Started reworking the instance system.

14 files changed, 533 insertions, 195 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index dbe86a83..1fcff14a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -93,13 +93,17 @@ main.cpp
 
 data/appsettings.cpp
 data/inifile.cpp
-data/instancebase.cpp
-data/instancemodel.cpp
-data/stdinstance.cpp
+#data/instancemodel.cpp
 data/version.cpp
 data/userinfo.cpp
 data/loginresponse.cpp
 
+data/inst/instance.cpp
+data/inst/instancelist.cpp
+
+data/version/instversion.cpp
+data/version/instversionlist.cpp
+
 gui/mainwindow.cpp
 gui/modeditwindow.cpp
 gui/settingsdialog.cpp
@@ -127,14 +131,18 @@ gui/taskdialog.h
 
 data/appsettings.h
 data/inifile.h
-data/instancebase.h
 data/instancemodel.h
-data/stdinstance.h
 data/version.h
 data/userinfo.h
 data/loginresponse.h
 data/siglist.h
-data/siglist_imp.h
+data/siglist_impl.h
+
+data/inst/instance.h
+data/inst/instancelist.h
+
+data/version/instversion.h
+data/version/instversionlist.h
 
 util/apputils.h
 util/pathutils.h
diff --git a/data/appsettings.h b/data/appsettings.h
index a9068bfd..8a786db0 100644
--- a/data/appsettings.h
+++ b/data/appsettings.h
@@ -39,8 +39,6 @@
 #define DEFINE_SETTING(name, valType, defVal) \
 	DEFINE_SETTING_ADVANCED(name, STR_VAL(name), valType, defVal)
 
-#define DEFINE_OVERRIDE_SETTING(overrideName) \
-	
 
 class SettingsBase : public QObject
 {
@@ -91,7 +89,6 @@ public:
 	DEFINE_SETTING(PreLaunchCommand, QString, "")
 	DEFINE_SETTING(PostExitCommand, QString, "")
 	
-protected:
 	virtual QVariant getValue(const QString& name, QVariant defVal = QVariant()) const = 0;
 	virtual void setValue(const QString& name, QVariant val) = 0;
 };
@@ -104,10 +101,10 @@ public:
 	
 	QSettings& getConfig() { return config; }
 	
-protected:
 	virtual QVariant getValue(const QString &name, QVariant defVal = QVariant()) const;
 	virtual void setValue(const QString& name, QVariant val);
-	
+
+protected:
 	QSettings config;
 };
 
diff --git a/data/stdinstance.cpp b/data/inst/instance.cpp
index 4618f5ca..5cde2233 100644
--- a/data/stdinstance.cpp
+++ b/data/inst/instance.cpp
@@ -13,10 +13,9 @@
  * limitations under the License.
  */
 
-#include "stdinstance.h"
+#include "instance.h"
 
