Implemented LWJGL version lists.

The LWJGL list actually doesn't use tasks for loading. Instead, it takes advantage of the
QNetworkAccessManager's asynchronous requests. This is a system that I may look to implement for other version
lists and things such as the Minecraft version list and possibly even instance mod lists.

Loading things this way means that code that wants to load a list can simply call the load list function, rather
than having to get a task from the list and execute the task. Unfortunately, it also means we can't have task
progress dialogs for loading lists, but it shouldn't really be too difficult to write one that works with this
system.

At some point in the future, I'll probably end up putting all the code for this method of loading lists into a
base class and then update the other lists to support it.

1 files changed, 204 insertions, 0 deletions

diff --git a/libmultimc/src/lwjglversionlist.cpp b/libmultimc/src/lwjglversionlist.cpp
new file mode 100644
index 00000000..af5cf2f5
--- /dev/null
+++ b/libmultimc/src/lwjglversionlist.cpp
@@ -0,0 +1,204 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "include/lwjglversionlist.h"
+
+#include <QtNetwork>
+
+#include <QtXml>
+
+#include <QRegExp>
+
+#define RSS_URL "http://sourceforge.net/api/file/index/project-id/58488/mtime/desc/rss"
+
+LWJGLVersionList mainVersionList;
+
+LWJGLVersionList &LWJGLVersionList::get()
+{
+	return mainVersionList;
+}
+
+
+LWJGLVersionList::LWJGLVersionList(QObject *parent) :
+	QAbstractListModel(parent)
+{
+	setLoading(false);
+}
+
+QVariant LWJGLVersionList::data(const QModelIndex &index, int role) const
+{
+	if (!index.isValid())
+		return QVariant();
+	
+	if (index.row() > count())
+		return QVariant();
+	
+	const LWJGLVersion &version = at(index.row());
+	
+	switch (role)
+	{
+	case Qt::DisplayRole:
+		return version.name();
+		
+	case Qt::ToolTipRole:
+		return version.url().toString();
+		
+	default:
+		return QVariant();
+	}
+}
+
+QVariant LWJGLVersionList::headerData(int section, Qt::Orientation orientation, int role) const
+{
+	switch (role)
+	{
+	case Qt::DisplayRole:
+		return "Version";
+		
+	case Qt::ToolTipRole:
+		return "LWJGL version name.";
+		
+	default:
+		return QVariant();
+	}
+}
+
+int LWJGLVersionList::columnCount(const QModelIndex &parent) const
+{
+	return 1;
+}
+
+bool LWJGLVersionList::isLoading() const
+{
+	return m_loading;
+}
+
+void LWJGLVersionList::loadList()
+{
+	Q_ASSERT_X(!m_loading, "loadList", "list is already loading (m_loading is true)");
+	
+	setLoading(true);
+	reply = netMgr.get(QNetworkRequest(QUrl(RSS_URL)));
+	connect(reply, SIGNAL(finished()), SLOT(netRequestComplete()));
+}
+
+inline QDomElement getDomElementByTagName(QDomElement parent, QString tagname)
+{
+	QDomNodeList elementList = parent.elementsByTagName(tagname);
+	if (elementList.count())
+		return elementList.at(0).toElement();
+	else
+		return QDomElement();
+}
+
+void LWJGLVersionList::netRequestComplete()
+{
+	if (reply->error() == QNetworkReply::NoError)
+	{
+		QRegExp lwjglRegex("lwjgl-(([0-9]\\.?)+)\\.zip");
+		Q_ASSERT_X(lwjglRegex.isValid(), "load LWJGL list", 
+				   "LWJGL regex is invalid");
+		
+		QDomDocument doc;
+		
+		QString xmlErrorMsg;
+		int errorLine;
+		if (!doc.setContent(reply->readAll(), false, &xmlErrorMsg, &errorLine))
+		{
+			failed("Failed to load LWJGL list. XML error: " + xmlErrorMsg +
+				   " at line " + QString::number(errorLine));
+			setLoading(false);
+			return;
+		}
+		
+		QDomNodeList items = doc.elementsByTagName("item");
+		
+		QList<LWJGLVersion> tempList;
+		
+		for (int i = 0; i < items.length(); i++)
+		{
+			Q_ASSERT_X(items.at(i).isElement(), "load LWJGL list",
+					   "XML element isn't an element... wat?");
+			
+			QDomElement linkElement = getDomElementByTagName(items.at(i).toElement(), "link");
+			if (linkElement.isNull())
+			{
+				qWarning() << "Link element" << i << "in RSS feed doesn't exist! Skipping.";
+				continue;
+			}
+			
+			QString link = linkElement.text();
+			
+			// Make sure it's a download link.
+			if (link.endsWith("/download") && link.contains(lwjglRegex))
+			{
+				QString name = link.mid(lwjglRegex.indexIn(link));
+				// Subtract 4 here to remove the .zip file extension.
+				name = name.left(lwjglRegex.matchedLength() - 4);
+				
+				QUrl url(link);
+				if (!url.isValid())
+				{
+					qWarning() << "LWJGL version URL isn't valid:" << link << "Skipping.";
+					continue;
+				}
+				
+				tempList.append(LWJGLVersion(name, link));
+			}
+		}
+		
+		beginResetModel();
+		m_vlist.swap(tempList);
+		endResetModel();
+		
+		qDebug("Loaded LWJGL list.");
+		finished();
+	}
+	else
+	{
+		failed("Failed to load LWJGL list. Network error: " + reply->errorString());
+	}
+	
+	setLoading(false);
+	reply->deleteLater();
+}
+
+const LWJGLVersion *LWJGLVersionList::getVersion(const QString &versionName)
+{
+	for (int i = 0; i < count(); i++)
+	{
+		if (at(i).name() == versionName)
+			return &at(i);
+	}
+	return NULL;
+}
+
+
+void LWJGLVersionList::failed(QString msg)
+{
+	qWarning() << msg;
+	emit loadListFailed(msg);
+}
+
+void LWJGLVersionList::finished()
+{
+	emit loadListFinished();
+}
+
+void LWJGLVersionList::setLoading(bool loading)
+{
+	m_loading = loading;
+	emit loadingStateUpdated(m_loading);
+}