- Qt 5.5
- Qt Core
- Local Fortune Client Example
- client.cpp Example File
- Qt 5.5.1 Reference Documentation

# client.cpp Example File

ipc/localfortuneclient/client.cpp

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    #include <QtWidgets>
    #include <QtNetwork>

    #include "client.h"

    Client::Client(QWidget *parent)
        : QDialog(parent)
    {
        hostLabel = new QLabel(tr("&Server name:"));
        hostLineEdit = new QLineEdit("fortune");

        hostLabel->setBuddy(hostLineEdit);

        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);

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

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

        socket = new QLocalSocket(this);

        connect(hostLineEdit, SIGNAL(textChanged(QString)),
                this, SLOT(enableGetFortuneButton()));
        connect(getFortuneButton, SIGNAL(clicked()),
                this, SLOT(requestNewFortune()));
        connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));
        connect(socket, SIGNAL(readyRead()), this, SLOT(readFortune()));
        connect(socket, SIGNAL(error(QLocalSocket::LocalSocketError)),
                this, SLOT(displayError(QLocalSocket::LocalSocketError)));

        QGridLayout *mainLayout = new QGridLayout;
        mainLayout->addWidget(hostLabel, 0, 0);
        mainLayout->addWidget(hostLineEdit, 0, 1);
        mainLayout->addWidget(statusLabel, 2, 0, 1, 2);
        mainLayout->addWidget(buttonBox, 3, 0, 1, 2);
        setLayout(mainLayout);

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

    void Client::requestNewFortune()
    {
        getFortuneButton->setEnabled(false);
        blockSize = 0;
        socket->abort();
        socket->connectToServer(hostLineEdit->text());
    }

    void Client::readFortune()
    {
        QDataStream in(socket);
        in.setVersion(QDataStream::Qt_4_0);

        if (blockSize == 0) {
            if (socket->bytesAvailable() < (int)sizeof(quint16))
                return;
            in >> blockSize;
        }

        if (in.atEnd())
            return;

        QString nextFortune;
        in >> nextFortune;

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

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

    void Client::displayError(QLocalSocket::LocalSocketError socketError)
    {
        switch (socketError) {
        case QLocalSocket::ServerNotFoundError:
            QMessageBox::information(this, tr("Fortune Client"),
                                     tr("The host was not found. Please check the "
                                        "host name and port settings."));
            break;
        case QLocalSocket::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;
        case QLocalSocket::PeerClosedError:
            break;
        default:
            QMessageBox::information(this, tr("Fortune Client"),
                                     tr("The following error occurred: %1.")
                                     .arg(socket->errorString()));
        }

        getFortuneButton->setEnabled(true);
    }

    void Client::enableGetFortuneButton()
    {
        getFortuneButton->setEnabled(!hostLineEdit->text().isEmpty());
    }