Материал из Wiki.crossplatform.ru

Внимание: Актуальная версия перевода документации находится здесь

__NOTOC__

[править] QSignalSpy Class Reference
^{[ QtTest module]}

The QSignalSpy class enables introspection of signal emission. Далее...

 #include <QSignalSpy>

Inherits QObject and QList<QList<QVariant> >.

• Список всех членов, включая унаследованные

[править] Открытые функции

• QSignalSpy ( QObject * object, const char * signal )
• bool isValid () const
• QByteArray signal () const

• 29 открытых функций, унаследованных от QObject
• 60 public functions inherited from QList

[править] Дополнительные унаследованные члены

• 1 свойство, унаследованное от QObject
• 1 открытый слот, унаследованный от QObject
• 1 сигнал, унаследованный от QObject
• 5 статических открытых членов, унаследованных от QObject
• 3 static public members inherited from QList
• 7 защищенных функций, унаследованных от QObject

[править] Подробное описание

The QSignalSpy class enables introspection of signal emission.

QSignalSpy can connect to any signal of any object and records its emission. QSignalSpy itself is a list of QVariant lists. Each emission of the signal will append one item to the list, containing the arguments of the signal.

The following example records all signal emissions for the clicked() signal of a QCheckBox:

 QCheckBox *box = ...;
 QSignalSpy spy(box, SIGNAL(clicked(bool)));
 
 // do something that triggers the signal
 box->animateClick();
 
 QCOMPARE(spy.count(), 1); // make sure the signal was emitted exactly one time
 QList<QVariant> arguments = spy.takeFirst(); // take the first signal
 
 QVERIFY(arguments.at(0).toBool() == true); // verify the first argument

spy.takeFirst() returns the arguments for the first emitted signal, as a list of QVariant objects. The clicked() signal has a single bool argument, which is stored as the first entry in the list of arguments.

The example below catches a signal from a custom object:

 QSignalSpy spy(myCustomObject, SIGNAL(mySignal(int, QString, double)));
 
 myCustomObject->doSomething(); // trigger emission of the signal
 
 QList<QVariant> arguments = spy.takeFirst();
 QVERIFY(arguments.at(0).type() == QVariant::Int);
 QVERIFY(arguments.at(1).type() == QVariant::QString);
 QVERIFY(arguments.at(2).type() == QVariant::double);

Note: Non-standard data types need to be registered, using the qRegisterMetaType() function, before you can create a QSignalSpy. Пример:

 qRegisterMetaType<QModelIndex>("QModelIndex");
 QSignalSpy spy(&amp;model, SIGNAL(whatever(QModelIndex)));

To retrieve the QModelIndex, you can use qvariant_cast:

 // get the first argument from the first received signal:
 QModelIndex result = qvariant_cast<QModelIndex>(spy.at(0).at(0));

[править] Описание функций-членов

[править]

QSignalSpy::QSignalSpy ( QObject * object, const char * signal )

Constructs a new QSignalSpy that listens for emissions of the signal from the QObject object. Neither signal nor object can be null.

Пример:

 QSignalSpy spy(myPushButton, SIGNAL(clicked(bool)));

[править]

bool QSignalSpy::isValid () const

Returns true if the signal spy listens to a valid signal, otherwise false.

[править]

QByteArray QSignalSpy::signal () const

Returns the normalized signal the spy is currently listening to.