--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/xml/rsslisting/rsslisting.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,239 @@
+/****************************************************************************
+**
+** 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 examples 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.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*
+rsslisting.cpp
+
+Provides a widget for displaying news items from RDF news sources.
+RDF is an XML-based format for storing items of information (see
+http://www.w3.org/RDF/ for details).
+
+The widget itself provides a simple user interface for specifying
+the URL of a news source, and controlling the downloading of news.
+
+The widget downloads and parses the XML asynchronously, feeding the
+data to an XML reader in pieces. This allows the user to interrupt
+its operation, and also allows very large data sources to be read.
+*/
+
+
+#include <QtCore>
+#include <QtGui>
+#include <QtNetwork>
+
+#include "rsslisting.h"
+
+
+/*
+ Constructs an RSSListing widget with a simple user interface, and sets
+ up the XML reader to use a custom handler class.
+
+ The user interface consists of a line edit, two push buttons, and a
+ list view widget. The line edit is used for entering the URLs of news
+ sources; the push buttons start and abort the process of reading the
+ news.
+*/
+
+RSSListing::RSSListing(QWidget *parent)
+ : QWidget(parent)
+{
+ lineEdit = new QLineEdit(this);
+ lineEdit->setText("http://labs.qt.nokia.com/blogs/feed");
+
+ fetchButton = new QPushButton(tr("Fetch"), this);
+ abortButton = new QPushButton(tr("Abort"), this);
+ abortButton->setEnabled(false);
+
+ treeWidget = new QTreeWidget(this);
+ connect(treeWidget, SIGNAL(itemActivated(QTreeWidgetItem*, int)),
+ this, SLOT(itemActivated(QTreeWidgetItem*)));
+ QStringList headerLabels;
+ headerLabels << tr("Title") << tr("Link");
+ treeWidget->setHeaderLabels(headerLabels);
+ treeWidget->header()->setResizeMode(QHeaderView::ResizeToContents);
+
+ connect(&http, SIGNAL(readyRead(const QHttpResponseHeader &)),
+ this, SLOT(readData(const QHttpResponseHeader &)));
+
+ connect(&http, SIGNAL(requestFinished(int, bool)),
+ this, SLOT(finished(int, bool)));
+
+ connect(lineEdit, SIGNAL(returnPressed()), this, SLOT(fetch()));
+ connect(fetchButton, SIGNAL(clicked()), this, SLOT(fetch()));
+ connect(abortButton, SIGNAL(clicked()), &http, SLOT(abort()));
+
+ QVBoxLayout *layout = new QVBoxLayout(this);
+
+ QHBoxLayout *hboxLayout = new QHBoxLayout;
+
+ hboxLayout->addWidget(lineEdit);
+ hboxLayout->addWidget(fetchButton);
+ hboxLayout->addWidget(abortButton);
+
+ layout->addLayout(hboxLayout);
+ layout->addWidget(treeWidget);
+
+ setWindowTitle(tr("RSS listing example"));
+ resize(640,480);
+}
+
+/*
+ Starts fetching data from a news source specified in the line
+ edit widget.
+
+ The line edit is made read only to prevent the user from modifying its
+ contents during the fetch; this is only for cosmetic purposes.
+ The fetch button is disabled, and the abort button is enabled to allow
+ the user to interrupt processing. The list view is cleared, and we
+ define the last list view item to be 0, meaning that there are no
+ existing items in the list.
+
+ The HTTP handler is supplied with the raw contents of the line edit and
+ a fetch is initiated. We keep the ID value returned by the HTTP handler
+ for future reference.
+*/
+
+void RSSListing::fetch()
+{
+ lineEdit->setReadOnly(true);
+ fetchButton->setEnabled(false);
+ abortButton->setEnabled(true);
+ treeWidget->clear();
+
+ xml.clear();
+
+ QUrl url(lineEdit->text());
+
+ http.setHost(url.host());
+ connectionId = http.get(url.path());
+}
+
+/*
+ Reads data received from the RDF source.
+
+ We read all the available data, and pass it to the XML
+ stream reader. Then we call the XML parsing function.
+
+ If parsing fails for any reason, we abort the fetch.
+*/
+
+void RSSListing::readData(const QHttpResponseHeader &resp)
+{
+ if (resp.statusCode() != 200)
+ http.abort();
+ else {
+ xml.addData(http.readAll());
+ parseXml();
+ }
+}
+
+/*
+ Finishes processing an HTTP request.
+
+ The default behavior is to keep the text edit read only.
+
+ If an error has occurred, the user interface is made available
+ to the user for further input, allowing a new fetch to be
+ started.
+
+ If the HTTP get request has finished, we make the
+ user interface available to the user for further input.
+*/
+
+void RSSListing::finished(int id, bool error)
+{
+ if (error) {
+ qWarning("Received error during HTTP fetch.");
+ lineEdit->setReadOnly(false);
+ abortButton->setEnabled(false);
+ fetchButton->setEnabled(true);
+ }
+ else if (id == connectionId) {
+ lineEdit->setReadOnly(false);
+ abortButton->setEnabled(false);
+ fetchButton->setEnabled(true);
+ }
+}
+
+
+/*
+ Parses the XML data and creates treeWidget items accordingly.
+*/
+void RSSListing::parseXml()
+{
+ while (!xml.atEnd()) {
+ xml.readNext();
+ if (xml.isStartElement()) {
+ if (xml.name() == "item")
+ linkString = xml.attributes().value("rss:about").toString();
+ currentTag = xml.name().toString();
+ } else if (xml.isEndElement()) {
+ if (xml.name() == "item") {
+
+ QTreeWidgetItem *item = new QTreeWidgetItem;
+ item->setText(0, titleString);
+ item->setText(1, linkString);
+ treeWidget->addTopLevelItem(item);
+
+ titleString.clear();
+ linkString.clear();
+ }
+
+ } else if (xml.isCharacters() && !xml.isWhitespace()) {
+ if (currentTag == "title")
+ titleString += xml.text().toString();
+ else if (currentTag == "link")
+ linkString += xml.text().toString();
+ }
+ }
+ if (xml.error() && xml.error() != QXmlStreamReader::PrematureEndOfDocumentError) {
+ qWarning() << "XML ERROR:" << xml.lineNumber() << ": " << xml.errorString();
+ http.abort();
+ }
+}
+
+/*
+ Open the link in the browser
+*/
+void RSSListing::itemActivated(QTreeWidgetItem * item)
+{
+ QDesktopServices::openUrl(QUrl(item->text(1)));
+}