settings improvements and refactoring

src/qtapp/mdemList.cpp

@@ -4,6 +4,7 @@
 #include <fstream>
 #include <iostream>
 #include <map>
+#include <filesystem>
 #include <qabstractbutton.h>
 #include <qapplication.h>
 #include <qboxlayout.h>
@@ -78,14 +79,14 @@
 // Memorybase info.
 // @Improve: set the default directory for convenience. It should be configured by user
 // or set to "".
-std::string              currentPath   = "/home/jorenchik/Code/mdemory/memorybase/";
+QString                  currentPath   = "";
 std::string              currentMdem   = "";
 QFileSystemModel        *model;
 QTreeView               *mdemList;
 QLabel                  *membaseLabel;
 
 std::map<std::string, MdemBuffer*>  buffers;
-MdemBuffer                         *currentMdemBuffer;
+MdemBuffer                         *currentMdemBuffer = nullptr;
 
 // Mdem scroll list.
 std::vector<Mdem*>  mdems = std::vector<Mdem*>();
@@ -646,7 +647,7 @@ void reloadMdem(std::string path) {
 		SwitchPage(0);
 		updateMdemInfo(filename, false);
 	} else {
-		std::cout << std::format("Could not open the file: {}", currentPath) << std::endl;
+		std::cout << std::format("Could not open the file: {}", currentPath.toStdString()) << std::endl;
 	}
 
 	hideQuestionElements();
@@ -654,7 +655,21 @@ void reloadMdem(std::string path) {
 }
 
 void pickDirectory(QString directory) {
-	currentPath = directory.toStdString();
+
+	auto path = std::filesystem::path(directory.toStdString());
+	if (
+		!std::filesystem::exists(directory.toStdString()) ||
+		!std::filesystem::is_directory(directory.toStdString())
+	) {
+		QMessageBox::information(
+			nullptr,
+			"Error",
+			"The directory that is specified as the default memorybase does not exist."
+		);
+		return;
+    }
+
+	currentPath = directory;
 
 	// Update tree view.
 	if (directory.length() <= 0) {
@@ -668,7 +683,7 @@ void pickDirectory(QString directory) {
 	membaseLabel->setText(QString::fromStdString(
 		std::format(
 			"memorybase: {}",
-			getFilename(currentPath)
+			getFilename(currentPath.toStdString())
 		)
 	));
 
@@ -933,12 +948,16 @@ QMainWindow *initMdemListWindow() {
 			practice,
 			&QToolButton::clicked,
 			[cbAlgorithm]() {
-				trainWindow->show();
-				trainWindow->resize(600, 300);
-				initiatePractice(
-					currentMdemBuffer,
-					static_cast<PracticeAlgorithm>(cbAlgorithm->currentData().toInt())
-				);
+				if (currentMdemBuffer) {
+					trainWindow->show();
+					trainWindow->resize(600, 300);
+					initiatePractice(
+						currentMdemBuffer,
+						static_cast<PracticeAlgorithm>(
+							cbAlgorithm->currentData().toInt()
+						)
+					);
+				}
 			}
 		);
 	}
@@ -1046,8 +1065,9 @@ QMainWindow *initMdemListWindow() {
     window->setCentralWidget(hSplitter);
     window->show();
 
-	if (currentPath.length() > 0) {
-		pickDirectory(QString::fromStdString(currentPath));
+	currentPath = settings->value(SETTING_MEMORYBASE).toString();
+	if (currentPath.size() > 0) {
+		pickDirectory(currentPath);
 	}
 
 	QShortcut* shortcutSaveFile = new QShortcut(QKeySequence("Ctrl+S"), window);
@@ -1055,5 +1075,10 @@ QMainWindow *initMdemListWindow() {
 		saveMdem();
 	});
 
+	QShortcut* shortcutSettings = new QShortcut(QKeySequence("Ctrl+C"), window);
+	QObject::connect(shortcutSettings, &QShortcut::activated, [settingsWindow]() {
+		settingsWindow->show();
+	});
+
 	return window;
 }