Qt 4.3: client.cpp Example File (network/fortuneclient/client.cpp)

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# client.cpp Example File
network/fortuneclient/client.cpp

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     #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"));

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

         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)));

         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("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());
     }