/* eslint-disable */ // @ts-nocheck
// Copied from https://github.com/medialize/ally.js
// License: MIT
// Copyright (c) 2015 Rodney Rehm
//
// Entrypoint: ally.js/maintain/tab-focus
import _platform from "next/dist/compiled/platform";
import cssEscape from "next/dist/compiled/css.escape";
// input may be undefined, selector-tring, Node, NodeList, HTMLCollection, array of Nodes
// yes, to some extent this is a bad replica of jQuery's constructor function
function nodeArray(input) {
    if (!input) {
        return [];
    }
    if (Array.isArray(input)) {
        return input;
    }
    // instanceof Node - does not work with iframes
    if (input.nodeType !== undefined) {
        return [
            input
        ];
    }
    if (typeof input === "string") {
        input = document.querySelectorAll(input);
    }
    if (input.length !== undefined) {
        return [].slice.call(input, 0);
    }
    throw new TypeError("unexpected input " + String(input));
}
function contextToElement(_ref) {
    var context = _ref.context, _ref$label = _ref.label, label = _ref$label === undefined ? "context-to-element" : _ref$label, resolveDocument = _ref.resolveDocument, defaultToDocument = _ref.defaultToDocument;
    var element = nodeArray(context)[0];
    if (resolveDocument && element && element.nodeType === Node.DOCUMENT_NODE) {
        element = element.documentElement;
    }
    if (!element && defaultToDocument) {
        return document.documentElement;
    }
    if (!element) {
        throw new TypeError(label + " requires valid options.context");
    }
    if (element.nodeType !== Node.ELEMENT_NODE && element.nodeType !== Node.DOCUMENT_FRAGMENT_NODE) {
        throw new TypeError(label + " requires options.context to be an Element");
    }
    return element;
}
function getShadowHost() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context;
    var element = contextToElement({
        label: "get/shadow-host",
        context: context
    });
    // walk up to the root
    var container = null;
    while(element){
        container = element;
        element = element.parentNode;
    }
    // https://developer.mozilla.org/en-US/docs/Web/API/Node.nodeType
    // NOTE: Firefox 34 does not expose ShadowRoot.host (but 37 does)
    if (container.nodeType === container.DOCUMENT_FRAGMENT_NODE && container.host) {
        // the root is attached to a fragment node that has a host
        return container.host;
    }
    return null;
}
function getDocument(node) {
    if (!node) {
        return document;
    }
    if (node.nodeType === Node.DOCUMENT_NODE) {
        return node;
    }
    return node.ownerDocument || document;
}
function isActiveElement(context) {
    var element = contextToElement({
        label: "is/active-element",
        resolveDocument: true,
        context: context
    });
    var _document = getDocument(element);
    if (_document.activeElement === element) {
        return true;
    }
    var shadowHost = getShadowHost({
        context: element
    });
    if (shadowHost && shadowHost.shadowRoot.activeElement === element) {
        return true;
    }
    return false;
}
// [elem, elem.parent, elem.parent.parent, …, html]
// will not contain the shadowRoot (DOCUMENT_FRAGMENT_NODE) and shadowHost
function getParents() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context;
    var list = [];
    var element = contextToElement({
        label: "get/parents",
        context: context
    });
    while(element){
        list.push(element);
        // IE does know support parentElement on SVGElement
        element = element.parentNode;
        if (element && element.nodeType !== Node.ELEMENT_NODE) {
            element = null;
        }
    }
    return list;
}
// Element.prototype.matches may be available at a different name
// https://developer.mozilla.org/en/docs/Web/API/Element/matches
var names = [
    "matches",
    "webkitMatchesSelector",
    "mozMatchesSelector",
    "msMatchesSelector"
];
var name = null;
function findMethodName(element) {
    names.some(function(_name) {
        if (!element[_name]) {
            return false;
        }
        name = _name;
        return true;
    });
}
function elementMatches(element, selector) {
    if (!name) {
        findMethodName(element);
    }
    return element[name](selector);
}
// deep clone of original platform
var platform = JSON.parse(JSON.stringify(_platform));
// operating system
var os = platform.os.family || "";
var ANDROID = os === "Android";
var WINDOWS = os.slice(0, 7) === "Windows";
var OSX = os === "OS X";
var IOS = os === "iOS";
// layout
var BLINK = platform.layout === "Blink";
var GECKO = platform.layout === "Gecko";
var TRIDENT = platform.layout === "Trident";
var EDGE = platform.layout === "EdgeHTML";
var WEBKIT = platform.layout === "WebKit";
// browser version (not layout engine version!)
