import { IScheduler } from '../Scheduler';
import { Observable } from '../Observable';
import { TeardownLogic } from '../Subscription';
import { Subscriber } from '../Subscriber';
/**
 * We need this JSDoc comment for affecting ESDoc.
 * @extends {Ignored}
 * @hide true
 */
export declare class TimerObservable extends Observable<number> {
    /**
     * Creates an Observable that starts emitting after an `initialDelay` and
     * emits ever increasing numbers after each `period` of time thereafter.
     *
     * <span class="informal">Its like {@link interval}, but you can specify when
     * should the emissions start.</span>
     *
     * <img src="./img/timer.png" width="100%">
     *
     * `timer` returns an Observable that emits an infinite sequence of ascending
     * integers, with a constant interval of time, `period` of your choosing
     * between those emissions. The first emission happens after the specified
     * `initialDelay`. The initial delay may be a {@link Date}. By default, this
     * operator uses the `async` IScheduler to provide a notion of time, but you
     * may pass any IScheduler to it. If `period` is not specified, the output
     * Observable emits only one value, `0`. Otherwise, it emits an infinite
     * sequence.
     *
     * @example <caption>Emits ascending numbers, one every second (1000ms), starting after 3 seconds</caption>
     * var numbers = Rx.Observable.timer(3000, 1000);
     * numbers.subscribe(x => console.log(x));
     *
     * @example <caption>Emits one number after five seconds</caption>
     * var numbers = Rx.Observable.timer(5000);
     * numbers.subscribe(x => console.log(x));
     *
     * @see {@link interval}
     * @see {@link delay}
     *
     * @param {number|Date} initialDelay The initial delay time to wait before
     * emitting the first value of `0`.
     * @param {number} [period] The period of time between emissions of the
     * subsequent numbers.
     * @param {Scheduler} [scheduler=async] The IScheduler to use for scheduling
     * the emission of values, and providing a notion of "time".
     * @return {Observable} An Observable that emits a `0` after the
     * `initialDelay` and ever increasing numbers after each `period` of time
     * thereafter.
     * @static true
     * @name timer
     * @owner Observable
     */
    static create(initialDelay?: number | Date, period?: number | IScheduler, scheduler?: IScheduler): Observable<number>;
    static dispatch(state: any): any;
    private period;
    private dueTime;
    private scheduler;
    constructor(dueTime?: number | Date, period?: number | IScheduler, scheduler?: IScheduler);
    protected _subscribe(subscriber: Subscriber<number>): TeardownLogic;
}
