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32<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>
33
34<p>The QPtrQueue class is a template class that provides a queue.
35<a href="#details">More...</a>
36<p><tt>#include &lt;<a href="qptrqueue-h.html">qptrqueue.h</a>&gt;</tt>
37<p><a href="qptrqueue-members.html">List of all member functions.</a>
38<h2>Public Members</h2>
39<ul>
40<li class=fn><a href="#QPtrQueue"><b>QPtrQueue</b></a> ()</li>
41<li class=fn><a href="#QPtrQueue-2"><b>QPtrQueue</b></a> ( const&nbsp;QPtrQueue&lt;type&gt;&nbsp;&amp;&nbsp;queue )</li>
42<li class=fn><a href="#~QPtrQueue"><b>~QPtrQueue</b></a> ()</li>
43<li class=fn>QPtrQueue&lt;type&gt; &amp; <a href="#operator-eq"><b>operator=</b></a> ( const&nbsp;QPtrQueue&lt;type&gt;&nbsp;&amp;&nbsp;queue )</li>
44<li class=fn>bool <a href="#autoDelete"><b>autoDelete</b></a> () const</li>
45<li class=fn>void <a href="#setAutoDelete"><b>setAutoDelete</b></a> ( bool&nbsp;enable )</li>
46<li class=fn>uint <a href="#count"><b>count</b></a> () const</li>
47<li class=fn>bool <a href="#isEmpty"><b>isEmpty</b></a> () const</li>
48<li class=fn>void <a href="#enqueue"><b>enqueue</b></a> ( const&nbsp;type&nbsp;*&nbsp;d )</li>
49<li class=fn>type * <a href="#dequeue"><b>dequeue</b></a> ()</li>
50<li class=fn>bool <a href="#remove"><b>remove</b></a> ()</li>
51<li class=fn>void <a href="#clear"><b>clear</b></a> ()</li>
52<li class=fn>type * <a href="#head"><b>head</b></a> () const</li>
53<li class=fn><a href="#operator-type-*"><b>operator type *</b></a> () const</li>
54<li class=fn>type * <a href="#current"><b>current</b></a> () const</li>
55</ul>
56<h2>Protected Members</h2>
57<ul>
58<li class=fn>virtual QDataStream &amp; <a href="#read"><b>read</b></a> ( QDataStream&nbsp;&amp;&nbsp;s, QPtrCollection::Item&nbsp;&amp;&nbsp;item )</li>
59<li class=fn>virtual QDataStream &amp; <a href="#write"><b>write</b></a> ( QDataStream&nbsp;&amp;&nbsp;s, QPtrCollection::Item&nbsp;item ) const</li>
60</ul>
61<hr><a name="details"></a><h2>Detailed Description</h2>
62
63
64The QPtrQueue class is a template class that provides a queue.
65<p>
66
67<p> <a href="qvaluevector.html">QValueVector</a> can be used as an STL-compatible alternative to this
68class.
69<p> A template instance QPtrQueue&lt;X&gt; is a queue that operates on
70pointers to X (X*).
71<p> A queue is a first in, first out structure. Items are added to the
72tail of the queue with <a href="#enqueue">enqueue</a>() and retrieved from the head with
73<a href="#dequeue">dequeue</a>(). You can peek at the head item without dequeing it using
74<a href="#head">head</a>().
75<p> You can control the queue's deletion policy with <a href="#setAutoDelete">setAutoDelete</a>().
76<p> For compatibility with the <a href="qptrcollection.html">QPtrCollection</a> classes, <a href="#current">current</a>() and
77<a href="#remove">remove</a>() are provided; both operate on the head().
78<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>.
79
80<hr><h2>Member Function Documentation</h2>
81<h3 class=fn><a name="QPtrQueue"></a>QPtrQueue::QPtrQueue ()
82</h3>
83
84<p> Creates an empty queue with <a href="#autoDelete">autoDelete</a>() set to FALSE.
85
86<h3 class=fn><a name="QPtrQueue-2"></a>QPtrQueue::QPtrQueue ( const&nbsp;<a href="qptrqueue.html">QPtrQueue</a>&lt;type&gt;&nbsp;&amp;&nbsp;queue )
87</h3>
88
89<p> Creates a queue from <em>queue</em>.
90<p> Only the pointers are copied; the items are not. The <a href="#autoDelete">autoDelete</a>()
91flag is set to FALSE.
92
93<h3 class=fn><a name="~QPtrQueue"></a>QPtrQueue::~QPtrQueue ()
94</h3>
95
96<p> Destroys the queue. Items in the queue are deleted if <a href="#autoDelete">autoDelete</a>()
97is TRUE.
98
99<h3 class=fn>bool <a name="autoDelete"></a>QPtrQueue::autoDelete () const
100</h3>
101
102<p> Returns the setting of the auto-delete option. The default is
103FALSE.
104<p> <p>See also <a href="#setAutoDelete">setAutoDelete</a>().
105
106<h3 class=fn>void <a name="clear"></a>QPtrQueue::clear ()
107</h3>
108
109<p> Removes all items from the queue, and deletes them if <a href="#autoDelete">autoDelete</a>()
110is TRUE.
111<p> <p>See also <a href="#remove">remove</a>().
112
113<h3 class=fn>uint <a name="count"></a>QPtrQueue::count () const
114</h3>
115
116<p> Returns the number of items in the queue.
