NOISSUE split GUI stuff from logic library

22 files changed, 1556 insertions, 0 deletions

diff --git a/libraries/logic/launch/LaunchStep.cpp b/libraries/logic/launch/LaunchStep.cpp
new file mode 100644
index 00000000..3078043b
--- /dev/null
+++ b/libraries/logic/launch/LaunchStep.cpp
@@ -0,0 +1,27 @@
+/* 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 "LaunchStep.h"
+#include "LaunchTask.h"
+
+void LaunchStep::bind(LaunchTask *parent)
+{
+	m_parent = parent;
+	connect(this, &LaunchStep::readyForLaunch, parent, &LaunchTask::onReadyForLaunch);
+	connect(this, &LaunchStep::logLine, parent, &LaunchTask::onLogLine);
+	connect(this, &LaunchStep::logLines, parent, &LaunchTask::onLogLines);
+	connect(this, &LaunchStep::finished, parent, &LaunchTask::onStepFinished);
+	connect(this, &LaunchStep::progressReportingRequest, parent, &LaunchTask::onProgressReportingRequested);
+}
diff --git a/libraries/logic/launch/LaunchStep.h b/libraries/logic/launch/LaunchStep.h
new file mode 100644
index 00000000..ea472c0d
--- /dev/null
+++ b/libraries/logic/launch/LaunchStep.h
@@ -0,0 +1,48 @@
+/* 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 "tasks/Task.h"
+#include "MessageLevel.h"
+
+#include <QStringList>
+
+class LaunchTask;
+class LaunchStep: public Task
+{
+	Q_OBJECT
+public: /* methods */
+	explicit LaunchStep(LaunchTask *parent):Task(nullptr), m_parent(parent)
+	{
+		bind(parent);
+	};
+	virtual ~LaunchStep() {};
+
+protected: /* methods */
+	virtual void bind(LaunchTask *parent);
+
+signals:
+	void logLines(QStringList lines, MessageLevel::Enum level);
+	void logLine(QString line, MessageLevel::Enum level);
+	void readyForLaunch();
+	void progressReportingRequest();
+
+public slots:
+	virtual void proceed() {};
+
+protected: /* data */
+	LaunchTask *m_parent;
+};
\ No newline at end of file
diff --git a/libraries/logic/launch/LaunchTask.cpp b/libraries/logic/launch/LaunchTask.cpp
new file mode 100644
index 00000000..5b7ff182
--- /dev/null
+++ b/libraries/logic/launch/LaunchTask.cpp
@@ -0,0 +1,228 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Authors: Orochimarufan <orochimarufan.x3@gmail.com>
+ *
+ * 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 "launch/LaunchTask.h"
+#include "MessageLevel.h"
+#include "MMCStrings.h"
+#include "java/JavaChecker.h"
+#include "tasks/Task.h"
+#include <QDebug>
+#include <QDir>
+#include <QEventLoop>
+#include <QRegularExpression>
+#include <QCoreApplication>
+#include <QStandardPaths>
+#include <assert.h>
+
+void LaunchTask::init()
+{
+	m_instance->setRunning(true);
+}
+
+std::shared_ptr<LaunchTask> LaunchTask::create(InstancePtr inst)
+{
+	std::shared_ptr<LaunchTask> proc(new LaunchTask(inst));
+	proc->init();
+	return proc;
+}
+
+LaunchTask::LaunchTask(InstancePtr instance): m_instance(instance)
+{
+}
+
+void LaunchTask::appendStep(std::shared_ptr<LaunchStep> step)
+{
+	m_steps.append(step);
+}
+
+void LaunchTask::prependStep(std::shared_ptr<LaunchStep> step)
+{
+	m_steps.prepend(step);
+}
+
+void LaunchTask::executeTask()
+{
+	if(!m_steps.size())
+	{
+		state = LaunchTask::Finished;
+		emitSucceeded();
+	}
+	state = LaunchTask::Running;
+	onStepFinished();
+}
+
+void LaunchTask::onReadyForLaunch()
+{
+	state = LaunchTask::Waiting;
+	emit readyForLaunch();
+}
+
+void LaunchTask::onStepFinished()
+{
+	// initial -> just start the first step
+	if(currentStep == -1)
+	{
+		currentStep ++;
+		m_steps[currentStep]->start();
+		return;
+	}
+
+	auto step = m_steps[currentStep];
+	if(step->successful())
+	{
+		// end?
