qobjectcleanuphandler(3qt)

1QObjectCleanupHandler(3qt)                          QObjectCleanupHandler(3qt)
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NAME

6       QObjectCleanupHandler - Watches the lifetime of multiple QObjects
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SYNOPSIS

9       #include <qobjectcleanuphandler.h>
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11       Inherits QObject.
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13   Public Members
14       QObjectCleanupHandler ()
15       ~QObjectCleanupHandler ()
16       QObject * add ( QObject * object )
17       void remove ( QObject * object )
18       bool isEmpty () const
19       void clear ()
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DESCRIPTION

22       The QObjectCleanupHandler class watches the lifetime of multiple
23       QObjects.
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25       A QObjectCleanupHandler is useful whenever you need to know when a
26       number of QObjects that are owned by someone else have been deleted.
27       This is important, for example, when referencing memory in an
28       application that has been allocated in a shared library.
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30       Example:
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32           class FactoryComponent : public FactoryInterface, public QLibraryInterface
33           {
34           public:
35               ...
36               QObject *createObject();
37               bool init();
38               void cleanup();
39               bool canUnload() const;
40           private:
41               QObjectCleanupHandler objects;
42           };
43           // allocate a new object, and add it to the cleanup handler
44           QObject *FactoryComponent::createObject()
45           {
46               return objects.add( new QObject() );
47           }
48           // QLibraryInterface implementation
49           bool FactoryComponent::init()
50           {
51               return TRUE;
52           }
53           void FactoryComponent::cleanup()
54           {
55           }
56           // it is only safe to unload the library when all QObject's have been destroyed
57           bool FactoryComponent::canUnload() const
58           {
59               return objects.isEmpty();
60           }
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62       See also Object Model.
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MEMBER FUNCTION DOCUMENTATION

QObjectCleanupHandler::QObjectCleanupHandler ()

66       Constructs an empty QObjectCleanupHandler.
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QObjectCleanupHandler::~QObjectCleanupHandler ()

69       Destroys the cleanup handler. All objects in this cleanup handler will
70       be deleted.
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QObject * QObjectCleanupHandler::add ( QObject * object )

73       Adds object to this cleanup handler and returns the pointer to the
74       object.
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void QObjectCleanupHandler::clear ()

77       Deletes all objects in this cleanup handler. The cleanup handler
78       becomes empty.
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bool QObjectCleanupHandler::isEmpty () const

81       Returns TRUE if this cleanup handler is empty or if all objects in this
82       cleanup handler have been destroyed; otherwise return FALSE.
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void QObjectCleanupHandler::remove ( QObject * object )

85       Removes the object from this cleanup handler. The object will not be
86       destroyed.
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COPYRIGHT

94       Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com.  See the
95       license file included in the distribution for a complete license
96       statement.
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AUTHOR

99       Generated automatically from the source code.
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BUGS

102       If you find a bug in Qt, please report it as described in
103       http://doc.trolltech.com/bughowto.html.  Good bug reports help us to
104       help you. Thank you.
105
106       The definitive Qt documentation is provided in HTML format; it is
107       located at $QTDIR/doc/html and can be read using Qt Assistant or with a
108       web browser. This man page is provided as a convenience for those users
109       who prefer man pages, although this format is not officially supported
110       by Trolltech.
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112       If you find errors in this manual page, please report them to qt-
113       bugs@trolltech.com.  Please include the name of the manual page
114       (qobjectcleanuphandler.3qt) and the Qt version (3.3.8).
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118Trolltech AS                    2 February 2007     QObjectCleanupHandler(3qt)