-StdInstance::StdInstance(QString rootDir, QObject* parent) : 
-	InstanceBase(rootDir, parent)
+Instance::Instance(QObject *parent) :
+	SettingsBase(parent)
 {
-	
 }
diff --git a/data/inst/instance.h b/data/inst/instance.h
new file mode 100644
index 00000000..6b1991b6
--- /dev/null
+++ b/data/inst/instance.h
@@ -0,0 +1,320 @@
+/* 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.
+ */
+
+#ifndef INSTANCE_H
+#define INSTANCE_H
+
+#include <QObject>
+#include <QDateTime>
+
+#include "data/appsettings.h"
+#include "data/inifile.h"
+
+#define DEFINE_OVERRIDDEN_SETTING_ADVANCED(funcName, cfgEntryName, typeName) \
+	typeName get ## funcName() const { return getField(cfgEntryName, settings->get ## funcName()).value<typeName>(); }
+
+#define DEFINE_OVERRIDDEN_SETTING(funcName, typeName) \
+	DEFINE_OVERRIDDEN_SETTING_ADVANCED(funcName, STR_VAL(funcName), typeName)
+
+class InstanceList;
+
+/*!
+ * \brief Base class for instances.
+ * This class implements many functions that are common between instances and 
+ * provides a standard interface for all instances.
+ * 
+ * To create a new instance type, create a new class inheriting from this class
+ * and implement the pure virtual functions.
+ */
+class Instance : public SettingsBase
+{
+	Q_OBJECT
+public:
+	explicit Instance(QObject *parent = 0);
+	
+	// Please, for the sake of my (and everyone else's) sanity, at least keep this shit
+	// *somewhat* organized. Also, documentation is semi-important here. Please don't
+	// leave undocumented stuff behind.
+	
+	
+	//////// STUFF ////////
+	
+	/*!
+	 * \brief Get the instance's ID. 
+	 *        This is a unique identifier string that is, by default, set to the
+	 *        instance's folder name. It's not always the instance's folder name, 
+	 *        however, as any class deriving from Instance can override the id() 
+	 *        method and change how the ID is determined. The instance's ID 
+	 *        should always remain constant. Undefined behavior results if an 
+	 *        already loaded instance's ID changes.
+	 * 
+	 * \return The instance's ID.
+	 */
+	virtual QString id();
+	
+	/*!
+	 * \brief Gets the path to the instance's root directory.
+	 * \return  The path to the instance's root directory.
+	 */
+	virtual QString rootDir();
+	
+	/*!
+	 * \brief Gets the instance list that this instance is a part of. 
+	 *        Returns NULL if this instance is not in a list 
+	 *        (the parent is not an InstanceList).
+	 * \return A pointer to the InstanceList containing this instance. 
+	 */
+	virtual InstanceList *instList();
+	
+	
+	/*!
+	 * \brief Gets this instance's group.
+	 *        This function is used by the instance grouping system and should 
+	 *        not be touched by classes deriving from Instance.
+	 * \return The instance's group name.
+	 * \sa setGroup() 
+	 */
+	QString group() const { return m_group; }
+	
+	/*!
+	 * \brief Sets the instance's group.
+	 * \param group The instance's new group name.
+	 * \sa group()
+	 */
+	void setGroup(const QString &group) { m_group = group; emit groupChanged(this, group); }
+	
+	
+	//////// FIELDS AND SETTINGS ////////
+	// Fields are options stored in the instance's config file that are specific
+	// to instances (not a part of SettingsBase). Settings are things overridden
+	// from SettingsBase.
+	
+	
+	////// Fields //////
+	
+	//// General Info ////
+	
+	/*!
+	 * \brief Gets this instance's name.
+	 *        This is the name that will be displayed to the user.
+	 * \return The instance's name.
+	 * \sa setName
+	 */
+	virtual QString name() { return getField("name", "Unnamed Instance").value<QString>(); }
+	
+	/*!
+	 * \brief Sets the instance's name
+	 * \param val The instance's new name.
