source: trunk/doc/src/q3ptrqueue.qdoc@ 109

Last change on this file since 109 was 2, checked in by Dmitry A. Kuminov, 16 years ago

Initially imported qt-all-opensource-src-4.5.1 from Trolltech.
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41
42/*!
43 \class Q3PtrQueue
44 \brief The Q3PtrQueue class is a template class that provides a queue.
45 \compat
46
47 Q3ValueVector can be used as an STL-compatible alternative to this
48 class.
49
50 A template instance Q3PtrQueue\<X\> is a queue that operates on
51 pointers to X (X*).
52
53 A queue is a first in, first out structure. Items are added to the
54 tail of the queue with enqueue() and retrieved from the head with
55 dequeue(). You can peek at the head item without dequeing it using
56 head().
57
58 You can control the queue's deletion policy with setAutoDelete().
59
60 For compatibility with the Q3PtrCollection classes, current() and
61 remove() are provided; both operate on the head().
62
63 \sa Q3PtrList Q3PtrStack
64*/
65
66/*!
67 \fn Q3PtrQueue::Q3PtrQueue ()
68
69 Creates an empty queue with autoDelete() set to FALSE.
70*/
71
72/*!
73 \fn Q3PtrQueue::Q3PtrQueue( const Q3PtrQueue<type>& queue )
74
75 Creates a queue from \a queue.
76
77 Only the pointers are copied; the items are not. The autoDelete()
78 flag is set to FALSE.
79*/
80
81/*!
82 \fn Q3PtrQueue::~Q3PtrQueue()
83
84 Destroys the queue. Items in the queue are deleted if autoDelete()
85 is TRUE.
86*/
87
88/*!
89 \fn Q3PtrQueue<type>& Q3PtrQueue::operator= (const Q3PtrQueue<type>& queue)
90
91 Assigns \a queue to this queue and returns a reference to this
92 queue.
93
94 This queue is first cleared and then each item in \a queue is
95 enqueued to this queue. Only the pointers are copied.
96
97 \warning The autoDelete() flag is not modified. If it is TRUE for
98 both \a queue and this queue, deleting the two lists will cause \e
99 double-deletion of the items.
100*/
101
102/*!
103 \fn bool Q3PtrQueue::isEmpty() const
104
105 Returns TRUE if the queue is empty; otherwise returns FALSE.
106
107 \sa count() dequeue() head()
108*/
109
110/*!
111 \fn void Q3PtrQueue::enqueue (const type* d)
112
113 Adds item \a d to the tail of the queue.
114
115 \sa count() dequeue()
116*/
117
118/*!
119 \fn type* Q3PtrQueue::dequeue ()
120
121 Takes the head item from the queue and returns a pointer to it.
122 Returns 0 if the queue is empty.
123
124 \sa enqueue() count()
125*/
126
127/*!
128 \fn bool Q3PtrQueue::remove()
129
130 Removes the head item from the queue, and returns TRUE if there
131 was an item, i.e. the queue wasn't empty; otherwise returns FALSE.
132
133 The item is deleted if autoDelete() is TRUE.
134
135 \sa head() isEmpty() dequeue()
136*/
137
138/*!
139 \fn void Q3PtrQueue::clear()
140
141 Removes all items from the queue, and deletes them if autoDelete()
142 is TRUE.
143
144 \sa remove()
145*/
146
147/*!
148 \fn uint Q3PtrQueue::count() const
149
150 Returns the number of items in the queue.
151
152 \sa isEmpty()
153*/
154
155/*!
156 \fn type* Q3PtrQueue::head() const
157
158 Returns a pointer to the head item in the queue. The queue is not
159 changed. Returns 0 if the queue is empty.
160
161 \sa dequeue() isEmpty()
162*/
163
164/*!
165 \fn Q3PtrQueue::operator type*() const
166
167 Returns a pointer to the head item in the queue. The queue is not
168 changed. Returns 0 if the queue is empty.
169
170 \sa dequeue() isEmpty()
171*/
172
173/*!
174 \fn type* Q3PtrQueue::current() const
175
176 Returns a pointer to the head item in the queue. The queue is not
177 changed. Returns 0 if the queue is empty.
178
179 \sa dequeue() isEmpty()
180*/
181
182/*!
183 \fn bool Q3PtrQueue::autoDelete() const
184
185 Returns the setting of the auto-delete option. The default is
186 FALSE.
187
188 \sa setAutoDelete()
189*/
190
191/*!
192 \fn void Q3PtrQueue::setAutoDelete( bool enable )
193
194 Sets the queue to auto-delete its contents if \a enable is TRUE
195 and not to delete them if \a enable is FALSE.
196
197 If auto-deleting is turned on, all the items in a queue are
198 deleted when the queue itself is deleted. This can be quite
199 convenient if the queue has the only pointer to the items.
200
201 The default setting is FALSE, for safety. If you turn it on, be
202 careful about copying the queue: you might find yourself with two
203 queues deleting the same items.
204
205 \sa autoDelete()
206*/
207
208/*!
209 \fn QDataStream& Q3PtrQueue::read( QDataStream& s,
210 Q3PtrCollection::Item& item )
211
212 Reads a queue item, \a item, from the stream \a s and returns a
213 reference to the stream.
214
215 The default implementation sets \a item to 0.
216
217 \sa write()
218*/
219
220/*!
221 \fn QDataStream& Q3PtrQueue::write( QDataStream& s,
222 Q3PtrCollection::Item item ) const
223
224 Writes a queue item, \a item, to the stream \a s and returns a
225 reference to the stream.
226
227 The default implementation does nothing.
228
229 \sa read()
230*/
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