+		if(currentStep == m_steps.size() - 1)
+		{
+			emitSucceeded();
+		}
+		else
+		{
+			currentStep ++;
+			step = m_steps[currentStep];
+			step->start();
+		}
+	}
+	else
+	{
+		emitFailed(step->failReason());
+	}
+}
+
+void LaunchTask::onProgressReportingRequested()
+{
+	state = LaunchTask::Waiting;
+	emit requestProgress(m_steps[currentStep].get());
+}
+
+void LaunchTask::setCensorFilter(QMap<QString, QString> filter)
+{
+	m_censorFilter = filter;
+}
+
+QString LaunchTask::censorPrivateInfo(QString in)
+{
+	auto iter = m_censorFilter.begin();
+	while (iter != m_censorFilter.end())
+	{
+		in.replace(iter.key(), iter.value());
+		iter++;
+	}
+	return in;
+}
+
+void LaunchTask::proceed()
+{
+	if(state != LaunchTask::Waiting)
+	{
+		return;
+	}
+	m_steps[currentStep]->proceed();
+}
+
+bool LaunchTask::abort()
+{
+	switch(state)
+	{
+		case LaunchTask::Aborted:
+		case LaunchTask::Failed:
+		case LaunchTask::Finished:
+			return true;
+		case LaunchTask::NotStarted:
+		{
+			state = LaunchTask::Aborted;
+			emitFailed("Aborted");
+			return true;
+		}
+		case LaunchTask::Running:
+		case LaunchTask::Waiting:
+		{
+			auto step = m_steps[currentStep];
+			if(!step->canAbort())
+			{
+				return false;
+			}
+			if(step->abort())
+			{
+				state = LaunchTask::Aborted;
+				return true;
+			}
+		}
+		default:
+			break;
+	}
+	return false;
+}
+
+void LaunchTask::onLogLines(const QStringList &lines, MessageLevel::Enum defaultLevel)
+{
+	for (auto & line: lines)
+	{
+		onLogLine(line, defaultLevel);
+	}
+}
+
+void LaunchTask::onLogLine(QString line, MessageLevel::Enum level)
+{
+	// if the launcher part set a log level, use it
+	auto innerLevel = MessageLevel::fromLine(line);
+	if(innerLevel != MessageLevel::Unknown)
+	{
+		level = innerLevel;
+	}
+
+	// If the level is still undetermined, guess level
+	if (level == MessageLevel::StdErr || level == MessageLevel::StdOut || level == MessageLevel::Unknown)
+	{
+		level = m_instance->guessLevel(line, level);
+	}
+
+	// censor private user info
+	line = censorPrivateInfo(line);
+
+	emit log(line, level);
+}
+
+void LaunchTask::emitSucceeded()
+{
+	m_instance->cleanupAfterRun();
+	m_instance->setRunning(false);
+	Task::emitSucceeded();
+}
+
+void LaunchTask::emitFailed(QString reason)
+{
+	m_instance->cleanupAfterRun();
+	m_instance->setRunning(false);
+	Task::emitFailed(reason);
+}
+
+QString LaunchTask::substituteVariables(const QString &cmd) const
+{
+	QString out = cmd;
+	auto variables = m_instance->getVariables();
+	for (auto it = variables.begin(); it != variables.end(); ++it)
+	{
+		out.replace("$" + it.key(), it.value());
+	}
+	auto env = QProcessEnvironment::systemEnvironment();
+	for (auto var : env.keys())
+	{
+		out.replace("$" + var, env.value(var));
+	}
+	return out;
+}
+
diff --git a/libraries/logic/launch/LaunchTask.h b/libraries/logic/launch/LaunchTask.h
new file mode 100644
index 00000000..447445ca
--- /dev/null
+++ b/libraries/logic/launch/LaunchTask.h
@@ -0,0 +1,122 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Authors: Orochimarufan <orochimarufan.x3@gmail.com>
+ *
+ * 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 <QProcess>
+#include "BaseInstance.h"
+#include "MessageLevel.h"
+#include "LoggedProcess.h"
+#include "LaunchStep.h"
+
+#include "multimc_logic_export.h"
+
+class MULTIMC_LOGIC_EXPORT LaunchTask: public Task
+{
+	Q_OBJECT
+protected:
