I have a Google map where as the user moves around the blue dot (myLocation) moves - standard behaviour. This works well until the user moves beyond the bounds of the current zoom level - and the blue dot disappears off one of the edges of the map. I don't want to refocus the map every single time that the user moves and I get a location update - it isn't necessary for the myLocation dot to always be in the center of the screen - but it is necessary for the myLocation to always be visible, so if the user moves off one side of the map I want to refocus the map so that he becomes visible again.
How can I tell that the myLocation has moved out of the visible area of the screen?