qmautopointer.hpp

可以播放MP3,wma等文件格式的播放器

/* ;-*-c++-*-
 * qmautopointer.hpp
 *
 * $Id: qmautopointer.hpp,v 1.2 2002/03/05 13:09:13 amos Exp $
 *
 * Apollo sound player: http://www.apolloplayer.org
 * Copyright(C) 2000-2001 Apollo Team.  See CREDITS file.
 *
 * 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.
 *
 * The GNU General Public License is also available online at:
 *
 * http://www.gnu.org/copyleft/gpl.html
 */

#ifndef QMAUTOPOINTER_H_INCLUDED
#define QMAUTOPOINTER_H_INCLUDED

/*! \file qmautopointer.h
  Declaration of QmAutoPointer template class.
*/

template<class T>
class QmAutoPointer
{
public:
    QmAutoPointer( T *ptr = 0 ) throw();
    QmAutoPointer( QmAutoPointer<T> &a ) throw();
    ~QmAutoPointer()  throw();

    void reset( T *ptr ) throw();
    T *get() const throw();
    T *release() throw();
    bool isNull() const throw();

    T *operator->() const throw();
    T &operator *() const throw();
    operator T *() const throw();
    QmAutoPointer &operator =( QmAutoPointer &ptr ) throw();
    QmAutoPointer &operator=( T * ) throw();

private:
    T *Pointer;
};

/*!
  Creates the object and takes ownership of the object.
  \param ptr Pointer to the object which this class should manage.
*/

template<class T>
inline QmAutoPointer<T>::QmAutoPointer( T *ptr ) throw()
    : Pointer( ptr )
{
}

/*!
  Takes the ownership from another auto pointer.
*/

template<class T>
inline QmAutoPointer<T>::QmAutoPointer( QmAutoPointer<T> &a ) throw()
    : Pointer( a.Pointer )
{
    a.Pointer = 0;
}

/*!
  Destroys this object and the managed object.
*/

template<class T>
inline QmAutoPointer<T>::~QmAutoPointer() throw()
{
    delete Pointer;
}

/*!
  Returns true if the pointer is zero.
*/

template<class T>
inline bool QmAutoPointer<T>::isNull() const throw()
{
    return Pointer == 0;
}


/*!
  Makes it possible to access the dynamic object without having the pointer to it.
  \return The pointer the dynamic object.
*/

template<class T>
inline T *QmAutoPointer<T>::operator->() const throw()
{
    return Pointer;
}

/*!
  \return The current pointer in use.
*/

template<class T>
inline T &QmAutoPointer<T>::operator *() const throw()
{
    return *Pointer;
}

/*!
  \return The current pointer in use.
*/

template<class T>
inline QmAutoPointer<T>::operator T *() const throw()
{
    return Pointer;
}

/*!
  Assignment from another auto pointer.
*/

template<class T>
inline QmAutoPointer<T> &QmAutoPointer<T>::operator =( QmAutoPointer &ptr ) throw()
{
    delete Pointer;
    Pointer = ptr.Pointer;
    ptr.Pointer = 0;
    return *this;
}

/*!
  Changes the pointer, thus deleting the old one.
  \param ptr Pointer to the object which this class should manage.
*/

template<class T>
inline QmAutoPointer<T> &QmAutoPointer<T>::operator=( T *ptr ) throw()
{
    reset( ptr );
    return *this;
}

/*!
  Changes the pointer, thus deleting the old one.
  \param ptr Pointer to the object which this class should manage.
*/

template<class T>
inline void QmAutoPointer<T>::reset( T *ptr ) throw()
{
    if ( ptr != Pointer )
    {
        delete Pointer;
        Pointer = ptr;
    }
}

/*!
  Returns the pointer in use.
*/

template<class T>
inline T *QmAutoPointer<T>::get() const throw()
{
    return Pointer;
}

/*!
  Relinquish ownership, pointer is no longer maintained.
*/

template<class T>
inline T *QmAutoPointer<T>::release() throw()
{
    T *ptr = Pointer;
    Pointer = 0;
    return ptr;
}

#endif // QMAUTOPOINTER_H_INCLUDED