title: Can I create an overlay layer to disable all touches, even on menus?
body: <p>I need to show a popup layer on a scene, creating a semi-transparent background layer that will also prevent touch events propagation. I am using the latest cocos2d-x v. 3.0-alpha-0.</p>
  
  <p>What I want to achieve is a popup layer that fully handles touches (eg. buttons, menu items, scroll views, etc.), laying on a background layer (for design purposes), that covers the current scene. All items in the scene should not respond to touches any more.</p>
  
  <p>Is this achievable using the new <code>EventDispatcher</code> class? I've been able to disable all touches to the main scene, but all instances of <code>MenuItem</code> that live in the scene are still touchable and active.
  How can I achieve this? And, also, how can I create a touch listener that prevents all touches to the main scene but not to the popup?</p>