QObjectCleanupHandler Class Reference

\inmodule QtCore More...

#include <qobjectcleanuphandler.h>

Inheritance diagram for QObjectCleanupHandler:

Collaboration diagram for QObjectCleanupHandler:

Public Member Functions
	QObjectCleanupHandler ()
	Constructs an empty QObjectCleanupHandler.
	~QObjectCleanupHandler ()
	Destroys the cleanup handler.
QObject *	add (QObject *object)
	Adds object to this cleanup handler and returns the pointer to the object.
void	remove (QObject *object)
	Removes the object from this cleanup handler.
bool	isEmpty () const
	Returns true if this cleanup handler is empty or if all objects in this cleanup handler have been destroyed; otherwise return false.
void	clear ()
	Deletes all objects in this cleanup handler.
Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)
	Constructs an object with parent object parent.
virtual	~QObject ()
	Destroys the object, deleting all its child objects.
virtual bool	event (QEvent *event)
	This virtual function receives events to an object and should return true if the event e was recognized and processed.
virtual bool	eventFilter (QObject *watched, QEvent *event)
	Filters events if this object has been installed as an event filter for the watched object.
QString	objectName () const
Q_WEAK_OVERLOAD void	setObjectName (const QString &name)
	Sets the object's name to name.
void	setObjectName (QAnyStringView name)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
QBindable< QString >	bindableObjectName ()
bool	isWidgetType () const
	Returns true if the object is a widget; otherwise returns false.
bool	isWindowType () const
	Returns true if the object is a window; otherwise returns false.
bool	isQuickItemType () const
	Returns true if the object is a QQuickItem; otherwise returns false.
bool	signalsBlocked () const noexcept
	Returns true if signals are blocked; otherwise returns false.
bool	blockSignals (bool b) noexcept
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).
QThread *	thread () const
	Returns the thread in which the object lives.
void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children.
int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
	This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.
int	startTimer (std::chrono::milliseconds time, Qt::TimerType timerType=Qt::CoarseTimer)
void	killTimer (int id)
	Kills the timer with timer identifier, id.
template<typename T >
T	findChild (const QString &aName=QString(), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.
template<typename T >
QList< T >	findChildren (const QString &aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects.
template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
const QObjectList &	children () const
	Returns a list of child objects.
void	setParent (QObject *parent)
	Makes the object a child of parent.
void	installEventFilter (QObject *filterObj)
	Installs an event filter filterObj on this object.
void	removeEventFilter (QObject *obj)
	Removes an event filter object obj from this object.
QMetaObject::Connection	connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
bool	disconnect (const char *signal=nullptr, const QObject *receiver=nullptr, const char *member=nullptr) const
bool	disconnect (const QObject *receiver, const char *member=nullptr) const
void	dumpObjectTree () const
	Dumps a tree of children to the debug output.
void	dumpObjectInfo () const
	Dumps information about signal connections, etc.
bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value.
bool	setProperty (const char *name, QVariant &&value)
QVariant	property (const char *name) const
	Returns the value of the object's name property.
QList< QByteArray >	dynamicPropertyNames () const
QBindingStorage *	bindingStorage ()
const QBindingStorage *	bindingStorage () const
QObject *	parent () const
	Returns a pointer to the parent object.
bool	inherits (const char *classname) const
	Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false.

