src/dbus/qdbuscontext.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/dbus/qdbuscontext.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,204 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtDBus module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qdbusmessage.h"
+#include "qdbusconnection.h"
+#include "qdbusabstractadaptor.h"
+
+#include "qdbuscontext.h"
+#include "qdbuscontext_p.h"
+
+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 0;
+}
+
+/*!
+    \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
+    {QtDBus XML Compiler (qdbusxml2cpp)}.
+
+    QDBusContext is used by subclassing it from the objects being
+    exported using QDBusConnection::registerObject(). The following
+    example illustrates the usage:
+
+    \snippet doc/src/snippets/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(0)
+{
+}
+
+/*!
+  An empty destructor.
+ */
+QDBusContext::~QDBusContext()
+{
+}
+
+/*!
+    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.
+*/
+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 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, QtDBus will automatically generate a reply
+    back to the caller, if needed, as soon as the called slot returns.
+
+    If \a enable is true, QtDBus 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 QtDBus.
+*/
+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 QtDBus.
+*/
+void QDBusContext::sendErrorReply(QDBusError::ErrorType type, const QString &msg) const
+{
+    setDelayedReply(true);
+    connection().send(message().createErrorReply(type, msg));
+}
+
+QT_END_NAMESPACE