NOISSUE implement direct java launch

Just running the Java process and giving it params on the command line

16 files changed, 888 insertions, 189 deletions

diff --git a/api/logic/minecraft/MinecraftInstance.cpp b/api/logic/minecraft/MinecraftInstance.cpp
index 405ccd26..8cc4f805 100644
--- a/api/logic/minecraft/MinecraftInstance.cpp
+++ b/api/logic/minecraft/MinecraftInstance.cpp
@@ -1,4 +1,6 @@
 #include "MinecraftInstance.h"
+#include <minecraft/launch/ExtractNatives.h>
+#include <minecraft/launch/PrintInstanceInfo.h>
 #include <settings/Setting.h>
 #include "settings/SettingsObject.h"
 #include "Env.h"
@@ -9,6 +11,15 @@
 #include <FileSystem.h>
 #include <java/JavaVersion.h>
 
+#include "launch/LaunchTask.h"
+#include "launch/steps/PostLaunchCommand.h"
+#include "launch/steps/Update.h"
+#include "launch/steps/PreLaunchCommand.h"
+#include "launch/steps/TextPrint.h"
+#include "minecraft/launch/LauncherPartLaunch.h"
+#include "minecraft/launch/ModMinecraftJar.h"
+#include "java/launch/CheckJava.h"
+
 #define IBUS "@im=ibus"
 
 // all of this because keeping things compatible with deprecated old settings
@@ -52,6 +63,7 @@ MinecraftInstance::MinecraftInstance(SettingsObjectPtr globalSettings, SettingsO
 	// special!
 	m_settings->registerPassthrough(globalSettings->getSetting("JavaTimestamp"), javaOrLocation);
 	m_settings->registerPassthrough(globalSettings->getSetting("JavaVersion"), javaOrLocation);
+	m_settings->registerPassthrough(globalSettings->getSetting("JavaArchitecture"), javaOrLocation);
 
 	// Window Size
 	auto windowSetting = m_settings->registerSetting("OverrideWindow", false);
@@ -64,6 +76,10 @@ MinecraftInstance::MinecraftInstance(SettingsObjectPtr globalSettings, SettingsO
 	m_settings->registerOverride(globalSettings->getSetting("MinMemAlloc"), memorySetting);
 	m_settings->registerOverride(globalSettings->getSetting("MaxMemAlloc"), memorySetting);
 	m_settings->registerOverride(globalSettings->getSetting("PermGen"), memorySetting);
+
+	// Minecraft launch method
+	auto launchMethodOverride = m_settings->registerSetting("OverrideMCLaunchMethod", false);
+	m_settings->registerOverride(globalSettings->getSetting("MCLaunchMethod"), launchMethodOverride);
 }
 
 QString MinecraftInstance::minecraftRoot() const
@@ -105,7 +121,7 @@ QStringList MinecraftInstance::javaArguments() const
 	args << QString("-Xmx%1m").arg(settings()->get("MaxMemAlloc").toInt());
 
 	// No PermGen in newer java.
-	JavaVersion javaVersion(settings()->get("JavaVersion").toString());
+	JavaVersion javaVersion = getJavaVersion();
 	if(javaVersion.requiresPermGen())
 	{
 		auto permgen = settings()->get("PermGen").toInt();
@@ -116,7 +132,6 @@ QStringList MinecraftInstance::javaArguments() const
 	}
 
 	args << "-Duser.language=en";
-	args << "-jar" << FS::PathCombine(QCoreApplication::applicationDirPath(), "jars", "NewLaunch.jar");
 
 	return args;
 }
@@ -366,4 +381,95 @@ QString MinecraftInstance::getStatusbarDescription()
 	return description;
 }
 
