@openui5/sap.ui.core/src/sap/ui/dom/activeElementFix.js

OpenUI5 Core Library sap.ui.core

/*!
 * OpenUI5
 * (c) Copyright 2009-2021 SAP SE or an SAP affiliate company.
 * Licensed under the Apache License, Version 2.0 - see LICENSE.txt.
 */
/*
 * IMPORTANT: This is a private module, its API must not be used and is subject to change.
 * Code other than the OpenUI5 libraries must not introduce dependencies to this module.
 */

sap.ui.define(["sap/base/Log"], function(Log) {
	"use strict";

	/*
	 * Fix for accessing <code>document.activeElement</code> synchronously from within an iframe while that iframe is loading.
	 * In IE11 and some versions of Edge this leads to an "Unspecified error" exception.
	 *
	 * This code will suppress that exception.
	 */
	return function() {
		var desc = Object.getOwnPropertyDescriptor(Document.prototype, 'activeElement');
		if (!desc) {
			Log.warning("activeElementFix: Unable to retrieve property descriptor for 'Document.prototype.activeElement'");
			return;
		}

		var getActiveElement = desc.get;
		if (!getActiveElement) {
			Log.warning("activeElementFix: Unable to retrieve getter of property 'Document.prototype.activeElement'");
			return;
		}

		Object.defineProperty(Document.prototype, 'activeElement', {
			configurable: true,
			enumerable: true,
			get: function() {
				var ae = null;
				try {
					ae = getActiveElement.call(this);
				} catch (e) {
					// ignore
				}
				return (ae && ae.nodeType) ? ae : document.body;
			}
		});
	};
});