interface Button  { /* ... */ }
interface TextBox { /* ... */ }

interface GUIFactory {
    public Button createButton();
    public Window createTextBox();
    // ...
}


class WinButton implements Button   { /* ... */ }
class WinTextBox implements TextBox { /* ... */ }
 
class WinFactory implements GUIFactory {
    public Button createButton() {
        return new WinButton();
    }
    
    public TextBox createTextBox() {
        return new WinTextBox();
    }

    // ...
}