+std::shared_ptr<LaunchTask> MinecraftInstance::createLaunchTask(AuthSessionPtr session)
+{
+	auto process = LaunchTask::create(std::dynamic_pointer_cast<MinecraftInstance>(getSharedPtr()));
+	auto pptr = process.get();
+
+	// print a header
+	{
+		process->appendStep(std::make_shared<TextPrint>(pptr, "Minecraft folder is:\n" + minecraftRoot() + "\n\n", MessageLevel::MultiMC));
+	}
+
+	// check java
+	{
+		auto step = std::make_shared<CheckJava>(pptr);
+		process->appendStep(step);
+	}
+
+	// check launch method
+	QStringList validMethods = validLaunchMethods();
+	QString method = launchMethod();
+	if(!validMethods.contains(method))
+	{
+		process->appendStep(std::make_shared<TextPrint>(pptr, "Selected launch method \"" + method + "\" is not valid.\n", MessageLevel::Fatal));
+		return process;
+	}
+
+	// run pre-launch command if that's needed
+	if(getPreLaunchCommand().size())
+	{
+		auto step = std::make_shared<PreLaunchCommand>(pptr);
+		step->setWorkingDirectory(minecraftRoot());
+		process->appendStep(step);
+	}
+
+	// if we aren't in offline mode,.
+	if(session->status != AuthSession::PlayableOffline)
+	{
+		process->appendStep(std::make_shared<Update>(pptr));
+	}
+
+	// if there are any jar mods
+	if(getJarMods().size())
+	{
+		auto step = std::make_shared<ModMinecraftJar>(pptr);
+		process->appendStep(step);
+	}
+
+	// print some instance info here...
+	{
+		auto step = std::make_shared<PrintInstanceInfo>(pptr, session);
+		process->appendStep(step);
+	}
+
+	// extract native jars if needed
+	auto jars = getNativeJars();
+	if(jars.size())
+	{
+		auto step = std::make_shared<ExtractNatives>(pptr);
+		process->appendStep(step);
+	}
+
+	{
+		// actually launch the game
+		auto step = createMainLaunchStep(pptr, session);
+		process->appendStep(step);
+	}
+
+	// run post-exit command if that's needed
+	if(getPostExitCommand().size())
+	{
+		auto step = std::make_shared<PostLaunchCommand>(pptr);
+		step->setWorkingDirectory(minecraftRoot());
+		process->appendStep(step);
+	}
+	if (session)
+	{
+		process->setCensorFilter(createCensorFilterFromSession(session));
+	}
+	return process;
+}
+
+QString MinecraftInstance::launchMethod()
+{
+	return m_settings->get("MCLaunchMethod").toString();
+}
+
+JavaVersion MinecraftInstance::getJavaVersion() const
+{
+	return JavaVersion(settings()->get("JavaVersion").toString());
+}
+
+
 #include "MinecraftInstance.moc"
diff --git a/api/logic/minecraft/MinecraftInstance.h b/api/logic/minecraft/MinecraftInstance.h
index cd3a8d90..3aef2969 100644
--- a/api/logic/minecraft/MinecraftInstance.h
+++ b/api/logic/minecraft/MinecraftInstance.h
@@ -1,5 +1,6 @@
 #pragma once
 #include "BaseInstance.h"
+#include <java/JavaVersion.h>
 #include "minecraft/Mod.h"
 #include <QProcess>
 
@@ -7,6 +8,7 @@
 
 class ModList;
 class WorldList;
+class LaunchStep;
 
 class MULTIMC_LOGIC_EXPORT MinecraftInstance: public BaseInstance
 {
@@ -36,7 +38,7 @@ public:
 		return QList<Mod>();
 	}
 
-	/// get the launch script to be used with this 
+	virtual std::shared_ptr<LaunchTask> createLaunchTask(AuthSessionPtr account) override;
 	virtual QString createLaunchScript(AuthSessionPtr session) = 0;
 
 	//FIXME: nuke?
@@ -60,8 +62,22 @@ public:
 
 	virtual QString getStatusbarDescription() override;
 
