Finish implementing update installation.

Also add the option to update on exit.

MultiMC.cpp

@@ -2,10 +2,12 @@
 #include "MultiMC.h"
 #include <iostream>
 #include <QDir>
+#include <QFileInfo>
 #include <QNetworkAccessManager>
 #include <QTranslator>
 #include <QLibraryInfo>
 #include <QMessageBox>
+#include <QStringList>
 
 #include "gui/MainWindow.h"
 #include "gui/dialogs/VersionSelectDialog.h"
@@ -409,6 +411,65 @@ std::shared_ptr<JavaVersionList> MultiMC::javalist()
 	return m_javalist;
 }
 
+#ifdef WINDOWS
+#define UPDATER_BIN "updater.exe"
+#elif LINUX
+#define UPDATER_BIN "updater"
+#elif OSX
+#define UPDATER_BIN "updater"
+#else
+#error Unsupported operating system.
+#endif
+
+void MultiMC::installUpdates(const QString& updateFilesDir, bool restartOnFinish)
+{
+	QLOG_INFO() << "Installing updates.";
+#if LINUX
+	// On Linux, the MultiMC executable file is actually in the bin folder inside the installation directory.
+	// This means that MultiMC's *actual* install path is the parent folder.
+	// We need to tell the updater to run with this directory as the install path, rather than the bin folder where the executable is.
+	// On other operating systems, we'll just use the path to the executable.
+	QString appDir = QFileInfo(MMC->applicationDirPath()).dir().path();
+
+	// On Linux, we also need to set the finish command to the launch script, rather than the binary.
+	QString finishCmd = PathCombine(appDir, "MultiMC");
+#else
+	QString appDir = MMC->applicationDirPath();
+	QString finishCmd = MMC->applicationFilePath();
+#endif
+
+	// Build the command we'll use to run the updater.
+	// Note, the above comment about the app dir path on Linux is irrelevant here because the updater binary is always in the
+	// same folder as the main binary.
+	QString updaterBinary = PathCombine(MMC->applicationDirPath(), UPDATER_BIN);
+	QStringList args;
+	// ./updater --install-dir $INSTALL_DIR --package-dir $UPDATEFILES_DIR --script $UPDATEFILES_DIR/file_list.xml --wait $PID --mode main
+	args << "--install-dir" << appDir;
+	args << "--package-dir" << updateFilesDir;
+	args << "--script"      << PathCombine(updateFilesDir, "file_list.xml");
+	args << "--wait"        << QString::number(MMC->applicationPid());
+
+	if (restartOnFinish)
+		args << "--finish-cmd"  << finishCmd;
+
+	QLOG_INFO() << "Running updater with command" << updaterBinary << args.join(" ");
+
+	QProcess::startDetached(updaterBinary, args);
+
+	// Now that we've started the updater, quit MultiMC.
+	MMC->quit();
+}
+
+void MultiMC::setUpdateOnExit(const QString& updateFilesDir)
+{
+	m_updateOnExitPath = updateFilesDir;
+}
+
+QString MultiMC::getExitUpdatePath() const
+{
+	return m_updateOnExitPath;
+}
+
 int main_gui(MultiMC &app)
 {
 	// show main window
@@ -417,7 +478,13 @@ int main_gui(MultiMC &app)
 	mainWin.restoreGeometry(QByteArray::fromBase64(MMC->settings()->get("MainWindowGeometry").toByteArray()));
 	mainWin.show();
 	mainWin.checkSetDefaultJava();
-	return app.exec();
+	auto exitCode = app.exec();
+
+	// Update if necessary.
+	if (!app.getExitUpdatePath().isEmpty())
+		app.installUpdates(app.getExitUpdatePath(), false);
+
+	return exitCode;
 }
 
 int main(int argc, char *argv[])

MultiMC.h

@@ -98,6 +98,22 @@ public:
 
 	std::shared_ptr<JavaVersionList> javalist();
 
+	/*!
+	 * Installs update from the given update files directory.
+	 */
+	void installUpdates(const QString& updateFilesDir, bool restartOnFinish=false);
+
+	/*!
+	 * Sets MultiMC to install updates from the given directory when it exits.
+	 */
+	void setUpdateOnExit(const QString& updateFilesDir);
+
+	/*!
+	 * Gets the path to install updates from on exit.
+	 * If this is an empty string, no updates should be installed on exit.
+	 */
+	QString getExitUpdatePath() const;
+
 private:
 	void initLogger();
 
