- Qt 5.5
- Qt Network
- Blocking Fortune Client Example
- blockingclient.cpp Example File
- Qt 5.5.1 Reference Documentation

# blockingclient.cpp Example File

blockingfortuneclient/blockingclient.cpp

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    #include <QtWidgets>
    #include <QtNetwork>

    #include "blockingclient.h"

    BlockingClient::BlockingClient(QWidget *parent)
        : QWidget(parent)
    {
        hostLabel = new QLabel(tr("&Server name:"));
        portLabel = new QLabel(tr("S&erver port:"));

        // find out which IP to connect to
        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();

        hostLineEdit = new QLineEdit(ipAddress);
        portLineEdit = new QLineEdit;
        portLineEdit->setValidator(new QIntValidator(1, 65535, this));

        hostLabel->setBuddy(hostLineEdit);
        portLabel->setBuddy(portLineEdit);

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

        getFortuneButton = new QPushButton(tr("Get Fortune"));
        getFortuneButton->setDefault(true);
        getFortuneButton->setEnabled(false);

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

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

        connect(getFortuneButton, SIGNAL(clicked()), this, SLOT(requestNewFortune()));
        connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));

        connect(hostLineEdit, SIGNAL(textChanged(QString)),
                this, SLOT(enableGetFortuneButton()));
        connect(portLineEdit, SIGNAL(textChanged(QString)),
                this, SLOT(enableGetFortuneButton()));
        connect(&thread, SIGNAL(newFortune(QString)),
                this, SLOT(showFortune(QString)));
        connect(&thread, SIGNAL(error(int,QString)),
                this, SLOT(displayError(int,QString)));

        QGridLayout *mainLayout = new QGridLayout;
        mainLayout->addWidget(hostLabel, 0, 0);
        mainLayout->addWidget(hostLineEdit, 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);
        setLayout(mainLayout);

        setWindowTitle(tr("Blocking Fortune Client"));
        portLineEdit->setFocus();
    }

    void BlockingClient::requestNewFortune()
    {
        getFortuneButton->setEnabled(false);
        thread.requestNewFortune(hostLineEdit->text(),
                                 portLineEdit->text().toInt());
    }

    void BlockingClient::showFortune(const QString &nextFortune)
    {
        if (nextFortune == currentFortune) {
            requestNewFortune();
            return;
        }

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

    void BlockingClient::displayError(int socketError, const QString &message)
    {
        switch (socketError) {
        case QAbstractSocket::HostNotFoundError:
            QMessageBox::information(this, tr("Blocking Fortune Client"),
                                     tr("The host was not found. Please check the "
                                        "host and port settings."));
            break;
        case QAbstractSocket::ConnectionRefusedError:
            QMessageBox::information(this, tr("Blocking 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("Blocking Fortune Client"),
                                     tr("The following error occurred: %1.")
                                     .arg(message));
        }

        getFortuneButton->setEnabled(true);
    }

    void BlockingClient::enableGetFortuneButton()
    {
        bool enable(!hostLineEdit->text().isEmpty() && !portLineEdit->text().isEmpty());
        getFortuneButton->setEnabled(enable);
    }