qt 6.5.1 original

examples/network/network-chat/CMakeLists.txt

@@ -0,0 +1,42 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(network-chat LANGUAGES CXX)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/network/network-chat")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui Network Widgets)
+
+qt_standard_project_setup()
+
+qt_add_executable(network-chat
+    chatdialog.cpp chatdialog.h chatdialog.ui
+    client.cpp client.h
+    connection.cpp connection.h
+    main.cpp
+    peermanager.cpp peermanager.h
+    server.cpp server.h
+)
+
+set_target_properties(network-chat PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(network-chat PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::Network
+    Qt6::Widgets
+)
+
+install(TARGETS network-chat
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)

examples/network/network-chat/chatdialog.cpp

@@ -0,0 +1,104 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QtWidgets>
+
+#include "chatdialog.h"
+
+ChatDialog::ChatDialog(QWidget *parent)
+    : QDialog(parent)
+{
+    setupUi(this);
+
+    lineEdit->setFocusPolicy(Qt::StrongFocus);
+    textEdit->setFocusPolicy(Qt::NoFocus);
+    textEdit->setReadOnly(true);
+    listWidget->setFocusPolicy(Qt::NoFocus);
+
+    connect(lineEdit, &QLineEdit::returnPressed,
+            this, &ChatDialog::returnPressed);
+    connect(&client, &Client::newMessage,
+            this, &ChatDialog::appendMessage);
+    connect(&client, &Client::newParticipant,
+            this, &ChatDialog::newParticipant);
+    connect(&client, &Client::participantLeft,
+            this, &ChatDialog::participantLeft);
+
+    myNickName = client.nickName();
+    newParticipant(myNickName);
+    tableFormat.setBorder(0);
+    QTimer::singleShot(10 * 1000, this, SLOT(showInformation()));
+}
+
+void ChatDialog::appendMessage(const QString &from, const QString &message)
+{
+    if (from.isEmpty() || message.isEmpty())
+        return;
+
+    QTextCursor cursor(textEdit->textCursor());
+    cursor.movePosition(QTextCursor::End);
+    QTextTable *table = cursor.insertTable(1, 2, tableFormat);
+    table->cellAt(0, 0).firstCursorPosition().insertText('<' + from + "> ");
+    table->cellAt(0, 1).firstCursorPosition().insertText(message);
+    QScrollBar *bar = textEdit->verticalScrollBar();
+    bar->setValue(bar->maximum());
+}
+
+void ChatDialog::returnPressed()
+{
+    QString text = lineEdit->text();
+    if (text.isEmpty())
+        return;
+
+    if (text.startsWith(QChar('/'))) {
+        QColor color = textEdit->textColor();
+        textEdit->setTextColor(Qt::red);
+        textEdit->append(tr("! Unknown command: %1")
+                         .arg(text.left(text.indexOf(' '))));
+        textEdit->setTextColor(color);
+    } else {
+        client.sendMessage(text);
+        appendMessage(myNickName, text);
+    }
+
+    lineEdit->clear();
+}
+
+void ChatDialog::newParticipant(const QString &nick)
+{
+    if (nick.isEmpty())
+        return;
+
+    QColor color = textEdit->textColor();
+    textEdit->setTextColor(Qt::gray);
+    textEdit->append(tr("* %1 has joined").arg(nick));
+    textEdit->setTextColor(color);
+    listWidget->addItem(nick);
+}
+
+void ChatDialog::participantLeft(const QString &nick)
+{
+    if (nick.isEmpty())
+        return;
+
+    QList<QListWidgetItem *> items = listWidget->findItems(nick,
+                                                           Qt::MatchExactly);
+    if (items.isEmpty())
+        return;
+
+    delete items.at(0);
+    QColor color = textEdit->textColor();
+    textEdit->setTextColor(Qt::gray);
+    textEdit->append(tr("* %1 has left").arg(nick));
+    textEdit->setTextColor(color);
+}
+
+void ChatDialog::showInformation()
+{
+    if (listWidget->count() == 1) {
+        QMessageBox::information(this, tr("Chat"),
+                                 tr("Launch several instances of this "
+                                    "program on your local network and "
+                                    "start chatting!"));
+    }
+}