+	virtual QStringList getClassPath() const = 0;
+	virtual QStringList getNativeJars() const = 0;
+
+	virtual QString getMainClass() const = 0;
+
+	virtual QString getNativePath() const = 0;
+
+	virtual QStringList processMinecraftArgs(AuthSessionPtr account) const = 0;
+
+	virtual JavaVersion getJavaVersion() const;
+
 protected:
 	QMap<QString, QString> createCensorFilterFromSession(AuthSessionPtr session);
+	virtual QStringList validLaunchMethods() = 0;
+	virtual QString launchMethod();
+	virtual std::shared_ptr<LaunchStep> createMainLaunchStep(LaunchTask *parent, AuthSessionPtr session) = 0;
 private:
 	QString prettifyTimeDuration(int64_t duration);
 };
diff --git a/api/logic/minecraft/MinecraftProfile.cpp b/api/logic/minecraft/MinecraftProfile.cpp
index 70d0cee4..19127a54 100644
--- a/api/logic/minecraft/MinecraftProfile.cpp
+++ b/api/logic/minecraft/MinecraftProfile.cpp
@@ -573,6 +573,26 @@ const QList<LibraryPtr> & MinecraftProfile::getLibraries() const
 	return m_libraries;
 }
 
+void MinecraftProfile::getLibraryFiles(const QString& architecture, QStringList& jars, QStringList& nativeJars) const
+{
+	QStringList native32, native64;
+	jars.clear();
+	nativeJars.clear();
+	for (auto lib : getLibraries())
+	{
+		lib->getApplicableFiles(currentSystem, jars, nativeJars, native32, native64);
+	}
+	if(architecture == "32")
+	{
+		nativeJars.append(native32);
+	}
+	else if(architecture == "64")
+	{
+		nativeJars.append(native64);
+	}
+}
+
+
 QString MinecraftProfile::getMainJarUrl() const
 {
 	auto iter = mojangDownloads.find("client");
diff --git a/api/logic/minecraft/MinecraftProfile.h b/api/logic/minecraft/MinecraftProfile.h
index ca9288ad..cc9b89b1 100644
--- a/api/logic/minecraft/MinecraftProfile.h
+++ b/api/logic/minecraft/MinecraftProfile.h
@@ -110,6 +110,7 @@ public: /* getters for profile variables */
 	const QStringList & getTweakers() const;
 	const QList<JarmodPtr> & getJarMods() const;
 	const QList<LibraryPtr> & getLibraries() const;
+	void getLibraryFiles(const QString & architecture, QStringList & jars, QStringList & nativeJars) const;
 	QString getMainJarUrl() const;
 	bool hasTrait(const QString & trait) const;
 	ProblemSeverity getProblemSeverity() const;
diff --git a/api/logic/minecraft/launch/DirectJavaLaunch.cpp b/api/logic/minecraft/launch/DirectJavaLaunch.cpp
new file mode 100644
index 00000000..c46cdcd4
--- /dev/null
+++ b/api/logic/minecraft/launch/DirectJavaLaunch.cpp
@@ -0,0 +1,149 @@
+/* Copyright 2013-2015 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 "DirectJavaLaunch.h"
+#include <launch/LaunchTask.h>
+#include <minecraft/MinecraftInstance.h>
+#include <FileSystem.h>
+#include <QStandardPaths>
+
+DirectJavaLaunch::DirectJavaLaunch(LaunchTask *parent) : LaunchStep(parent)
+{
+	connect(&m_process, &LoggedProcess::log, this, &DirectJavaLaunch::logLines);
+	connect(&m_process, &LoggedProcess::stateChanged, this, &DirectJavaLaunch::on_state);
+}
+
+void DirectJavaLaunch::executeTask()
+{
+	auto instance = m_parent->instance();
+	std::shared_ptr<MinecraftInstance> minecraftInstance = std::dynamic_pointer_cast<MinecraftInstance>(instance);
+	QStringList args = minecraftInstance->javaArguments();
+
+	// HACK: this is a workaround for MCL-3732 - 'server-resource-packs' is created.
+	if(!FS::ensureFolderPathExists(FS::PathCombine(minecraftInstance->minecraftRoot(), "server-resource-packs")))
+	{
+		emit logLine(tr("Couldn't create the 'server-resource-packs' folder"), MessageLevel::Error);
