在没有加载地图的情况下，获取给定边界框的Google Map边界？

Question

I'm building a store finder and would like to implement the following workflow:

1. User enters a location
2. We geocode it using Google Geocoder
3. We examine the geocoded results for the bounding box
4. We zoom the map in to fit the specified bounds and query for stores within those bounds
5. If there are stores within the map bounds, display them all on the map
6. But if there now no stores within the map bounding box, zoom one level further out, and repeat (5) until we find some stores

The above is fine, but it would be better UX if the map did not actually appear to move until some stores have been found.

So, is it possible to query Google Maps as follows: Given a bounding box, can we find the the bounds of the correctly zoomed Google Map that contains that particular bounding box, without actually loading the Google Map?

I'm not sure it's possible, because it depends on the width of the map div in my page, I guess.

geocoder.geocode( {'address': search_text }, function(results, status) {
  if (status == google.maps.GeocoderStatus.OK) {
    map.panTo(results[0].geometry.location);
    map.fitBounds(results[0].geometry.bounds);
    var bounds_to_check_for_stores = map.getBounds();
    // QUESTION: get bounds_to_check_for_stores without the three preceding steps?
    } 
 }

Answer 1

The google.maps.LatLngBounds ^api-doc has a method: extend(point:LatLng) which will allow you to extend a bounds to ensure that the bounds are adjusted to include the LatLng point passed as a parameter. The extend method returns a LatLngBounds that has been adjusted.

With this, you could:

1. Expand the radius of your geocode lookup until you find appropriate stores.
2. Find the closest store or group of stores that you wish to use.
3. Retrieve the current bounds from the map: Map.getBounds() .
4. Call LatLngBounds.extend to adjust the bounds, using the .geometry.location property of the stores you selected in Step 2.
5. Call Map.panToBounds to change the map's viewport, keeping the user's experience simple, because only one change to the view will be performed.