client.cpp Example File

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  #include <QtWidgets>
  #include <QtNetwork>

  #include "client.h"

  Client::Client(QWidget *parent)
      : QDialog(parent)
      , hostCombo(new QComboBox)
      , portLineEdit(new QLineEdit)
      , getFortuneButton(new QPushButton(tr("Get Fortune")))
      , tcpSocket(new QTcpSocket(this))
  {
      setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
      hostCombo->setEditable(true);
      // find out name of this machine
      QString name = QHostInfo::localHostName();
      if (!name.isEmpty()) {
          hostCombo->addItem(name);
          QString domain = QHostInfo::localDomainName();
          if (!domain.isEmpty())
              hostCombo->addItem(name + QChar('.') + domain);
      }
      if (name != QLatin1String("localhost"))
          hostCombo->addItem(QString("localhost"));
      // find out IP addresses of this machine
      QList<QHostAddress> ipAddressesList = QNetworkInterface::allAddresses();
      // add non-localhost addresses
      for (int i = 0; i < ipAddressesList.size(); ++i) {
          if (!ipAddressesList.at(i).isLoopback())
              hostCombo->addItem(ipAddressesList.at(i).toString());
      }
      // add localhost addresses
      for (int i = 0; i < ipAddressesList.size(); ++i) {
          if (ipAddressesList.at(i).isLoopback())
              hostCombo->addItem(ipAddressesList.at(i).toString());
      }

      portLineEdit->setValidator(new QIntValidator(1, 65535, this));

      auto hostLabel = new QLabel(tr("&Server name:"));
      hostLabel->setBuddy(hostCombo);
      auto portLabel = new QLabel(tr("S&erver port:"));
      portLabel->setBuddy(portLineEdit);

      statusLabel = new QLabel(tr("This examples requires that you run the "
                                  "Fortune Server example as well."));

      getFortuneButton->setDefault(true);
      getFortuneButton->setEnabled(false);

      auto quitButton = new QPushButton(tr("Quit"));

      auto buttonBox = new QDialogButtonBox;
      buttonBox->addButton(getFortuneButton, QDialogButtonBox::ActionRole);
      buttonBox->addButton(quitButton, QDialogButtonBox::RejectRole);

      in.setDevice(tcpSocket);
      in.setVersion(QDataStream::Qt_4_0);

      connect(hostCombo, &QComboBox::editTextChanged,
              this, &Client::enableGetFortuneButton);
      connect(portLineEdit, &QLineEdit::textChanged,
              this, &Client::enableGetFortuneButton);
      connect(getFortuneButton, &QAbstractButton::clicked,
              this, &Client::requestNewFortune);
      connect(quitButton, &QAbstractButton::clicked, this, &QWidget::close);
      connect(tcpSocket, &QIODevice::readyRead, this, &Client::readFortune);
      connect(tcpSocket, QOverload<QAbstractSocket::SocketError>::of(&QAbstractSocket::error),
              this, &Client::displayError);

      QGridLayout *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 QGridLayout(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 QGridLayout(this);
      }
      mainLayout->addWidget(hostLabel, 0, 0);
      mainLayout->addWidget(hostCombo, 0, 1);
      mainLayout->addWidget(portLabel, 1, 0);
      mainLayout->addWidget(portLineEdit, 1, 1);
      mainLayout->addWidget(statusLabel, 2, 0, 1, 2);
      mainLayout->addWidget(buttonBox, 3, 0, 1, 2);

      setWindowTitle(QGuiApplication::applicationDisplayName());
      portLineEdit->setFocus();

      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, &Client::sessionOpened);

          getFortuneButton->setEnabled(false);
          statusLabel->setText(tr("Opening network session."));
          networkSession->open();
      }
  }

  void Client::requestNewFortune()
  {
      getFortuneButton->setEnabled(false);
      tcpSocket->abort();
      tcpSocket->connectToHost(hostCombo->currentText(),
                               portLineEdit->text().toInt());
  }

  void Client::readFortune()
  {
      in.startTransaction();

      QString nextFortune;
      in >> nextFortune;

      if (!in.commitTransaction())
          return;

      if (nextFortune == currentFortune) {
          QTimer::singleShot(0, this, &Client::requestNewFortune);
          return;
      }

      currentFortune = nextFortune;
      statusLabel->setText(currentFortune);
      getFortuneButton->setEnabled(true);
  }

  void Client::displayError(QAbstractSocket::SocketError socketError)
  {
      switch (socketError) {
      case QAbstractSocket::RemoteHostClosedError:
          break;
      case QAbstractSocket::HostNotFoundError:
          QMessageBox::information(this, tr("Fortune Client"),
                                   tr("The host was not found. Please check the "
                                      "host name and port settings."));
          break;
      case QAbstractSocket::ConnectionRefusedError:
          QMessageBox::information(this, tr("Fortune Client"),
                                   tr("The connection was refused by the peer. "
                                      "Make sure the fortune server is running, "
                                      "and check that the host name and port "
                                      "settings are correct."));
          break;
      default:
          QMessageBox::information(this, tr("Fortune Client"),
                                   tr("The following error occurred: %1.")
                                   .arg(tcpSocket->errorString()));
      }

      getFortuneButton->setEnabled(true);
  }

  void Client::enableGetFortuneButton()
  {
      getFortuneButton->setEnabled((!networkSession || networkSession->isOpen()) &&
                                   !hostCombo->currentText().isEmpty() &&
                                   !portLineEdit->text().isEmpty());

  }

  void Client::sessionOpened()
  {
      // Save the used configuration
      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();

      statusLabel->setText(tr("This examples requires that you run the "
                              "Fortune Server example as well."));

      enableGetFortuneButton();
  }