Google maps v3 zoom end

Question

I have a problem with google maps v3 zoom_change, as it doesn't solve my need perfectly.

I have 2 unmet requirements:

• I need to get the bounds and show points that are inside the bounds after the user clicked in zoom control and zoom has been reajusted in the map. The method zoom_change do it before reajusting zoom, and the bounds aren't the ones I need.

• The method zoom_change is called every time, for example, whenever I execute fitBounds or setZoom. I only need it when when zoomcontrol is clicked or when mousewheel is moved.

Is there a solution available in the v3 API for those issues?

Answer 1

Listen for the idle event.

From Google Maps Javascript API V3 Reference:

idle: This event is fired when the map becomes idle after panning or zooming.

Answer 2

The event is called zoom_changed (NOTzoom_change). The event handler of this event is called AFTER the zoom has changed. It is indeed not straightforward to distnguish the zoom change caused by the user from that one caused by the program. A possible solution is to maintain a "global" variable say userZoom which denotes whether the user triggered the zoom.

var userZoom = true; // initial value: be prepared for user action
// Install listener
google.maps.event.addListener(Map.self, 'zoom_changed', function() {
    if (userZoom) {      
        // the user changed zoom: do what should be done
    }
    else {
        // zoom change caused by a program action: ignore
    }
    userZoom = true;  // be prepared for the user zoom action    
});

Before you call any of the program actions that change the zoom, set userZoom = false, e.g.

userZoom = false;
map.setZoom(9);