var version = parseFloat(platform.version);
var majorVersion = Math.floor(version);
platform.majorVersion = majorVersion;
platform.is = {
    // operating system
    ANDROID: ANDROID,
    WINDOWS: WINDOWS,
    OSX: OSX,
    IOS: IOS,
    // layout
    BLINK: BLINK,
    GECKO: GECKO,
    TRIDENT: TRIDENT,
    EDGE: EDGE,
    WEBKIT: WEBKIT,
    // INTERNET EXPLORERS
    IE9: TRIDENT && majorVersion === 9,
    IE10: TRIDENT && majorVersion === 10,
    IE11: TRIDENT && majorVersion === 11
};
function before() {
    var data = {
        // remember what had focus to restore after test
        activeElement: document.activeElement,
        // remember scroll positions to restore after test
        windowScrollTop: window.scrollTop,
        windowScrollLeft: window.scrollLeft,
        bodyScrollTop: document.body.scrollTop,
        bodyScrollLeft: document.body.scrollLeft
    };
    // wrap tests in an element hidden from screen readers to prevent them
    // from announcing focus, which can be quite irritating to the user
    var iframe = document.createElement("iframe");
    iframe.setAttribute("style", "position:absolute; position:fixed; top:0; left:-2px; width:1px; height:1px; overflow:hidden;");
    iframe.setAttribute("aria-live", "off");
    iframe.setAttribute("aria-busy", "true");
    iframe.setAttribute("aria-hidden", "true");
    document.body.appendChild(iframe);
    var _window = iframe.contentWindow;
    var _document = _window.document;
    _document.open();
    _document.close();
    var wrapper = _document.createElement("div");
    _document.body.appendChild(wrapper);
    data.iframe = iframe;
    data.wrapper = wrapper;
    data.window = _window;
    data.document = _document;
    return data;
}
// options.element:
//  {string} element name
//  {function} callback(wrapper, document) to generate an element
// options.mutate: (optional)
//  {function} callback(element, wrapper, document) to manipulate element prior to focus-test.
//             Can return DOMElement to define focus target (default: element)
// options.validate: (optional)
//  {function} callback(element, focusTarget, document) to manipulate test-result
function test(data, options) {
    // make sure we operate on a clean slate
    data.wrapper.innerHTML = "";
    // create dummy element to test focusability of
    var element = typeof options.element === "string" ? data.document.createElement(options.element) : options.element(data.wrapper, data.document);
    // allow callback to further specify dummy element
    // and optionally define element to focus
    var focus = options.mutate && options.mutate(element, data.wrapper, data.document);
    if (!focus && focus !== false) {
        focus = element;
    }
    // element needs to be part of the DOM to be focusable
    !element.parentNode && data.wrapper.appendChild(element);
    // test if the element with invalid tabindex can be focused
    focus && focus.focus && focus.focus();
    // validate test's result
    return options.validate ? options.validate(element, focus, data.document) : data.document.activeElement === focus;
}
function after(data) {
    // restore focus to what it was before test and cleanup
    if (data.activeElement === document.body) {
        document.activeElement && document.activeElement.blur && document.activeElement.blur();
        if (platform.is.IE10) {
            // IE10 does not redirect focus to <body> when the activeElement is removed
            document.body.focus();
        }
    } else {
        data.activeElement && data.activeElement.focus && data.activeElement.focus();
    }
    document.body.removeChild(data.iframe);
    // restore scroll position
    window.scrollTop = data.windowScrollTop;
    window.scrollLeft = data.windowScrollLeft;
    document.body.scrollTop = data.bodyScrollTop;
    document.body.scrollLeft = data.bodyScrollLeft;
}
function detectFocus(tests) {
    var data = before();
    var results = {};
    Object.keys(tests).map(function(key) {
        results[key] = test(data, tests[key]);
    });
    after(data);
    return results;
}
// this file is overwritten by `npm run build:pre`
var version$1 = "1.4.1";
/*
    Facility to cache test results in localStorage.

