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/*!
    \class QSignalSpy
    \inmodule QtTest

    \brief 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 \c clicked() signal
    of a QCheckBox:

    \snippet code/doc_src_qsignalspy.cpp 0

    \c{spy.takeFirst()} returns the arguments for the first emitted signal, as a
    list of QVariant objects. The \c 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:

    \snippet code/doc_src_qsignalspy.cpp 1

    \b {Note:} Non-standard data types need to be registered, using
    the qRegisterMetaType() function, before you can create a
    QSignalSpy. For example:

    \snippet code/doc_src_qsignalspy.cpp 2

    To retrieve the instance, you can use qvariant_cast:

    \snippet code/doc_src_qsignalspy.cpp 3
 */

/*! \fn QSignalSpy::QSignalSpy(const QObject *object, const char *signal)

    Constructs a new QSignalSpy that listens for emissions of the \a signal
    from the QObject \a object. If QSignalSpy is not able to listen for a
    valid signal (for example, because \a object is null or \a signal does
    not denote a valid signal of \a object), an explanatory warning message
    will be output using qWarning() and subsequent calls to \c isValid() will
    return false.

    Example:
    \snippet code/doc_src_qsignalspy.cpp 4
*/

/*! \fn QSignalSpy::QSignalSpy(const QObject *object, PointerToMemberFunction signal)
    \since 5.4

    Constructs a new QSignalSpy that listens for emissions of the \a signal
    from the QObject \a object. If QSignalSpy is not able to listen for a
    valid signal (for example, because \a object is null or \a signal does
    not denote a valid signal of \a object), an explanatory warning message
    will be output using qWarning() and subsequent calls to \c isValid() will
    return false.

    Example:
    \snippet code/doc_src_qsignalspy.cpp 6
*/

/*! \fn QSignalSpy::isValid() const

    Returns \c true if the signal spy listens to a valid signal, otherwise false.
*/

/*! \fn QSignalSpy::signal() const

    Returns the normalized signal the spy is currently listening to.
*/

/*! \fn int QSignalSpy::qt_metacall(QMetaObject::Call call, int id, void **a)
    \internal
*/

/*! \fn QSignalSpy::wait(int timeout)

    \since 5.0

    Starts an event loop that runs until the given signal is received.
    Optionally the event loop can return earlier on a \a timeout (in milliseconds).

    Returns \c true if the signal was emitted at least once in \a timeout milliseconds, otherwise returns \c false.

    Example:
    \snippet code/doc_src_qsignalspy.cpp 5
*/