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),
       hostLineEdit(new QLineEdit("fortune")),
       getFortuneButton(new QPushButton(tr("Get Fortune"))),
       statusLabel(new QLabel(tr("This examples requires that you run the "
                                 "Local Fortune Server example as well."))),
       socket(new QLocalSocket(this))
 {
     setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
     QLabel *hostLabel = new QLabel(tr("&Server name:"));
     hostLabel->setBuddy(hostLineEdit);

     statusLabel->setWordWrap(true);

     getFortuneButton->setDefault(true);
     QPushButton *quitButton = new QPushButton(tr("Quit"));

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

     in.setDevice(socket);
     in.setVersion(QDataStream::Qt_5_10);

     connect(hostLineEdit, &QLineEdit::textChanged,
             this, &Client::enableGetFortuneButton);
     connect(getFortuneButton, &QPushButton::clicked,
             this, &Client::requestNewFortune);
     connect(quitButton, &QPushButton::clicked, this, &Client::close);
     connect(socket, &QLocalSocket::readyRead, this, &Client::readFortune);
     connect(socket, QOverload<QLocalSocket::LocalSocketError>::of(&QLocalSocket::error),
             this, &Client::displayError);

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

     setWindowTitle(QGuiApplication::applicationDisplayName());
     hostLineEdit->setFocus();
 }

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

 void Client::readFortune()
 {
     if (blockSize == 0) {
         // Relies on the fact that QDataStream serializes a quint32 into
         // sizeof(quint32) bytes
         if (socket->bytesAvailable() < (int)sizeof(quint32))
             return;
         in >> blockSize;
     }

     if (socket->bytesAvailable() < blockSize || in.atEnd())
         return;

     QString nextFortune;
     in >> nextFortune;

     if (nextFortune == currentFortune) {
         QTimer::singleShot(0, this, &Client::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("Local Fortune Client"),
                                  tr("The host was not found. Please make sure "
                                     "that the server is running and that the "
                                     "server name is correct."));
         break;
     case QLocalSocket::ConnectionRefusedError:
         QMessageBox::information(this, tr("Local Fortune Client"),
                                  tr("The connection was refused by the peer. "
                                     "Make sure the fortune server is running, "
                                     "and check that the server name "
                                     "is correct."));
         break;
     case QLocalSocket::PeerClosedError:
         break;
     default:
         QMessageBox::information(this, tr("Local Fortune Client"),
                                  tr("The following error occurred: %1.")
                                  .arg(socket->errorString()));
     }

     getFortuneButton->setEnabled(true);
 }

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