+	 */
+	virtual void setName(QString val) { setField("name", val); }
+	
+	/*!
+	 * \brief Gets the instance's icon key.
+	 * \return The instance's icon key.
+	 * \sa setIconKey()
+	 */
+	virtual QString iconKey() const { return getField("iconKey", "default").value<QString>(); }
+	
+	/*!
+	 * \brief Sets the instance's icon key.
+	 * \param val The new icon key.
+	 */
+	virtual void setIconKey(QString val) { setField("iconKey", val); }
+	
+	
+	/*!
+	 * \brief Gets the instance's notes.
+	 * \return The instances notes.
+	 */
+	virtual QString notes() const { return getField("notes", "").value<QString>(); }
+	
+	/*!
+	 * \brief Sets the instance's notes.
+	 * \param val The instance's new notes.
+	 */
+	virtual void setNotes(QString val) { setField("notes", val); }
+	
+	
+	/*!
+	 * \brief Checks if	the instance's minecraft.jar needs to be rebuilt.
+	 *        If this is true, the instance's mods will be reinstalled to its
+	 *        minecraft.jar file. This value is automatically set to true when
+	 *        the jar mod list changes.
+	 * \return Whether or not the instance's jar file should be rebuilt.
+	 */
+	virtual bool shouldRebuild() const { return getField("NeedsRebuild", false).value<bool>(); }
+	
+	/*!
+	 * \brief Sets whether or not the instance's minecraft.jar needs to be rebuilt.
+	 * \param val Whether the instance's minecraft needs to be rebuilt or not.
+	 */
+	virtual void setShouldRebuild(bool val) { setField("NeedsRebuild", val); }
+	
+	
+	//// Version Stuff ////
+	
+	/*!
+	 * \brief Sets the instance's current version.
+	 *        This value represents the instance's current version. If this value
+	 *        is different from intendedVersion(), the instance should be updated.
+	 *        This value is updated by the updateCurrentVersion() function.
+	 * \return A string representing the instance's current version.
+	 */
+	virtual QString currentVersion() { return getField("JarVersion", "Unknown").value<QString>(); }
+	
+	/*!
+	 * \brief Sets the instance's current version.
+	 *        This is used to keep track of the instance's current version. Don't
+	 *        mess with this unless you know what you're doing.
+	 * \param val The new value.
+	 */
+	virtual void setCurrentVersion(QString val) { setField("JarVersion", val); }
+	
+	
+	/*!
+	 * \brief Gets the version of LWJGL that this instance should use.
+	 *        If no LWJGL version is specified in the instance's config file, 
+	 *        defaults to "Mojang"
+	 * \return The instance's LWJGL version.
+	 */
+	virtual QString lwjglVersion() { return getField("LwjglVersion", "Mojang").value<QString>(); }
+	
+	/*!
+	 * \brief Sets the version of LWJGL that this instance should use.
+	 * \param val The LWJGL version to use
+	 */
+	virtual void setLWJGLVersion(QString val) { setField("LwjglVersion", val); }
+	
+	
+	/*!
+	 * \brief Gets the version that this instance should try to update to.
+	 *        If this value differs from currentVersion(), the instance will
+	 *        download the intended version when it launches.
+	 * \return The instance's intended version.
+	 */
+	virtual QString intendedVersion() { return getField("IntendedJarVersion", currentVersion()).value<QString>(); }
+	
+	/*!
+	 * \brief Sets the version that this instance should try to update to.
+	 * \param val The instance's new intended version.
+	 */
+	virtual void setIntendedVersion(QString val) { setField("IntendedJarVersion", val); }
+	
+	
+	
+	//// Timestamps ////
+	
+	/*!
+	 * \brief Gets the time that the instance was last launched.
+	 *        Measured in milliseconds since epoch. QDateTime::currentMSecsSinceEpoch()
+	 * \return The time that the instance was last launched.
+	 */
