Move RSS parsing to another thread to avoid freezing the UI

RSS items are now displayed as soon as they have been parsed
instead of displaying all of them in one batch once the whole
feed is parsed.

First step to address issue #34.

src/rss/rssparser.h

@@ -0,0 +1,73 @@
+/*
+ * Bittorrent Client using Qt4 and libtorrent.
+ * Copyright (C) 2012  Christophe Dumez
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ *
+ * Contact : chris@qbittorrent.org
+ */
+
+#ifndef RSSPARSER_H
+#define RSSPARSER_H
+
+#include "rssarticle.h"
+#include <QMutex>
+#include <QQueue>
+#include <QThread>
+#include <QWaitCondition>
+
+struct ParsingJob;
+
+class RssParser : public QThread
+{
+  Q_OBJECT
+
+public:
+  explicit RssParser(QObject *parent = 0);
+  virtual ~RssParser();
+
+signals:
+  void newArticle(const QString& feedUrl, const QVariantHash& rssArticle);
+  void feedTitle(const QString& feedUrl, const QString& title);
+  void feedParsingFinished(const QString& feedUrl, const QString& error);
+
+public slots:
+  void parseRssFile(const QString& feedUrl, const QString& filePath);
+
+protected:
+  virtual void run();
+  static QDateTime parseDate(const QString& string);
+  void parseRssArticle(QXmlStreamReader& xml, const QString& feedUrl);
+  void parseRSSChannel(QXmlStreamReader& xml, const QString& feedUrl);
+  void parseRSS(const ParsingJob& job);
+  void reportFailure(const ParsingJob& job, const QString& error);
+
+private:
+  bool m_running;
+  QMutex m_mutex;
+  QQueue<ParsingJob> m_queue;
+  QWaitCondition m_waitCondition;
+};
+
+#endif // RSSPARSER_H