title: In Cocos2d, how to create a layer that I can set its area size, and only its children that belongs in this area will be shown?
body: <p>Currently, no matter how big the layer is, when I add a child sprite to it, the sprite will be shown on the screen. But if I want to restrict the visible area of the layer and only show children that is inside this area, how can I do it?</p>