client.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 2004-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the example classes of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include <QtGui>
#include <QtNetwork>

#include "client.h"

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

    hostLineEdit = new QLineEdit("Localhost");
    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."));

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

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

    tcpSocket = new QTcpSocket(this);

    connect(hostLineEdit, SIGNAL(textChanged(const QString &)),
            this, SLOT(enableGetFortuneButton()));
    connect(portLineEdit, SIGNAL(textChanged(const QString &)),
            this, SLOT(enableGetFortuneButton()));
    connect(getFortuneButton, SIGNAL(clicked()),
            this, SLOT(requestNewFortune()));
    connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));
    connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(readFortune()));
    connect(tcpSocket, SIGNAL(error(QAbstractSocket::SocketError)), this, SLOT(displayError(QAbstractSocket::SocketError)));

    QHBoxLayout *buttonLayout = new QHBoxLayout;
    buttonLayout->addStretch(1);
    buttonLayout->addWidget(getFortuneButton);
    buttonLayout->addWidget(quitButton);

    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->addLayout(buttonLayout, 3, 0, 1, 2);
    setLayout(mainLayout);

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

void Client::requestNewFortune()
{
    getFortuneButton->setEnabled(false);
    blockSize = 0;
    tcpSocket->abort();
    tcpSocket->connectToHost(hostLineEdit->text(),
                             portLineEdit->text().toInt());
}

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

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

        in >> blockSize;
    }

    if (tcpSocket->bytesAvailable() < blockSize)
        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(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(!hostLineEdit->text().isEmpty()
                                 && !portLineEdit->text().isEmpty());
}