/**
* Copyright (c) 2000-present Liferay, Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
* details.
*/
/**
* Checks if element is disabled or whether it exists in a disabled element tree
* @param {!Element} element The DOM element to check.
* @return {boolean}
*/
function isDisabled(node) {
return !!(node.disabled || node.closest('[disabled]'));
}
/**
* Listens to the specified event on the given DOM element, but only calls the
* given callback listener when it's triggered by elements that match the
* given selector or target element.
* @param {!Element} element The DOM element the event should be listened on.
* @param {string} eventName The name of the event to listen to.
* @param {string} selector Css selector that should match the event for the
* listener to be triggered.
* @param {!function(!Object)} callback Function to be called when the event
* is triggered. It will receive the normalized event object.
* @return {function} Can be used to remove the listener.
*/
function delegate(element, eventName, selector, callback) {
const eventHandler = (event) => {
const {defaultPrevented, target} = event;
if (defaultPrevented || (eventName === 'click' && isDisabled(target))) {
return;
}
const delegateTarget = target.closest(selector);
if (delegateTarget) {
event.delegateTarget = delegateTarget;
callback(event);
}
};
element.addEventListener(eventName, eventHandler);
return {
dispose() {
element.removeEventListener(eventName, eventHandler);
},
};
}
export default delegate;