import { LayerJSONType } from '../Layer';
import TileLayer, { TileLayerOptionsType, TilesType } from './TileLayer';
import Size from '../../geo/Size';
/**
 * @classdesc
 * A layer used to display a group of tile layers. <br>
 * Its performance is better than add TileLayers seperately and it can help prevent limits of active webgl contexts: <br>
 * "WARNING: Too many active WebGL contexts. Oldest context will be lost"
 * @category layer
 * @extends TileLayer
 * @param {String|Number} id - tile layer's id
 * @param {TileLayer[]} layers  - TileLayers to add
 * @param {Object} [options=null] - options defined in [TileLayer]{@link TileLayer#options}
 * @example
 * new GroupTileLayer("group-tiles",[
    new maptalks.WMSTileLayer('wms', {
      'urlTemplate' : 'https://demo.boundlessgeo.com/geoserver/ows',
      'crs' : 'EPSG:3857',
      'layers' : 'ne:ne',
      'styles' : '',
      'version' : '1.3.0',
      'format': 'image/png',
      'transparent' : true,
      'uppercase' : true
    }),
    new maptalks.TileLayer('tile2',{
      urlTemplate: 'http://korona.geog.uni-heidelberg.de/tiles/adminb/x={x}&y={y}&z={z}'
    })
  ])
 */
declare class GroupTileLayer extends TileLayer {
    layers: TileLayer[];
    layerMap: Record<string, TileLayer>;
    /**
     * Reproduce a GroupTileLayer from layer's profile JSON.
     * @param layerJSON - layer's profile JSON
     * @return
     * @static
     * @private
     * @function
     */
    static fromJSON(layerJSON: {
        [x: string]: any;
    }): GroupTileLayer;
    /**
     * @param id    - layer's id
     * @param layers  - TileLayers to add
     * @param [options=null]          - construct options
     * @param [options.*=null]             - options defined in [TileLayer]{@link TileLayer#options}
     */
    constructor(id: string, layers: TileLayer[], options?: GroupTileLayerOptionsType);
    /**
     * Get children TileLayer
     */
    getLayers(): TileLayer[];
    /**
     * add tilelayers
     * @param tileLayers
     */
    addLayer(tileLayers?: TileLayer[]): this;
    /**
     * remove tilelayers
     * @param tileLayers
     */
    removeLayer(tileLayers?: TileLayer[]): this;
    /**
   * clear tilelayers
   */
    clearLayers(): this;
    /**
     * Export the GroupTileLayer's profile json. <br>
     * Layer's profile is a snapshot of the layer in JSON format. <br>
     * It can be used to reproduce the instance by [fromJSON]{@link Layer#fromJSON} method
     * @return layer's profile JSON
     */
    toJSON(): LayerJSONType;
    getTileSize(id: number | string): Size;
    /**
     * Get tiles at zoom (or current zoom)
     * @param z
     * @returns tiles
     */
    getTiles(z: number, parentLayer: any): TilesType;
    onAdd(): void;
    onRemove(): void;
    getLayer(id: string | number): TileLayer;
    getChildLayer(id: string | number): TileLayer;
    isVisible(): boolean;
}
export default GroupTileLayer;
export type GroupTileLayerOptionsType = TileLayerOptionsType & {
    maxCacheSize?: number;
};
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