QDBusContext Class Reference

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

#include <qdbuscontext.h>

Inheritance diagram for QDBusContext:

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

Friends
class	QDBusContextPrivate

Detailed Description

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

Since

4.3

\inmodule QtDBus

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 doesn't involve modifying the code generated by the \l {Qt D-Bus XML compiler (qdbusxml2cpp)}.

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

The example illustrates the two typical uses, that of sending error replies and that of delayed replies.

Note: do not subclass QDBusContext and QDBusAbstractAdaptor at the same time. QDBusContext should appear in the real object, not the adaptor. If it's necessary from the adaptor code to determine the context, use a public inheritance and access the functions via QObject::parent().

Definition at line 56 of file qdbuscontext.h.

Constructor & Destructor Documentation

QDBusContext()

QDBusContext::QDBusContext

(

)

Constructs an empty QDBusContext.

Definition at line 106 of file qdbuscontext.cpp.

~QDBusContext()

QDBusContext::~QDBusContext

(

)

An empty destructor.

Definition at line 114 of file qdbuscontext.cpp.

Member Function Documentation

calledFromDBus()

bool QDBusContext::calledFromDBus

(

)

const

Returns true if we are processing a D-Bus call. If this function returns true, the rest of the functions in this class are available.

Accessing those functions when this function returns false is undefined and may lead to crashes.

Definition at line 126 of file qdbuscontext.cpp.

Here is the caller graph for this function:

connection()

QDBusConnection QDBusContext::connection

(

)

const

Returns the connection from which this call was received.

Definition at line 134 of file qdbuscontext.cpp.

Here is the caller graph for this function:

isDelayedReply()

bool QDBusContext::isDelayedReply

(

)

const

Returns true if this call will have a delayed reply.

See also

setDelayedReply()

Definition at line 152 of file qdbuscontext.cpp.

Here is the call graph for this function:

message()

const QDBusMessage & QDBusContext::message

(

)

const

Returns the message that generated this call.

Definition at line 142 of file qdbuscontext.cpp.

Here is the caller graph for this function:

sendErrorReply() [1/2]

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 Qt D-Bus.

Definition at line 184 of file qdbuscontext.cpp.

Here is the call graph for this function:

Here is the caller graph for this function:

sendErrorReply() [2/2]

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

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. 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 Qt D-Bus.

Definition at line 198 of file qdbuscontext.cpp.

Here is the call graph for this function:

setDelayedReply()

void QDBusContext::setDelayedReply

(

bool

enable

)

const

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

If enable is false, Qt D-Bus will automatically generate a reply back to the caller, if needed, as soon as the called slot returns.

If enable is true, Qt D-Bus 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.

Definition at line 172 of file qdbuscontext.cpp.

Here is the call graph for this function:

Here is the caller graph for this function:

Friends And Related Function Documentation

QDBusContextPrivate

friend class QDBusContextPrivate

friend

Definition at line 75 of file qdbuscontext.h.

---

The documentation for this class was generated from the following files:

• src/dbus/qdbuscontext.h
• src/dbus/qdbuscontext.cpp