tqt3/doc/tqptrqueue.doc

/****************************************************************************
**
** TQPtrQueue class documentation
**
** Copyright (C) 1992-2008 Trolltech ASA.  All rights reserved.
**
** This file is part of the TQt GUI Toolkit.
**
** This file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free
** Software Foundation and appearing in the files LICENSE.GPL2
** and LICENSE.GPL3 included in the packaging of this file.
** Alternatively you may (at your option) use any later version
** of the GNU General Public License if such license has been
** publicly approved by Trolltech ASA (or its successors, if any)
** and the KDE Free TQt Foundation.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at sales@trolltech.com.
**
** This file may be used under the terms of the Q Public License as
** defined by Trolltech ASA and appearing in the file LICENSE.QPL
** included in the packaging of this file.  Licensees holding valid Qt
** Commercial licenses may use this file in accordance with the Qt
** Commercial License Agreement provided with the Software.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
** herein.
**
**********************************************************************/


/*!
    \class TQPtrQueue
    \brief The TQPtrQueue class is a template class that provides a queue.

    \ingroup collection
    \ingroup tools

    TQValueVector can be used as an STL-compatible alternative to this
    class.

    A template instance TQPtrQueue\<X\> is a queue that operates on
    pointers to X (X*).

    A queue is a first in, first out structure. Items are added to the
    tail of the queue with enqueue() and retrieved from the head with
    dequeue(). You can peek at the head item without dequeing it using
    head().

    You can control the queue's deletion policy with setAutoDelete().

    For compatibility with the TQPtrCollection classes, current() and
    remove() are provided; both operate on the head().

    \sa TQPtrList TQPtrStack
*/

/*!
    \fn TQPtrQueue::TQPtrQueue ()

    Creates an empty queue with autoDelete() set to FALSE.
*/

/*!
    \fn TQPtrQueue::TQPtrQueue( const TQPtrQueue<type>& queue )

    Creates a queue from \a queue.

    Only the pointers are copied; the items are not. The autoDelete()
    flag is set to FALSE.
*/

/*!
    \fn TQPtrQueue::~TQPtrQueue()

    Destroys the queue. Items in the queue are deleted if autoDelete()
    is TRUE.
*/

/*!
    \fn TQPtrQueue<type>& TQPtrQueue::operator= (const TQPtrQueue<type>& queue)

    Assigns \a queue to this queue and returns a reference to this
    queue.

    This queue is first cleared and then each item in \a queue is
    enqueued to this queue. Only the pointers are copied.

    \warning The autoDelete() flag is not modified. If it it TRUE for
    both \a queue and this queue, deleting the two lists will cause \e
    double-deletion of the items.
*/

/*!
    \fn bool TQPtrQueue::isEmpty() const

    Returns TRUE if the queue is empty; otherwise returns FALSE.

    \sa count() dequeue() head()
*/

/*!
    \fn void TQPtrQueue::enqueue (const type* d)

    Adds item \a d to the tail of the queue.

    \sa count() dequeue()
*/

/*!
    \fn type* TQPtrQueue::dequeue ()

    Takes the head item from the queue and returns a pointer to it.
    Returns 0 if the queue is empty.

    \sa enqueue() count()
*/

/*!
    \fn bool TQPtrQueue::remove()

    Removes the head item from the queue, and returns TRUE if there
    was an item, i.e. the queue wasn't empty; otherwise returns FALSE.

    The item is deleted if autoDelete() is TRUE.

    \sa head() isEmpty() dequeue()
*/

/*!
    \fn void TQPtrQueue::clear()

    Removes all items from the queue, and deletes them if autoDelete()
    is TRUE.

    \sa remove()
*/

/*!
    \fn uint TQPtrQueue::count() const

    Returns the number of items in the queue.

    \sa isEmpty()
*/

/*!
    \fn type* TQPtrQueue::head() const

    Returns a pointer to the head item in the queue. The queue is not
    changed. Returns 0 if the queue is empty.

    \sa dequeue() isEmpty()
*/

/*!
    \fn TQPtrQueue::operator type*() const

    Returns a pointer to the head item in the queue. The queue is not
    changed. Returns 0 if the queue is empty.

    \sa dequeue() isEmpty()
*/

/*!
    \fn type* TQPtrQueue::current() const

    Returns a pointer to the head item in the queue. The queue is not
    changed. Returns 0 if the queue is empty.

    \sa dequeue() isEmpty()
*/

/*!
    \fn bool TQPtrQueue::autoDelete() const
    
    Returns the setting of the auto-delete option. The default is
    FALSE.

    \sa setAutoDelete()
*/

/*!
    \fn void TQPtrQueue::setAutoDelete( bool enable )

    Sets the queue to auto-delete its contents if \a enable is TRUE
    and not to delete them if \a enable is FALSE.

    If auto-deleting is turned on, all the items in a queue are
    deleted when the queue itself is deleted. This can be quite
    convenient if the queue has the only pointer to the items.
    
    The default setting is FALSE, for safety. If you turn it on, be
    careful about copying the queue: you might find yourself with two
    queues deleting the same items.

    \sa autoDelete()
*/

/*!
    \fn TQDataStream& TQPtrQueue::read( TQDataStream& s,
					TQPtrCollection::Item& item )

    Reads a queue item, \a item, from the stream \a s and returns a
    reference to the stream.

    The default implementation sets \a item to 0.

    \sa write()
*/

/*!
    \fn TQDataStream& TQPtrQueue::write( TQDataStream& s,
					TQPtrCollection::Item item ) const

    Writes a queue item, \a item, to the stream \a s and returns a
    reference to the stream.

    The default implementation does nothing.

    \sa read()
*/