loopcontextbase.h

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

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** Copyright (C) 2000-2005 Trolltech AS.  All rights reserved.
**
** This file is part of the Qtopia Environment.
** 
** 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.
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** A copy of the GNU GPL license version 2 is included in this package as 
** LICENSE.GPL.
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** 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.
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** the code of this program with Qtopia applications copyrighted, developed
** and distributed by Trolltech under the terms of the Qtopia Personal Use
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** in all respects for all of the code used other than the applications
** licensed under the Qtopia Personal Use License Agreement. If you modify
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#ifndef LOOP_CONTEXT_BASE_H
#define LOOP_CONTEXT_BASE_H


#define THREAD_SUPPORT
#include <qobject.h>
#include "mutex.h"


class LoopContextBase : public QObject {
    Q_OBJECT
public:
    LoopContextBase(bool preferThreaded, bool realtime = FALSE, bool fifo = TRUE, int priority = 50);
    virtual ~LoopContextBase();

    virtual void init() = 0;
    virtual void stats() = 0;
    void start();
    void stop();
    bool isMore();
    bool isStopping();
    void setStopping(bool b);

    bool enabled;
    int streamId;
    long current;
    long size;

    long time() {
	return ( enabled && rate != 0.0 && size ) ? (long)(size / rate) : -1;
    }

    typedef struct {
	long rateNumerator;
        long rateDenominator;
    } rateStruct;

    union {
        double rate;
	rateStruct rateNumDen;	
    };

    Mutex mutex;
    Mutex stoppingMutex;

public slots:
    void signalThread();

protected:
    void timerEvent(QTimerEvent *te);

private:
    virtual long timerInterval() = 0;
    virtual bool playMore() = 0;

#ifdef THREAD_SUPPORT
    void setJoin(bool j);
    bool join();
    bool joinThread;
    pthread_attr_t threadAttr;
    pthread_t threadId;
    void createThread(void *(*func)(void *), void *arg, bool realtime, bool fifo, int priority);
    static void *startThreadLoop(LoopContextBase*);
    void playingLoop();
#endif

    int timerId;
    bool sleep;
    bool more;
    bool stopping;
    bool threaded;
    bool realtime;
    bool needFirstPlay;
    void play();
    //friend class LoopControl;
};


#endif // LOOP_CONTEXT_BASE_H