client.cpp Example File

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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());
  }