+	}
+
+	args.append("-Djava.library.path=" + minecraftInstance->getNativePath());
+
+	auto classPathEntries = minecraftInstance->getClassPath();
+	args.append("-cp");
+	QString classpath;
+#ifdef Q_OS_WIN32
+	classpath = classPathEntries.join(';');
+#else
+	classpath = classPathEntries.join(':');
+#endif
+	args.append(classpath);
+	args.append(minecraftInstance->getMainClass());
+
+	QString allArgs = args.join(", ");
+	emit logLine("Java Arguments:\n[" + m_parent->censorPrivateInfo(allArgs) + "]\n\n", MessageLevel::MultiMC);
+
+	auto javaPath = FS::ResolveExecutable(instance->settings()->get("JavaPath").toString());
+
+	m_process.setProcessEnvironment(instance->createEnvironment());
+
+	auto mcArgs = minecraftInstance->processMinecraftArgs(m_session);
+	args.append(mcArgs);
+
+	QString wrapperCommand = instance->getWrapperCommand();
+	if(!wrapperCommand.isEmpty())
+	{
+		auto realWrapperCommand = QStandardPaths::findExecutable(wrapperCommand);
+		if (realWrapperCommand.isEmpty())
+		{
+			QString reason = tr("The wrapper command \"%1\" couldn't be found.").arg(wrapperCommand);
+			emit logLine(reason, MessageLevel::Fatal);
+			emitFailed(reason);
+			return;
+		}
+		emit logLine("Wrapper command is:\n" + wrapperCommand + "\n\n", MessageLevel::MultiMC);
+		args.prepend(javaPath);
+		m_process.start(wrapperCommand, args);
+	}
+	else
+	{
+		m_process.start(javaPath, args);
+	}
+}
+
+void DirectJavaLaunch::on_state(LoggedProcess::State state)
+{
+	switch(state)
+	{
+		case LoggedProcess::FailedToStart:
+		{
+			//: Error message displayed if instace can't start
+			QString reason = tr("Could not launch minecraft!");
+			emit logLine(reason, MessageLevel::Fatal);
+			emitFailed(reason);
+			return;
+		}
+		case LoggedProcess::Aborted:
+		case LoggedProcess::Crashed:
+
+		{
+			m_parent->setPid(-1);
+			emitFailed("Game crashed.");
+			return;
+		}
+		case LoggedProcess::Finished:
+		{
+			m_parent->setPid(-1);
+			// if the exit code wasn't 0, report this as a crash
+			auto exitCode = m_process.exitCode();
+			if(exitCode != 0)
+			{
+				emitFailed("Game crashed.");
+				return;
+			}
+			//FIXME: make this work again
+			// m_postlaunchprocess.processEnvironment().insert("INST_EXITCODE", QString(exitCode));
+			// run post-exit
+			emitSucceeded();
+			break;
+		}
+		case LoggedProcess::Running:
+			emit logLine(tr("Minecraft process ID: %1\n\n").arg(m_process.processId()), MessageLevel::MultiMC);
+			m_parent->setPid(m_process.processId());
+			m_parent->instance()->setLastLaunch();
+			break;
+		default:
+			break;
+	}
+}
+
+void DirectJavaLaunch::setWorkingDirectory(const QString &wd)
+{
+	m_process.setWorkingDirectory(wd);
+}
+
+void DirectJavaLaunch::proceed()
+{
+	// nil
+}
+
+bool DirectJavaLaunch::abort()
+{
+	auto state = m_process.state();
+	if (state == LoggedProcess::Running || state == LoggedProcess::Starting)
+	{
+		m_process.kill();
+	}
+	return true;
+}
+
diff --git a/api/logic/minecraft/launch/DirectJavaLaunch.h b/api/logic/minecraft/launch/DirectJavaLaunch.h
new file mode 100644
index 00000000..0e3d66cc
--- /dev/null
+++ b/api/logic/minecraft/launch/DirectJavaLaunch.h
@@ -0,0 +1,47 @@
+/* Copyright 2013-2015 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 <launch/LaunchStep.h>
+#include <launch/LoggedProcess.h>
+#include <minecraft/auth/AuthSession.h>
+
+class DirectJavaLaunch: public LaunchStep
+{
+	Q_OBJECT
+public:
+	explicit DirectJavaLaunch(LaunchTask *parent);
+	virtual void executeTask();
