Qt 5.11 | Qt Network | Fortune Server Example | server.cpp Example File

Qt 5.11.3 Reference Documentation

# server.cpp Example File

fortuneserver/server.cpp

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      #include <QtWidgets>
      #include <QtNetwork>
      #include <QtCore>

      #include "server.h"

      Server::Server(QWidget *parent)
          : QDialog(parent)
          , statusLabel(new QLabel)
      {
          setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
          statusLabel->setTextInteractionFlags(Qt::TextBrowserInteraction);

          QNetworkConfigurationManager manager;
          if (manager.capabilities() & QNetworkConfigurationManager::NetworkSessionRequired) {
              // Get saved network configuration
              QSettings settings(QSettings::UserScope, QLatin1String("QtProject"));
              settings.beginGroup(QLatin1String("QtNetwork"));
              const QString id = settings.value(QLatin1String("DefaultNetworkConfiguration")).toString();
              settings.endGroup();

              // If the saved network configuration is not currently discovered use the system default
              QNetworkConfiguration config = manager.configurationFromIdentifier(id);
              if ((config.state() & QNetworkConfiguration::Discovered) !=
                  QNetworkConfiguration::Discovered) {
                  config = manager.defaultConfiguration();
              }

              networkSession = new QNetworkSession(config, this);
              connect(networkSession, &QNetworkSession::opened, this, &Server::sessionOpened);

              statusLabel->setText(tr("Opening network session."));
              networkSession->open();
          } else {
              sessionOpened();
          }

          fortunes << tr("You've been leading a dog's life. Stay off the furniture.")
                   << tr("You've got to think about tomorrow.")
                   << tr("You will be surprised by a loud noise.")
                   << tr("You will feel hungry again in another hour.")
                   << tr("You might have mail.")
                   << tr("You cannot kill time without injuring eternity.")
                   << tr("Computers are not intelligent. They only think they are.");
          auto quitButton = new QPushButton(tr("Quit"));
          quitButton->setAutoDefault(false);
          connect(quitButton, &QAbstractButton::clicked, this, &QWidget::close);
          connect(tcpServer, &QTcpServer::newConnection, this, &Server::sendFortune);

          auto buttonLayout = new QHBoxLayout;
          buttonLayout->addStretch(1);
          buttonLayout->addWidget(quitButton);
          buttonLayout->addStretch(1);

          QVBoxLayout *mainLayout = nullptr;
          if (QGuiApplication::styleHints()->showIsFullScreen() || QGuiApplication::styleHints()->showIsMaximized()) {
              auto outerVerticalLayout = new QVBoxLayout(this);
              outerVerticalLayout->addItem(new QSpacerItem(0, 0, QSizePolicy::Ignored, QSizePolicy::MinimumExpanding));
              auto outerHorizontalLayout = new QHBoxLayout;
              outerHorizontalLayout->addItem(new QSpacerItem(0, 0, QSizePolicy::MinimumExpanding, QSizePolicy::Ignored));
              auto groupBox = new QGroupBox(QGuiApplication::applicationDisplayName());
              mainLayout = new QVBoxLayout(groupBox);
              outerHorizontalLayout->addWidget(groupBox);
              outerHorizontalLayout->addItem(new QSpacerItem(0, 0, QSizePolicy::MinimumExpanding, QSizePolicy::Ignored));
              outerVerticalLayout->addLayout(outerHorizontalLayout);
              outerVerticalLayout->addItem(new QSpacerItem(0, 0, QSizePolicy::Ignored, QSizePolicy::MinimumExpanding));
          } else {
              mainLayout = new QVBoxLayout(this);
          }

          mainLayout->addWidget(statusLabel);
          mainLayout->addLayout(buttonLayout);

          setWindowTitle(QGuiApplication::applicationDisplayName());
      }

      void Server::sessionOpened()
      {
          // Save the used configuration
          if (networkSession) {
              QNetworkConfiguration config = networkSession->configuration();
              QString id;
              if (config.type() == QNetworkConfiguration::UserChoice)
                  id = networkSession->sessionProperty(QLatin1String("UserChoiceConfiguration")).toString();
              else
                  id = config.identifier();

              QSettings settings(QSettings::UserScope, QLatin1String("QtProject"));
              settings.beginGroup(QLatin1String("QtNetwork"));
              settings.setValue(QLatin1String("DefaultNetworkConfiguration"), id);
              settings.endGroup();
          }

          tcpServer = new QTcpServer(this);
          if (!tcpServer->listen()) {
              QMessageBox::critical(this, tr("Fortune Server"),
                                    tr("Unable to start the server: %1.")
                                    .arg(tcpServer->errorString()));
              close();
              return;
          }
          QString ipAddress;
          QList<QHostAddress> ipAddressesList = QNetworkInterface::allAddresses();
          // use the first non-localhost IPv4 address
          for (int i = 0; i < ipAddressesList.size(); ++i) {
              if (ipAddressesList.at(i) != QHostAddress::LocalHost &&
                  ipAddressesList.at(i).toIPv4Address()) {
                  ipAddress = ipAddressesList.at(i).toString();
                  break;
              }
          }
          // if we did not find one, use IPv4 localhost
          if (ipAddress.isEmpty())
              ipAddress = QHostAddress(QHostAddress::LocalHost).toString();
          statusLabel->setText(tr("The server is running on\n\nIP: %1\nport: %2\n\n"
                                  "Run the Fortune Client example now.")
                               .arg(ipAddress).arg(tcpServer->serverPort()));
      }

      void Server::sendFortune()
      {
          QByteArray block;
          QDataStream out(&block, QIODevice::WriteOnly);
          out.setVersion(QDataStream::Qt_5_10);

          out << fortunes[QRandomGenerator::global()->bounded(fortunes.size())];

          QTcpSocket *clientConnection = tcpServer->nextPendingConnection();
          connect(clientConnection, &QAbstractSocket::disconnected,
                  clientConnection, &QObject::deleteLater);

          clientConnection->write(block);
          clientConnection->disconnectFromHost();
      }