/**
 * Copyright 2023 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
/// <reference types="google.maps" />
/** The MapState type describes the current viewport state of the map. */
export type MapState = {
    zoom: number;
    heading: number;
    tilt: number;
    center: google.maps.LatLng;
    bounds: google.maps.LatLngBounds;
};
export type MapStateListener = (state: MapState) => void;
/**
 * Since we have many more markers than maps, it doesn't make sense to have each
 * marker observe the map for changes by itself. Instead, a MapStateObserver is
 * created for every map that receives 'bounds_changed'-events from the map and
 * triggers updates for all added markers.
 */
export declare class MapStateObserver {
    private static instances_;
    /**
     * Returns the observer instance for the given map.
     *
     * @param map
     */
    static getInstance(map: google.maps.Map): MapStateObserver;
    private map_;
    private mapState_;
    private listeners_;
    private constructor();
    /**
     * Add a listener to be notified of map-state changes.
     *
     * @param callback
     */
    addListener(callback: MapStateListener): google.maps.MapsEventListener;
    /**
     * Returns the map-state as it will be passed into the dynamic attribute
     * callbacks of the markers.
     */
    getMapState(): MapState;
    private handleBoundsChange;
}