Implemented application login.

Minor UI improvement.
Fixed memory leaks.

application/mainwindow.cpp

@@ -13,6 +13,22 @@ MainWindow::MainWindow(QWidget *parent) :
     ui(new Ui::MainWindow)
 {
     ui->setupUi(this);
+    m_lblUser = new QLabel(this);
+    ui->statusBar->addWidget(m_lblUser);
+
+    m_loginDialog = new LoginDialog(this);
+
+    connect(m_loginDialog, &LoginDialog::accepted, [this]{
+        PermissionService service;
+        QSharedPointer<User> u = service.loadUser(m_loginDialog->login());
+        m_lblUser->setText(u->name());
+        m_loginDialog->reset();
+        Context::instance().setCurrentUser(u);
+    });
+
+    connect(m_loginDialog, &LoginDialog::rejected, [this]{
+        close();
+    });
 
     Context::instance().loadPlugins();
     int i = 0;
@@ -27,6 +43,11 @@ MainWindow::MainWindow(QWidget *parent) :
     }
 
    ((QVBoxLayout*)ui->navigation->layout())->addStretch(1);
+
+    if (Context::instance().db() != NULL)
+    {
+        ui->navigation->setEnabled(true);
+    }
 }
 
 MainWindow::~MainWindow()
@@ -59,13 +80,37 @@ void MainWindow::openPlugin()
 
 void MainWindow::on_actionOpen_database_triggered()
 {
-    QFileDialog dialog(this);
+    /*QFileDialog dialog(this);
     dialog.setNameFilter(tr("Database Files (*.db)"));
-    dialog.setWindowTitle(tr("Open Database"));
-    Context::instance().openDb(dialog.getOpenFileName());
+    dialog.setWindowTitle(tr("Open Database"));*/
+
+    QString dbFile = QFileDialog::getOpenFileName(this, "Open Database", "", "Database Files (*.db)");
+    if (!dbFile.isEmpty())
+    {
+        Context::instance().openDb(dbFile);
+        ui->navigation->setEnabled(true);
+        on_actionLogin_triggered();
+    }
 }
 
 void MainWindow::on_tabWidget_tabCloseRequested(int index)
 {
     ui->tabWidget->removeTab(index);
 }
+
+void MainWindow::on_actionLogin_triggered()
+{
+    QSharedPointer<User> u;
+    Context::instance().setCurrentUser(u);
+    m_lblUser->setText("");
+    m_loginDialog->show();
+}
+
+void MainWindow::showEvent(QShowEvent *evt)
+{
+    QWidget::showEvent(evt);
+    if (Context::instance().db() != NULL && Context::instance().currentUser().data() == NULL)
+    {
+        m_loginDialog->show();
+    }
+}