TableFilter/src/event.js

import {root} from './root';

/**
 * DOM event utilities
 */

export default {
    /**
     * Add event handler for specified event on passed element
     *
     * @param {DOMElement} obj Element
     * @param {String} type Event type
     * @param {Function} Handler
     * @param {Boolean} capture Specifiy whether the event should be executed in
     * the capturing or in the bubbling phase
     */
    add(obj, type, func, capture) {
        if (obj.addEventListener) {
            obj.addEventListener(type, func, capture);
        }
        else if (obj.attachEvent) {
            obj.attachEvent('on' + type, func);
        } else {
            obj['on' + type] = func;
        }
    },
    /**
     * Remove event handler for specified event on passed element
     *
     * @param {DOMElement} obj Element
     * @param {String} type Event type
     * @param {Function} Handler
     * @param {Boolean} capture Specifiy whether the event should be executed in
     * the capturing or in the bubbling phase
     */
    remove(obj, type, func, capture) {
        if (obj.detachEvent) {
            obj.detachEvent('on' + type, func);
        }
        else if (obj.removeEventListener) {
            obj.removeEventListener(type, func, capture);
        } else {
            obj['on' + type] = null;
        }
    },
    /**
     * Prevents further propagation of the current event in the bubbling phase
     *
     * @param {Event} evt Event on the DOM
     */
    stop(evt) {
        if (!evt) {
            evt = root.event;
        }
        if (evt.stopPropagation) {
            evt.stopPropagation();
        } else {
            evt.cancelBubble = true;
        }
    },
    /**
     * Cancels the event if it is cancelable, without stopping further
     * propagation of the event.
     *
     * @param {Event} evt Event on the DOM
     */
    cancel(evt) {
        if (!evt) {
            evt = root.event;
        }
        if (evt.preventDefault) {
            evt.preventDefault();
        } else {
            evt.returnValue = false;
        }
    },
    /**
     * Reference to the object that dispatched the event
     *
     * @param {Event} evt Event on the DOM
     * @returns {DOMElement}
     */
    target(evt) {
        if (!evt) {
            evt = root.event;
        }
        return evt.target || evt.srcElement;
    },
    /**
     * Returns the Unicode value of pressed key
     *
     * @param {Event} evt Event on the DOM
     * @returns {Number}
     */
    keyCode(evt) {
        return evt.charCode ? evt.charCode :
            (evt.keyCode ? evt.keyCode : (evt.which ? evt.which : 0));
    }
};