs/cal.c
index f89d5c820f..cb92f391b5 100644
--- a/calendar/pcs/cal.c
+++ b/calendar/pcs/cal.c
@@ -674,6 +674,37 @@ cal_notify_remove (Cal *cal, const char *uid)
 }
 
 /**
+ * cal_notify_categories_changed:
+ * @cal: A calendar client interface.
+ * @categories: List of categories.
+ * 
+ * Notifies a listener attached to a calendar client interface object about the
+ * current set of categories in a calendar backend.
+ **/
+void
+cal_notify_categories_changed (Cal *cal, GNOME_Evolution_Calendar_StringSeq *categories)
+{
+	CalPrivate *priv;
+	CORBA_Environment ev;
+
+	g_return_if_fail (cal != NULL);
+	g_return_if_fail (IS_CAL (cal));
+	g_return_if_fail (categories != NULL);
+
+	priv = cal->priv;
+	g_return_if_fail (priv->listener != CORBA_OBJECT_NIL);
+
+	CORBA_exception_init (&ev);
+	GNOME_Evolution_Calendar_Listener_notifyCategoriesChanged (priv->listener, categories, &ev);
+
+	if (ev._major != CORBA_NO_EXCEPTION)
+		g_message ("cal_notify_categories_changed(): Could not notify the listener "
+			   "about the current set of categories");
+
+	CORBA_exception_free (&ev);
+}
+
+/**
  * cal_get_password:
  * @cal: A calendar client interface.
  * @prompt: The message to show to the user when asking for the password.
diff --git a/calendar/pcs/cal.h b/calendar/pcs/cal.h
index 35e870739c..6797b5df25 100644
--- a/calendar/pcs/cal.h
+++ b/calendar/pcs/cal.h
@@ -65,6 +65,8 @@ Cal *cal_new (CalBackend *backend, GNOME_Evolution_Calendar_Listener listener);
 void cal_notify_update (Cal *cal, const char *uid);
 void cal_notify_remove (Cal *cal, const char *uid);
 
+void cal_notify_categories_changed (Cal *cal, GNOME_Evolution_Calendar_StringSeq *categories);
+
 char *cal_get_password (Cal *cal, const char *prompt, const char *key);
 void  cal_forget_password (Cal *cal, const char *key);