Question

I want to show a modal window (instead the confirm) when a user close the browser. The GWT documention remarks that (during the handler operation) no user UI may be displayed during the shutdown. Exists any way cancel the operation, from the client not from the user?

Thanks in advance,
Oscar.

Answer 1

You can’t cancel the close event. The best you can do is to let the user press cancel. I think the reason for this is to prevent “bad” javascript from not letting you close your browser.

This displays a dialog with a cancel option.

    Window.addWindowCloseListener(new WindowCloseListener()
    {
        public String onWindowClosing()
        {
            return "You are about to exit from the application. Are you sure?";
        }

        public void onWindowClosed()
        {
            //cleanup code  
        }
    });