complexpingpong example: Modernize the code

Use C++ IO streams and qWarning() instead of (f)printf() for console IO.
Make user-visible strings translatable. Use invokeMethod() instead
of QTimer.

Fixes: QTBUG-111366
Pick-to: 6.5
Change-Id: I6990b964c2097267e04cd361b9cd8fc0a22a0135
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

examples/dbus/complexpingpong/complexping.cpp

@@ -5,54 +5,58 @@
 #include "complexping.h"
 
 #include <QCoreApplication>
+#include <QDBusInterface>
 #include <QDBusReply>
 #include <QDBusServiceWatcher>
-#include <QFile>
 #include <QDebug>
 #include <QProcess>
 
-#include <stdio.h>
+#include <iostream>
+#include <string>
 
 void Ping::start(const QString &name)
 {
     if (name != SERVICE_NAME)
         return;
 
-    // open stdin for reading
-    qstdin.open(stdin, QIODevice::ReadOnly);
-
+    auto connection = QDBusConnection::sessionBus();
     // find our remote
-    iface = new QDBusInterface(SERVICE_NAME, "/", "org.example.QtDBus.ComplexPong.Pong",
-                               QDBusConnection::sessionBus(), this);
+    auto iface = new QDBusInterface(SERVICE_NAME, "/", "org.example.QtDBus.ComplexPong.Pong",
+                                    connection, this);
     if (!iface->isValid()) {
-        fprintf(stderr, "%s\n",
-                qPrintable(QDBusConnection::sessionBus().lastError().message()));
+        qWarning().noquote() << connection.lastError().message();
         QCoreApplication::instance()->quit();
     }
 
     connect(iface, SIGNAL(aboutToQuit()), QCoreApplication::instance(), SLOT(quit()));
 
-    while (true) {
-        printf("Ask your question: ");
+    std::string s;
+
+    while (true) {
+        std::cout << qPrintable(tr("Ask your question: ")) << std::flush;
+
+        std::getline(std::cin, s);
+        auto line = QString::fromStdString(s).trimmed();
 
-        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()));
+                std::cout << "value = " << qPrintable(reply.toString()) << std::endl;
         } 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 (reply.isValid()) {
+                std::cout << qPrintable(tr("Reply was: %1").arg(reply.value().variant().toString()))
+                          << std::endl;
+            }
         }
 
         if (iface->lastError().isValid())
-            fprintf(stderr, "Call failed: %s\n", qPrintable(iface->lastError().message()));
+            qWarning().noquote() << tr("Call failed: %1").arg(iface->lastError().message());
     }
 }
 
@@ -61,9 +65,11 @@ 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"
+        qWarning().noquote() << QCoreApplication::translate(
+                "complexping",
+                "Cannot connect to the D-Bus session bus.\n"
                 "To start it, run:\n"
-                "\teval `dbus-launch --auto-syntax`\n");
+                "\teval `dbus-launch --auto-syntax`");
         return 1;
     }
 

examples/dbus/complexpingpong/complexping.h

@@ -5,17 +5,12 @@
 #define COMPLEXPING_H
 
 #include <QtCore/QObject>
-#include <QtCore/QFile>
-#include <QtDBus/QDBusInterface>
 
-class Ping: public QObject
+class Ping : public QObject
 {
     Q_OBJECT
 public slots:
-    void start(const QString &);
-public:
-    QFile qstdin;
-    QDBusInterface *iface;
+    void start(const QString &name);
 };
 
 #endif

examples/dbus/complexpingpong/complexpong.cpp

@@ -7,12 +7,8 @@
 #include <QCoreApplication>
 #include <QDBusConnection>
 #include <QDBusError>
-#include <QTimer>
+#include <QDebug>
 
-#include <stdio.h>
-#include <stdlib.h>
-
-// the property
 QString Pong::value() const
 {
     return m_value;
@@ -25,7 +21,8 @@ void Pong::setValue(const QString &newValue)
 
 void Pong::quit()
 {
-    QTimer::singleShot(0, QCoreApplication::instance(), &QCoreApplication::quit);
+    QMetaObject::invokeMethod(QCoreApplication::instance(), &QCoreApplication::quit,
+                              Qt::QueuedConnection);
 }
 
 QDBusVariant Pong::query(const QString &query)
@@ -54,12 +51,13 @@ int main(int argc, char **argv)
     Pong *pong = new Pong(&obj);
     QObject::connect(&app, &QCoreApplication::aboutToQuit, pong, &Pong::aboutToQuit);
     pong->setProperty("value", "initial value");
-    QDBusConnection::sessionBus().registerObject("/", &obj);
 
-    if (!QDBusConnection::sessionBus().registerService(SERVICE_NAME)) {
-        fprintf(stderr, "%s\n",
-                qPrintable(QDBusConnection::sessionBus().lastError().message()));
-        exit(1);
+    auto connection = QDBusConnection::sessionBus();
+    connection.registerObject("/", &obj);
+
+    if (!connection.registerService(SERVICE_NAME)) {
+        qWarning().noquote() << connection.lastError().message();
+        return 1;
     }
 
     app.exec();

examples/dbus/complexpingpong/complexpong.h

@@ -8,23 +8,26 @@
 #include <QtDBus/QDBusAbstractAdaptor>
 #include <QtDBus/QDBusVariant>
 
-class Pong: public QDBusAbstractAdaptor
+class Pong : public QDBusAbstractAdaptor
 {
     Q_OBJECT
     Q_CLASSINFO("D-Bus Interface", "org.example.QtDBus.ComplexPong.Pong")
     Q_PROPERTY(QString value READ value WRITE setValue)
 public:
-    QString m_value;
     QString value() const;
     void setValue(const QString &newValue);
 
-    Pong(QObject *obj) : QDBusAbstractAdaptor(obj)
-    { }
+    Pong(QObject *obj) : QDBusAbstractAdaptor(obj) { }
+
 signals:
     void aboutToQuit();
+
 public slots:
     QDBusVariant query(const QString &query);
     Q_NOREPLY void quit();
+
+private:
+    QString m_value;
 };
 
 #endif