Qt 5.9 | Qt Network | Blocking Fortune Client Example | blockingclient.cpp Example File

Qt 5.9.9 Reference Documentation

# blockingclient.cpp Example File

blockingfortuneclient/blockingclient.cpp

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      #include <QtWidgets>
      #include <QtNetwork>

      #include "blockingclient.h"

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

          // find out which IP to connect to
          QString ipAddress;
          QList<QHostAddress> ipAddressesList = QNetworkInterface::allAddresses();
          // use the first non-localhost IPv4 address
          for (int i = 0; i < ipAddressesList.size(); ++i) {
              if (ipAddressesList.at(i) != QHostAddress::LocalHost &&
                  ipAddressesList.at(i).toIPv4Address()) {
                  ipAddress = ipAddressesList.at(i).toString();
                  break;
              }
          }
          // if we did not find one, use IPv4 localhost
          if (ipAddress.isEmpty())
              ipAddress = QHostAddress(QHostAddress::LocalHost).toString();

          hostLineEdit = new QLineEdit(ipAddress);
          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."));
          statusLabel->setWordWrap(true);

          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);

          connect(getFortuneButton, SIGNAL(clicked()), this, SLOT(requestNewFortune()));
          connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));

          connect(hostLineEdit, SIGNAL(textChanged(QString)),
                  this, SLOT(enableGetFortuneButton()));
          connect(portLineEdit, SIGNAL(textChanged(QString)),
                  this, SLOT(enableGetFortuneButton()));
          connect(&thread, SIGNAL(newFortune(QString)),
                  this, SLOT(showFortune(QString)));
          connect(&thread, SIGNAL(error(int,QString)),
                  this, SLOT(displayError(int,QString)));

          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("Blocking Fortune Client"));
          portLineEdit->setFocus();
      }

      void BlockingClient::requestNewFortune()
      {
          getFortuneButton->setEnabled(false);
          thread.requestNewFortune(hostLineEdit->text(),
                                   portLineEdit->text().toInt());
      }

      void BlockingClient::showFortune(const QString &nextFortune)
      {
          if (nextFortune == currentFortune) {
              requestNewFortune();
              return;
          }

          currentFortune = nextFortune;
          statusLabel->setText(currentFortune);
          getFortuneButton->setEnabled(true);
      }

      void BlockingClient::displayError(int socketError, const QString &message)
      {
          switch (socketError) {
          case QAbstractSocket::HostNotFoundError:
              QMessageBox::information(this, tr("Blocking Fortune Client"),
                                       tr("The host was not found. Please check the "
                                          "host and port settings."));
              break;
          case QAbstractSocket::ConnectionRefusedError:
              QMessageBox::information(this, tr("Blocking 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("Blocking Fortune Client"),
                                       tr("The following error occurred: %1.")
                                       .arg(message));
          }

          getFortuneButton->setEnabled(true);
      }

      void BlockingClient::enableGetFortuneButton()
      {
          bool enable(!hostLineEdit->text().isEmpty() && !portLineEdit->text().isEmpty());
          getFortuneButton->setEnabled(enable);
      }