I have seen many questions in the forum, about how to capture the data of the polygons, polylines and circles by clicking on them. These events are not built into the GoogleMap or GoogleMapExtras libraries. But I managed to capture these and other events. Here is an example:
I put a marker in center of polyline. For all polylines. When I clic on the yellow marker, I show all informations about that polyline from db. That's work very well for all yellow markers.