- Qt 5.5
- Qt Network
- Network Chat Example
- connection.h Example File
- Qt 5.5.1 Reference Documentation

# connection.h Example File

network-chat/connection.h

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
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    #ifndef CONNECTION_H
    #define CONNECTION_H

    #include <QHostAddress>
    #include <QString>
    #include <QTcpSocket>
    #include <QTime>
    #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 = 0);

        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) Q_DECL_OVERRIDE;

    private slots:
        void processReadyRead();
        void sendPing();
        void sendGreetingMessage();

    private:
        int readDataIntoBuffer(int maxSize = MaxBufferSize);
        int dataLengthForCurrentDataType();
        bool readProtocolHeader();
        bool hasEnoughData();
        void processData();

        QString greetingMessage;
        QString username;
        QTimer pingTimer;
        QTime pongTime;
        QByteArray buffer;
        ConnectionState state;
        DataType currentDataType;
        int numBytesForCurrentDataType;
        int transferTimerId;
        bool isGreetingMessageSent;
    };

    #endif