private:
    Ui::MainWindow *ui;
     // Widgets
    QWidget *mainWidget;
    QVBoxLayout *centralWidgetLayout; //for widgets
    QGridLayout *gridLayout; //for form creation
    QHBoxLayout *buttonsLayout;//for buttons
    QLabel *nameLabel;
    QLabel *dateOfBirthLabel;
    QLabel *phoneNumberLabel;
    QPushButton *savePushButton;
    QPushButton *clearPushButton;
    QLineEdit *nameLineEdit;
    QDateEdit *dateOfBirthEdit;
    QLineEdit *phoneNumberLineEdit;
    QTableView *appTable;
    QStandardItemModel *model;
    // Menus
    QMenu *fileMenu;
    QMenu *helpMenu;
    // Actions
    QAction *quitAction;
    QAction *aboutAction;
    QAction *saveAction;
    QAction *cancelAction;
    QAction *openAction;
    QAction *newAction;
    QAction *aboutQtAction;
    QAction *newToolBarAction;
    QAction *openToolBarAction;
    QAction *closeToolBarAction;
    QAction *clearToolBarAction;
    // Toolbar
    QToolBar *toolbar;
    // Icons
    QPixmap newIcon;
    QPixmap openIcon;
    QPixmap closeIcon;
    QPixmap clearIcon;
    // init methods
    void clearFields();
    void createIcons();
    void createMenuBar();
    void createToolBar();
    void setupSignalsAndSlot();
    void setupCoreWidgets();
    void setupSignalsAndSlots();