IdentifiantMot de passe
Loading...
Mot de passe oublié ?Je m'inscris ! (gratuit)

QDBusPendingCallWatcher Class

The QDBusPendingCallWatcher class provides a convenient way for waiting for asynchronous replies.

Article lu   fois.

L'auteur

Liens sociaux

Viadeo Twitter Facebook Share on Google+   

QDBusPendingCallWatcher Class

  • Header: QDBusPendingCallWatcher

  • CMake:

    find_package(Qt6 REQUIRED COMPONENTS Dbus)

    target_link_libraries(mytarget PRIVATE Qt6::Dbus)

  • qmake: QT += dbus

  • Inherits: QObject and QDBusPendingCall

Detailed Description

The QDBusPendingCallWatcher provides the finished() signal that will be emitted when a reply arrives.

It is usually used like the following example:

 
Sélectionnez
    QDBusPendingCall async = iface->asyncCall("RemoteMethod", value1, value2);
    QDBusPendingCallWatcher *watcher = new QDBusPendingCallWatcher(async, this);

    QObject::connect(watcher, SIGNAL(finished(QDBusPendingCallWatcher*)),
                     this, SLOT(callFinishedSlot(QDBusPendingCallWatcher*)));

Note that it is not necessary to keep the original QDBusPendingCall object around since QDBusPendingCallWatcher inherits from that class too.

The slot connected to by the above code could be something similar to the following:

 
Sélectionnez
void DBus_PendingCall_Interface::callFinishedSlot(QDBusPendingCallWatcher *call)
{
    QDBusPendingReply<QString, QByteArray> reply = *call;
    if (reply.isError()) {
        showError();
    } else {
        QString text = reply.argumentAt<0>();
        QByteArray data = reply.argumentAt<1>();
        showReply(text, data);
    }
    call->deleteLater();
}

Note the use of QDBusPendingReply to validate the argument types in the reply. If the reply did not contain exactly two arguments (one string and one QByteArray), QDBusPendingReply::isError() will return true.

See Also

Member Function Documentation

 

[explicit] QDBusPendingCallWatcher::QDBusPendingCallWatcher(const QDBusPendingCall &call, QObject *parent = nullptr)

Creates a QDBusPendingCallWatcher object to watch for replies on the asynchronous pending call call and sets this object's parent to parent.

[virtual] QDBusPendingCallWatcher::~QDBusPendingCallWatcher()

Destroys this object. If this QDBusPendingCallWatcher object was the last reference to the unfinished pending call, the call will be canceled.

void QDBusPendingCallWatcher::finished(QDBusPendingCallWatcher *self = nullptr)

This signal is emitted when the pending call has finished and its reply is available. The self parameter is a pointer to the object itself, passed for convenience so that the slot can access the properties and determine the contents of the reply.

bool QDBusPendingCallWatcher::isFinished() const

Returns true if the pending call has finished processing and the reply has been received.

Note that this function only changes state if you call waitForFinished() or if an external D-Bus event happens, which in general only happens if you return to the event loop execution.

See Also

void QDBusPendingCallWatcher::waitForFinished()

Suspends the execution of the calling thread until the reply is received and processed. After this function returns, isFinished() should return true, indicating the reply's contents are ready to be processed.

See Also

Vous avez aimé ce tutoriel ? Alors partagez-le en cliquant sur les boutons suivants : Viadeo Twitter Facebook Share on Google+