export declare type EventCallbackData = unknown;
export interface EventCallback {
    (data: EventCallbackData, event: string): void;
}
interface EventSubscriber {
    callback: EventCallback;
    key?: string;
}
interface EventSubscribers {
    [key: string]: EventSubscriber[];
}
/**
 * Events class
 */
export declare class Events {
    protected readonly _subscribers: EventSubscribers;
    /**
     * Subscribe to event
     *
     * @param event Event name
     * @param callback Callback function
     * @param key Optional unique key for unsubscribe. If key is set, any other event listener with same key will be removed
     */
    subscribe(event: string, callback: EventCallback, key?: string): void;
    /**
     * Unsubscribe from event
     *
     * @param event Event name
     * @param value Callback or key
     */
    unsubscribe(event: string, value: EventCallback | string): void;
    /**
     * Check if event has listeners
     *
     * @param event Event name
     */
    hasListeners(event: string): boolean;
    /**
     * Fire event
     *
     * @param event Event name
     * @param data Payload
     * @param delay True if event should fire on next tick
     */
    fire(event: string, data: EventCallbackData, delay?: boolean): void;
    /**
     * Fire event
     *
     * @param event
     * @param data
     */
    _fire(event: string, data: EventCallbackData): void;
}
export {};
//# sourceMappingURL=events.d.ts.map