[2] | 1 | /****************************************************************************
|
---|
| 2 | **
|
---|
[846] | 3 | ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
|
---|
[561] | 4 | ** All rights reserved.
|
---|
| 5 | ** Contact: Nokia Corporation ([email protected])
|
---|
[2] | 6 | **
|
---|
| 7 | ** This file is part of the examples of the Qt Toolkit.
|
---|
| 8 | **
|
---|
[846] | 9 | ** $QT_BEGIN_LICENSE:BSD$
|
---|
| 10 | ** You may use this file under the terms of the BSD license as follows:
|
---|
[2] | 11 | **
|
---|
[846] | 12 | ** "Redistribution and use in source and binary forms, with or without
|
---|
| 13 | ** modification, are permitted provided that the following conditions are
|
---|
| 14 | ** met:
|
---|
| 15 | ** * Redistributions of source code must retain the above copyright
|
---|
| 16 | ** notice, this list of conditions and the following disclaimer.
|
---|
| 17 | ** * Redistributions in binary form must reproduce the above copyright
|
---|
| 18 | ** notice, this list of conditions and the following disclaimer in
|
---|
| 19 | ** the documentation and/or other materials provided with the
|
---|
| 20 | ** distribution.
|
---|
| 21 | ** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
|
---|
| 22 | ** the names of its contributors may be used to endorse or promote
|
---|
| 23 | ** products derived from this software without specific prior written
|
---|
| 24 | ** permission.
|
---|
[2] | 25 | **
|
---|
[846] | 26 | ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
---|
| 27 | ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
---|
| 28 | ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
---|
| 29 | ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
---|
| 30 | ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
---|
| 31 | ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
---|
| 32 | ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
---|
| 33 | ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
---|
| 34 | ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
---|
| 35 | ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
---|
| 36 | ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
|
---|
[2] | 37 | ** $QT_END_LICENSE$
|
---|
| 38 | **
|
---|
| 39 | ****************************************************************************/
|
---|
| 40 |
|
---|
| 41 | /*
|
---|
| 42 | rsslisting.cpp
|
---|
| 43 |
|
---|
| 44 | Provides a widget for displaying news items from RDF news sources.
|
---|
| 45 | RDF is an XML-based format for storing items of information (see
|
---|
| 46 | http://www.w3.org/RDF/ for details).
|
---|
| 47 |
|
---|
| 48 | The widget itself provides a simple user interface for specifying
|
---|
| 49 | the URL of a news source, and controlling the downloading of news.
|
---|
| 50 |
|
---|
| 51 | The widget downloads and parses the XML asynchronously, feeding the
|
---|
| 52 | data to an XML reader in pieces. This allows the user to interrupt
|
---|
| 53 | its operation, and also allows very large data sources to be read.
|
---|
| 54 | */
|
---|
| 55 |
|
---|
| 56 |
|
---|
| 57 | #include <QtCore>
|
---|
| 58 | #include <QtGui>
|
---|
| 59 | #include <QtNetwork>
|
---|
| 60 |
|
---|
| 61 | #include "rsslisting.h"
|
---|
| 62 |
|
---|
| 63 |
|
---|
| 64 | /*
|
---|
| 65 | Constructs an RSSListing widget with a simple user interface, and sets
|
---|
| 66 | up the XML reader to use a custom handler class.
|
---|
| 67 |
|
---|
[846] | 68 | The user interface consists of a line edit, a push button, and a
|
---|
[2] | 69 | list view widget. The line edit is used for entering the URLs of news
|
---|
[846] | 70 | sources; the push button starts the process of reading the
|
---|
[2] | 71 | news.
