Available update can be checked via menu action Help/"Check for update".

mainwindow.cpp

@@ -1,14 +1,21 @@
 #include "mainwindow.h"
 #include "./ui_mainwindow.h"
 
-#include "../../libs/GenericCore/genericcore.h"
+#include <QCloseEvent>
+#include <QMessageBox>
+
+#include "data/settingshandler.h"
+#include "genericcore.h"
+
+static QString updateTextClean = "Do you want to update the application now?";
+static QString updateTextDirty = "Do you want to save the tasks & update the application now?";
 
 MainWindow::MainWindow(QWidget* parent)
     : QMainWindow(parent)
     , ui(new Ui::MainWindow) {
   ui->setupUi(this);
 
-  m_core = std::make_shared<GenericCore>();
+  m_core = new GenericCore();
 
   /// application icon
   const QString iconString = "://feature.png";
@@ -21,11 +28,81 @@ MainWindow::MainWindow(QWidget* parent)
 #else
   setWindowIcon(QIcon(iconString));
 #endif
+
+  /// TODO restore window geometry and state (& save it in closeEvent)
+  const QVariantMap settings = SettingsHandler::getSettings("GUI");
+  restoreGeometry(settings.value("geometry").toByteArray());
+  restoreState(settings.value("windowState").toByteArray());
+
+  connect(m_core, &GenericCore::displayStatusMessage, this, &MainWindow::displayStatusMessage);
+  connect(this, &MainWindow::displayStatusMessage, this, &MainWindow::showStatusMessage);
+  connect(this, &MainWindow::checkForUpdates, this,
+          &MainWindow::on_actionCheck_for_update_triggered, Qt::QueuedConnection);
 }
 
-MainWindow::~MainWindow() { delete ui; }
+MainWindow::~MainWindow() {
+  delete ui;
+  delete m_core;
+}
 
 void MainWindow::on_pushButton_clicked() {
   const QString prefix("Backend provided by: ");
   ui->label->setText(prefix + m_core->toString());
 }
+
+void MainWindow::showStatusMessage(const QString text) {
+  qInfo() << text;
+  ui->statusbar->showMessage(text);
+}
+
+void MainWindow::on_actionCheck_for_update_triggered() {
+  showStatusMessage("Checking for update...");
+  const bool updateAvailable = m_core->isApplicationUpdateAvailable();
+  if (updateAvailable) {
+    const QString text = isWindowModified() ? updateTextDirty : updateTextClean;
+    const QMessageBox::StandardButton clickedButton = QMessageBox::question(
+        this, tr("Update available."), text, QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);
+    if (clickedButton == QMessageBox::Yes) {
+      m_core->triggerApplicationUpdate();
+      close();
+    }
+  }
+}
+
+void MainWindow::closeEvent(QCloseEvent* event) {
+  if (isWindowModified()) {
+    QMessageBox msgBox;
+    msgBox.setWindowTitle(windowTitle() + " - Save dialog");
+    msgBox.setText("The document has been modified.");
+    msgBox.setInformativeText("Do you want to save your changes?");
+    msgBox.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel);
+    msgBox.setDefaultButton(QMessageBox::Save);
+    int ret = msgBox.exec();
+
+    switch (ret) {
+      case QMessageBox::Save:
+        // TODO m_core->saveItems();
+        event->accept();
+        break;
+      case QMessageBox::Discard:
+        event->accept();
+        break;
+      case QMessageBox::Cancel:
+        event->ignore();
+        break;
+      default:
+        /// should never be reached
+        qCritical() << "unexpected switch case in closeEvent:" << ret;
+        event->ignore();
+        break;
+    }
+  } else {
+    event->accept();
+  }
+
+  if (event->isAccepted()) {
+    qInfo() << "Saving GUI settings...";
+    SettingsHandler::saveSettings({{"geometry", saveGeometry()}, {"windowState", saveState()}},
+                                  "GUI");
+  }
+}

mainwindow.h

@@ -19,12 +19,22 @@ class MainWindow : public QMainWindow {
   MainWindow(QWidget* parent = nullptr);
   ~MainWindow();
 
+ signals:
+  void displayStatusMessage(QString message);
+  void checkForUpdates();
+
+ protected:
+  void closeEvent(QCloseEvent* event) override;
+
  private slots:
+  void showStatusMessage(const QString text);
+
   void on_pushButton_clicked();
+  void on_actionCheck_for_update_triggered();
 
  private:
   Ui::MainWindow* ui;
 
-  std::shared_ptr<GenericCore> m_core;
+  GenericCore* m_core;
 };
 #endif  // MAINWINDOW_H

mainwindow.ui

@@ -40,8 +40,38 @@
      <height>25</height>
     </rect>
    </property>
+   <widget class="QMenu" name="menu_File">
+    <property name="title">
+     <string>&amp;File</string>
+    </property>
+   </widget>
+   <widget class="QMenu" name="menu_Edit">
+    <property name="title">
+     <string>&amp;Edit</string>
+    </property>
+   </widget>
+   <widget class="QMenu" name="menu_View">
+    <property name="title">
+     <string>&amp;View</string>
+    </property>
+   </widget>
+   <widget class="QMenu" name="menu_Help">
+    <property name="title">
+     <string>&amp;Help</string>
+    </property>
+    <addaction name="actionCheck_for_update"/>
+   </widget>
+   <addaction name="menu_File"/>
+   <addaction name="menu_Edit"/>
+   <addaction name="menu_View"/>
+   <addaction name="menu_Help"/>
   </widget>
   <widget class="QStatusBar" name="statusbar"/>
+  <action name="actionCheck_for_update">
+   <property name="text">
+    <string>Check for &amp;update</string>
+   </property>
+  </action>
  </widget>
  <resources/>
  <connections/>