    USAGE:
      cache.get('key');
      cache.set('key', 'value');
 */ function readLocalStorage(key) {
    // allow reading from storage to retrieve previous support results
    // even while the document does not have focus
    var data = void 0;
    try {
        data = window.localStorage && window.localStorage.getItem(key);
        data = data ? JSON.parse(data) : {};
    } catch (e) {
        data = {};
    }
    return data;
}
function writeLocalStorage(key, value) {
    if (!document.hasFocus()) {
        // if the document does not have focus when tests are executed, focus() may
        // not be handled properly and events may not be dispatched immediately.
        // This can happen when a document is reloaded while Developer Tools have focus.
        try {
            window.localStorage && window.localStorage.removeItem(key);
        } catch (e) {
        // ignore
        }
        return;
    }
    try {
        window.localStorage && window.localStorage.setItem(key, JSON.stringify(value));
    } catch (e) {
    // ignore
    }
}
var userAgent = typeof window !== "undefined" && window.navigator.userAgent || "";
var cacheKey = "ally-supports-cache";
var cache = readLocalStorage(cacheKey);
// update the cache if ally or the user agent changed (newer version, etc)
if (cache.userAgent !== userAgent || cache.version !== version$1) {
    cache = {};
}
cache.userAgent = userAgent;
cache.version = version$1;
var cache$1 = {
    get: function get() {
        return cache;
    },
    set: function set(values) {
        Object.keys(values).forEach(function(key) {
            cache[key] = values[key];
        });
        cache.time = new Date().toISOString();
        writeLocalStorage(cacheKey, cache);
    }
};
function cssShadowPiercingDeepCombinator() {
    var combinator = void 0;
    // see https://dev.w3.org/csswg/css-scoping-1/#deep-combinator
    // https://bugzilla.mozilla.org/show_bug.cgi?id=1117572
    // https://code.google.com/p/chromium/issues/detail?id=446051
    try {
        document.querySelector("html >>> :first-child");
        combinator = ">>>";
    } catch (noArrowArrowArrow) {
        try {
            // old syntax supported at least up to Chrome 41
            // https://code.google.com/p/chromium/issues/detail?id=446051
            document.querySelector("html /deep/ :first-child");
            combinator = "/deep/";
        } catch (noDeep) {
            combinator = "";
        }
    }
    return combinator;
}
var gif = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7";
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-usemap
var focusAreaImgTabindex = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = '<map name="image-map-tabindex-test">' + '<area shape="rect" coords="63,19,144,45"></map>' + '<img usemap="#image-map-tabindex-test" tabindex="-1" alt="" src="' + gif + '">';
        return element.querySelector("area");
    }
};
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-usemap
var focusAreaTabindex = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = '<map name="image-map-tabindex-test">' + '<area href="#void" tabindex="-1" shape="rect" coords="63,19,144,45"></map>' + '<img usemap="#image-map-tabindex-test" alt="" src="' + gif + '">';
        return false;
    },
    validate: function validate(element, focusTarget, _document) {
        if (platform.is.GECKO) {
            // fixes https://github.com/medialize/ally.js/issues/35
            // Firefox loads the DataURI asynchronously, causing a false-negative
            return true;
        }
        var focus = element.querySelector("area");
        focus.focus();
        return _document.activeElement === focus;
    }
};
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-usemap
var focusAreaWithoutHref = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = '<map name="image-map-area-href-test">' + '<area shape="rect" coords="63,19,144,45"></map>' + '<img usemap="#image-map-area-href-test" alt="" src="' + gif + '">';
        return element.querySelector("area");
    },
    validate: function validate(element, focusTarget, _document) {
        if (platform.is.GECKO) {
            // fixes https://github.com/medialize/ally.js/issues/35
            // Firefox loads the DataURI asynchronously, causing a false-negative
            return true;
        }
        return _document.activeElement === focusTarget;
    }
};
var focusAudioWithoutControls = {
    name: "can-focus-audio-without-controls",
    element: "audio",
    mutate: function mutate(element) {
        try {
            // invalid media file can trigger warning in console, data-uri to prevent HTTP request
            element.setAttribute("src", gif);
        } catch (e) {
        // IE9 may throw "Error: Not implemented"
