import TiledLayer from './TiledLayer' ; import { NokiaTiledLayer } from './Nokia' ; import { GoogleTiledLayer } from './Google' ; import { OsmTiledLayer } from './OpenStreetMap' ; export default class BlendTiledLayer extends TiledLayer { getTileUrl ( level , row , column ) { var array = [ NokiaTiledLayer , GoogleTiledLayer , OsmTiledLayer ] ; var sum = level + row + column ; var idx = sum % 3 ; var url = array [ idx ] . prototype . getTileUrl . apply ( this , arguments ) ; return url ; } } ;