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();
 }