|
---|
| 72 | */
|
---|
| 73 |
|
---|
| 74 | RSSListing::RSSListing(QWidget *parent)
|
---|
[846] | 75 | : QWidget(parent), currentReply(0)
|
---|
[2] | 76 | {
|
---|
| 77 | lineEdit = new QLineEdit(this);
|
---|
[561] | 78 | lineEdit->setText("http://labs.qt.nokia.com/blogs/feed");
|
---|
[2] | 79 |
|
---|
| 80 | fetchButton = new QPushButton(tr("Fetch"), this);
|
---|
| 81 |
|
---|
| 82 | treeWidget = new QTreeWidget(this);
|
---|
[561] | 83 | connect(treeWidget, SIGNAL(itemActivated(QTreeWidgetItem*,int)),
|
---|
[2] | 84 | this, SLOT(itemActivated(QTreeWidgetItem*)));
|
---|
| 85 | QStringList headerLabels;
|
---|
| 86 | headerLabels << tr("Title") << tr("Link");
|
---|
| 87 | treeWidget->setHeaderLabels(headerLabels);
|
---|
| 88 | treeWidget->header()->setResizeMode(QHeaderView::ResizeToContents);
|
---|
| 89 |
|
---|
[846] | 90 | connect(&manager, SIGNAL(finished(QNetworkReply*)),
|
---|
| 91 | this, SLOT(finished(QNetworkReply*)));
|
---|
[2] | 92 |
|
---|
| 93 | connect(lineEdit, SIGNAL(returnPressed()), this, SLOT(fetch()));
|
---|
| 94 | connect(fetchButton, SIGNAL(clicked()), this, SLOT(fetch()));
|
---|
| 95 |
|
---|
| 96 | QVBoxLayout *layout = new QVBoxLayout(this);
|
---|
| 97 |
|
---|
| 98 | QHBoxLayout *hboxLayout = new QHBoxLayout;
|
---|
| 99 |
|
---|
| 100 | hboxLayout->addWidget(lineEdit);
|
---|
| 101 | hboxLayout->addWidget(fetchButton);
|
---|
| 102 |
|
---|
| 103 | layout->addLayout(hboxLayout);
|
---|
| 104 | layout->addWidget(treeWidget);
|
---|
| 105 |
|
---|
| 106 | setWindowTitle(tr("RSS listing example"));
|
---|
| 107 | resize(640,480);
|
---|
| 108 | }
|
---|
| 109 |
|
---|
| 110 | /*
|
---|
[846] | 111 | Starts the network request and connects the needed signals
|
---|
| 112 | */
|
---|
| 113 | void RSSListing::get(const QUrl &url)
|
---|
| 114 | {
|
---|
| 115 | QNetworkRequest request(url);
|
---|
| 116 | if (currentReply) {
|
---|
| 117 | currentReply->disconnect(this);
|
---|
| 118 | currentReply->deleteLater();
|
---|
| 119 | }
|
---|
| 120 | currentReply = manager.get(request);
|
---|
| 121 | connect(currentReply, SIGNAL(readyRead()), this, SLOT(readyRead()));
|
---|
| 122 | connect(currentReply, SIGNAL(metaDataChanged()), this, SLOT(metaDataChanged()));
|
---|
| 123 | connect(currentReply, SIGNAL(error(QNetworkReply::NetworkError)), this, SLOT(error(QNetworkReply::NetworkError)));
|
---|
| 124 | }
|
---|
| 125 |
|
---|
| 126 | /*
|
---|
[2] | 127 | Starts fetching data from a news source specified in the line
|
---|
| 128 | edit widget.
|
---|
| 129 |
|
---|
| 130 | The line edit is made read only to prevent the user from modifying its
|
---|
| 131 | contents during the fetch; this is only for cosmetic purposes.
|
---|
[846] | 132 | The fetch button is disabled, the list view is cleared, and we
|
---|
[2] | 133 | define the last list view item to be 0, meaning that there are no
|
---|
| 134 | existing items in the list.
|
---|
| 135 |
|
---|
[846] | 136 | A URL is created with the raw contents of the line edit and
|
---|
| 137 | a get is initiated.
|
---|
[2] | 138 | */
|
---|
| 139 |
|
---|
| 140 | void RSSListing::fetch()
|
---|
| 141 | {
|
---|
| 142 | lineEdit->setReadOnly(true);
|
---|
| 143 | fetchButton->setEnabled(false);
|
---|
| 144 | treeWidget->clear();
|
---|
| 145 |
|
---|
| 146 | xml.clear();
|
---|
| 147 |
|
---|
| 148 | QUrl url(lineEdit->text());
|
---|
[846] | 149 | get(url);
|
---|
| 150 | }
|
---|
[2] | 151 |
|
---|
[846] | 152 | void RSSListing::metaDataChanged()
|
---|
| 153 | {
|
---|
| 154 | QUrl redirectionTarget = currentReply->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl();
|
---|
| 155 | if (redirectionTarget.isValid()) {
|
---|
| 156 | get(redirectionTarget);
|
---|
| 157 | }
|
---|
[2] | 158 | }
|
---|
| 159 |
|
---|
| 160 | /*
|
---|
| 161 | Reads data received from the RDF source.
