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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2008 by Miika Pekkarinen
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef _EVENTS_H
#define _EVENTS_H
#include <stdbool.h>
/**
* Synchronouos event system.
*
* Callbacks are subscribed with add_event() or add_event_ex(). events
* are fired using send_event().
*
* Events are always dispatched synchronously: the callbacks are called
* in the thread context of the event sender, without context switch. This
* also means that callbacks should be as simple as possible to avoid
* blocking the sender and other callbacks
*
* Use the kernel-level event_queue for cross-thread event dispatching.
* */
/*
* Only CLASS defines and firmware/ level events should be defined here.
* apps/ level events are defined in apps/appevents.h
*
* High byte = Event class definition
* Low byte = Event ID
*/
#define EVENT_CLASS_DISK 0x0100
#define EVENT_CLASS_PLAYBACK 0x0200
#define EVENT_CLASS_BUFFERING 0x0400
#define EVENT_CLASS_GUI 0x0800
#define EVENT_CLASS_RECORDING 0x1000
#define EVENT_CLASS_LCD 0x2000
#define EVENT_CLASS_VOICE 0x4000
/**
* Subscribe to an event with a simple callback. The callback will be called
* synchronously everytime the event fires, passing the event id and data to
* the callback.
*
* Must be removed with remove_event().
*/
bool add_event(unsigned short id, void (*handler)(unsigned short id, void *event_data));
/**
* Subscribe to an event with a detailed callback. The callback will be called
* synchronously everytime the event fires, passing the event id and data, as
* well as the user_data pointer passed here, to the callback.
*
* With oneshot == true, the callback is unsubscribed automatically after
* the event fired for the first time. In this case the event need not to be
* removed with remove_event_ex().
*
* Must be removed with remove_event_ex(). remove_event() will never remove
* events added with this function.
*/
bool add_event_ex(unsigned short id, bool oneshot, void (*handler)(unsigned short id, void *event_data, void *user_data), void *user_data);
/**
* Unsubscribe a callback from an event. The handler pointer is matched.
*
* This will only work for subscriptions made with add_event().
*/
void remove_event(unsigned short id, void (*handler)(unsigned short id, void *data));
/**
* Unsubscribe a callback from an event. The handler and user_data pointers
* are matched. That means the same user_data that was passed to add_event_ex()
* must be passed to this too.
*
* This will only work for subscriptions made with add_event_ex().
*/
void remove_event_ex(unsigned short id, void (*handler)(unsigned short id, void *event_data, void *user_data), void *user_data);
/**
* Fire an event, which synchronously calls all subscribed callbacks. The
* event id and data pointer are passed to the callbacks as well, and
* optionally the user_data pointer from add_event_ex().
*/
void send_event(unsigned short id, void *data);
#endif
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