+	virtual qint64 lastLaunch() { return getField("lastLaunchTime", 0).value<qint64>(); }
+	
+	/*!
+	 * \brief Sets the time that the instance was last launched.
+	 * \param val The time to set. Defaults to QDateTime::currentMSecsSinceEpoch()
+	 */
+	virtual void setLastLaunch(qint64 val = QDateTime::currentMSecsSinceEpoch()) 
+	{ setField("lastLaunchTime", val); }
+	
+	
+	////// Settings //////
+	
+	//// Java Settings ////
+	DEFINE_OVERRIDDEN_SETTING_ADVANCED(JavaPath, JPATHKEY, QString)
+	DEFINE_OVERRIDDEN_SETTING(JvmArgs, QString)
+	
+	//// Custom Commands ////
+	DEFINE_OVERRIDDEN_SETTING(PreLaunchCommand, QString)
+	DEFINE_OVERRIDDEN_SETTING(PostExitCommand, QString)
+	
+	//// Memory ////
+	DEFINE_OVERRIDDEN_SETTING(MinMemAlloc, int)
+	DEFINE_OVERRIDDEN_SETTING(MaxMemAlloc, int)
+	
+	//// Auto login ////
+	DEFINE_OVERRIDDEN_SETTING(AutoLogin, bool)
+	
+	// This little guy here is to keep Qt Creator from being a dumbass and 
+	// auto-indenting the lines below the macros. Seriously, it's really annoying.
+	;
+	
+	
+	//////// OTHER FUNCTIONS ////////
+	
+	//// Version System ////
+	
+	/*!
+	 * \brief Checks whether or not the currentVersion of the instance needs to be updated. 
+	 *        If this returns true, updateCurrentVersion is called. In the 
+	 *        standard instance, this is determined by checking a timestamp 
+	 *        stored in the instance config file against the last modified time of Minecraft.jar.
+	 * \return True if updateCurrentVersion() should be called.
+	 */
+	virtual bool shouldUpdateCurrentVersion() = 0;
+	
+	/*!
+	 * \brief Updates the current version. 
+	 *        This function should first set the current version timestamp 
+	 *        (setCurrentVersionTimestamp()) to the current time. Next, if 
+	 *        keepCurrent is false, this function should check what the 
+	 *        instance's current version is and call setCurrentVersion() to 
+	 *        update it. This function will automatically be called when the 
+	 *        instance is loaded if shouldUpdateCurrentVersion returns true.
+	 * \param keepCurrent If true, only the version timestamp will be updated.
+	 */
+	virtual void updateCurrentVersion(bool keepCurrent = false) = 0; 
+	
+signals:
+	/*!
+	 * \brief Signal emitted when the instance's group changes.
+	 * \param inst Pointer to the instance whose group changed.
+	 * \param newGroup The instance's new group.
+	 */
+	void groupChanged(Instance *inst, QString newGroup);
+	
+protected:
+	/*!
+	 * \brief Gets the value of the given field in the instance's config file.
+	 *        If the value isn't in the config file, defVal is returned instead.
+	 * \param name The name of the field in the config file.
+	 * \param defVal The default value.
+	 * \return The value of the given field or defVal if the field doesn't exist.
+	 * \sa setField()
+	 */
+	virtual QVariant getField(const QString &name, QVariant defVal = QVariant()) const;
+	
+	/*!
+	 * \brief Sets the value of the given field in the config file.
+	 * \param name The name of the field in the config file.
+	 * \param val The value to set the field to.
+	 * \sa getField()
+	 */
+	virtual void setField(const QString &name, QVariant val);
+	
+	// Overrides for SettingBase stuff.
+	virtual QVariant getValue(const QString &name, QVariant defVal = QVariant()) const
+	{ return settings->getValue(name, defVal); }
+	virtual void setValue(const QString &name, QVariant val)
+	{ setField(name, val); }
+	
+	INIFile config;
+	
+private:
+	QString m_group;
+};
+
+#endif // INSTANCE_H
diff --git a/data/stdinstance.h b/data/inst/instancelist.cpp
index 79b87601..62367ed6 100644
--- a/data/stdinstance.h
+++ b/data/inst/instancelist.cpp
@@ -13,16 +13,11 @@
  * limitations under the License.
  */
 
