Equivalent of getBoundsZoomLevel() in gmaps api 3
In API v2, the map object had a handy method getBoundsZoomLevel(). I used it to get the zoom level which fits the bounds best, then manipulated this optimal zoom level somehow and finally set the desired zoom level.
I cannot find similar function in API v3. (What a continuous frustrating experience when moving from v2 to v3)
Do I really have to use map.fitBounds() , map.getZoom() , manipulate and setZoom() again? That's really stupid!
以下是我实施的功能：
/**
* Returns the zoom level at which the given rectangular region fits in the map view.
* The zoom level is computed for the currently selected map type.
* @param {google.maps.Map} map
* @param {google.maps.LatLngBounds} bounds
* @return {Number} zoom level
**/
function getZoomByBounds( map, bounds ){
var MAX_ZOOM = map.mapTypes.get( map.getMapTypeId() ).maxZoom || 21 ;
var MIN_ZOOM = map.mapTypes.get( map.getMapTypeId() ).minZoom || 0 ;
var ne= map.getProjection().fromLatLngToPoint( bounds.getNorthEast() );
var sw= map.getProjection().fromLatLngToPoint( bounds.getSouthWest() );
var worldCoordWidth = Math.abs(ne.x-sw.x);
var worldCoordHeight = Math.abs(ne.y-sw.y);
//Fit padding in pixels
var FIT_PAD = 40;
for( var zoom = MAX_ZOOM; zoom >= MIN_ZOOM; --zoom ){
if( worldCoordWidth*(1<<zoom)+2*FIT_PAD < $(map.getDiv()).width() &&
worldCoordHeight*(1<<zoom)+2*FIT_PAD < $(map.getDiv()).height() )
return zoom;
}
return 0;
}