import { Events } from './Events';
/**
 * observe property change.
 */
export declare namespace observe {
    /**
     * get events of target object.
     *
     * @export
     * @param {*} target
     * @returns {Events}
     */
    function getEvents(target: any): Events;
    /**
     * target has envents or not.
     *
     * @export
     * @param {*} target
     * @returns {boolean}
     */
    function hasEvents(target: any): boolean;
    /**
     * on property change.
     *
     * @export
     * @param {*} target subscribe change handle of target.
     * @param {(string | ((tag: T) => any))} property subscribe change handle of target property.
     * @param {(vaule?: any, old?: any, target?: any, prop?: string) => void} onChange change handle.
     * @returns
     */
    function onPropertyChange<T extends Object = any>(target: T, property: string | ((tag: T) => any), onChange: (vaule?: any, old?: any, target?: T, prop?: string) => void, changed?: (target?: T, prop?: string, vaule?: any, old?: any) => void): void;
    /**
     * on property changed.
     *
     * @export
     * @template T
     * @param {T} target
     * @param {(string | ((tag: T) => any))} property
     * @param {(vaule?: any, old?: any, target?: T, prop?: string) => void} callback
     */
    function onChanged<T extends Object = any>(target: T, property: string | ((tag: T) => any), callback: (vaule?: any, old?: any, target?: T, prop?: string) => void, changed?: (target?: T, prop?: string, vaule?: any, old?: any) => void): void;
}