<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/doc/qptrqueue.doc:37 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>QPtrQueue Class</title> <style type="text/css"><!-- fn { margin-left: 1cm; text-indent: -1cm; } a:link { color: #004faf; text-decoration: none } a:visited { color: #672967; text-decoration: none } body { background: #ffffff; color: black; } --></style> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr bgcolor="#E5E5E5"> <td valign=center> <a href="index.html"> <font color="#004faf">Home</font></a> | <a href="classes.html"> <font color="#004faf">All Classes</font></a> | <a href="mainclasses.html"> <font color="#004faf">Main Classes</font></a> | <a href="annotated.html"> <font color="#004faf">Annotated</font></a> | <a href="groups.html"> <font color="#004faf">Grouped Classes</font></a> | <a href="functions.html"> <font color="#004faf">Functions</font></a> </td> <td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QPtrQueue Class Reference</h1> <p>The QPtrQueue class is a template class that provides a queue. <a href="#details">More...</a> <p><tt>#include <<a href="qptrqueue-h.html">qptrqueue.h</a>></tt> <p><a href="qptrqueue-members.html">List of all member functions.</a> <h2>Public Members</h2> <ul> <li class=fn><a href="#QPtrQueue"><b>QPtrQueue</b></a> ()</li> <li class=fn><a href="#QPtrQueue-2"><b>QPtrQueue</b></a> ( const QPtrQueue<type> & queue )</li> <li class=fn><a href="#~QPtrQueue"><b>~QPtrQueue</b></a> ()</li> <li class=fn>QPtrQueue<type> & <a href="#operator-eq"><b>operator=</b></a> ( const QPtrQueue<type> & queue )</li> <li class=fn>bool <a href="#autoDelete"><b>autoDelete</b></a> () const</li> <li class=fn>void <a href="#setAutoDelete"><b>setAutoDelete</b></a> ( bool enable )</li> <li class=fn>uint <a href="#count"><b>count</b></a> () const</li> <li class=fn>bool <a href="#isEmpty"><b>isEmpty</b></a> () const</li> <li class=fn>void <a href="#enqueue"><b>enqueue</b></a> ( const type * d )</li> <li class=fn>type * <a href="#dequeue"><b>dequeue</b></a> ()</li> <li class=fn>bool <a href="#remove"><b>remove</b></a> ()</li> <li class=fn>void <a href="#clear"><b>clear</b></a> ()</li> <li class=fn>type * <a href="#head"><b>head</b></a> () const</li> <li class=fn><a href="#operator-type-*"><b>operator type *</b></a> () const</li> <li class=fn>type * <a href="#current"><b>current</b></a> () const</li> </ul> <h2>Protected Members</h2> <ul> <li class=fn>virtual QDataStream & <a href="#read"><b>read</b></a> ( QDataStream & s, QPtrCollection::Item & item )</li> <li class=fn>virtual QDataStream & <a href="#write"><b>write</b></a> ( QDataStream & s, QPtrCollection::Item item ) const</li> </ul> <hr><a name="details"></a><h2>Detailed Description</h2> The QPtrQueue class is a template class that provides a queue. <p> <p> <a href="qvaluevector.html">QValueVector</a> can be used as an STL-compatible alternative to this class. <p> A template instance QPtrQueue<X> is a queue that operates on pointers to X (X*). <p> A queue is a first in, first out structure. Items are added to the tail of the queue with <a href="#enqueue">enqueue</a>() and retrieved from the head with <a href="#dequeue">dequeue</a>(). You can peek at the head item without dequeing it using <a href="#head">head</a>(). <p> You can control the queue's deletion policy with <a href="#setAutoDelete">setAutoDelete</a>(). <p> For compatibility with the <a href="qptrcollection.html">QPtrCollection</a> classes, <a href="#current">current</a>() and <a href="#remove">remove</a>() are provided; both operate on the head(). <p> <p>See also <a href="qptrlist.html">QPtrList</a>, <a href="qptrstack.html">QPtrStack</a>, <a href="collection.html">Collection Classes</a>, and <a href="tools.html">Non-GUI Classes</a>. <hr><h2>Member Function Documentation</h2> <h3 class=fn><a name="QPtrQueue"></a>QPtrQueue::QPtrQueue () </h3> <p> Creates an empty queue with <a href="#autoDelete">autoDelete</a>() set to FALSE. <h3 class=fn><a name="QPtrQueue-2"></a>QPtrQueue::QPtrQueue ( const <a href="qptrqueue.html">QPtrQueue</a><type> & queue ) </h3> <p> Creates a queue from <em>queue</em>. <p> Only the pointers are copied; the items are not. The <a href="#autoDelete">autoDelete</a>() flag is set to FALSE. <h3 class=fn><a name="~QPtrQueue"></a>QPtrQueue::~QPtrQueue () </h3> <p> Destroys the queue. Items in the queue are deleted if <a href="#autoDelete">autoDelete</a>() is TRUE. <h3 class=fn>bool <a name="autoDelete"></a>QPtrQueue::autoDelete () const </h3> <p> Returns the setting of the auto-delete option. The default is FALSE. <p> <p>See also <a href="#setAutoDelete">setAutoDelete</a>(). <h3 class=fn>void <a name="clear"></a>QPtrQueue::clear () </h3> <p> Removes all items from the queue, and deletes them if <a href="#autoDelete">autoDelete</a>() is TRUE. <p> <p>See also <a href="#remove">remove</a>(). <h3 class=fn>uint <a name="count"></a>QPtrQueue::count () const </h3> <p> Returns the number of items in the queue. <p> <p>See also <a href="#isEmpty">isEmpty</a>(). <h3 class=fn>type * <a name="current"></a>QPtrQueue::current () const </h3> <p> Returns a pointer to the head item in the queue. The queue is not changed. Returns 0 if the queue is empty. <p> <p>See also <a href="#dequeue">dequeue</a>() and <a href="#isEmpty">isEmpty</a>(). <h3 class=fn>type * <a name="dequeue"></a>QPtrQueue::dequeue () </h3> <p> Takes the head item from the queue and returns a pointer to it. Returns 0 if the queue is empty. <p> <p>See also <a href="#enqueue">enqueue</a>() and <a href="#count">count</a>(). <h3 class=fn>void <a name="enqueue"></a>QPtrQueue::enqueue ( const type * d ) </h3> <p> Adds item <em>d</em> to the tail of the queue. <p> <p>See also <a href="#count">count</a>() and <a href="#dequeue">dequeue</a>(). <h3 class=fn>type * <a name="head"></a>QPtrQueue::head () const </h3> <p> Returns a pointer to the head item in the queue. The queue is not changed. Returns 0 if the queue is empty. <p> <p>See also <a href="#dequeue">dequeue</a>() and <a href="#isEmpty">isEmpty</a>(). <h3 class=fn>bool <a name="isEmpty"></a>QPtrQueue::isEmpty () const </h3> <p> Returns TRUE if the queue is empty; otherwise returns FALSE. <p> <p>See also <a href="#count">count</a>(), <a href="#dequeue">dequeue</a>(), and <a href="#head">head</a>(). <h3 class=fn><a name="operator-type-*"></a>QPtrQueue::operator type * () const </h3> <p> Returns a pointer to the head item in the queue. The queue is not changed. Returns 0 if the queue is empty. <p> <p>See also <a href="#dequeue">dequeue</a>() and <a href="#isEmpty">isEmpty</a>(). <h3 class=fn><a href="qptrqueue.html">QPtrQueue</a><type> & <a name="operator-eq"></a>QPtrQueue::operator= ( const <a href="qptrqueue.html">QPtrQueue</a><type> & queue ) </h3> <p> Assigns <em>queue</em> to this queue and returns a reference to this queue. <p> This queue is first cleared and then each item in <em>queue</em> is enqueued to this queue. Only the pointers are copied. <p> <b>Warning:</b> The <a href="#autoDelete">autoDelete</a>() flag is not modified. If it it TRUE for both <em>queue</em> and this queue, deleting the two lists will cause <em>double-deletion</em> of the items. <h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="read"></a>QPtrQueue::read ( <a href="qdatastream.html">QDataStream</a> & s, <a href="qptrcollection.html#Item">QPtrCollection::Item</a> & item )<tt> [virtual protected]</tt> </h3> <p> Reads a queue item, <em>item</em>, from the stream <em>s</em> and returns a reference to the stream. <p> The default implementation sets <em>item</em> to 0. <p> <p>See also <a href="#write">write</a>(). <h3 class=fn>bool <a name="remove"></a>QPtrQueue::remove () </h3> <p> 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. <p> The item is deleted if <a href="#autoDelete">autoDelete</a>() is TRUE. <p> <p>See also <a href="#head">head</a>(), <a href="#isEmpty">isEmpty</a>(), and <a href="#dequeue">dequeue</a>(). <h3 class=fn>void <a name="setAutoDelete"></a>QPtrQueue::setAutoDelete ( bool enable ) </h3> <p> Sets the queue to auto-delete its contents if <em>enable</em> is TRUE and not to delete them if <em>enable</em> is FALSE. <p> 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. <p> 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. <p> <p>See also <a href="#autoDelete">autoDelete</a>(). <h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="write"></a>QPtrQueue::write ( <a href="qdatastream.html">QDataStream</a> & s, <a href="qptrcollection.html#Item">QPtrCollection::Item</a> item ) const<tt> [virtual protected]</tt> </h3> <p> Writes a queue item, <em>item</em>, to the stream <em>s</em> and returns a reference to the stream. <p> The default implementation does nothing. <p> <p>See also <a href="#read">read</a>(). <!-- eof --> <hr><p> This file is part of the <a href="index.html">Qt toolkit</a>. Copyright © 1995-2007 <a href="http://www.trolltech.com/">Trolltech</a>. 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