Layers are a natural way to implement UI controls, because the compositor will
take care of repaint automagically. However, it's currently more awkward than
it should be, because you have to push paint() calls and pointer events
manually down to the "controller" for each layer.
If each layer's controller could simply get callbacks for pointer events and
painting, it would be trivially easy to implement buttons and other UI
components without all this extra wiring.
For pointer events, I imagine adding an overload like
pointer().setListener(Layer, Listener), so that the pointer-specific stuff
remains where it belongs (the pointer implementation would now need to know
about layers, though). Note that I'm *not* proposing adding keyboard events to
the mix, because that would imply a full focus system, which seems like
overkill (and I strongly suspect most games will want to handle the keyboard
globally).
For paint callbacks, I believe it makes sense to propagate the alpha parameter
as usual, but I don't believe there's any reason to add update(delta), because
that should really be handled in the overall game logic.
Original issue reported on code.google.com by jgw@google.com on 13 May 2011 at 9:17
Original issue reported on code.google.com by
jgw@google.comon 13 May 2011 at 9:17