-#ifndef STDINSTANCE_H
-#define STDINSTANCE_H
+#include "instancelist.h"
 
-#include "instancebase.h"
+#include "data/siglist_impl.h"
 
-// Standard client instance.
-class StdInstance : public InstanceBase
+InstanceList::InstanceList(QObject *parent) :
+	QObject(parent)
 {
-public:
-	explicit StdInstance(QString rootDir, QObject *parent = 0);
-};
-
-#endif // STDINSTANCE_H
+}
diff --git a/data/inst/instancelist.h b/data/inst/instancelist.h
new file mode 100644
index 00000000..72dec5f0
--- /dev/null
+++ b/data/inst/instancelist.h
@@ -0,0 +1,39 @@
+/* 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.
+ */
+
+#ifndef INSTANCELIST_H
+#define INSTANCELIST_H
+
+#include <QObject>
+
+#include <QSharedPointer>
+
+#include "data/siglist.h"
+
+class Instance;
+
+class InstanceList : public QObject, SigList<QSharedPointer<Instance>>
+{
+	Q_OBJECT
+public:
+	explicit InstanceList(QObject *parent = 0);
+	
+signals:
+	
+public slots:
+	
+};
+
+#endif // INSTANCELIST_H
diff --git a/data/instancebase.cpp b/data/instancebase.cpp
deleted file mode 100644
index a5ef35a2..00000000
--- a/data/instancebase.cpp
+++ /dev/null
@@ -1,109 +0,0 @@
-/* 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 "instancebase.h"
-
-#include <QFileInfo>
-#include <QDir>
-
-#include "../util/pathutils.h"
-
-InstanceBase::InstanceBase(QString dir, QObject *parent) :
-	QObject(parent), 
-	rootDir(dir)
-{
-	QFileInfo cfgFile(PathCombine(rootDir, "instance.cfg"));
-	
-	if (cfgFile.exists())
-	{
-		if(!config.loadFile(cfgFile.absoluteFilePath()))
-		{
-			QString debugmsg("Can't load instance config file for instance ");
-			debugmsg+= getInstID();
-			qDebug(debugmsg.toLocal8Bit());
-		}
-	}
-	else
-	{
-		QString debugmsg("Can't find instance config file for instance ");
-		debugmsg+= getInstID();
-		debugmsg += " : ";
-		debugmsg += 
-		debugmsg+=" ... is this an instance even?";
-		qDebug(debugmsg.toLocal8Bit());
-	}
-	currentGroup = nullptr;
-}
-
-QString InstanceBase::getRootDir() const
-{
-	return rootDir;
-}
-
-
-///////////// Config Values /////////////
-
-// Name
-QString InstanceBase::getInstName() const
-{
-	return config.get("name", "Unnamed").toString();
-}
-
-void InstanceBase::setInstName(QString name)
-{
-	config.set("name", name);
-}
-
-QString InstanceBase::getInstID() const
-{
-	return QDir(rootDir).dirName();
-}
-
-InstanceModelItem* InstanceBase::getParent() const
-{
-	return currentGroup;
-}
-
-QVariant InstanceBase::data ( int role ) const
-{
-	switch(role)
-	{
-		case Qt::DisplayRole:
-			return getInstName();
-		default:
-			return QVariant();
-	}
-}
-int InstanceBase::getRow() const
-{
-	return currentGroup->getIndexOf((InstanceBase*)this);
-}
-
-InstanceModelItem* InstanceBase::getChild ( int index ) const
-{
-	return nullptr;
-}
-InstanceModel* InstanceBase::getModel() const
-{
-	return currentGroup->getModel();
-}
-IMI_type InstanceBase::getModelItemType() const
-{
-	return IMI_Instance;
-}
-int InstanceBase::numChildren() const
-{
-	return 0;
-}
diff --git a/data/instancebase.h b/data/instancebase.h
deleted file mode 100644
index fa043c5f..00000000
--- a/data/instancebase.h
+++ /dev/null
@@ -1,58 +0,0 @@
-/* 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.
- */
-
-#ifndef INSTANCEBASE_H
-#define INSTANCEBASE_H
-
-#include <QObject>
-#include <QString>
-
-#include "../data/inifile.h"
-#include "instancemodel.h"
-
-class InstanceBase : public QObject, public InstanceModelItem
-{
-	friend class InstanceGroup;
-	Q_OBJECT
-public:
-	explicit InstanceBase(QString rootDir, QObject *parent = 0);
-	
-	QString getRootDir() const;
-	
-	QString getInstName() const;
-	void setInstName(QString name);
-	
-	QString getInstID() const;
-	
-	virtual IMI_type getModelItemType() const;
-	virtual InstanceModelItem* getParent() const;
-	virtual int numChildren() const;
-	virtual InstanceModelItem* getChild ( int index ) const;
-	virtual InstanceModel* getModel() const;
-	virtual QVariant data ( int column ) const;
-	virtual int getRow() const;
-	
-private:
-	void setGroup ( InstanceGroup* group )
-	{
-		currentGroup = group;
-	};
-	
-	QString rootDir;
-	INIFile config;
-	InstanceGroup * currentGroup;
-};
-
-#endif // INSTANCEBASE_H
diff --git a/data/instancemodel.h b/data/instancemodel.h
index 4bd34831..9678fef0 100644
--- a/data/instancemodel.h
+++ b/data/instancemodel.h
@@ -13,8 +13,8 @@
  * limitations under the License.
  */
 
-#ifndef INSTANCELIST_H
-#define INSTANCELIST_H
+#ifndef INSTANCEMODEL_H
+#define INSTANCEMODEL_H
 