examples/network/network-chat/chatdialog.h

@@ -0,0 +1,32 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef CHATDIALOG_H
+#define CHATDIALOG_H
+
+#include "ui_chatdialog.h"
+#include "client.h"
+
+class ChatDialog : public QDialog, private Ui::ChatDialog
+{
+    Q_OBJECT
+
+public:
+    ChatDialog(QWidget *parent = nullptr);
+
+public slots:
+    void appendMessage(const QString &from, const QString &message);
+
+private slots:
+    void returnPressed();
+    void newParticipant(const QString &nick);
+    void participantLeft(const QString &nick);
+    void showInformation();
+
+private:
+    Client client;
+    QString myNickName;
+    QTextTableFormat tableFormat;
+};
+
+#endif

examples/network/network-chat/chatdialog.ui

@@ -0,0 +1,79 @@
+<ui version="4.0" >
+ <class>ChatDialog</class>
+ <widget class="QDialog" name="ChatDialog" >
+  <property name="geometry" >
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>513</width>
+    <height>349</height>
+   </rect>
+  </property>
+  <property name="windowTitle" >
+   <string>Chat</string>
+  </property>
+  <layout class="QVBoxLayout" >
+   <property name="margin" >
+    <number>9</number>
+   </property>
+   <property name="spacing" >
+    <number>6</number>
+   </property>
+   <item>
+    <layout class="QHBoxLayout" >
+     <property name="margin" >
+      <number>0</number>
+     </property>
+     <property name="spacing" >
+      <number>6</number>
+     </property>
+     <item>
+      <widget class="QTextEdit" name="textEdit" >
+       <property name="focusPolicy" >
+        <enum>Qt::NoFocus</enum>
+       </property>
+       <property name="readOnly" >
+        <bool>true</bool>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QListWidget" name="listWidget" >
+       <property name="maximumSize" >
+        <size>
+         <width>180</width>
+         <height>16777215</height>
+        </size>
+       </property>
+       <property name="focusPolicy" >
+        <enum>Qt::NoFocus</enum>
+       </property>
+      </widget>
+     </item>
+    </layout>
+   </item>
+   <item>
+    <layout class="QHBoxLayout" >
+     <property name="margin" >
+      <number>0</number>
+     </property>
+     <property name="spacing" >
+      <number>6</number>
+     </property>
+     <item>
+      <widget class="QLabel" name="label" >
+       <property name="text" >
+        <string>Message:</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QLineEdit" name="lineEdit" />
+     </item>
+    </layout>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>

examples/network/network-chat/client.cpp

@@ -0,0 +1,100 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QtNetwork>
+
+#include "client.h"
+#include "connection.h"
+#include "peermanager.h"
+
+Client::Client()
+{
+    peerManager = new PeerManager(this);
+    peerManager->setServerPort(server.serverPort());
+    peerManager->startBroadcasting();
+
+    connect(peerManager, &PeerManager::newConnection,
+            this, &Client::newConnection);
+    connect(&server, &Server::newConnection,
+            this, &Client::newConnection);
+}
+
+void Client::sendMessage(const QString &message)
+{
+    if (message.isEmpty())
+        return;
+
+    for (Connection *connection : std::as_const(peers))
+        connection->sendMessage(message);
+}
+
+QString Client::nickName() const
+{
+    return peerManager->userName() + '@' + QHostInfo::localHostName()
+           + ':' + QString::number(server.serverPort());
+}
+
+bool Client::hasConnection(const QHostAddress &senderIp, int senderPort) const
+{
+    if (senderPort == -1)
+        return peers.contains(senderIp);
+
+    if (!peers.contains(senderIp))
+        return false;
+
+    const QList<Connection *> connections = peers.values(senderIp);
+    for (const Connection *connection : connections) {
+        if (connection->peerPort() == senderPort)
+            return true;
+    }
+
+    return false;
+}
+
+void Client::newConnection(Connection *connection)
+{
+    connection->setGreetingMessage(peerManager->userName());
+
+    connect(connection, &Connection::errorOccurred, this, &Client::connectionError);
+    connect(connection, &Connection::disconnected, this, &Client::disconnected);
+    connect(connection, &Connection::readyForUse, this, &Client::readyForUse);
+}
+
+void Client::readyForUse()
+{
+    Connection *connection = qobject_cast<Connection *>(sender());
+    if (!connection || hasConnection(connection->peerAddress(),
+                                     connection->peerPort()))
+        return;
+
+    connect(connection,  &Connection::newMessage,
+            this, &Client::newMessage);
+
+    peers.insert(connection->peerAddress(), connection);
+    QString nick = connection->name();
+    if (!nick.isEmpty())
+        emit newParticipant(nick);
+}
+
+void Client::disconnected()
+{
+    if (Connection *connection = qobject_cast<Connection *>(sender()))
+        removeConnection(connection);
+}
+
+void Client::connectionError(QAbstractSocket::SocketError /* socketError */)
+{
+    if (Connection *connection = qobject_cast<Connection *>(sender()))
+        removeConnection(connection);
+}
+
+void Client::removeConnection(Connection *connection)
+{
+    if (peers.contains(connection->peerAddress())) {
+        peers.remove(connection->peerAddress());
+        QString nick = connection->name();
+        if (!nick.isEmpty())
+            emit participantLeft(nick);
+    }
+    connection->deleteLater();
+}

