+ _updateZoomLevels: function () {
+ var i,
+ minZoom = Infinity,
+ maxZoom = -Infinity;
+
+ for (i in this._zoomBoundLayers) {
+ if (this._zoomBoundLayers.hasOwnProperty(i)) {
+ var layer = this._zoomBoundLayers[i];
+ if (!isNaN(layer.options.minZoom)) {
+ minZoom = Math.min(minZoom, layer.options.minZoom);
+ }
+ if (!isNaN(layer.options.maxZoom)) {
+ maxZoom = Math.max(maxZoom, layer.options.maxZoom);
+ }
+ }
+ }
+
+ if (i === undefined) { // we have no tilelayers
+ this._layersMaxZoom = this._layersMinZoom = undefined;
+ } else {
+ this._layersMaxZoom = maxZoom;
+ this._layersMinZoom = minZoom;
+ }
+ },