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39
40#include "qobjectcleanuphandler.h"
41
42QT_BEGIN_NAMESPACE
43
44/*!
45 \class QObjectCleanupHandler
46 \inmodule QtCore
47 \brief The QObjectCleanupHandler class watches the lifetime of multiple QObjects.
48
49 \ingroup objectmodel
50
51 A QObjectCleanupHandler is useful whenever you need to know when a
52 number of \l{QObject}s that are owned by someone else have been
53 deleted. This is important, for example, when referencing memory
54 in an application that has been allocated in a shared library.
55
56 To keep track of some \l{QObject}s, create a
57 QObjectCleanupHandler, and add() the objects you are interested
58 in. If you are no longer interested in tracking a particular
59 object, use remove() to remove it from the cleanup handler. If an
60 object being tracked by the cleanup handler gets deleted by
61 someone else it will automatically be removed from the cleanup
62 handler. You can delete all the objects in the cleanup handler
63 with clear(), or by destroying the cleanup handler. isEmpty()
64 returns \c true if the QObjectCleanupHandler has no objects to keep
65 track of.
66
67 \sa QPointer
68*/
69
70/*!
71 Constructs an empty QObjectCleanupHandler.
72*/
73QObjectCleanupHandler::QObjectCleanupHandler()
74{
75}
76
77/*!
78 Destroys the cleanup handler. All objects in this cleanup handler
79 will be deleted.
80
81 \sa clear()
82*/
83QObjectCleanupHandler::~QObjectCleanupHandler()
84{
85 clear();
86}
87
88/*!
89 Adds \a object to this cleanup handler and returns the pointer to
90 the object.
91
92 \sa remove()
93*/
94QObject *QObjectCleanupHandler::add(QObject *object)
95{
96 if (!object)
97 return nullptr;
98
99 connect(object, SIGNAL(destroyed(QObject *)), this, SLOT(objectDestroyed(QObject *)));
100 cleanupObjects.insert(0, object);
101 return object;
102}
103
104/*!
105 Removes the \a object from this cleanup handler. The object will
106 not be destroyed.
107
108 \sa add()
109*/
110void QObjectCleanupHandler::remove(QObject *object)
111{
112 int index;
113 if ((index = cleanupObjects.indexOf(object)) != -1) {
114 cleanupObjects.removeAt(index);
115 disconnect(object, SIGNAL(destroyed(QObject *)), this, SLOT(objectDestroyed(QObject *)));
116 }
117}
118
119/*!
120 Returns \c true if this cleanup handler is empty or if all objects in
121 this cleanup handler have been destroyed; otherwise return false.
122
123 \sa add(), remove(), clear()
124*/
125bool QObjectCleanupHandler::isEmpty() const
126{
127 return cleanupObjects.isEmpty();
128}
129
130/*!
131 Deletes all objects in this cleanup handler. The cleanup handler
132 becomes empty.
133
134 \sa isEmpty()
135*/
136void QObjectCleanupHandler::clear()
137{
138 while (!cleanupObjects.isEmpty())
139 delete cleanupObjects.takeFirst();
140}
141
142void QObjectCleanupHandler::objectDestroyed(QObject *object)
143{
144 remove(object);
145}
146
147QT_END_NAMESPACE
148
149#include "moc_qobjectcleanuphandler.cpp"
150