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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
/*
* Simplied selector targetting elements that can receive the focus, full
* version at http://stackoverflow.com/questions/1599660/which-html-elements-can-receive-focus
*/
const focusableSelector = [
"a[href]:not([tabindex='-1'])",
"button:not([disabled], [tabindex='-1'])",
"iframe:not([tabindex='-1'])",
"input:not([disabled], [tabindex='-1'])",
"select:not([disabled], [tabindex='-1'])",
"textarea:not([disabled], [tabindex='-1'])",
"[tabindex]:not([tabindex='-1'])",
].join(", ");
/**
* Wrap and move keyboard focus to first/last focusable element inside a container
* element to prevent the focus from escaping the container.
*
* @param {Array} elms
* focusable elements inside a container
* @param {DOMNode} current
* currently focused element inside containter
* @param {Boolean} back
* direction
* @return {DOMNode}
* newly focused element
*/
function wrapMoveFocus(elms, current, back) {
let next;
if (elms.length === 0) {
return false;
}
if (back) {
if (elms.indexOf(current) === 0) {
next = elms[elms.length - 1];
next.focus();
}
} else if (elms.indexOf(current) === elms.length - 1) {
next = elms[0];
next.focus();
}
return next;
}
/**
* Get a list of all elements that are focusable with a keyboard inside the parent element
*
* @param {DOMNode} parentEl
* parent DOM element to be queried
* @return {Array}
* array of focusable children elements inside the parent
*/
function getFocusableElements(parentEl) {
return parentEl
? Array.from(parentEl.querySelectorAll(focusableSelector))
: [];
}
// Make this available to both AMD and CJS environments
define(function(require, exports, module) {
module.exports.focusableSelector = focusableSelector;
exports.wrapMoveFocus = wrapMoveFocus;
exports.getFocusableElements = getFocusableElements;
});
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