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/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
** of its contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
/*
handler.cpp
Provides a handler for processing XML elements found by the reader.
The handler looks for <title> and <link> elements within <item> elements,
and records the text found within them. Link information stored within
rdf:about attributes of <item> elements is also recorded when it is
available.
For each item found, a signal is emitted which specifies its title and
link information. This may be used by user interfaces for the purpose of
displaying items as they are read.
*/
#include <QtGui>
#include "handler.h"
/*
Reset the state of the handler to ensure that new documents are
read correctly.
We return true to indicate that parsing should continue.
*/
bool Handler::startDocument()
{
inItem = false;
inTitle = false;
inLink = false;
return true;
}
/*
Process each starting element in the XML document.
Nested item, title, or link elements are not allowed, so we return false
if we encounter any of these. We also prohibit multiple definitions of
title strings.
Link destinations are read by this function if they are specified as
attributes in item elements.
For all cases not explicitly checked for, we return true to indicate that
the element is acceptable, and that parsing should continue. By doing
this, we can ignore elements in which we are not interested.
*/
bool Handler::startElement(const QString &, const QString &,
const QString & qName, const QXmlAttributes &attr)
{
if (qName == "item") {
if (inItem)
return false;
else {
inItem = true;
linkString = attr.value("rdf:about");
}
}
else if (qName == "title") {
if (inTitle)
return false;
else if (!titleString.isEmpty())
return false;
else if (inItem)
inTitle = true;
}
else if (qName == "link") {
if (inLink)
return false;
else if (inItem)
inLink = true;
}
return true;
}
/*
Process each ending element in the XML document.
For recognized elements, we reset flags to ensure that we can read new
instances of these elements. If we have read an item element, emit a
signal to indicate that a new item is available for display.
We return true to indicate that parsing should continue.
*/
bool Handler::endElement(const QString &, const QString &,
const QString & qName)
{
if (qName == "title" && inTitle)
inTitle = false;
else if (qName == "link" && inLink)
inLink = false;
else if (qName == "item") {
if (!titleString.isEmpty() && !linkString.isEmpty())
emit newItem(titleString, linkString);
inItem = false;
titleString = "";
linkString = "";
}
return true;
}
/*
Collect characters when reading the contents of title or link elements
when they occur within an item element.
We return true to indicate that parsing should continue.
*/
bool Handler::characters (const QString &chars)
{
if (inTitle)
titleString += chars;
else if (inLink)
linkString += chars;
return true;
}
/*
Report a fatal parsing error, and return false to indicate to the reader
that parsing should stop.
*/
//! [0]
bool Handler::fatalError (const QXmlParseException & exception)
{
qWarning() << "Fatal error on line" << exception.lineNumber()
<< ", column" << exception.columnNumber() << ":"
<< exception.message();
return false;
}
//! [0]
|
