import type { ISubscribable } from "../events/ISubscribable";
import type { ISubscription } from "../events/ISubscription";
import type { SubscriptionChangeEventHandler } from "./SubscriptionChangeEventHandler";
import type { IPropagationStatus } from "./IPropagationStatus";
/**
 * Base class for implementation of the dispatcher. It facilitates the subscribe
 * and unsubscribe methods based on generic handlers. The TEventType specifies
 * the type of event that should be exposed. Use the asEvent to expose the
 * dispatcher as event.
 *
 * @export
 * @abstract
 * @class DispatcherBase
 * @implements {ISubscribable<TEventHandler>}
 * @template TEventHandler The type of event handler.
 */
export declare abstract class DispatcherBase<TEventHandler> implements ISubscribable<TEventHandler> {
    private _wrap;
    private _onSubscriptionChange;
    /**
     * The subscriptions.
     *
     * @protected
     *
     * @memberOf DispatcherBase
     */
    protected _subscriptions: ISubscription<TEventHandler>[];
    /**
     * Returns the number of subscriptions.
     *
     * @readonly
     * @type {number}
     * @memberOf DispatcherBase
     */
    get count(): number;
    /**
     * Triggered when subscriptions are changed (added or removed).
     *
     * @readonly
     * @type {ISubscribable<SubscriptionChangeEventHandler>}
     * @memberOf DispatcherBase
     */
    get onSubscriptionChange(): ISubscribable<SubscriptionChangeEventHandler>;
    /**
     * Subscribe to the event dispatcher.
     *
     * @param {TEventHandler} fn The event handler that is called when the event is dispatched.
     * @returns A function that unsubscribes the event handler from the event.
     *
     * @memberOf DispatcherBase
     */
    subscribe(fn: TEventHandler): () => void;
    /**
     * Subscribe to the event dispatcher.
     *
     * @param {TEventHandler} fn The event handler that is called when the event is dispatched.
     * @returns A function that unsubscribes the event handler from the event.
     *
     * @memberOf DispatcherBase
     */
    sub(fn: TEventHandler): () => void;
    /**
     * Subscribe once to the event with the specified name.
     *
     * @param {TEventHandler} fn The event handler that is called when the event is dispatched.
     * @returns A function that unsubscribes the event handler from the event.
     *
     * @memberOf DispatcherBase
     */
    one(fn: TEventHandler): () => void;
    /**
     * Checks it the event has a subscription for the specified handler.
     *
     * @param {TEventHandler} fn The event handler.
     *
     * @memberOf DispatcherBase
     */
    has(fn: TEventHandler): boolean;
    /**
     * Unsubscribes the handler from the dispatcher.
     *
     * @param {TEventHandler} fn The event handler.
     *
     * @memberOf DispatcherBase
     */
    unsubscribe(fn: TEventHandler): void;
    /**
     * Unsubscribes the handler from the dispatcher.
     *
     * @param {TEventHandler} fn The event handler.
     *
     * @memberOf DispatcherBase
     */
    unsub(fn: TEventHandler): void;
    /**
     * Generic dispatch will dispatch the handlers with the given arguments.
     *
     * @protected
     * @param {boolean} executeAsync `True` if the even should be executed async.
     * @param {*} scope The scope of the event. The scope becomes the `this` for handler.
     * @param {IArguments} args The arguments for the event.
     * @returns {(IPropagationStatus | null)} The propagation status, or if an `executeAsync` is used `null`.
     *
     * @memberOf DispatcherBase
     */
    protected _dispatch(executeAsync: boolean, scope: any, args: IArguments): IPropagationStatus | null;
    /**
     * Creates a subscription.
     *
     * @protected
     * @param {TEventHandler} handler The handler.
     * @param {boolean} isOnce True if the handler should run only one.
     * @returns {ISubscription<TEventHandler>} The subscription.
     *
     * @memberOf DispatcherBase
     */
    protected createSubscription(handler: TEventHandler, isOnce: boolean): ISubscription<TEventHandler>;
    /**
     * Cleans up subs that ran and should run only once.
     *
     * @protected
     * @param {ISubscription<TEventHandler>} sub The subscription.
     *
     * @memberOf DispatcherBase
     */
    protected cleanup(sub: ISubscription<TEventHandler>): void;
    /**
     * Creates an event from the dispatcher. Will return the dispatcher
     * in a wrapper. This will prevent exposure of any dispatcher methods.
     *
     * @returns {ISubscribable<TEventHandler>}
     *
     * @memberOf DispatcherBase
     */
    asEvent(): ISubscribable<TEventHandler>;
    /**
     * Clears the subscriptions.
     *
     * @memberOf DispatcherBase
     */
    clear(): void;
    /**
     * Triggers the subscription change event.
     *
     * @private
     *
     * @memberOf DispatcherBase
     */
    private triggerSubscriptionChange;
}
/**
 * Dispatcher for subscription changes.
 *
 * @export
 * @class SubscriptionChangeEventDispatcher
 * @extends {DispatcherBase<SubscriptionChangeEventHandler>}
 */
export declare class SubscriptionChangeEventDispatcher extends DispatcherBase<SubscriptionChangeEventHandler> {
    /**
     * Dispatches the event.
     *
     * @param {number} count The currrent number of subscriptions.
     *
     * @memberOf SubscriptionChangeEventDispatcher
     */
    dispatch(count: number): void;
}