examples/network/network-chat/client.h

@@ -0,0 +1,45 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef CLIENT_H
+#define CLIENT_H
+
+#include <QAbstractSocket>
+#include <QHash>
+#include <QHostAddress>
+
+#include "server.h"
+
+class PeerManager;
+
+class Client : public QObject
+{
+    Q_OBJECT
+
+public:
+    Client();
+
+    void sendMessage(const QString &message);
+    QString nickName() const;
+    bool hasConnection(const QHostAddress &senderIp, int senderPort = -1) const;
+
+signals:
+    void newMessage(const QString &from, const QString &message);
+    void newParticipant(const QString &nick);
+    void participantLeft(const QString &nick);
+
+private slots:
+    void newConnection(Connection *connection);
+    void connectionError(QAbstractSocket::SocketError socketError);
+    void disconnected();
+    void readyForUse();
+
+private:
+    void removeConnection(Connection *connection);
+
+    PeerManager *peerManager;
+    Server server;
+    QMultiHash<QHostAddress, Connection *> peers;
+};
+
+#endif

examples/network/network-chat/connection.cpp

@@ -0,0 +1,231 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// Copyright (C) 2018 Intel Corporation.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "connection.h"
+
+#include <QtNetwork>
+
+static const int TransferTimeout = 30 * 1000;
+static const int PongTimeout = 60 * 1000;
+static const int PingInterval = 5 * 1000;
+
+/*
+ * Protocol is defined as follows, using the CBOR Data Definition Language:
+ *
+ *  protocol    = [
+ *     greeting,        ; must start with a greeting command
+ *     * command        ; zero or more regular commands after
+ *  ]
+ *  command     = plaintext / ping / pong / greeting
+ *  plaintext   = { 0 => text }
+ *  ping        = { 1 => null }
+ *  pong        = { 2 => null }
+ *  greeting    = { 3 => text }
+ */
+
+Connection::Connection(QObject *parent)
+    : QTcpSocket(parent), writer(this)
+{
+    greetingMessage = tr("undefined");
+    username = tr("unknown");
+    state = WaitingForGreeting;
+    currentDataType = Undefined;
+    transferTimerId = -1;
+    isGreetingMessageSent = false;
+    pingTimer.setInterval(PingInterval);
+
+    connect(this, &QTcpSocket::readyRead, this,
+            &Connection::processReadyRead);
+    connect(this, &QTcpSocket::disconnected,
+            &pingTimer, &QTimer::stop);
+    connect(&pingTimer, &QTimer::timeout,
+            this, &Connection::sendPing);
+    connect(this, &QTcpSocket::connected,
+            this, &Connection::sendGreetingMessage);
+}
+
+Connection::Connection(qintptr socketDescriptor, QObject *parent)
+    : Connection(parent)
+{
+    setSocketDescriptor(socketDescriptor);
+    reader.setDevice(this);
+}
+
+Connection::~Connection()
+{
+    if (isGreetingMessageSent) {
+        // Indicate clean shutdown.
+        writer.endArray();
+        waitForBytesWritten(2000);
+    }
+}
+
+QString Connection::name() const
+{
+    return username;
+}
+
+void Connection::setGreetingMessage(const QString &message)
+{
+    greetingMessage = message;
+}
+
+bool Connection::sendMessage(const QString &message)
+{
+    if (message.isEmpty())
+        return false;
+
+    writer.startMap(1);
+    writer.append(PlainText);
+    writer.append(message);
+    writer.endMap();
+    return true;
+}
+
+void Connection::timerEvent(QTimerEvent *timerEvent)
+{
+    if (timerEvent->timerId() == transferTimerId) {
+        abort();
+        killTimer(transferTimerId);
+        transferTimerId = -1;
+    }
+}
+
+void Connection::processReadyRead()
+{
+    // we've got more data, let's parse
+    reader.reparse();
+    while (reader.lastError() == QCborError::NoError) {
+        if (state == WaitingForGreeting) {