+	explicit LaunchTask(InstancePtr instance);
+	void init();
+
+public:
+	enum State
+	{
+		NotStarted,
+		Running,
+		Waiting,
+		Failed,
+		Aborted,
+		Finished
+	};
+
+public: /* methods */
+	static std::shared_ptr<LaunchTask> create(InstancePtr inst);
+	virtual ~LaunchTask() {};
+
+	void appendStep(std::shared_ptr<LaunchStep> step);
+	void prependStep(std::shared_ptr<LaunchStep> step);
+	void setCensorFilter(QMap<QString, QString> filter);
+
+	InstancePtr instance()
+	{
+		return m_instance;
+	}
+
+	void setPid(qint64 pid)
+	{
+		m_pid = pid;
+	}
+
+	qint64 pid()
+	{
+		return m_pid;
+	}
+
+	/**
+	 * @brief prepare the process for launch (for multi-stage launch)
+	 */
+	virtual void executeTask() override;
+
+	/**
+	 * @brief launch the armed instance
+	 */
+	void proceed();
+
+	/**
+	 * @brief abort launch
+	 */
+	virtual bool abort() override;
+
+public:
+	QString substituteVariables(const QString &cmd) const;
+	QString censorPrivateInfo(QString in);
+
+protected: /* methods */
+	virtual void emitFailed(QString reason) override;
+	virtual void emitSucceeded() override;
+
+signals:
+	/**
+	 * @brief emitted when the launch preparations are done
+	 */
+	void readyForLaunch();
+
+	void requestProgress(Task *task);
+
+	void requestLogging();
+
+	/**
+	 * @brief emitted when we want to log something
+	 * @param text the text to log
+	 * @param level the level to log at
+	 */
+	void log(QString text, MessageLevel::Enum level = MessageLevel::MultiMC);
+
+public slots:
+	void onLogLines(const QStringList& lines, MessageLevel::Enum defaultLevel = MessageLevel::MultiMC);
+	void onLogLine(QString line, MessageLevel::Enum defaultLevel = MessageLevel::MultiMC);
+	void onReadyForLaunch();
+	void onStepFinished();
+	void onProgressReportingRequested();
+
+protected: /* data */
+	InstancePtr m_instance;
+	QList <std::shared_ptr<LaunchStep>> m_steps;
+	QMap<QString, QString> m_censorFilter;
+	int currentStep = -1;
+	State state = NotStarted;
+	qint64 m_pid = -1;
+};
diff --git a/libraries/logic/launch/LoggedProcess.cpp b/libraries/logic/launch/LoggedProcess.cpp
new file mode 100644
index 00000000..88ca40aa
--- /dev/null
+++ b/libraries/logic/launch/LoggedProcess.cpp
@@ -0,0 +1,163 @@
+#include "LoggedProcess.h"
+#include "MessageLevel.h"
+#include <QDebug>
+
+LoggedProcess::LoggedProcess(QObject *parent) : QProcess(parent)
+{
+	// QProcess has a strange interface... let's map a lot of those into a few.
+	connect(this, &QProcess::readyReadStandardOutput, this, &LoggedProcess::on_stdOut);
+	connect(this, &QProcess::readyReadStandardError, this, &LoggedProcess::on_stdErr);
+	connect(this, SIGNAL(finished(int,QProcess::ExitStatus)), SLOT(on_exit(int,QProcess::ExitStatus)));
+	connect(this, SIGNAL(error(QProcess::ProcessError)), this, SLOT(on_error(QProcess::ProcessError)));
+	connect(this, &QProcess::stateChanged, this, &LoggedProcess::on_stateChange);
+}
+
+QStringList reprocess(const QByteArray & data, QString & leftover)
+{
+	QString str = leftover + QString::fromLocal8Bit(data);
+
+	str.remove('\r');
+	QStringList lines = str.split("\n");
+	leftover = lines.takeLast();
+	return lines;
+}
+
+void LoggedProcess::on_stdErr()
+{
+	auto lines = reprocess(readAllStandardError(), m_err_leftover);
+	emit log(lines, MessageLevel::StdErr);
+}
+
+void LoggedProcess::on_stdOut()
+{
+	auto lines = reprocess(readAllStandardOutput(), m_out_leftover);
+	emit log(lines, MessageLevel::StdOut);
