HTML panel: "image changed" event in CC/CC2014?

Hi everyone,

I want to make a panel that would register if an image underwent any change (to be more specific, brush stroke). AFAIK this can be done via Generator and imageChanged event but I really this on a panel.

So my questions are:

1) Is there a way to get image changed event on a panel in CC/CC2014? (I think in CC2015 CEP6 there's such an event, but I'm on CC2014)

2) If now, is there a way to communicate between Generator scripts and panels, for example to turn Generator on and off from the panel.

Thanks!