How to listen for user generated zoom in Google Maps?

Question

I want to know when a Google Maps zoom_changed event is fired specifically by a user interaction with the +/- zoom buttons. If I use a general event listener for zoom_changed,

Answer 1

I wouldn't just hook in to the +/- buttons (or buttons on your own custom control for that matter). The user can change the zoom on the map with the mouse wheel, or by double-clicking on the map. Plus, you'd be relying on implementation detail rather than documented API, which is a major no-no.

This really means the only reliable, documented way to detect a change in zoom is to listen to the zoom_changed event of the Map.

If your event handler can't determine whether the event came from user action or an API call, there's two approaches:

• Set a flag before calling an API function so that you know you can ignore this change.
• Can you re-architect your app such that it does not matter whether a zoom change came from code or the user?