text: /****************************************************************************
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  ** This file is part of the examples of the Qt Toolkit.
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  #include <QtWidgets>
  #include <QtNetwork>
  
  #include "receiver.h"
  
  Receiver::Receiver(QWidget *parent)
      : QDialog(parent),
        groupAddress(QStringLiteral("239.255.43.21"))
  {
      statusLabel = new QLabel(tr("Listening for multicasted messages"));
      QWidget* quitButton = new QPushButton(tr("&Quit"));
  
      QHBoxLayout* buttonLayout = new QHBoxLayout;
      buttonLayout->addStretch(1);
      buttonLayout->addWidget(quitButton);
      buttonLayout->addStretch(1);
  
      QVBoxLayout* mainLayout = new QVBoxLayout;
      mainLayout->addWidget(statusLabel);
      mainLayout->addLayout(buttonLayout);
      setLayout(mainLayout);
  
      setWindowTitle(tr("Multicast Receiver"));
  
      udpSocket.bind(QHostAddress::AnyIPv4, 45454, QUdpSocket::ShareAddress);
      udpSocket.joinMulticastGroup(groupAddress);
  
      connect(&udpSocket, SIGNAL(readyRead()),
              this, SLOT(processPendingDatagrams()));
      connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));
  }
  
  void Receiver::processPendingDatagrams()
  {
      QByteArray datagram;
      while (udpSocket.hasPendingDatagrams()) {
          datagram.resize(int(udpSocket.pendingDatagramSize()));
          udpSocket.readDatagram(datagram.data(), datagram.size());
          statusLabel->setText(tr("Received datagram: \"%1\"")
                               .arg(datagram.constData()));
      }
  }
  