        }
    }
};
var invalidGif = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ";
// NOTE: https://github.com/medialize/ally.js/issues/35
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-usemap
var focusBrokenImageMap = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = '<map name="broken-image-map-test"><area href="#void" shape="rect" coords="63,19,144,45"></map>' + '<img usemap="#broken-image-map-test" alt="" src="' + invalidGif + '">';
        return element.querySelector("area");
    }
};
// Children of focusable elements with display:flex are focusable in IE10-11
var focusChildrenOfFocusableFlexbox = {
    element: "div",
    mutate: function mutate(element) {
        element.setAttribute("tabindex", "-1");
        element.setAttribute("style", "display: -webkit-flex; display: -ms-flexbox; display: flex;");
        element.innerHTML = '<span style="display: block;">hello</span>';
        return element.querySelector("span");
    }
};
// fieldset[tabindex=0][disabled] should not be focusable, but Blink and WebKit disagree
// @specification https://www.w3.org/TR/html5/disabled-elements.html#concept-element-disabled
// @browser-issue Chromium https://crbug.com/453847
// @browser-issue WebKit https://bugs.webkit.org/show_bug.cgi?id=141086
var focusFieldsetDisabled = {
    element: "fieldset",
    mutate: function mutate(element) {
        element.setAttribute("tabindex", 0);
        element.setAttribute("disabled", "disabled");
    }
};
var focusFieldset = {
    element: "fieldset",
    mutate: function mutate(element) {
        element.innerHTML = "<legend>legend</legend><p>content</p>";
    }
};
// elements with display:flex are focusable in IE10-11
var focusFlexboxContainer = {
    element: "span",
    mutate: function mutate(element) {
        element.setAttribute("style", "display: -webkit-flex; display: -ms-flexbox; display: flex;");
        element.innerHTML = '<span style="display: block;">hello</span>';
    }
};
// form[tabindex=0][disabled] should be focusable as the
// specification doesn't know the disabled attribute on the form element
// @specification https://www.w3.org/TR/html5/forms.html#the-form-element
var focusFormDisabled = {
    element: "form",
    mutate: function mutate(element) {
        element.setAttribute("tabindex", 0);
        element.setAttribute("disabled", "disabled");
    }
};
// NOTE: https://github.com/medialize/ally.js/issues/35
// fixes https://github.com/medialize/ally.js/issues/20
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-ismap
var focusImgIsmap = {
    element: "a",
    mutate: function mutate(element) {
        element.href = "#void";
        element.innerHTML = '<img ismap src="' + gif + '" alt="">';
        return element.querySelector("img");
    }
};
// NOTE: https://github.com/medialize/ally.js/issues/35
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-usemap
var focusImgUsemapTabindex = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = '<map name="image-map-tabindex-test"><area href="#void" shape="rect" coords="63,19,144,45"></map>' + '<img usemap="#image-map-tabindex-test" tabindex="-1" alt="" ' + 'src="' + gif + '">';
        return element.querySelector("img");
    }
};
var focusInHiddenIframe = {
    element: function element(wrapper, _document) {
        var iframe = _document.createElement("iframe");
        // iframe must be part of the DOM before accessing the contentWindow is possible
        wrapper.appendChild(iframe);
        // create the iframe's default document (<html><head></head><body></body></html>)
        var iframeDocument = iframe.contentWindow.document;
        iframeDocument.open();
        iframeDocument.close();
        return iframe;
    },
    mutate: function mutate(iframe) {
        iframe.style.visibility = "hidden";
        var iframeDocument = iframe.contentWindow.document;
        var input = iframeDocument.createElement("input");
        iframeDocument.body.appendChild(input);
        return input;
    },
    validate: function validate(iframe) {
        var iframeDocument = iframe.contentWindow.document;
        var focus = iframeDocument.querySelector("input");
        return iframeDocument.activeElement === focus;
    }
};
var result = !platform.is.WEBKIT;
function focusInZeroDimensionObject() {
    return result;
}
// Firefox allows *any* value and treats invalid values like tabindex="-1"
// @browser-issue Gecko https://bugzilla.mozilla.org/show_bug.cgi?id=1128054
var focusInvalidTabindex = {
    element: "div",
    mutate: function mutate(element) {
        element.setAttribute("tabindex", "invalid-value");
    }
};
var focusLabelTabindex = {
    element: "label",
    mutate: function mutate(element) {
        element.setAttribute("tabindex", "-1");