+	virtual bool abort();
+	virtual void proceed();
+	virtual bool canAbort() const
+	{
+		return true;
+	}
+	void setWorkingDirectory(const QString &wd);
+	void setAuthSession(AuthSessionPtr session)
+	{
+		m_session = session;
+	}
+private slots:
+	void on_state(LoggedProcess::State state);
+
+private:
+	LoggedProcess m_process;
+	QString m_command;
+	AuthSessionPtr m_session;
+};
+
diff --git a/api/logic/minecraft/launch/ExtractNatives.cpp b/api/logic/minecraft/launch/ExtractNatives.cpp
new file mode 100644
index 00000000..089e2559
--- /dev/null
+++ b/api/logic/minecraft/launch/ExtractNatives.cpp
@@ -0,0 +1,86 @@
+/* Copyright 2013-2016 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 "ExtractNatives.h"
+#include <minecraft/MinecraftInstance.h>
+#include <launch/LaunchTask.h>
+
+#include <quazip.h>
+#include <JlCompress.h>
+#include <quazipdir.h>
+#include "MMCZip.h"
+#include "FileSystem.h"
+#include <QDir>
+
+static QString replaceSuffix (QString target, const QString &suffix, const QString &replacement)
+{
+	if (!target.endsWith(suffix))
+	{
+		return target;
+	}
+	target.resize(target.length() - suffix.length());
+	return target + replacement;
+}
+
+static bool unzipNatives(QString source, QString targetFolder, bool applyJnilibHack)
+{
+	QuaZip zip(source);
+	if(!zip.open(QuaZip::mdUnzip))
+	{
+		return false;
+	}
+	QDir directory(targetFolder);
+	if (!zip.goToFirstFile())
+	{
+		return false;
+	}
+	do
+	{
+		QString name = zip.getCurrentFileName();
+		if(applyJnilibHack)
+		{
+			name = replaceSuffix(name, ".jnilib", ".dylib");
+		}
+		QString absFilePath = directory.absoluteFilePath(name);
+		if (!MMCZip::extractFile(&zip, "", absFilePath))
+		{
+			return false;
+		}
+	} while (zip.goToNextFile());
+	zip.close();
+	if(zip.getZipError()!=0)
+	{
+		return false;
+	}
+	return true;
+}
+
+void ExtractNatives::executeTask()
+{
+	auto instance = m_parent->instance();
+	std::shared_ptr<MinecraftInstance> minecraftInstance = std::dynamic_pointer_cast<MinecraftInstance>(instance);
+	auto outputPath  = minecraftInstance->getNativePath();
+	auto toExtract = minecraftInstance->getNativeJars();
+	auto javaVersion = minecraftInstance->getJavaVersion();
+	bool jniHackEnabled = javaVersion.major() >= 8;
+	for(const auto &source: toExtract)
+	{
+		if(!unzipNatives(source, outputPath, jniHackEnabled))
+		{
+			emitFailed(tr("Couldn't extract native jar '%1' to destination '%2'").arg(source, outputPath));
+		}
+	}
+	emitSucceeded();
+}
diff --git a/api/logic/minecraft/launch/ExtractNatives.h b/api/logic/minecraft/launch/ExtractNatives.h
new file mode 100644
index 00000000..699657d7
--- /dev/null
+++ b/api/logic/minecraft/launch/ExtractNatives.h
@@ -0,0 +1,37 @@
+/* Copyright 2013-2016 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 <launch/LaunchStep.h>
+#include <memory>
+#include "minecraft/auth/AuthSession.h"
+
+// FIXME: temporary wrapper for existing task.
+class ExtractNatives: public LaunchStep
+{
+	Q_OBJECT
+public:
+	explicit ExtractNatives(LaunchTask *parent) : LaunchStep(parent){};
+	virtual ~ExtractNatives(){};
+
+	virtual void executeTask();
+	virtual bool canAbort() const
+	{
+		return false;
+	}
+};
+
+
diff --git a/api/logic/minecraft/launch/LaunchMinecraft.cpp b/api/logic/minecraft/launch/LauncherPartLaunch.cpp
index 9b8cc0fb..5f233700 100644
--- a/api/logic/minecraft/launch/LaunchMinecraft.cpp
+++ b/api/logic/minecraft/launch/LauncherPartLaunch.cpp
@@ -13,25 +13,25 @@
  * limitations under the License.
  */
 
