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Diffstat (limited to 'src/dbus/qdbusreply.cpp')
| -rw-r--r-- | src/dbus/qdbusreply.cpp | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/src/dbus/qdbusreply.cpp b/src/dbus/qdbusreply.cpp new file mode 100644 index 0000000000..d360f27290 --- /dev/null +++ b/src/dbus/qdbusreply.cpp @@ -0,0 +1,248 @@ +/**************************************************************************** +** +** Copyright (C) 2011 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 "qdbusreply.h" +#include "qdbusmetatype.h" +#include "qdbusmetatype_p.h" +#include <QDebug> + +#ifndef QT_NO_DBUS + +QT_BEGIN_NAMESPACE + +/*! + \class QDBusReply + \inmodule QtDBus + \since 4.2 + + \brief The QDBusReply class stores the reply for a method call to a remote object. + + A QDBusReply object is a subset of the QDBusMessage object that represents a method call's + reply. It contains only the first output argument or the error code and is used by + QDBusInterface-derived classes to allow returning the error code as the function's return + argument. + + It can be used in the following manner: + \snippet doc/src/snippets/code/src_qdbus_qdbusreply.cpp 0 + + If the remote method call cannot fail, you can skip the error checking: + \snippet doc/src/snippets/code/src_qdbus_qdbusreply.cpp 1 + + However, if it does fail under those conditions, the value returned by QDBusReply::value() is + a default-constructed value. It may be indistinguishable from a valid return value. + + QDBusReply objects are used for remote calls that have no output + arguments or return values (i.e., they have a "void" return + type). Use the isValid() function to test if the reply succeeded. + + \sa QDBusMessage, QDBusInterface +*/ + +/*! + \fn QDBusReply::QDBusReply(const QDBusMessage &reply) + Automatically construct a QDBusReply object from the reply message \a reply, extracting the + first return value from it if it is a success reply. +*/ + +/*! + \fn QDBusReply::QDBusReply(const QDBusPendingReply<T> &reply) + Constructs a QDBusReply object from the pending reply message, \a reply. +*/ + +/*! + \fn QDBusReply::QDBusReply(const QDBusPendingCall &pcall) + Automatically construct a QDBusReply object from the asynchronous + pending call \a pcall. If the call isn't finished yet, QDBusReply + will call QDBusPendingCall::waitForFinished(), which is a blocking + operation. + + If the return types patch, QDBusReply will extract the first + return argument from the reply. +*/ + +/*! + \fn QDBusReply::QDBusReply(const QDBusError &error) + Constructs an error reply from the D-Bus error code given by \a error. +*/ + +/*! + \fn QDBusReply::operator=(const QDBusReply &other) + Makes this object be a copy of the object \a other. +*/ + +/*! + \fn QDBusReply::operator=(const QDBusError &error) + Sets this object to contain the error code given by \a error. You + can later access it with error(). +*/ + +/*! + \fn QDBusReply::operator=(const QDBusMessage &message) + + Makes this object contain the reply specified by message \a + message. If \a message is an error message, this function will + copy the error code and message into this object + + If \a message is a standard reply message and contains at least + one parameter, it will be copied into this object, as long as it + is of the correct type. If it's not of the same type as this + QDBusError object, this function will instead set an error code + indicating a type mismatch. +*/ + +/*! + \fn QDBusReply::operator=(const QDBusPendingCall &pcall) + + Makes this object contain the reply specified by the pending + asynchronous call \a pcall. If the call is not finished yet, this + function will call QDBusPendingCall::waitForFinished() to block + until the reply arrives. + + If \a pcall finishes with an error message, this function will + copy the error code and message into this object + + If \a pcall finished with a standard reply message and contains at + least one parameter, it will be copied into this object, as long + as it is of the correct type. If it's not of the same type as this + QDBusError object, this function will instead set an error code + indicating a type mismatch. +*/ + +/*! + \fn bool QDBusReply::isValid() const + + Returns true if no error occurred; otherwise, returns false. + + \sa error() +*/ + +/*! + \fn QDBusReply::error() + + Returns the error code that was returned from the remote function call. If the remote call did + not return an error (i.e., if it succeeded), then the QDBusError object that is returned will + not be a valid error code (QDBusError::isValid() will return false). + + \sa isValid() +*/ + +/*! + \fn QDBusReply::value() const + Returns the remote function's calls return value. If the remote call returned with an error, + the return value of this function is undefined and may be undistinguishable from a valid return + value. + + This function is not available if the remote call returns \c void. +*/ + +/*! + \fn QDBusReply::operator Type() const + Returns the same as value(). + + This function is not available if the remote call returns \c void. +*/ + +/*! + \internal + Fills in the QDBusReply data \a error and \a data from the reply message \a reply. +*/ +void qDBusReplyFill(const QDBusMessage &reply, QDBusError &error, QVariant &data) +{ + error = reply; + + if (error.isValid()) { + data = QVariant(); // clear it + return; + } + + if (reply.arguments().count() >= 1 && reply.arguments().at(0).userType() == data.userType()) { + data = reply.arguments().at(0); + return; + } + + const char *expectedSignature = QDBusMetaType::typeToSignature(data.userType()); + const char *receivedType = 0; + QByteArray receivedSignature; + + if (reply.arguments().count() >= 1) { + if (reply.arguments().at(0).userType() == QDBusMetaTypeId::argument) { + // compare signatures instead + QDBusArgument arg = qvariant_cast<QDBusArgument>(reply.arguments().at(0)); + receivedSignature = arg.currentSignature().toLatin1(); + if (receivedSignature == expectedSignature) { + // matched. Demarshall it + QDBusMetaType::demarshall(arg, data.userType(), data.data()); + return; + } + } else { + // not an argument and doesn't match? + int type = reply.arguments().at(0).userType(); + receivedType = QVariant::typeToName(QVariant::Type(type)); + receivedSignature = QDBusMetaType::typeToSignature(type); + } + } + + // error + if (receivedSignature.isEmpty()) + receivedSignature = "no signature"; + QString errorMsg; + if (receivedType) { + errorMsg = QString::fromLatin1("Unexpected reply signature: got \"%1\" (%4), " + "expected \"%2\" (%3)") + .arg(QLatin1String(receivedSignature), + QLatin1String(expectedSignature), + QLatin1String(data.typeName()), + QLatin1String(receivedType)); + } else { + errorMsg = QString::fromLatin1("Unexpected reply signature: got \"%1\", " + "expected \"%2\" (%3)") + .arg(QLatin1String(receivedSignature), + QLatin1String(expectedSignature), + QLatin1String(data.typeName())); + } + + error = QDBusError(QDBusError::InvalidSignature, errorMsg); + data = QVariant(); // clear it +} + +QT_END_NAMESPACE + +#endif // QT_NO_DBUS |