|
---|
| 162 |
|
---|
| 163 | We read all the available data, and pass it to the XML
|
---|
| 164 | stream reader. Then we call the XML parsing function.
|
---|
| 165 | */
|
---|
| 166 |
|
---|
[846] | 167 | void RSSListing::readyRead()
|
---|
[2] | 168 | {
|
---|
[846] | 169 | int statusCode = currentReply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
|
---|
| 170 | if (statusCode >= 200 && statusCode < 300) {
|
---|
| 171 | QByteArray data = currentReply->readAll();
|
---|
| 172 | xml.addData(data);
|
---|
[2] | 173 | parseXml();
|
---|
| 174 | }
|
---|
| 175 | }
|
---|
| 176 |
|
---|
| 177 | /*
|
---|
| 178 | Finishes processing an HTTP request.
|
---|
| 179 |
|
---|
| 180 | The default behavior is to keep the text edit read only.
|
---|
| 181 |
|
---|
| 182 | If an error has occurred, the user interface is made available
|
---|
| 183 | to the user for further input, allowing a new fetch to be
|
---|
| 184 | started.
|
---|
| 185 |
|
---|
| 186 | If the HTTP get request has finished, we make the
|
---|
| 187 | user interface available to the user for further input.
|
---|
| 188 | */
|
---|
| 189 |
|
---|
[846] | 190 | void RSSListing::finished(QNetworkReply *reply)
|
---|
[2] | 191 | {
|
---|
[846] | 192 | Q_UNUSED(reply);
|
---|
| 193 | lineEdit->setReadOnly(false);
|
---|
| 194 | fetchButton->setEnabled(true);
|
---|
[2] | 195 | }
|
---|
| 196 |
|
---|
| 197 |
|
---|
| 198 | /*
|
---|
| 199 | Parses the XML data and creates treeWidget items accordingly.
|
---|
| 200 | */
|
---|
| 201 | void RSSListing::parseXml()
|
---|
| 202 | {
|
---|
| 203 | while (!xml.atEnd()) {
|
---|
| 204 | xml.readNext();
|
---|
| 205 | if (xml.isStartElement()) {
|
---|
| 206 | if (xml.name() == "item")
|
---|
| 207 | linkString = xml.attributes().value("rss:about").toString();
|
---|
| 208 | currentTag = xml.name().toString();
|
---|
| 209 | } else if (xml.isEndElement()) {
|
---|
| 210 | if (xml.name() == "item") {
|
---|
| 211 |
|
---|
| 212 | QTreeWidgetItem *item = new QTreeWidgetItem;
|
---|
| 213 | item->setText(0, titleString);
|
---|
| 214 | item->setText(1, linkString);
|
---|
| 215 | treeWidget->addTopLevelItem(item);
|
---|
| 216 |
|
---|
| 217 | titleString.clear();
|
---|
| 218 | linkString.clear();
|
---|
| 219 | }
|
---|
| 220 |
|
---|
| 221 | } else if (xml.isCharacters() && !xml.isWhitespace()) {
|
---|
| 222 | if (currentTag == "title")
|
---|
| 223 | titleString += xml.text().toString();
|
---|
| 224 | else if (currentTag == "link")
|
---|
| 225 | linkString += xml.text().toString();
|
---|
| 226 | }
|
---|
| 227 | }
|
---|
| 228 | if (xml.error() && xml.error() != QXmlStreamReader::PrematureEndOfDocumentError) {
|
---|
| 229 | qWarning() << "XML ERROR:" << xml.lineNumber() << ": " << xml.errorString();
|
---|
| 230 | }
|
---|
| 231 | }
|
---|
| 232 |
|
---|
| 233 | /*
|
---|
| 234 | Open the link in the browser
|
---|
| 235 | */
|
---|
| 236 | void RSSListing::itemActivated(QTreeWidgetItem * item)
|
---|
| 237 | {
|
---|
| 238 | QDesktopServices::openUrl(QUrl(item->text(1)));
|
---|
| 239 | }
|
---|
[846] | 240 |
|
---|
| 241 | void RSSListing::error(QNetworkReply::NetworkError)
|
---|
| 242 | {
|
---|
| 243 | qWarning("error retrieving RSS feed");
|
---|
| 244 | currentReply->disconnect(this);
|
---|
| 245 | currentReply->deleteLater();
|
---|
| 246 | currentReply = 0;
|
---|
| 247 | }
|
---|