+            if (!reader.isArray())
+                break;                  // protocol error
+
+            reader.enterContainer();    // we'll be in this array forever
+            state = ReadingGreeting;
+        } else if (reader.containerDepth() == 1) {
+            // Current state: no command read
+            // Next state: read command ID
+            if (!reader.hasNext()) {
+                reader.leaveContainer();
+                disconnectFromHost();
+                return;
+            }
+
+            if (!reader.isMap() || !reader.isLengthKnown() || reader.length() != 1)
+                break;                  // protocol error
+            reader.enterContainer();
+        } else if (currentDataType == Undefined) {
+            // Current state: read command ID
+            // Next state: read command payload
+            if (!reader.isInteger())
+                break;                  // protocol error
+            currentDataType = DataType(reader.toInteger());
+            reader.next();
+        } else {
+            // Current state: read command payload
+            if (reader.isString()) {
+                auto r = reader.readString();
+                buffer += r.data;
+                if (r.status != QCborStreamReader::EndOfString)
+                    continue;
+            } else if (reader.isNull()) {
+                reader.next();
+            } else {
+                break;                   // protocol error
+            }
+
+            // Next state: no command read
+            reader.leaveContainer();
+            if (transferTimerId != -1) {
+                killTimer(transferTimerId);
+                transferTimerId = -1;
+            }
+
+            if (state == ReadingGreeting) {
+                if (currentDataType != Greeting)
+                    break;              // protocol error
+                processGreeting();
+            } else {
+                processData();
+            }
+        }
+    }
+
+    if (reader.lastError() != QCborError::EndOfFile)
+        abort();       // parse error
+
+    if (transferTimerId != -1 && reader.containerDepth() > 1)
+        transferTimerId = startTimer(TransferTimeout);
+}
+
+void Connection::sendPing()
+{
+    if (pongTime.elapsed() > PongTimeout) {
+        abort();
+        return;
+    }
+
+    writer.startMap(1);
+    writer.append(Ping);
+    writer.append(nullptr);     // no payload
+    writer.endMap();
+}
+
+void Connection::sendGreetingMessage()
+{
+    writer.startArray();        // this array never ends
+
+    writer.startMap(1);
+    writer.append(Greeting);
+    writer.append(greetingMessage);
+    writer.endMap();
+    isGreetingMessageSent = true;
+
+    if (!reader.device())
+        reader.setDevice(this);
+}
+
+void Connection::processGreeting()
+{
+    username = buffer + '@' + peerAddress().toString() + ':'
+            + QString::number(peerPort());
+    currentDataType = Undefined;
+    buffer.clear();
+
+    if (!isValid()) {
+        abort();
+        return;
+    }
+
+    if (!isGreetingMessageSent)
+        sendGreetingMessage();
+
+    pingTimer.start();
+    pongTime.start();
+    state = ReadyForUse;
+    emit readyForUse();
+}
+
+void Connection::processData()
+{
+    switch (currentDataType) {
+    case PlainText:
+        emit newMessage(username, buffer);
+        break;
+    case Ping:
+        writer.startMap(1);
+        writer.append(Pong);
+        writer.append(nullptr);     // no payload
+        writer.endMap();
+        break;
+    case Pong:
+        pongTime.restart();
+        break;
+    default:
+        break;
+    }
+
+    currentDataType = Undefined;
+    buffer.clear();
+}

