Question

Can someone tell me how to set my X button in main application window visible to false and how to set Alt + F4 function not available or just disable it?

---

Update

I added it in:

public ZalumView(SingleFrameApplication app) { 
    super(app); 
    initComponents(); 
    mainFrame = this.getFrame(); 
    mainFrame.setTitle("Zalum - zarzadzanie zasobami ludzkimi"); 
    mainFrame.pack(); 
    mainFrame.setResizable(false); 
    mainFrame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

Answer 1

“A frame may have its native decorations (i.e. Frame and Titlebar) turned off with setUndecorated.”—Frame

Addendum: You can send a WINDOW_CLOSING event and bind that Action to your desired Keystroke, as shown here.