/**
 * @license
 * Copyright 2021 Google Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
import { MDCFoundation } from './foundation';
import { type Observer, type ObserverRecord } from './observer';
export declare class MDCObserverFoundation<Adapter> extends MDCFoundation<Adapter> {
    /** A set of cleanup functions to unobserve changes. */
    protected unobserves: Set<Function>;
    constructor(adapter: Adapter);
    destroy(): void;
    /**
     * Observe a target's properties for changes using the provided map of
     * property names and observer functions.
     *
     * @template T The target type.
     * @param target - The target to observe.
     * @param observers - An object whose keys are target properties and values
     *     are observer functions that are called when the associated property
     *     changes.
     * @return A cleanup function that can be called to unobserve the
     *     target.
     */
    protected observe<T extends object>(target: T, observers: ObserverRecord<T, this>): () => void;
    /**
     * Observe a target's property for changes. When a property changes, the
     * provided `Observer` function will be invoked with the properties current
     * and previous values.
     *
     * The returned cleanup function will stop listening to changes for the
     * provided `Observer`.
     *
     * @template T The observed target type.
     * @template K The observed property.
     * @param target - The target to observe.
     * @param property - The property of the target to observe.
     * @param observer - An observer function to invoke each time the property
     *     changes.
     * @return A cleanup function that will stop observing changes for the
     *     provided `Observer`.
     */
    protected observeProperty<T extends object, K extends keyof T>(target: T, property: K, observer: Observer<T, K>): () => void;
    /**
     * Enables or disables all observers for the provided target. Disabling
     * observers will prevent them from being called until they are re-enabled.
     *
     * @param target - The target to enable or disable observers for.
     * @param enabled - Whether or not observers should be called.
     */
    protected setObserversEnabled(target: object, enabled: boolean): void;
    /**
     * Clean up all observers and stop listening for property changes.
     */
    protected unobserve(): void;
}