-#include "LaunchMinecraft.h"
+#include "LauncherPartLaunch.h"
+#include <QCoreApplication>
 #include <launch/LaunchTask.h>
 #include <minecraft/MinecraftInstance.h>
 #include <FileSystem.h>
 #include <QStandardPaths>
 
-LaunchMinecraft::LaunchMinecraft(LaunchTask *parent) : LaunchStep(parent)
+LauncherPartLaunch::LauncherPartLaunch(LaunchTask *parent) : LaunchStep(parent)
 {
-	connect(&m_process, &LoggedProcess::log, this, &LaunchMinecraft::logLines);
-	connect(&m_process, &LoggedProcess::stateChanged, this, &LaunchMinecraft::on_state);
+	connect(&m_process, &LoggedProcess::log, this, &LauncherPartLaunch::logLines);
+	connect(&m_process, &LoggedProcess::stateChanged, this, &LauncherPartLaunch::on_state);
 }
 
-void LaunchMinecraft::executeTask()
+void LauncherPartLaunch::executeTask()
 {
 	auto instance = m_parent->instance();
 	std::shared_ptr<MinecraftInstance> minecraftInstance = std::dynamic_pointer_cast<MinecraftInstance>(instance);
 
 	m_launchScript = minecraftInstance->createLaunchScript(m_session);
-
 	QStringList args = minecraftInstance->javaArguments();
 
 	// HACK: this is a workaround for MCL-3732 - 'server-resource-packs' is created.
@@ -47,6 +47,8 @@ void LaunchMinecraft::executeTask()
 
 	m_process.setProcessEnvironment(instance->createEnvironment());
 
+	args << "-jar" << FS::PathCombine(QCoreApplication::applicationDirPath(), "jars", "NewLaunch.jar");
+
 	QString wrapperCommand = instance->getWrapperCommand();
 	if(!wrapperCommand.isEmpty())
 	{
@@ -68,7 +70,7 @@ void LaunchMinecraft::executeTask()
 	}
 }
 
-void LaunchMinecraft::on_state(LoggedProcess::State state)
+void LauncherPartLaunch::on_state(LoggedProcess::State state)
 {
 	switch(state)
 	{
@@ -120,12 +122,12 @@ void LaunchMinecraft::on_state(LoggedProcess::State state)
 	}
 }
 
-void LaunchMinecraft::setWorkingDirectory(const QString &wd)
+void LauncherPartLaunch::setWorkingDirectory(const QString &wd)
 {
 	m_process.setWorkingDirectory(wd);
 }
 
-void LaunchMinecraft::proceed()
+void LauncherPartLaunch::proceed()
 {
 	if(mayProceed)
 	{
@@ -135,7 +137,7 @@ void LaunchMinecraft::proceed()
 	}
 }
 
