@exmg/lit-base/src/utils/debounce/debounce.d.ts

Lit Base Elements for ExMachina

/**
@license
Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
Code distributed by Google as part of the polymer project is also
subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
*/
import './async.js';
import { AsyncInterface } from './async.js';
/**
 * @summary Collapse multiple callbacks into one invocation after a timer.
 */
export declare class Debouncer {
    _asyncModule: AsyncInterface | null;
    _callback: Function | null;
    _timer: number | null;
    /**
     * Sets the scheduler; that is, a module with the Async interface,
     * a callback and optional arguments to be passed to the run function
     * from the async module.
     *
     * @param {!AsyncInterface} asyncModule Object with Async interface.
     * @param {function()} callback Callback to run.
     * @return {void}
     */
    setConfig(asyncModule: AsyncInterface, callback: Function): void;
    /**
     * Cancels an active debouncer and returns a reference to itself.
     *
     * @return {void}
     */
    cancel(): void;
    /**
     * Cancels a debouncer's async callback.
     *
     * @return {void}
     */
    _cancelAsync(): void;
    /**
     * Flushes an active debouncer and returns a reference to itself.
     *
     * @return {void}
     */
    flush(): void;
    /**
     * Returns true if the debouncer is active.
     *
     * @return {boolean} True if active.
     */
    isActive(): boolean;
    /**
     * Creates a debouncer if no debouncer is passed as a parameter
     * or it cancels an active debouncer otherwise. The following
     * example shows how a debouncer can be called multiple times within a
     * microtask and "debounced" such that the provided callback function is
     * called once. Add this method to a custom element:
     *
     * ```js
     * import {microTask} from '@polymer/polymer/lib/utils/async.js';
     * import {Debouncer} from '@polymer/polymer/lib/utils/debounce.js';
     * // ...
     *
     * _debounceWork() {
     *   this._debounceJob = Debouncer.debounce(this._debounceJob,
     *       microTask, () => this._doWork());
     * }
     * ```
     *
     * If the `_debounceWork` method is called multiple times within the same
     * microtask, the `_doWork` function will be called only once at the next
     * microtask checkpoint.
     *
     * Note: In testing it is often convenient to avoid asynchrony. To accomplish
     * this with a debouncer, you can use `enqueueDebouncer` and
     * `flush`. For example, extend the above example by adding
     * `enqueueDebouncer(this._debounceJob)` at the end of the
     * `_debounceWork` method. Then in a test, call `flush` to ensure
     * the debouncer has completed.
     *
     * @param {Debouncer?} debouncer Debouncer object.
     * @param {!AsyncInterface} asyncModule Object with Async interface
     * @param {function()} callback Callback to run.
     * @return {!Debouncer} Returns a debouncer object.
     */
    static debounce(debouncer: Debouncer, asyncModule: AsyncInterface, callback: Function): Debouncer;
}
/**
 * Adds a `Debouncer` to a list of globally flushable tasks.
 *
 * @param {!Debouncer} debouncer Debouncer to enqueue
 * @return {void}
 */
export declare const enqueueDebouncer: (debouncer: any) => void;
/**
 * Flushes any enqueued debouncers
 *
 * @return {boolean} Returns whether any debouncers were flushed
 */
export declare const flushDebouncers: () => boolean;