CopperSpice DBUS  1.7.4
QDBusContext Class Reference

The QDBusContext class allows slots to determine the D-Bus context of the calls. More...

Public Methods

 QDBusContext ()
 
 ~QDBusContext ()
 
bool calledFromDBus () const
 
QDBusConnection connection () const
 
bool isDelayedReply () const
 
const QDBusMessagemessage () const
 
void sendErrorReply (const QString &name, const QString &msg=QString ()) const
 
void sendErrorReply (QDBusError::ErrorType type, const QString &msg=QString ()) const
 
void setDelayedReply (bool enable) const
 

Detailed Description

The QDBusContext class allows slots to determine the D-Bus context of the calls. When a slot is called in an object due to a signal delivery or due to a remote method call, it is sometimes necessary to know the context in which that happened. In particular, if the slot determines that it wants to send the reply at a later opportunity or if it wants to reply with an error, the context is needed.

The QDBusContext class is an alternative to accessing the context that does not involve modifying the code generated by the &CsDbus XML compiler (qdbusxml2cpp).

QDBusContext is used by subclassing it from the objects being exported using QDBusConnection::registerObject(). The following example illustrates the usage:

BROOM - fix

class MyObject : public QObject, protected QDBusContext
{
CS_OBJECT(MyObject)
public:
// slots
void methodWithError();
QString methodWithDelayedReply();
protected:
// slot
void process();
private:
};
void MyObject::methodWithError()
{
sendErrorReply(QDBusError::NotSupported, "The method call 'methodWithError()' is not supported");
}
QString MyObject::methodWithDelayedReply()
{
conn = connection();
msg = message();
QMetaObject::invokeMethod(this, "process", Qt::QueuedConnection);
return QString();
}
See also
setDelayedReply()

Constructor & Destructor Documentation

QDBusContext::QDBusContext ( )

Constructs an empty QDBusContext.

QDBusContext::~QDBusContext ( )

The destructor does nothing.

Method Documentation

bool QDBusContext::calledFromDBus ( ) const

broom text

Returns true if a CsDbus call is currently being processed. If this method returns false, then calling other methods in this class can result in undefined behavior.

QDBusConnection QDBusContext::connection ( ) const

Returns the connection from which this call was received.

bool QDBusContext::isDelayedReply ( ) const

Returns true if this call will have a delayed reply.

See also
setDelayedReply()
const QDBusMessage & QDBusContext::message ( ) const

Returns the message that generated this call.

void QDBusContext::sendErrorReply ( const QString &  name,
const QString &  msg = QString() 
) const

Sends an error name as a reply to the caller. The optional msg parameter is a human-readable text explaining the failure. If an error is sent the return value and any output parameters from the called slot will be ignored by &CsDbus.

void QDBusContext::sendErrorReply ( QDBusError::ErrorType  type,
const QString &  msg = QString() 
) const

Sends an error type as a reply to the caller. The optional msg parameter is a human-readable text explaining the failure. If an error is sent, the return value and any output parameters from the called slot will be ignored by &CsDbus.

void QDBusContext::setDelayedReply ( bool  enable) const

Sets whether this call will have a delayed reply or not.

If enable is false &CsDbus will automatically generate a reply back to the caller, if needed, as soon as the called slot returns. If enable is true &CsDbus will not generate automatic replies. It will also ignore the return value from the slot and any output parameters. Instead, the called object is responsible for storing the incoming message and send a reply or error at a later time.

Failing to send a reply will result in an automatic timeout error being generated by D-Bus.

See also
isDelayedReply()