OOP projekt GUI

package View;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 *
 * @author kovko
 */
public class GUI extends JFrame{

    public static final int WIDTH = 1080;
    public static final int HEIGHT = 800;
    public static final int BUTTON_OFFSET = 10;
    public static final int BUTTON_HEIGHT = 20;
    public static final int BUTTON_WIDTH = 120;

    private JPanel menuDefault;
    private JPanel menuSetFocus;

    private JButton switchToSetFocusMenu;
    private JButton switchToDefaultMenu;
    private JButton tankDriverFocusSetter;
    private JButton tankGunnerFocusSetter;

    public GUI(Surface surface){
        add(surface);
        setTitle("Warsong Tank Edition");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(WIDTH, HEIGHT);
        setMenus();
        add(menuDefault);
    }

    private void setMenus(){
        menuDefault = new JPanel();
        menuDefault.setBounds(HEIGHT, 0, WIDTH-HEIGHT, HEIGHT);
        menuDefault.setLayout(null);
        setDefaultMenuButtons();

        menuSetFocus = new JPanel();
        menuSetFocus.setBounds(HEIGHT, 0, WIDTH-HEIGHT, HEIGHT);
        menuSetFocus.setLayout(null);
        setSetFocusMenuButton();
    }

    private void switchMenus(JPanel toActivate, JPanel toDeactivate){
        remove(toDeactivate);
        add(toActivate);
        revalidate();
        repaint();
    }

    private JButton createButton(String name, JPanel parent){
        JButton button = new JButton(name);
        int x = parent.getBounds().x + (BUTTON_WIDTH*(parent.getComponentCount()%2))+(BUTTON_OFFSET*(parent.getComponentCount()%2));
        int y = parent.getBounds().y + (BUTTON_HEIGHT*(parent.getComponentCount()/2))+(BUTTON_OFFSET*(parent.getComponentCount()/2));
        button.setBounds(x, y, BUTTON_WIDTH, BUTTON_HEIGHT);
        parent.add(button);
        return button;
    }

    private void setDefaultMenuButtons(){
        switchToSetFocusMenu = createButton("Vybrat tank", menuDefault);
         switchToSetFocusMenu.addActionListener(e->{switchMenus(menuSetFocus, menuDefault);});
    };

    private void setSetFocusMenuButton(){
        switchToDefaultMenu = createButton("Spat", menuSetFocus);
        switchToDefaultMenu.addActionListener(e->{switchMenus(menuDefault, menuSetFocus);});

        tankDriverFocusSetter = createButton("Vodic", menuSetFocus);
        tankDriverFocusSetter.addActionListener(e->{switchMenus(menuDefault, menuSetFocus);});

        tankGunnerFocusSetter = createButton("Strelec", menuSetFocus);
        tankGunnerFocusSetter.addActionListener(e->{switchMenus(menuDefault, menuSetFocus);});
    }
}