-bool LaunchMinecraft::abort()
+bool LauncherPartLaunch::abort()
 {
 	if(mayProceed)
 	{
diff --git a/api/logic/minecraft/launch/LaunchMinecraft.h b/api/logic/minecraft/launch/LauncherPartLaunch.h
index 6b9f7919..209902e0 100644
--- a/api/logic/minecraft/launch/LaunchMinecraft.h
+++ b/api/logic/minecraft/launch/LauncherPartLaunch.h
@@ -19,11 +19,11 @@
 #include <launch/LoggedProcess.h>
 #include <minecraft/auth/AuthSession.h>
 
-class LaunchMinecraft: public LaunchStep
+class LauncherPartLaunch: public LaunchStep
 {
 	Q_OBJECT
 public:
-	explicit LaunchMinecraft(LaunchTask *parent);
+	explicit LauncherPartLaunch(LaunchTask *parent);
 	virtual void executeTask();
 	virtual bool abort();
 	virtual void proceed();
@@ -36,13 +36,14 @@ public:
 	{
 		m_session = session;
 	}
+
 private slots:
 	void on_state(LoggedProcess::State state);
 
 private:
 	LoggedProcess m_process;
 	QString m_command;
-	QString m_launchScript;
 	AuthSessionPtr m_session;
+	QString m_launchScript;
 	bool mayProceed = false;
 };
diff --git a/api/logic/minecraft/launch/PrintInstanceInfo.cpp b/api/logic/minecraft/launch/PrintInstanceInfo.cpp
new file mode 100644
index 00000000..b863eb98
--- /dev/null
+++ b/api/logic/minecraft/launch/PrintInstanceInfo.cpp
@@ -0,0 +1,25 @@
+/* Copyright 2013-2016 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 "PrintInstanceInfo.h"
+#include <launch/LaunchTask.h>
+
+void PrintInstanceInfo::executeTask()
+{
+	auto instance = m_parent->instance();
+	auto lines = instance->verboseDescription(m_session);
+	logLines(lines, MessageLevel::MultiMC);
+	emitSucceeded();
+}
diff --git a/api/logic/minecraft/launch/PrintInstanceInfo.h b/api/logic/minecraft/launch/PrintInstanceInfo.h
new file mode 100644
index 00000000..5dd2bdb3
--- /dev/null
+++ b/api/logic/minecraft/launch/PrintInstanceInfo.h
@@ -0,0 +1,38 @@
+/* Copyright 2013-2016 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 <launch/LaunchStep.h>
+#include <memory>
+#include "minecraft/auth/AuthSession.h"
+
+// FIXME: temporary wrapper for existing task.
+class PrintInstanceInfo: public LaunchStep
+{
+	Q_OBJECT
+public:
+	explicit PrintInstanceInfo(LaunchTask *parent, AuthSessionPtr session) : LaunchStep(parent), m_session(session) {};
+	virtual ~PrintInstanceInfo(){};
+
+	virtual void executeTask();
+	virtual bool canAbort() const
+	{
+		return false;
+	}
+private:
+	AuthSessionPtr m_session;
+};
+
diff --git a/api/logic/minecraft/legacy/LegacyInstance.cpp b/api/logic/minecraft/legacy/LegacyInstance.cpp
index 28fd8872..7c552369 100644
--- a/api/logic/minecraft/legacy/LegacyInstance.cpp
+++ b/api/logic/minecraft/legacy/LegacyInstance.cpp
@@ -14,6 +14,7 @@
  */
 
 #include <QFileInfo>
+#include <minecraft/launch/LauncherPartLaunch.h>
 #include <QDir>
 #include <settings/Setting.h>
 
@@ -21,14 +22,6 @@
 
 #include "minecraft/legacy/LegacyUpdate.h"
 #include "minecraft/legacy/LegacyModList.h"
-#include "launch/LaunchTask.h"
-#include <launch/steps/PostLaunchCommand.h>
-#include <launch/steps/Update.h>
-#include <launch/steps/PreLaunchCommand.h>
-#include <launch/steps/TextPrint.h>
-#include "minecraft/launch/LaunchMinecraft.h"
-#include "minecraft/launch/ModMinecraftJar.h"
-#include "java/launch/CheckJava.h"
 #include "minecraft/ModList.h"
 #include "minecraft/WorldList.h"
 #include <MMCZip.h>
@@ -102,58 +95,6 @@ std::shared_ptr<Task> LegacyInstance::createUpdateTask()
 	return std::shared_ptr<Task>(new LegacyUpdate(this, this));
 }
 