    },
    validate: function validate(element, focusTarget, _document) {
        // force layout in Chrome 49, otherwise the element won't be focusable
        /* eslint-disable no-unused-vars */ var variableToPreventDeadCodeElimination = element.offsetHeight;
        /* eslint-enable no-unused-vars */ element.focus();
        return _document.activeElement === element;
    }
};
var svg = "data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHhtb" + "G5zOnhsaW5rPSJodHRwOi8vd3d3LnczLm9yZy8xOTk5L3hsaW5rIiBpZD0ic3ZnIj48dGV4dCB4PSIxMCIgeT0iMjAiIGlkPSJ" + "zdmctbGluay10ZXh0Ij50ZXh0PC90ZXh0Pjwvc3ZnPg==";
// Note: IE10 on BrowserStack does not like this test
var focusObjectSvgHidden = {
    element: "object",
    mutate: function mutate(element) {
        element.setAttribute("type", "image/svg+xml");
        element.setAttribute("data", svg);
        element.setAttribute("width", "200");
        element.setAttribute("height", "50");
        element.style.visibility = "hidden";
    }
};
// Note: IE10 on BrowserStack does not like this test
var focusObjectSvg = {
    name: "can-focus-object-svg",
    element: "object",
    mutate: function mutate(element) {
        element.setAttribute("type", "image/svg+xml");
        element.setAttribute("data", svg);
        element.setAttribute("width", "200");
        element.setAttribute("height", "50");
    },
    validate: function validate(element, focusTarget, _document) {
        if (platform.is.GECKO) {
            // Firefox seems to be handling the object creation asynchronously and thereby produces a false negative test result.
            // Because we know Firefox is able to focus object elements referencing SVGs, we simply cheat by sniffing the user agent string
            return true;
        }
        return _document.activeElement === element;
    }
};
// Every Environment except IE9 considers SWF objects focusable
var result$1 = !platform.is.IE9;
function focusObjectSwf() {
    return result$1;
}
var focusRedirectImgUsemap = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = '<map name="focus-redirect-img-usemap"><area href="#void" shape="rect" coords="63,19,144,45"></map>' + '<img usemap="#focus-redirect-img-usemap" alt="" ' + 'src="' + gif + '">';
        // focus the <img>, not the <div>
        return element.querySelector("img");
    },
    validate: function validate(element, focusTarget, _document) {
        var target = element.querySelector("area");
        return _document.activeElement === target;
    }
};
// see https://jsbin.com/nenirisage/edit?html,js,console,output
var focusRedirectLegend = {
    element: "fieldset",
    mutate: function mutate(element) {
        element.innerHTML = '<legend>legend</legend><input tabindex="-1"><input tabindex="0">';
        // take care of focus in validate();
        return false;
    },
    validate: function validate(element, focusTarget, _document) {
        var focusable = element.querySelector('input[tabindex="-1"]');
        var tabbable = element.querySelector('input[tabindex="0"]');
        // Firefox requires this test to focus the <fieldset> first, while this is not necessary in
        // https://jsbin.com/nenirisage/edit?html,js,console,output
        element.focus();
        element.querySelector("legend").focus();
        return _document.activeElement === focusable && "focusable" || _document.activeElement === tabbable && "tabbable" || "";
    }
};
// https://github.com/medialize/ally.js/issues/21
var focusScrollBody = {
    element: "div",
    mutate: function mutate(element) {
        element.setAttribute("style", "width: 100px; height: 50px; overflow: auto;");
        element.innerHTML = '<div style="width: 500px; height: 40px;">scrollable content</div>';
        return element.querySelector("div");
    }
};
// https://github.com/medialize/ally.js/issues/21
var focusScrollContainerWithoutOverflow = {
    element: "div",
    mutate: function mutate(element) {
        element.setAttribute("style", "width: 100px; height: 50px;");
        element.innerHTML = '<div style="width: 500px; height: 40px;">scrollable content</div>';
    }
};
// https://github.com/medialize/ally.js/issues/21
var focusScrollContainer = {
    element: "div",
    mutate: function mutate(element) {
        element.setAttribute("style", "width: 100px; height: 50px; overflow: auto;");
        element.innerHTML = '<div style="width: 500px; height: 40px;">scrollable content</div>';
    }
};
var focusSummary = {
    element: "details",
    mutate: function mutate(element) {
        element.innerHTML = "<summary>foo</summary><p>content</p>";
        return element.firstElementChild;
    }
};
function makeFocusableForeignObject() {
    // Constructs <foreignObject width="30" height="30"><input type="text"/></foreignObject>
