qt5base-lts/examples/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());
}