examples/network/network-chat/connection.h

@@ -0,0 +1,73 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef CONNECTION_H
+#define CONNECTION_H
+
+#include <QCborStreamReader>
+#include <QCborStreamWriter>
+#include <QElapsedTimer>
+#include <QHostAddress>
+#include <QString>
+#include <QTcpSocket>
+#include <QTimer>
+
+static const int MaxBufferSize = 1024000;
+
+class Connection : public QTcpSocket
+{
+    Q_OBJECT
+
+public:
+    enum ConnectionState {
+        WaitingForGreeting,
+        ReadingGreeting,
+        ReadyForUse
+    };
+    enum DataType {
+        PlainText,
+        Ping,
+        Pong,
+        Greeting,
+        Undefined
+    };
+
+    Connection(QObject *parent = nullptr);
+    Connection(qintptr socketDescriptor, QObject *parent = nullptr);
+    ~Connection();
+
+    QString name() const;
+    void setGreetingMessage(const QString &message);
+    bool sendMessage(const QString &message);
+
+signals:
+    void readyForUse();
+    void newMessage(const QString &from, const QString &message);
+
+protected:
+    void timerEvent(QTimerEvent *timerEvent) override;
+
+private slots:
+    void processReadyRead();
+    void sendPing();
+    void sendGreetingMessage();
+
+private:
+    bool hasEnoughData();
+    void processGreeting();
+    void processData();
+
+    QCborStreamReader reader;
+    QCborStreamWriter writer;
+    QString greetingMessage;
+    QString username;
+    QTimer pingTimer;
+    QElapsedTimer pongTime;
+    QString buffer;
+    ConnectionState state;
+    DataType currentDataType;
+    int transferTimerId;
+    bool isGreetingMessageSent;
+};
+
+#endif

examples/network/network-chat/main.cpp

@@ -0,0 +1,17 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QApplication>
+
+#include "chatdialog.h"
+
+#include <QtCore/QSettings>
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+
+    ChatDialog dialog;
+    dialog.show();
+    return app.exec();
+}

examples/network/network-chat/network-chat.pro

@@ -0,0 +1,21 @@
+HEADERS       = chatdialog.h \
+                client.h \
+                connection.h \
+                peermanager.h \
+                server.h
+SOURCES       = chatdialog.cpp \
+                client.cpp \
+                connection.cpp \
+                main.cpp \
+                peermanager.cpp \
+                server.cpp
+FORMS         = chatdialog.ui
+QT           += network widgets
+requires(qtConfig(udpsocket))
+requires(qtConfig(listwidget))
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/network/network-chat
+INSTALLS += target
+
+

