Can I create an overlay layer to disable all touches, even on menus? - cocos2d-x

Question

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.
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.
Is this achievable using the new EventDispatcher class? I've been able to disable all touches to the main scene, but all instances of MenuItem 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?

Answer 1

You can disable menu items by setting setDisable property of menuitems to false.
Example
_menuItem->setEnabled(false);
For Layers use setTouchEnabled property
_backGroungLayer->setTouchEnabled(false);
Make sure that popup layer is not child of layer you want to disable.
To disable all items in menus do this
Suppose _menu contain various menuitems.
CCARRAY_FOREACH(_menu->getChildren(), item)
{
item.isEnabled=NO;
}
if you want to disable selected items just give them tags.There is no need to make any list.

Answer 2

I had the same problem and solved it with mm. It was dirty, but it worked:
Create a button using ccui.button.
Set the button size to your screen size.
Add this button as a background to your popup layer.
This will prevent any thing behind it being clicked.

Answer 3

By default, all CCMenu's have a set priority (kCCMenuHandlerPriority = -128) in cocos2d 2.1. So in a class (usually a CCNode descendant) that wants to swallow everything and preempt anything i do like in this dialog sequencer example below :
- (void)onEnter {
backdrop_.visible = self.isBackDropShown;
MPLOG(#"Adding self as a swallower touch delegate, above the rest of the planet.");
[[[CCDirector sharedDirector] touchDispatcher] addTargetedDelegate:self priority:_dialogTouchPriority swallowsTouches:YES];
for (CCMenu *mn in _menus) {
mn.touchPriotity = _dialogTouchPriority -1 ;
}
[super onEnter];
}
where _dialogTouchPriority is kCCMenuHandlerPriority-1 by default. It will be served before everything 'below'. It is a bad hack (cocos2d internals could be changed and break this), i know , but bullet proof. Use carefully, make certain you only ever have one of these in your scene.