An overlay which can be added over top of an iframe to control how user events are propagated to the iframe.
Events are captured by an overlay that covers the iframe. Those events are forwarded to the iframe via postMessage using Poster https://github.com/kevinb7/poster and then retrigger inside the iframe using EventSim https://github.com/kevinb7/eventsim.
- iframeOverlay.createOverlay(iframe)
- called in the parent to specify which iframe to create an overlay on top of
- returns an object wtih two properties: down and paused
- paused controls whether or not events are being forwarded
- iframeOverlay.createRelay(element)
- called inside the iframe to specify which element to retrigger events on
- improve the API: better naming, better way to control forwarding (maybe a delegate)