export interface TimerStartOptions {
    /** Invokes a timer callback immediately and starts the timer. */
    readonly immediately?: boolean | undefined;
    /** Stops after a timer callback is invoked. */
    readonly once?: boolean | undefined;
}
interface TimerStopOptions {
    /** If there is a pending invocation of the callback function, invoke it immediately. */
    readonly flush?: boolean;
}
export interface Timer {
    /** @deprecated Use isActive(). */
    readonly active: boolean;
    readonly isActive: () => boolean;
    readonly start: (options?: TimerStartOptions) => void;
    readonly stop: (options?: TimerStopOptions) => void;
    readonly pause: VoidFunction;
    readonly getState: () => 'active' | 'stopped' | 'paused';
}
interface Options {
    readonly callback: ((timer: Timer) => void) | ((timer: Timer) => Promise<void>);
    /** - function - can be used as a dynamically changing timer interval (evaluated at each timer tick). */
    readonly interval: number | (() => number);
    /** Defaults to `true`. */
    readonly autostart?: boolean | undefined;
    /** Used only if `interval` is a function and callback returns `Promise`. */
    readonly waitCallback?: boolean | undefined;
    readonly onStart?: VoidFunction | undefined;
    readonly onStop?: VoidFunction | undefined;
    readonly onPause?: VoidFunction | undefined;
}
export declare function getTimer({ callback, interval, onStart, onStop, onPause, autostart, waitCallback, }: Options): Timer;
export {};