-std::shared_ptr<LaunchTask> LegacyInstance::createLaunchTask(AuthSessionPtr session)
-{
-	auto process = LaunchTask::create(std::dynamic_pointer_cast<MinecraftInstance>(getSharedPtr()));
-	auto pptr = process.get();
-
-	// print a header
-	{
-		process->appendStep(std::make_shared<TextPrint>(pptr, "Minecraft folder is:\n" + minecraftRoot() + "\n\n", MessageLevel::MultiMC));
-	}
-	{
-		auto step = std::make_shared<CheckJava>(pptr);
-		process->appendStep(step);
-	}
-	// run pre-launch command if that's needed
-	if(getPreLaunchCommand().size())
-	{
-		auto step = std::make_shared<PreLaunchCommand>(pptr);
-		step->setWorkingDirectory(minecraftRoot());
-		process->appendStep(step);
-	}
-	// if we aren't in offline mode,.
-	if(session->status != AuthSession::PlayableOffline)
-	{
-		process->appendStep(std::make_shared<Update>(pptr));
-	}
-	// if there are any jar mods
-	if(getJarMods().size())
-	{
-		auto step = std::make_shared<ModMinecraftJar>(pptr);
-		process->appendStep(step);
-	}
-	// actually launch the game
-	{
-		auto step = std::make_shared<LaunchMinecraft>(pptr);
-		step->setWorkingDirectory(minecraftRoot());
-		step->setAuthSession(session);
-		process->appendStep(step);
-	}
-	// run post-exit command if that's needed
-	if(getPostExitCommand().size())
-	{
-		auto step = std::make_shared<PostLaunchCommand>(pptr);
-		step->setWorkingDirectory(minecraftRoot());
-		process->appendStep(step);
-	}
-	if (session)
-	{
-		process->setCensorFilter(createCensorFilterFromSession(session));
-	}
-	return process;
-}
-
 std::shared_ptr<Task> LegacyInstance::createJarModdingTask()
 {
 	class JarModTask : public Task
@@ -255,11 +196,35 @@ QString LegacyInstance::createLaunchScript(AuthSessionPtr session)
 	launchScript += "sessionId " + session->session + "\n";
 	launchScript += "windowTitle " + windowTitle() + "\n";
 	launchScript += "windowParams " + windowParams + "\n";
-	launchScript += "lwjgl " + lwjgl + "\n";
-	launchScript += "launcher legacy\n";
+	launchScript += "cp bin/minecraft.jar\n";
+	launchScript += "cp " + lwjgl + "/lwjgl.jar\n";
+	launchScript += "cp " + lwjgl + "/lwjgl_util.jar\n";
+	launchScript += "cp " + lwjgl + "/jinput.jar\n";
+	launchScript += "natives " + lwjgl + "/natives\n";
+	launchScript += "traits legacyLaunch\n";
+	launchScript += "launcher onesix\n";
 	return launchScript;
 }
 
+std::shared_ptr<LaunchStep> LegacyInstance::createMainLaunchStep(LaunchTask * parent, AuthSessionPtr session)
+{
+	auto step = std::make_shared<LauncherPartLaunch>(parent);
+	step->setWorkingDirectory(minecraftRoot());
+	step->setAuthSession(session);
+	return step;
+}
+
+QString LegacyInstance::launchMethod()
+{
+	return "Legacy";
+}
+
+QStringList LegacyInstance::validLaunchMethods()
+{
+	return {"Legacy"};
+}
+
+
 void LegacyInstance::cleanupAfterRun()
 {
 	// FIXME: delete the launcher