WindowHolder

WindowHolder.java

class WindowHolder extends EntityComponent {
    final DefaultWindow defaultWindow = new DefaultWindow();
    Window activeWindow = defaultWindow;

    Window getActiveWindow() {
        return activeWindow;
    }

    DefaultWindow getDefaultWindow() {
        return defaultWindow;
    }

    void openWindow(Window window) {
        activeWindow = window;
        window.open();
    }

    void closeWindow() {
        activeWindow.close();
        activeWindow = defaultWindow;
    }
}