+}
+
+void LoggedProcess::on_exit(int exit_code, QProcess::ExitStatus status)
+{
+	// save the exit code
+	m_exit_code = exit_code;
+
+	// Flush console window
+	if (!m_err_leftover.isEmpty())
+	{
+		emit log({m_err_leftover}, MessageLevel::StdErr);
+		m_err_leftover.clear();
+	}
+	if (!m_out_leftover.isEmpty())
+	{
+		emit log({m_err_leftover}, MessageLevel::StdOut);
+		m_out_leftover.clear();
+	}
+
+	// based on state, send signals
+	if (!m_is_aborting)
+	{
+		if (status == QProcess::NormalExit)
+		{
+			//: Message displayed on instance exit
+			emit log({tr("Process exited with code %1.").arg(exit_code)}, MessageLevel::MultiMC);
+			changeState(LoggedProcess::Finished);
+		}
+		else
+		{
+			//: Message displayed on instance crashed
+			if(exit_code == -1)
+				emit log({tr("Process crashed.")}, MessageLevel::MultiMC);
+			else
+				emit log({tr("Process crashed with exitcode %1.").arg(exit_code)}, MessageLevel::MultiMC);
+			changeState(LoggedProcess::Crashed);
+		}
+	}
+	else
+	{
+		//: Message displayed after the instance exits due to kill request
+		emit log({tr("Process was killed by user.")}, MessageLevel::Error);
+		changeState(LoggedProcess::Aborted);
+	}
+}
+
+void LoggedProcess::on_error(QProcess::ProcessError error)
+{
+	switch(error)
+	{
+		case QProcess::FailedToStart:
+		{
+			emit log({tr("The process failed to start.")}, MessageLevel::Fatal);
+			changeState(LoggedProcess::FailedToStart);
+			break;
+		}
+		// we'll just ignore those... never needed them
+		case QProcess::Crashed:
+		case QProcess::ReadError:
+		case QProcess::Timedout:
+		case QProcess::UnknownError:
+		case QProcess::WriteError:
+			break;
+	}
+}
+
+void LoggedProcess::kill()
+{
+	m_is_aborting = true;
+	QProcess::kill();
+}
+
+int LoggedProcess::exitCode() const
+{
+	return m_exit_code;
+}
+
+void LoggedProcess::changeState(LoggedProcess::State state)
+{
+	if(state == m_state)
+		return;
+	m_state = state;
+	emit stateChanged(m_state);
+}
+
+LoggedProcess::State LoggedProcess::state() const
+{
+	return m_state;
+}
+
+void LoggedProcess::on_stateChange(QProcess::ProcessState state)
+{
+	switch(state)
+	{
+		case QProcess::NotRunning:
+			break; // let's not - there are too many that handle this already.
+		case QProcess::Starting:
+		{
+			if(m_state != LoggedProcess::NotRunning)
+			{
+				qWarning() << "Wrong state change for process from state" << m_state << "to" << (int) LoggedProcess::Starting;
+			}
+			changeState(LoggedProcess::Starting);
+			return;
+		}
+		case QProcess::Running:
+		{
+			if(m_state != LoggedProcess::Starting)
+			{
+				qWarning() << "Wrong state change for process from state" << m_state << "to" << (int) LoggedProcess::Running;
+			}
+			changeState(LoggedProcess::Running);
+			return;
+		}
+	}
+}
+
+#if defined Q_OS_WIN32
+#include <windows.h>
+#endif
+
+qint64 LoggedProcess::processId() const
+{
+#ifdef Q_OS_WIN
+    return pid() ? pid()->dwProcessId : 0;
+#else
+    return pid();
+#endif
+}
diff --git a/libraries/logic/launch/LoggedProcess.h b/libraries/logic/launch/LoggedProcess.h
new file mode 100644
index 00000000..baa53d79
--- /dev/null
+++ b/libraries/logic/launch/LoggedProcess.h
@@ -0,0 +1,76 @@
+/* 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 <QProcess>
+#include "MessageLevel.h"
+
+/*
+ * This is a basic process.
+ * It has line-based logging support and hides some of the nasty bits.
