client.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2015 The Qt Company Ltd.
 ** Contact: http://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** You may use this file under the terms of the BSD license as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
 ** met:
 **   * Redistributions of source code must retain the above copyright
 **     notice, this list of conditions and the following disclaimer.
 **   * Redistributions in binary form must reproduce the above copyright
 **     notice, this list of conditions and the following disclaimer in
 **     the documentation and/or other materials provided with the
 **     distribution.
 **   * Neither the name of The Qt Company Ltd nor the names of its
 **     contributors may be used to endorse or promote products derived
 **     from this software without specific prior written permission.
 **
 **
 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <QtGui>
 #include <QtNetwork>

 #include "client.h"

 Client::Client(QWidget *parent)
 #ifdef Q_WS_MAEMO_5
     : QWidget(parent)
 #else
     : QDialog(parent)
 #endif
 {
     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());
 }