/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the QtXmlPatterns module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 3 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL3 included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 3 requirements ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 2.0 or (at your option) the GNU General ** Public license version 3 or any later version approved by the KDE Free ** Qt Foundation. The licenses are as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 ** included in the packaging of this file. Please review the following ** information to ensure the GNU General Public License requirements will ** be met: https://www.gnu.org/licenses/gpl-2.0.html and ** https://www.gnu.org/licenses/gpl-3.0.html. ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #include "private/qobject_p.h" #include "qabstractmessagehandler.h" QT_BEGIN_NAMESPACE /*! \class QAbstractMessageHandler \since 4.4 \ingroup xml-tools \inmodule QtXmlPatterns \brief The QAbstractMessageHandler class provides a callback interface for handling messages. QAbstractMessageHandler is an abstract base class that provides a callback interface for handling messages. For example, class QXmlQuery parses and runs an XQuery. When it detects a compile or runtime error, it generates an appropriate error message, but rather than output the message itself, it passes the message to the message() function of its QAbstractMessageHandler. See QXmlQuery::setMessageHandler(). You create a message handler by subclassing QAbstractMessageHandler and implementing handleMessage(). You then pass a pointer to an instance of your subclass to any classes that must generate messages. The messages are sent to the message handler via the message() function, which forwards them to your handleMessge(). A single instance of QAbstractMessageHandler can be called on to handle messages from multiple sources. Hence, the content of a message, which is the \e description parameter passed to message() and handleMessage(), must be interpreted in light of the context that required the message to be sent. That context is specified by the \e identifier and \e sourceLocation parameters to message() handleMessage(). */ /*! Constructs a QAbstractMessageHandler. The \a parent is passed to the QObject base class constructor. */ QAbstractMessageHandler::QAbstractMessageHandler(QObject *parent) : QObject(parent) { } /*! Destructs this QAbstractMessageHandler. */ QAbstractMessageHandler::~QAbstractMessageHandler() { } /*! Sends a message to this message handler. \a type is the kind of message being sent. \a description is the message content. The \a identifier is a URI that identifies the message and is the key to interpreting the other arguments. Typically, this class is used for reporting errors, as is the case for QXmlQuery, which uses a QAbstractMessageHandler to report compile and runtime XQuery errors. Hence, using a QUrl as the message \a identifier is was inspired by the explanation of \l{error handling in the XQuery language}. Because the \a identifier is composed of a namespace URI and a local part, identifiers with the same local part are unique. The caller is responsible for ensuring that \a identifier is either a valid QUrl or a default constructed QUrl. \a sourceLocation identifies a location in a resource (i.e., file or document) where the need for reporting a message was detected. This function unconditionally calls handleMessage(), passing all its parameters unmodified. \sa {http://www.w3.org/TR/xquery/#errors} */ void QAbstractMessageHandler::message(QtMsgType type, const QString &description, const QUrl &identifier, const QSourceLocation &sourceLocation) { handleMessage(type, description, identifier, sourceLocation); } /*! \fn void QAbstractMessageHandler::handleMessage(QtMsgType type, const QString &description, const QUrl &identifier = QUrl(), const QSourceLocation &sourceLocation = QSourceLocation()) = 0 This function must be implemented by the sub-class. message() will call this function, passing in its parameters, \a type, \a description, \a identifier and \a sourceLocation unmodified. This function can potentially be called from multiple threads. It's the reimplementation's responsibility to ensure thread safety. */ QT_END_NAMESPACE