+ */
+class LoggedProcess : public QProcess
+{
+Q_OBJECT
+public:
+	enum State
+	{
+		NotRunning,
+		Starting,
+		FailedToStart,
+		Running,
+		Finished,
+		Crashed,
+		Aborted
+	};
+
+public:
+    explicit LoggedProcess(QObject* parent = 0);
+    virtual ~LoggedProcess() {};
+
+	State state() const;
+	int exitCode() const;
+	qint64 processId() const;
+
+signals:
+	void log(QStringList lines, MessageLevel::Enum level);
+	void stateChanged(LoggedProcess::State state);
+
+public slots:
+	/**
+	 * @brief kill the process - equivalent to kill -9
+	 */
+	void kill();
+
+
+private slots:
+	void on_stdErr();
+	void on_stdOut();
+	void on_exit(int exit_code, QProcess::ExitStatus status);
+	void on_error(QProcess::ProcessError error);
+	void on_stateChange(QProcess::ProcessState);
+
+private:
+	void changeState(LoggedProcess::State state);
+
+private:
+	QString m_err_leftover;
+	QString m_out_leftover;
+	bool m_killed = false;
+	State m_state = NotRunning;
+	int m_exit_code = 0;
+	bool m_is_aborting = false;
+};
diff --git a/libraries/logic/launch/MessageLevel.cpp b/libraries/logic/launch/MessageLevel.cpp
new file mode 100644
index 00000000..a5191290
--- /dev/null
+++ b/libraries/logic/launch/MessageLevel.cpp
@@ -0,0 +1,36 @@
+#include "MessageLevel.h"
+
+MessageLevel::Enum MessageLevel::getLevel(const QString& levelName)
+{
+	if (levelName == "MultiMC")
+		return MessageLevel::MultiMC;
+	else if (levelName == "Debug")
+		return MessageLevel::Debug;
+	else if (levelName == "Info")
+		return MessageLevel::Info;
+	else if (levelName == "Message")
+		return MessageLevel::Message;
+	else if (levelName == "Warning")
+		return MessageLevel::Warning;
+	else if (levelName == "Error")
+		return MessageLevel::Error;
+	else if (levelName == "Fatal")
+		return MessageLevel::Fatal;
+	// Skip PrePost, it's not exposed to !![]!
+	// Also skip StdErr and StdOut
+	else
+		return MessageLevel::Unknown;
+}
+
+MessageLevel::Enum MessageLevel::fromLine(QString &line)
+{
+	// Level prefix
+	int endmark = line.indexOf("]!");
+	if (line.startsWith("!![") && endmark != -1)
+	{
+		auto level = MessageLevel::getLevel(line.left(endmark).mid(3));
+		line = line.mid(endmark + 2);
+		return level;
+	}
+	return MessageLevel::Unknown;
+}
diff --git a/libraries/logic/launch/MessageLevel.h b/libraries/logic/launch/MessageLevel.h
new file mode 100644
index 00000000..0128148d
--- /dev/null
+++ b/libraries/logic/launch/MessageLevel.h
@@ -0,0 +1,28 @@
+#pragma once
+
+#include <QString>
+
+/**
+ * @brief the MessageLevel Enum
+ * defines what level a log message is
+ */
+namespace MessageLevel
+{
+enum Enum
+{
+	Unknown, /**< No idea what this is or where it came from */
+	StdOut,  /**< Undetermined stderr messages */
+	StdErr,  /**< Undetermined stdout messages */
+	MultiMC, /**< MultiMC Messages */
+	Debug,   /**< Debug Messages */
+	Info,    /**< Info Messages */
+	Message, /**< Standard Messages */
+	Warning, /**< Warnings */
+	Error,   /**< Errors */
+	Fatal,   /**< Fatal Errors */
+};
+MessageLevel::Enum getLevel(const QString &levelName);
+
+/* Get message level from a line. Line is modified if it was successful. */
+MessageLevel::Enum fromLine(QString &line);
+}
diff --git a/libraries/logic/launch/steps/CheckJava.cpp b/libraries/logic/launch/steps/CheckJava.cpp
new file mode 100644
index 00000000..a4eaa307
--- /dev/null
+++ b/libraries/logic/launch/steps/CheckJava.cpp
@@ -0,0 +1,92 @@
+/* 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 "CheckJava.h"
+#include <launch/LaunchTask.h>
+#include <FileSystem.h>
+#include <QStandardPaths>
+#include <QFileInfo>
+
+void CheckJava::executeTask()
+{
+	auto instance = m_parent->instance();
+	auto settings = instance->settings();
+	m_javaPath = FS::ResolveExecutable(settings->get("JavaPath").toString());
+	bool perInstance = settings->get("OverrideJava").toBool() || settings->get("OverrideJavaLocation").toBool();
+
+	auto realJavaPath = QStandardPaths::findExecutable(m_javaPath);
+	if (realJavaPath.isEmpty())
+	{
+		if (perInstance)
+		{
+			emit logLine(
+				tr("The java binary \"%1\" couldn't be found. Please fix the java path "
+				   "override in the instance's settings or disable it.").arg(m_javaPath),
+				MessageLevel::Warning);
+		}
+		else
+		{
+			emit logLine(tr("The java binary \"%1\" couldn't be found. Please set up java in "
+							"the settings.").arg(m_javaPath),
+						 MessageLevel::Warning);
+		}
+		emitFailed(tr("Java path is not valid."));
+		return;
+	}
+	else
+	{
+		emit logLine("Java path is:\n" + m_javaPath + "\n\n", MessageLevel::MultiMC);
+	}
+
+	QFileInfo javaInfo(realJavaPath);
+	qlonglong javaUnixTime = javaInfo.lastModified().toMSecsSinceEpoch();
+	auto storedUnixTime = settings->get("JavaTimestamp").toLongLong();
+	m_javaUnixTime = javaUnixTime;
+	// if they are not the same, check!
