diff -r 73e448b2943d -r 68443f5be176 src/mainwindow.cpp
--- a/src/mainwindow.cpp	Thu Oct 03 23:44:28 2019 +0300
+++ b/src/mainwindow.cpp	Sat Oct 05 23:47:03 2019 +0300
@@ -1,21 +1,27 @@
+#include <QLabel>
+#include <QVBoxLayout>
+#include <QCloseEvent>
+#include <QFileDialog>
+#include <QMessageBox>
 #include "mainwindow.h"
 #include "ui_mainwindow.h"
+#include "settingseditor/settingseditor.h"
 #include "version.h"
-#include <QLabel>
-#include <QVBoxLayout>
 
 MainWindow::MainWindow(QWidget *parent) :
 	QMainWindow{parent},
 	ui{std::make_unique<Ui_MainWindow>()},
-	documents{this}
+	documents{this},
+	settings{},
+	libraries{this}
 {
 	this->ui->setupUi(this);
 	connect(ui->actionNew, &QAction::triggered, this, &MainWindow::newModel);
 	connect(ui->actionOpen, &QAction::triggered, this, &MainWindow::openModel);
 	connect(ui->actionQuit, &QAction::triggered, this, &QMainWindow::close);
+	connect(ui->actionSettingsEditor, &QAction::triggered, this, &MainWindow::runSettingsEditor);
 	this->updateTitle();
-	this->loadLocales();
-	changeLanguage(QLocale::system().name());
+	this->restoreSettings();
 }
 
 MainWindow::~MainWindow()
@@ -28,26 +34,28 @@
 	this->updateTabs();
 }
 
-#include <QFileDialog>
-#include <QMessageBox>
 void MainWindow::openModel()
 {
 	const QString path = QFileDialog::getOpenFileName(
-		this, tr("Open model"), "", tr("LDraw models (*.ldr *.dat)"));
+		this,
+		tr("Open model"),
+		"",
+		tr("LDraw models (*.ldr *.dat)"));
 	if (not path.isEmpty())
 	{
 		QFile file{path};
 		const bool open_result = file.open(QIODevice::ReadOnly);
 		if (open_result)
 		{
-
+			QMessageBox::critical(this, "Not implemented", "This functionality is not done yet");
 		}
 		else
 		{
-			QMessageBox::critical(this, tr("Problem opening file"),
-				tr("Could not open %1: %2")
-					.arg(path)
-					.arg(file.errorString()));
+			const QString errorString = format(
+				tr("Could not open %1: %2"),
+				path,
+				file.errorString());
+			QMessageBox::critical(this, tr("Problem opening file"), errorString);
 		}
 	}
 }
@@ -56,11 +64,15 @@
  * @brief Changes the application language to the specified language
  * @param localeCode Code of the locale to translate to
  */
-void MainWindow::changeLanguage(const QString& localeCode)
+void MainWindow::changeLanguage(QString localeCode)
 {
 	if (not localeCode.isEmpty() and localeCode != this->currentLanguage)
 	{
 		this->currentLanguage = localeCode;
+		if (localeCode == "system")
+		{
+			localeCode = QLocale::system().name();
+		}
 		QLocale::setDefault({localeCode});
 		qApp->removeTranslator(&this->translator);
 		const bool loadSuccessful = this->translator.load(pathToTranslation(localeCode));
@@ -71,13 +83,13 @@
 	}
 }
 
-void MainWindow::languageChangeRequested()
+void MainWindow::runSettingsEditor()
 {
-	QAction* const senderAction = qobject_cast<QAction*>(sender());
-	if (senderAction != nullptr)
+	SettingsEditor settingsEditor{&this->settings, this};
+	const int result = settingsEditor.exec();
+	if (result == QDialog::Accepted)
 	{
-		const QString localeCode = senderAction->data().toString();
-		this->changeLanguage(localeCode);
+		this->restoreSettings();
 	}
 }
 
@@ -98,6 +110,16 @@
 }
 
 /**
+ * @brief Handles closing the main window
+ * @param event Event information
+ */
+void MainWindow::closeEvent(QCloseEvent* event)
+{
+	saveSettings();
+	event->accept();
+}
+
+/**
  * @brief Creates a new tab widget for the specified model.
  * @param model Model to get a new tab widget for
  * @return widget
@@ -154,30 +176,29 @@
 	setWindowTitle(title);
 }
 
+/**
+ * @brief Stores the settings of the main window, storing geometry, etc
+ */
+void MainWindow::saveSettings()
+{
+	this->settings.setValue("mainwindow/geometry", this->saveGeometry());
+	this->libraries.storeToSettings(&this->settings);
+}
+
+/**
+ * @brief Restores saved settings relating to the main window
+ */
+void MainWindow::restoreSettings()
+{
+	this->restoreGeometry(this->settings.value("mainwindow/geometry").toByteArray());
+	const QString systemLocale = QLocale::system().name();
+	const QVariant defaultLocale = this->settings.value("locale", systemLocale);
+	changeLanguage(defaultLocale.toString());
+	this->libraries.restoreFromSettings(&this->settings);
+}
+
 QString MainWindow::pathToTranslation(const QString& localeCode)
 {
 	QDir dir {":/locale"};
 	return dir.filePath(localeCode + ".qm");
 }
-
-void MainWindow::loadLocales()
-{
-	QDir dir {":/locale"};
-	this->ui->menuLanguage->clear();
-	QVector<QString> localeCodes = {"en"};
-	for (const QFileInfo& file : dir.entryInfoList(QDir::Files))
-	{
-		localeCodes.append(file.baseName());
-	}
-	for (const QString& localeCode : localeCodes)
-	{
-		const QLocale locale{localeCode};
-		const QString languageName = QLocale::languageToString(locale.language());
-		const QIcon flag{":/flags/" + localeCode + ".png"};
-		QAction* action = new QAction{languageName, this};
-		action->setData(localeCode);
-		action->setIcon(flag);
-		this->ui->menuLanguage->addAction(action);
-		connect(action, &QAction::triggered, this, &MainWindow::languageChangeRequested);
-	}
-}