QCopChannel Class Reference

Detailed Description

The QCopChannel class provides communication capabilities between several clients.

The Qt Cop (QCOP) is a COmmunication Protocol, allowing clients to communicate both within the same address space and between different processes.

Currently, this facility is only available on Qt/Embedded. On X11 and Windows we are exploring the use of existing standards such as DCOP and COM.

QCopChannel provides send() and isRegistered() which are static functions usable without an object.

The channel() function returns the name of the channel.

In order to listen to the traffic on a channel, you should either subclass QCopChannel and reimplement receive(), or connect() to the received() signal.

Member Function Documentation

QCopChannel::QCopChannel ( const QCString & channel, QObject * parent = 0, const char * name = 0 )

QCopChannel::~QCopChannel () [virtual]

QCString QCopChannel::channel () const

bool QCopChannel::isRegistered ( const QCString & channel ) [static]

Returns TRUE if channel is registered; otherwise returns FALSE.

void QCopChannel::receive ( const QCString & msg, const QByteArray & data ) [virtual]

The default implementation emits the received() signal.

Note that the format of data has to be well defined in order to extract the information it contains.

Example:

    void MyClass::receive( const QCString &msg, const QByteArray &data )
    {
        QDataStream stream( data, IO_ReadOnly );
        if ( msg == "execute(QString,QString)" ) {
            QString cmd, arg;
            stream >> cmd >> arg;
            ...
        } else if ( msg == "delete(QString)" ) {
            QString filenname;
            stream >> filename;
            ...
        } else ...
    }
    

Using the DCOP convention is a recommendation, but not a requirement. Whatever convention you use the sender and receiver must agree on the argument types.

See also send().

void QCopChannel::received ( const QCString & msg, const QByteArray & data ) [signal]

This signal is emitted with the msg and data whenever the receive() function gets incoming data.

bool QCopChannel::send ( const QCString & channel, const QCString & msg, const QByteArray & data ) [static]

Note that QDataStream provides a convenient way to fill the byte array with auxiliary data.

Example:

    QByteArray ba;
    QDataStream stream( ba, IO_WriteOnly );
    stream << QString("cat") << QString("file.txt");
    QCopChannel::send( "System/Shell", "execute(QString,QString)", ba );
    

Using the DCOP convention is a recommendation, but not a requirement. Whatever convention you use the sender and receiver must agree on the argument types.

See also receive().

bool QCopChannel::send ( const QCString & channel, const QCString & msg ) [static]

Send the message msg on channel channel. The message will be distributed to all clients subscribed to the channel.

See also receive().

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