+	if (javaUnixTime != storedUnixTime)
+	{
+		m_JavaChecker = std::make_shared<JavaChecker>();
+		QString errorLog;
+		QString version;
+		emit logLine(tr("Checking Java version..."), MessageLevel::MultiMC);
+		connect(m_JavaChecker.get(), &JavaChecker::checkFinished, this,
+				&CheckJava::checkJavaFinished);
+		m_JavaChecker->m_path = realJavaPath;
+		m_JavaChecker->performCheck();
+		return;
+	}
+	emitSucceeded();
+}
+
+void CheckJava::checkJavaFinished(JavaCheckResult result)
+{
+	if (!result.valid)
+	{
+		// Error message displayed if java can't start
+		emit logLine(tr("Could not start java:"), MessageLevel::Error);
+		emit logLines(result.errorLog.split('\n'), MessageLevel::Error);
+		emit logLine("\nCheck your MultiMC Java settings.", MessageLevel::MultiMC);
+		emitFailed(tr("Could not start java!"));
+	}
+	else
+	{
+		auto instance = m_parent->instance();
+		emit logLine(tr("Java version is %1!\n").arg(result.javaVersion.toString()),
+					 MessageLevel::MultiMC);
+		instance->settings()->set("JavaVersion", result.javaVersion.toString());
+		instance->settings()->set("JavaTimestamp", m_javaUnixTime);
+		emitSucceeded();
+	}
+}
diff --git a/libraries/logic/launch/steps/CheckJava.h b/libraries/logic/launch/steps/CheckJava.h
new file mode 100644
index 00000000..b63dd4f4
--- /dev/null
+++ b/libraries/logic/launch/steps/CheckJava.h
@@ -0,0 +1,41 @@
+/* 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 <java/JavaChecker.h>
+
+class CheckJava: public LaunchStep
+{
+	Q_OBJECT
+public:
+	explicit CheckJava(LaunchTask *parent) :LaunchStep(parent){};
+	virtual ~CheckJava() {};
+
+	virtual void executeTask();
+	virtual bool canAbort() const
+	{
+		return false;
+	}
+private slots:
+	void checkJavaFinished(JavaCheckResult result);
+
+private:
+	QString m_javaPath;
+	qlonglong m_javaUnixTime;
+	JavaCheckerPtr m_JavaChecker;
+};
diff --git a/libraries/logic/launch/steps/LaunchMinecraft.cpp b/libraries/logic/launch/steps/LaunchMinecraft.cpp
new file mode 100644
index 00000000..77a89f17
--- /dev/null
+++ b/libraries/logic/launch/steps/LaunchMinecraft.cpp
@@ -0,0 +1,154 @@
+/* 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 "LaunchMinecraft.h"
+#include <launch/LaunchTask.h>
+#include <minecraft/MinecraftInstance.h>
+#include <FileSystem.h>
+#include <QStandardPaths>
+
+LaunchMinecraft::LaunchMinecraft(LaunchTask *parent) : LaunchStep(parent)
+{
+	connect(&m_process, &LoggedProcess::log, this, &LaunchMinecraft::logLines);
+	connect(&m_process, &LoggedProcess::stateChanged, this, &LaunchMinecraft::on_state);
+}
+
+void LaunchMinecraft::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.
+	if(!FS::ensureFo