117<p> <p>See also <a href="#isEmpty">isEmpty</a>().
118
119<h3 class=fn>type * <a name="current"></a>QPtrQueue::current () const
120</h3>
121
122<p> Returns a pointer to the head item in the queue. The queue is not
123changed. Returns 0 if the queue is empty.
124<p> <p>See also <a href="#dequeue">dequeue</a>() and <a href="#isEmpty">isEmpty</a>().
125
126<h3 class=fn>type * <a name="dequeue"></a>QPtrQueue::dequeue ()
127</h3>
128
129<p> Takes the head item from the queue and returns a pointer to it.
130Returns 0 if the queue is empty.
131<p> <p>See also <a href="#enqueue">enqueue</a>() and <a href="#count">count</a>().
132
133<h3 class=fn>void <a name="enqueue"></a>QPtrQueue::enqueue ( const&nbsp;type&nbsp;*&nbsp;d )
134</h3>
135
136<p> Adds item <em>d</em> to the tail of the queue.
137<p> <p>See also <a href="#count">count</a>() and <a href="#dequeue">dequeue</a>().
138
139<h3 class=fn>type * <a name="head"></a>QPtrQueue::head () const
140</h3>
141
142<p> Returns a pointer to the head item in the queue. The queue is not
143changed. Returns 0 if the queue is empty.
144<p> <p>See also <a href="#dequeue">dequeue</a>() and <a href="#isEmpty">isEmpty</a>().
145
146<h3 class=fn>bool <a name="isEmpty"></a>QPtrQueue::isEmpty () const
147</h3>
148
149<p> Returns TRUE if the queue is empty; otherwise returns FALSE.
150<p> <p>See also <a href="#count">count</a>(), <a href="#dequeue">dequeue</a>(), and <a href="#head">head</a>().
151
152<h3 class=fn><a name="operator-type-*"></a>QPtrQueue::operator type * () const
153</h3>
154
155<p> Returns a pointer to the head item in the queue. The queue is not
156changed. Returns 0 if the queue is empty.
157<p> <p>See also <a href="#dequeue">dequeue</a>() and <a href="#isEmpty">isEmpty</a>().
158
159<h3 class=fn><a href="qptrqueue.html">QPtrQueue</a>&lt;type&gt;&nbsp;&amp; <a name="operator-eq"></a>QPtrQueue::operator= ( const&nbsp;<a href="qptrqueue.html">QPtrQueue</a>&lt;type&gt;&nbsp;&amp;&nbsp;queue )
160</h3>
161
162<p> Assigns <em>queue</em> to this queue and returns a reference to this
163queue.
164<p> This queue is first cleared and then each item in <em>queue</em> is
165enqueued to this queue. Only the pointers are copied.
166<p> <b>Warning:</b> The <a href="#autoDelete">autoDelete</a>() flag is not modified. If it it TRUE for
167both <em>queue</em> and this queue, deleting the two lists will cause <em>double-deletion</em> of the items.
168
169<h3 class=fn><a href="qdatastream.html">QDataStream</a>&nbsp;&amp; <a name="read"></a>QPtrQueue::read ( <a href="qdatastream.html">QDataStream</a>&nbsp;&amp;&nbsp;s, <a href="qptrcollection.html#Item">QPtrCollection::Item</a>&nbsp;&amp;&nbsp;item )<tt> [virtual protected]</tt>
170</h3>
171
172<p> Reads a queue item, <em>item</em>, from the stream <em>s</em> and returns a
173reference to the stream.
174<p> The default implementation sets <em>item</em> to 0.
175<p> <p>See also <a href="#write">write</a>().
176
177<h3 class=fn>bool <a name="remove"></a>QPtrQueue::remove ()
178</h3>
179
180<p> Removes the head item from the queue, and returns TRUE if there
181was an item, i.e. the queue wasn't empty; otherwise returns FALSE.
182<p> The item is deleted if <a href="#autoDelete">autoDelete</a>() is TRUE.
183<p> <p>See also <a href="#head">head</a>(), <a href="#isEmpty">isEmpty</a>(), and <a href="#dequeue">dequeue</a>().
184
185<h3 class=fn>void <a name="setAutoDelete"></a>QPtrQueue::setAutoDelete ( bool&nbsp;enable )
186</h3>
187
188<p> Sets the queue to auto-delete its contents if <em>enable</em> is TRUE
189and not to delete them if <em>enable</em> is FALSE.
190<p> If auto-deleting is turned on, all the items in a queue are
191deleted when the queue itself is deleted. This can be quite
192convenient if the queue has the only pointer to the items.
193<p> The default setting is FALSE, for safety. If you turn it on, be
194careful about copying the queue: you might find yourself with two
195queues deleting the same items.
196<p> <p>See also <a href="#autoDelete">autoDelete</a>().
197
198<h3 class=fn><a href="qdatastream.html">QDataStream</a>&nbsp;&amp; <a name="write"></a>QPtrQueue::write ( <a href="qdatastream.html">QDataStream</a>&nbsp;&amp;&nbsp;s, <a href="qptrcollection.html#Item">QPtrCollection::Item</a>&nbsp;item ) const<tt> [virtual protected]</tt>
199</h3>
200
201<p> Writes a queue item, <em>item</em>, to the stream <em>s</em> and returns a
202reference to the stream.
203<p> The default implementation does nothing.
204<p> <p>See also <a href="#read">read</a>().
205
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