Add 'meshmc/' from commit 'fad6a1066616b69d7f5fef01178efdf014c59537'

git-subtree-dir: meshmc
git-subtree-mainline: 934382c8a1ce738589dee9ee0f14e1cec812770e
git-subtree-split: fad6a1066616b69d7f5fef01178efdf014c59537

1 files changed, 172 insertions, 0 deletions

diff --git a/meshmc/launcher/minecraft/legacy/LegacyInstance.h b/meshmc/launcher/minecraft/legacy/LegacyInstance.h
new file mode 100644
index 0000000000..6edcee96db
--- /dev/null
+++ b/meshmc/launcher/minecraft/legacy/LegacyInstance.h
@@ -0,0 +1,172 @@
+/* SPDX-FileCopyrightText: 2026 Project Tick
+ * SPDX-FileContributor: Project Tick
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ *   MeshMC - A Custom Launcher for Minecraft
+ *   Copyright (C) 2026 Project Tick
+ *
+ *   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 3 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, see <https://www.gnu.org/licenses/>.
+ *
+ *  This file incorporates work covered by the following copyright and
+ *  permission notice:
+ *
+ * Copyright 2013-2021 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.
+ */
+
+#pragma once
+
+#include "BaseInstance.h"
+#include "launch/LaunchTask.h"
+
+class ModFolderModel;
+class LegacyModList;
+class WorldList;
+class Task;
+/*
+ * WHY: Legacy instances - from MultiMC 3 and 4 - are here only to provide a way
+ * to upgrade them to the current format.
+ */
+class LegacyInstance : public BaseInstance
+{
+	Q_OBJECT
+  public:
+	explicit LegacyInstance(SettingsObjectPtr globalSettings,
+							SettingsObjectPtr settings, const QString& rootDir);
+
+	virtual void saveNow() override {}
+
+	/// Path to the instance's minecraft.jar
+	QString runnableJar() const;
+
+	//! Path to the instance's modlist file.
+	QString modListFile() const;
+
+	////// Directories //////
+	QString libDir() const;
+	QString savesDir() const;
+	QString texturePacksDir() const;
+	QString jarModsDir() const;
+	QString coreModsDir() const;
+	QString resourceDir() const;
+
+	QString instanceConfigFolder() const override;
+
+	QString
+	gameRoot() const override; // Path to the instance's minecraft directory.
+	QString
+	modsRoot() const override; // Path to the instance's minecraft directory.
+	QString binRoot() const; // Path to the instance's minecraft bin directory.
+
+	/// Get the curent base jar of this instance. By default, it's the
+	/// versions/$version/$version.jar
+	QString baseJar() const;
+
+	/// the default base jar of this instance
+	QString defaultBaseJar() const;
+	/// the default custom base jar of this instance
+	QString defaultCustomBaseJar() const;
+
+	// the main jar that we actually want to keep when migrating the instance
+	QString mainJarToPreserve() const;
+
+	/*!
+	 * Whether or not custom base jar is used
+	 */
+	bool shouldUseCustomBaseJar() const;
+
+	/*!
+	 * The value of the custom base jar
+	 */
+	QString customBaseJar() const;
+
+	std::shared_ptr<LegacyModList> jarModList() const;
+	std::shared_ptr<WorldList> worldList() const;
+
+	/*!
+	 * Whether or not the instance's minecraft.jar needs to be rebuilt.
+	 * If this is true, when the instance launches, its jar mods will be
+	 * re-added to a fresh minecraft.jar file.
+	 */
+	bool shouldRebuild() const;
+
+	QString currentVersionId() const;
+	QString intendedVersionId() const;
+
+	QSet<QString> traits() const override
+	{
+		return {"legacy-instance", "texturepacks"};
+	};
+
+	virtual bool shouldUpdate() const;
+	virtual Task::Ptr createUpdateTask(Net::Mode mode) override;
+
+	virtual QString typeName() const override;
+
+	bool canLaunch() const override
+	{
+		return false;
+	}
+	bool canEdit() const override
+	{
+		return true;
+	}
+	bool canExport() const override
+	{
+		return false;
+	}
+	shared_qobject_ptr<LaunchTask>
+	createLaunchTask(AuthSessionPtr account,
+					 MinecraftServerTargetPtr serverToJoin) override
+	{
+		return nullptr;
+	}
+	IPathMatcher::Ptr getLogFileMatcher() override
+	{
+		return nullptr;
+	}
+	QString getLogFileRoot() override
+	{
+		return gameRoot();
+	}
+
+	QString getStatusbarDescription() override;
+	QStringList
+	verboseDescription(AuthSessionPtr session,
+					   MinecraftServerTargetPtr serverToJoin) override;
+
+	QProcessEnvironment createEnvironment() override
+	{
+		return QProcessEnvironment();
+	}
+	QMap<QString, QString> getVariables() const override
+	{
+		return {};
+	}
+
+  protected:
+	mutable std::shared_ptr<LegacyModList> jar_mod_list;
+	mutable std::shared_ptr<WorldList> m_world_list;
+};