 #include <QList>
 #include <QMap>
@@ -134,4 +134,4 @@ private:
 	InstanceGroup * implicitGroup;
 };
 
-#endif // INSTANCELIST_H
+#endif // INSTANCEMODEL_H
diff --git a/data/siglist_imp.h b/data/siglist_impl.h
index 16ddd9b0..16ddd9b0 100644
--- a/data/siglist_imp.h
+++ b/data/siglist_impl.h
diff --git a/data/version/instversion.cpp b/data/version/instversion.cpp
new file mode 100644
index 00000000..1493153a
--- /dev/null
+++ b/data/version/instversion.cpp
@@ -0,0 +1,32 @@
+/* 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 "instversion.h"
+#include "instversionlist.h"
+
+InstVersion::InstVersion(InstVersionList *parent) :
+	QObject(parent)
+{
+	
+}
+
+InstVersionList *InstVersion::versionList() const
+{
+	// Parent should *always* be an InstVersionList
+	if (!parent() || !parent()->inherits("InstVersionList"))
+		return NULL;
+	else
+		return (InstVersionList *)parent();
+}
diff --git a/data/version/instversion.h b/data/version/instversion.h
new file mode 100644
index 00000000..361563fd
--- /dev/null
+++ b/data/version/instversion.h
@@ -0,0 +1,51 @@
+/* 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.
+ */
+
+#ifndef INSTVERSION_H
+#define INSTVERSION_H
+
+#include <QObject>
+
+class InstVersionList;
+
+class InstVersion : public QObject
+{
+	Q_OBJECT
+public:
+	// Constructs a new InstVersion with the given parent. The parent *must*
+	// be the InstVersionList that contains this InstVersion. The InstVersion
+	// should be added to the list immediately after being created as any calls
+	// to id() will likely fail unless the InstVersion is in a list.
+	explicit InstVersion(InstVersionList *parent = 0);
+	
+	// Returns this InstVersion's ID. This is usually just the InstVersion's index
+	// within its InstVersionList, but not always.
+	// If this InstVersion is not in an InstVersionList, returns -1.
+	virtual int id() const = 0;
+	
+	// Returns this InstVersion's name. This is displayed to the user in the GUI
+	// and is usually just the version number ("1.4.7"), for example.
+	virtual QString name() const = 0;
+	
+	// Returns this InstVersion's name. This is usually displayed to the user 
+	// in the GUI and specifies what kind of version this is. For example: it 
+	// could be "Snapshot", "Latest Version", "MCNostalgia", etc.
+	virtual QString type() const = 0;
+	
+	// Returns the version list that this InstVersion is a part of.
+	virtual InstVersionList *versionList() const;
+};
+
+#endif // INSTVERSION_H
diff --git a/data/version/instversionlist.cpp b/data/version/instversionlist.cpp
new file mode 100644
index 00000000..ab57f94c
--- /dev/null
+++ b/data/version/instversionlist.cpp
@@ -0,0 +1,21 @@
+/* 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 "instversionlist.h"
+
+InstVersionList::InstVersionList() :
+	QObject(NULL)
+{
+}
diff --git a/data/version/instversionlist.h b/data/version/instversionlist.h
new file mode 100644
index 00000000..f79bc1b0
--- /dev/null
+++ b/data/version/instversionlist.h
@@ -0,0 +1,43 @@
+/* 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.
+ */
+
+#ifndef INSTVERSIONLIST_H
+#define INSTVERSIONLIST_H
+
+#include <QObject>
+
+class InstVersion;
+
+// Class that each instance type's version list derives from. Version lists are 
+// the lists that keep track of the available game versions for that instance. 
+// This list will not be loaded on startup. It will be loaded when the list's 
+// load function is called.
+class InstVersionList : public QObject
+{
+	Q_OBJECT
+public:
+	explicit InstVersionList();
+	
+	// Reloads the version list.
+	virtual void loadVersionList() = 0;
+	
+	// Gets the version at the given index.
+	virtual const InstVersion *at(int i) const = 0;
+	
+	// Returns the number of versions in the list.
+	virtual int count() const = 0;
+};
+
+#endif // INSTVERSIONLIST_H