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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include "qdbusmessage.h"
#include "qdbusconnection.h"
#include "qdbusabstractadaptor.h"
#include "qdbuscontext.h"
#include "qdbuscontext_p.h"
#ifndef QT_NO_DBUS
QT_BEGIN_NAMESPACE
QDBusContextPrivate *QDBusContextPrivate::set(QObject *obj, QDBusContextPrivate *newContext)
{
// determine if this is an adaptor or not
if (qobject_cast<QDBusAbstractAdaptor *>(obj))
obj = obj->parent();
Q_ASSERT(obj);
void *ptr = obj->qt_metacast("QDBusContext");
QDBusContext *q_ptr = reinterpret_cast<QDBusContext *>(ptr);
if (q_ptr) {
QDBusContextPrivate *old = q_ptr->d_ptr;
q_ptr->d_ptr = newContext;
return old;
}
return nullptr;
}
/*!
\since 4.3
\class QDBusContext
\inmodule QtDBus
\brief 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 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:
\snippet code/src_qdbus_qdbuscontext.cpp 0
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().
*/
/*!
Constructs an empty QDBusContext.
*/
QDBusContext::QDBusContext()
: d_ptr(nullptr)
{
}
/*!
An empty destructor.
*/
QDBusContext::~QDBusContext()
{
}
/*!
Returns \c true if we are processing a D-Bus call. If this function
returns \c true, the rest of the functions in this class are
available.
Accessing those functions when this function returns \c false is
undefined and may lead to crashes.
*/
bool QDBusContext::calledFromDBus() const
{
return d_ptr;
}
/*!
Returns the connection from which this call was received.
*/
QDBusConnection QDBusContext::connection() const
{
return d_ptr->connection;
}
/*!
Returns the message that generated this call.
*/
const QDBusMessage &QDBusContext::message() const
{
return d_ptr->message;
}
/*!
Returns \c true if this call will have a delayed reply.
\sa setDelayedReply()
*/
bool QDBusContext::isDelayedReply() const
{
return message().isDelayedReply();
}
/*!
Sets whether this call will have a delayed reply or not.
If \a 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 \a 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.
*/
void QDBusContext::setDelayedReply(bool enable) const
{
message().setDelayedReply(enable);
}
/*!
Sends an error \a name as a reply to the caller. The optional \a
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.
*/
void QDBusContext::sendErrorReply(const QString &name, const QString &msg) const
{
setDelayedReply(true);
connection().send(message().createErrorReply(name, msg));
}
/*!
\overload
Sends an error \a type as a reply to the caller. The optional \a
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.
*/
void QDBusContext::sendErrorReply(QDBusError::ErrorType type, const QString &msg) const
{
setDelayedReply(true);
connection().send(message().createErrorReply(type, msg));
}
QT_END_NAMESPACE
#endif // QT_NO_DBUS
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