@@ -124,6 +140,8 @@ private:
 	QsLogging::DestinationPtr m_fileDestination;
 	QsLogging::DestinationPtr m_debugDestination;
 
+	QString m_updateOnExitPath;
+
 	Status m_status = MultiMC::Failed;
 	MultiMCVersion m_version;
 };

gui/MainWindow.cpp

@@ -439,20 +439,31 @@ void MainWindow::updateAvailable(QString repo, QString versionName, int versionI
 			QLOG_INFO() << "Update will be installed later.";
 			break;
 		case UPDATE_NOW:
-			{
-			QLOG_INFO() << "Installing update.";
-			ProgressDialog updateDlg(this);
-			DownloadUpdateTask updateTask(repo, versionId, &updateDlg);
-			updateDlg.exec(&updateTask);
-			}
+			downloadUpdates(repo, versionId);
 			break;
 		case UPDATE_ONEXIT:
-			// TODO: Implement installing updates on exit.
-			QLOG_INFO() << "Installing on exit is not implemented yet.";
+			downloadUpdates(repo, versionId, true);
 			break;
 	}
 }
 
+void MainWindow::downloadUpdates(QString repo, int versionId, bool installOnExit)
+{
+	QLOG_INFO() << "Downloading updates.";
+	// TODO: If the user chooses to update on exit, we should download updates in the background.
+	// Doing so is a bit complicated, because we'd have to make sure it finished downloading before actually exiting MultiMC.
+	ProgressDialog updateDlg(this);
+	DownloadUpdateTask updateTask(repo, versionId, &updateDlg);
+	// If the task succeeds, install the updates.
+	if (updateDlg.exec(&updateTask))
+	{
+		if (installOnExit)
+			MMC->setUpdateOnExit(updateTask.updateFilesDir());
+		else
+			MMC->installUpdates(updateTask.updateFilesDir());
+	}
+}
+
 void MainWindow::onCatToggled(bool state)
 {
 	setCatBackground(state);

gui/MainWindow.h

@@ -168,6 +168,11 @@ slots:
 	void changeActiveAccount();
 
 	void repopulateAccountsMenu();
+	
+	/*!
+	 * Runs the DownloadUpdateTask and installs updates.
+	 */
+	void downloadUpdates(QString repo, int versionId, bool installOnExit=false);
 
 protected:
 	bool eventFilter(QObject *obj, QEvent *ev);

gui/dialogs/UpdateDialog.ui

@@ -41,6 +41,13 @@
      </property>
     </widget>
    </item>
+   <item>
+    <widget class="QPushButton" name="btnUpdateOnExit">
+     <property name="text">
+      <string>Update after MultiMC closes</string>
+     </property>
+    </widget>
+   </item>
    <item>
     <widget class="QPushButton" name="btnUpdateLater">
      <property name="sizePolicy">

logic/updater/DownloadUpdateTask.cpp

@@ -391,3 +391,8 @@ void DownloadUpdateTask::fileDownloadProgressChanged(qint64 current, qint64 tota
 	setProgress((int)(((float)current / (float)total)*100));
 }
 
+QString DownloadUpdateTask::updateFilesDir()
+{
+	return m_updateFilesDir.path();
+}
+

logic/updater/DownloadUpdateTask.h

@@ -28,6 +28,11 @@ class DownloadUpdateTask : public Task
 
 public:
 	explicit DownloadUpdateTask(QString repoUrl, int versionId, QObject* parent=0);
+
+	/*!
+	 * Gets the directory that contains the update files.
+	 */
+	QString updateFilesDir();
 	
 protected:
 	// TODO: We should probably put these data structures into a separate header...

mmc_updater/src/UpdateInstaller.cpp

@@ -388,7 +388,7 @@ void UpdateInstaller::restartMainApp()
 {
 	try
 	{
-		std::string command = m_installDir + '/' + m_finishCmd;
+		std::string command = m_finishCmd;
 		std::list<std::string> args;
 
 		if (!command.empty())