Qt Reference Documentation

# complexping.cpp Example File

dbus/complexpingpong/complexping.cpp

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     #include <stdio.h>

     #include <QtCore/QCoreApplication>
     #include <QtCore/QFile>
     #include <QtCore/QDebug>
     #include <QtCore/QProcess>
     #include <QtDBus/QtDBus>

     #include "ping-common.h"
     #include "complexping.h"

     void Ping::start(const QString &name, const QString &oldValue, const QString &newValue)
     {
         Q_UNUSED(oldValue);

         if (name != SERVICE_NAME || newValue.isEmpty())
             return;

         // open stdin for reading
         qstdin.open(stdin, QIODevice::ReadOnly);

         // find our remote
         iface = new QDBusInterface(SERVICE_NAME, "/", "com.trolltech.QtDBus.ComplexPong.Pong",
                                    QDBusConnection::sessionBus(), this);
         if (!iface->isValid()) {
             fprintf(stderr, "%s\n",
                     qPrintable(QDBusConnection::sessionBus().lastError().message()));
             QCoreApplication::instance()->quit();
         }

         connect(iface, SIGNAL(aboutToQuit()), QCoreApplication::instance(), SLOT(quit()));

         while (true) {
             printf("Ask your question: ");

             QString line = QString::fromLocal8Bit(qstdin.readLine()).trimmed();
             if (line.isEmpty()) {
                 iface->call("quit");
                 return;
             } else if (line == "value") {
                 QVariant reply = iface->property("value");
                 if (!reply.isNull())
                     printf("value = %s\n", qPrintable(reply.toString()));
             } else if (line.startsWith("value=")) {
                 iface->setProperty("value", line.mid(6));
             } else {
                 QDBusReply<QDBusVariant> reply = iface->call("query", line);
                 if (reply.isValid())
                     printf("Reply was: %s\n", qPrintable(reply.value().variant().toString()));
             }

             if (iface->lastError().isValid())
                 fprintf(stderr, "Call failed: %s\n", qPrintable(iface->lastError().message()));
         }
     }

     int main(int argc, char **argv)
     {
         QCoreApplication app(argc, argv);

         if (!QDBusConnection::sessionBus().isConnected()) {
             fprintf(stderr, "Cannot connect to the D-Bus session bus.\n"
                     "To start it, run:\n"
                     "\teval `dbus-launch --auto-syntax`\n");
             return 1;
         }

         Ping ping;
         ping.connect(QDBusConnection::sessionBus().interface(),
                      SIGNAL(serviceOwnerChanged(QString,QString,QString)),
                      SLOT(start(QString,QString,QString)));

         QProcess pong;
         pong.start("./complexpong");

         app.exec();
     }