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe
Signals inherited from QObject
void	destroyed (QObject *=nullptr)
	This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.
void	objectNameChanged (const QString &objectName, QPrivateSignal)
	This signal is emitted after the object's name has been changed.
Static Public Member Functions inherited from QObject
static QMetaObject::Connection	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
	\threadsafe
static QMetaObject::Connection	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType *context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)
template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)
static bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
	\threadsafe
static bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
static bool	disconnect (const QMetaObject::Connection &)
	Disconnect a connection.
template<typename Func1 , typename Func2 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object *receiver, Func2 slot)
template<typename Func1 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const QObject *receiver, void **zero)
Protected Member Functions inherited from QObject
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.
int	senderSignalIndex () const
int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal.
bool	isSignalConnected (const QMetaMethod &signal) const
virtual void	timerEvent (QTimerEvent *event)
	This event handler can be reimplemented in a subclass to receive timer events for the object.
virtual void	childEvent (QChildEvent *event)
	This event handler can be reimplemented in a subclass to receive child events.
virtual void	customEvent (QEvent *event)
	This event handler can be reimplemented in a subclass to receive custom events.
virtual void	connectNotify (const QMetaMethod &signal)
virtual void	disconnectNotify (const QMetaMethod &signal)
	QObject (QObjectPrivate &dd, QObject *parent=nullptr)
Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr
Properties inherited from QObject
QString	objectName
	the name of this object
Related Symbols inherited from QObject
template< class T > T	qobject_cast (const QObject *object)
	Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.
template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()
template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()
	QObjectList
	\macro Q_CLASSINFO(Name, Value)

Detailed Description

\inmodule QtCore

The QObjectCleanupHandler class watches the lifetime of multiple QObjects.

A QObjectCleanupHandler is useful whenever you need to know when a number of \l{QObject}s that are owned by someone else have been deleted. This is important, for example, when referencing memory in an application that has been allocated in a shared library.

To keep track of some \l{QObject}s, create a QObjectCleanupHandler, and add() the objects you are interested in. If you are no longer interested in tracking a particular object, use remove() to remove it from the cleanup handler. If an object being tracked by the cleanup handler gets deleted by someone else it will automatically be removed from the cleanup handler. You can delete all the objects in the cleanup handler with clear(), or by destroying the cleanup handler. isEmpty() returns true if the QObjectCleanupHandler has no objects to keep track of.

See also

QPointer

Definition at line 11 of file qobjectcleanuphandler.h.

Constructor & Destructor Documentation

QObjectCleanupHandler()

QObjectCleanupHandler::QObjectCleanupHandler

(

)

Constructs an empty QObjectCleanupHandler.

Definition at line 37 of file qobjectcleanuphandler.cpp.

~QObjectCleanupHandler()

QObjectCleanupHandler::~QObjectCleanupHandler

(

)

Destroys the cleanup handler.

All objects in this cleanup handler will be deleted.

See also

clear()

Definition at line 47 of file qobjectcleanuphandler.cpp.

References clear().

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Member Function Documentation

add()

QObject * QObjectCleanupHandler::add

(

QObject *

object

)

Adds object to this cleanup handler and returns the pointer to the object.

See also

remove()

Definition at line 58 of file qobjectcleanuphandler.cpp.

References QObject::connect(), QObject::destroyed(), QList< T >::insert(), SIGNAL, and SLOT.

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clear()

void QObjectCleanupHandler::clear

(

)

Deletes all objects in this cleanup handler.

The cleanup handler becomes empty.

See also

isEmpty()

Definition at line 100 of file qobjectcleanuphandler.cpp.

References QList< T >::isEmpty(), and QList< T >::takeFirst().

Referenced by ~QObjectCleanupHandler().

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isEmpty()

bool QObjectCleanupHandler::isEmpty

(

)

const

Returns true if this cleanup handler is empty or if all objects in this cleanup handler have been destroyed; otherwise return false.

See also

add(), remove(), clear()

Definition at line 89 of file qobjectcleanuphandler.cpp.

References QList< T >::isEmpty().

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remove()

void QObjectCleanupHandler::remove

(

QObject *

object

)

Removes the object from this cleanup handler.

The object will not be destroyed.

See also

add()

Definition at line 74 of file qobjectcleanuphandler.cpp.

References QObject::destroyed(), disconnect(), QListSpecialMethodsBase< T >::indexOf(), QList< T >::removeAt(), SIGNAL, and SLOT.

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The documentation for this class was generated from the following files:

• qtbase/src/corelib/kernel/qobjectcleanuphandler.h
• qtbase/src/corelib/kernel/qobjectcleanuphandler.cpp