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bertos/mware/observer.h

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+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2006 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \brief Simple notifier for the subject/observer pattern (interface)
+ *
+ * \author Bernie Innocenti <bernie@codewiz.org>
+ */
+#ifndef MWARE_OBSERVER_H
+#define MWARE_OBSERVER_H
+
+#include <struct/list.h>
+
+/**
+ *
+ * Here's a simple example:
+ *
+ * \code
+ * Subject kbd_driver;
+ *
+ * Observer kbd_observer;
+ *
+ * void key_pressed(int event, void *_param)
+ * {
+ *     char *param = (char *)_param;
+ *
+ *     if (event == EVENT_KBD_PRESSED)
+ *         printf("You pressed %c\n", *param);
+ * }
+ *
+ * void register_kbd_listener(void)
+ * {
+ *     observer_SetEvent(&kbd_observer, key_pressed);
+ *     observer_Subscribe(&kbd_driver, &kbd_observer);
+ * }
+ * \endcode
+ */
+typedef struct Observer
+{
+	Node link;
+	void (*event)(int event_id, void *param);
+} Observer;
+
+typedef struct Subject
+{
+	/// Subscribed observers.
+	List observers;
+
+} Subject;
+
+void observer_SetEvent(Observer *observer, void (*event)(int event_id, void *param));
+
+#define OBSERVER_INITIALIZER(callback) { { NULL, NULL }, callback }
+
+void observer_InitSubject(Subject *subject);
+
+/// Aggiunge un Observer all'insieme
+void observer_Subscribe(Subject *subject, Observer *observer);
+
+/// Rimuove un Observer dall'insieme
+void observer_Unsubscribe(Subject *subject, Observer *observer);
+
+/// per tutti gli elementi nel set notifica l'evento, chiamando la relativa
+/// funzione event
+void observer_notify(Subject *subject, int event_id, void *param);
+
+#endif /* MWARE_OBSERVER_H */