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();
 }