examples/network/network-chat/peermanager.cpp

@@ -0,0 +1,149 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// Copyright (C) 2018 Intel Corporation.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QtNetwork>
+
+#include "client.h"
+#include "connection.h"
+#include "peermanager.h"
+
+static const qint32 BroadcastInterval = 2000;
+static const unsigned broadcastPort = 45000;
+
+PeerManager::PeerManager(Client *client)
+    : QObject(client)
+{
+    this->client = client;
+
+    static const char *envVariables[] = {
+        "USERNAME", "USER", "USERDOMAIN", "HOSTNAME", "DOMAINNAME"
+    };
+
+    for (const char *varname : envVariables) {
+        username = qEnvironmentVariable(varname);
+        if (!username.isNull())
+            break;
+    }
+
+    if (username.isEmpty())
+        username = "unknown";
+
+    updateAddresses();
+    serverPort = 0;
+
+    broadcastSocket.bind(QHostAddress::Any, broadcastPort, QUdpSocket::ShareAddress
+                         | QUdpSocket::ReuseAddressHint);
+    connect(&broadcastSocket, &QUdpSocket::readyRead,
+            this, &PeerManager::readBroadcastDatagram);
+
+    broadcastTimer.setInterval(BroadcastInterval);
+    connect(&broadcastTimer, &QTimer::timeout,
+            this, &PeerManager::sendBroadcastDatagram);
+}
+
+void PeerManager::setServerPort(int port)
+{
+    serverPort = port;
+}
+
+QString PeerManager::userName() const
+{
+    return username;
+}
+
+void PeerManager::startBroadcasting()
+{
+    broadcastTimer.start();
+}
+
+bool PeerManager::isLocalHostAddress(const QHostAddress &address) const
+{
+    for (const QHostAddress &localAddress : ipAddresses) {
+        if (address.isEqual(localAddress))
+            return true;
+    }
+    return false;
+}
+
+void PeerManager::sendBroadcastDatagram()
+{
+    QByteArray datagram;
+    {
+        QCborStreamWriter writer(&datagram);
+        writer.startArray(2);
+        writer.append(username);
+        writer.append(serverPort);
+        writer.endArray();
+    }
+
+    bool validBroadcastAddresses = true;
+    for (const QHostAddress &address : std::as_const(broadcastAddresses)) {
+        if (broadcastSocket.writeDatagram(datagram, address,
+                                          broadcastPort) == -1)
+            validBroadcastAddresses = false;
+    }
+
+    if (!validBroadcastAddresses)
+        updateAddresses();
+}
+
+void PeerManager::readBroadcastDatagram()
+{
+    while (broadcastSocket.hasPendingDatagrams()) {
+        QHostAddress senderIp;
+        quint16 senderPort;
+        QByteArray datagram;
+        datagram.resize(broadcastSocket.pendingDatagramSize());
+        if (broadcastSocket.readDatagram(datagram.data(), datagram.size(),
+                                         &senderIp, &senderPort) == -1)
+            continue;
+
+        int senderServerPort;
+        {
+            // decode the datagram
+            QCborStreamReader reader(datagram);
+            if (reader.lastError() != QCborError::NoError || !reader.isArray())
+                continue;
+            if (!reader.isLengthKnown() || reader.length() != 2)
+                continue;
+
+            reader.enterContainer();
+            if (reader.lastError() != QCborError::NoError || !reader.isString())
+                continue;
+            while (reader.readString().status == QCborStreamReader::Ok) {
+                // we don't actually need the username right now
+            }
+
+            if (reader.lastError() != QCborError::NoError || !reader.isUnsignedInteger())
+                continue;
+            senderServerPort = reader.toInteger();
+        }
+
+        if (isLocalHostAddress(senderIp) && senderServerPort == serverPort)
+            continue;
+
+        if (!client->hasConnection(senderIp)) {
+            Connection *connection = new Connection(this);
+            emit newConnection(connection);
+            connection->connectToHost(senderIp, senderServerPort);
+        }
+    }
+}
+
+void PeerManager::updateAddresses()
+{
+    broadcastAddresses.clear();
+    ipAddresses.clear();
+    const QList<QNetworkInterface> interfaces = QNetworkInterface::allInterfaces();
+    for (const QNetworkInterface &interface : interfaces) {
+        const QList<QNetworkAddressEntry> entries = interface.addressEntries();
+        for (const QNetworkAddressEntry &entry : entries) {
+            QHostAddress broadcastAddress = entry.broadcast();
+            if (broadcastAddress != QHostAddress::Null && entry.ip() != QHostAddress::LocalHost) {
+                broadcastAddresses << broadcastAddress;
+                ipAddresses << entry.ip();
+            }
+        }
+    }
+}

examples/network/network-chat/peermanager.h

@@ -0,0 +1,47 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef PEERMANAGER_H
+#define PEERMANAGER_H
+
+#include <QByteArray>
+#include <QList>
+#include <QObject>
+#include <QTimer>
+#include <QUdpSocket>
+
+class Client;
+class Connection;
+
+class PeerManager : public QObject
+{
+    Q_OBJECT
+
+public:
+    PeerManager(Client *client);
+
+    void setServerPort(int port);
+    QString userName() const;
+    void startBroadcasting();
+    bool isLocalHostAddress(const QHostAddress &address) const;
+
+signals:
+    void newConnection(Connection *connection);
+
+private slots:
+    void sendBroadcastDatagram();
+    void readBroadcastDatagram();
+
+private:
+    void updateAddresses();
+
+    Client *client;
+    QList<QHostAddress> broadcastAddresses;
+    QList<QHostAddress> ipAddresses;
+    QUdpSocket broadcastSocket;
+    QTimer broadcastTimer;
+    QString username;
+    int serverPort;
+};
+
+#endif

examples/network/network-chat/server.cpp

@@ -0,0 +1,19 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QtNetwork>
+
+#include "connection.h"
+#include "server.h"
+
+Server::Server(QObject *parent)
+    : QTcpServer(parent)
+{
+    listen(QHostAddress::Any);
+}
+
+void Server::incomingConnection(qintptr socketDescriptor)
+{
+    Connection *connection = new Connection(socketDescriptor, this);
+    emit newConnection(connection);
+}

examples/network/network-chat/server.h

@@ -0,0 +1,25 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef SERVER_H
+#define SERVER_H
+
+#include <QTcpServer>
+
+class Connection;
+
+class Server : public QTcpServer
+{
+    Q_OBJECT
+
+public:
+    Server(QObject *parent = nullptr);
+
+signals:
+    void newConnection(Connection *connection);
+
+protected:
+    void incomingConnection(qintptr socketDescriptor) override;
+};
+
+#endif