    // without raising a Trusted Types violation
    var foreignObject = document.createElementNS("http://www.w3.org/2000/svg", "foreignObject");
    foreignObject.width.baseVal.value = 30;
    foreignObject.height.baseVal.value = 30;
    foreignObject.appendChild(document.createElement("input"));
    foreignObject.lastChild.type = "text";
    return foreignObject;
}
function focusSvgForeignObjectHack(element) {
    // Edge13, Edge14: foreignObject focus hack
    // https://jsbin.com/kunehinugi/edit?html,js,output
    // https://jsbin.com/fajagi/3/edit?html,js,output
    var isSvgElement = element.ownerSVGElement || element.nodeName.toLowerCase() === "svg";
    if (!isSvgElement) {
        return false;
    }
    // inject and focus an <input> element into the SVG element to receive focus
    var foreignObject = makeFocusableForeignObject();
    element.appendChild(foreignObject);
    var input = foreignObject.querySelector("input");
    input.focus();
    // upon disabling the activeElement, IE and Edge
    // will not shift focus to <body> like all the other
    // browsers, but instead find the first focusable
    // ancestor and shift focus to that
    input.disabled = true;
    // clean up
    element.removeChild(foreignObject);
    return true;
}
function generate(element) {
    return '<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">' + element + "</svg>";
}
function focus(element) {
    if (element.focus) {
        return;
    }
    try {
        HTMLElement.prototype.focus.call(element);
    } catch (e) {
        focusSvgForeignObjectHack(element);
    }
}
function validate(element, focusTarget, _document) {
    focus(focusTarget);
    return _document.activeElement === focusTarget;
}
var focusSvgFocusableAttribute = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = generate('<text focusable="true">a</text>');
        return element.querySelector("text");
    },
    validate: validate
};
var focusSvgTabindexAttribute = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = generate('<text tabindex="0">a</text>');
        return element.querySelector("text");
    },
    validate: validate
};
var focusSvgNegativeTabindexAttribute = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = generate('<text tabindex="-1">a</text>');
        return element.querySelector("text");
    },
    validate: validate
};
var focusSvgUseTabindex = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = generate([
            '<g id="ally-test-target"><a xlink:href="#void"><text>link</text></a></g>',
            '<use xlink:href="#ally-test-target" x="0" y="0" tabindex="-1" />'
        ].join(""));
        return element.querySelector("use");
    },
    validate: validate
};
var focusSvgForeignobjectTabindex = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = generate('<foreignObject tabindex="-1"><input type="text" /></foreignObject>');
        // Safari 8's quersSelector() can't identify foreignObject, but getElementyByTagName() can
        return element.querySelector("foreignObject") || element.getElementsByTagName("foreignObject")[0];
    },
    validate: validate
};
// Firefox seems to be handling the SVG-document-in-iframe creation asynchronously
// and thereby produces a false negative test result. Thus the test is pointless
// and we resort to UA sniffing once again.
// see http://jsbin.com/vunadohoko/1/edit?js,console,output
var result$2 = Boolean(platform.is.GECKO && typeof SVGElement !== "undefined" && SVGElement.prototype.focus);
function focusSvgInIframe() {
    return result$2;
}
var focusSvg = {
    element: "div",
    mutate: function mutate(element) {
        element.innerHTML = generate("");
        return element.firstChild;
    },
    validate: validate
};
// Firefox allows *any* value and treats invalid values like tabindex="-1"
// @browser-issue Gecko https://bugzilla.mozilla.org/show_bug.cgi?id=1128054
var focusTabindexTrailingCharacters = {
    element: "div",
    mutate: function mutate(element) {
        element.setAttribute("tabindex", "3x");
    }
};
var focusTable = {
    element: "table",
    mutate: function mutate(element, wrapper, _document) {
        // IE9 has a problem replacing TBODY contents with innerHTML.
        // https://stackoverflow.com/a/8097055/515124
        // element.innerHTML = '<tr><td>cell</td></tr>';
        var fragment = _document.createDocumentFragment();
        fragment.innerHTML = "<tr><td>cell</td></tr>";
        element.appendChild(fragment);
    }
};
var focusVideoWithoutControls = {
    element: "video",
    mutate: function mutate(element) {
        try {
            // invalid media file can trigger warning in console, data-uri to prevent HTTP request
            element.setAttribute("src", gif);
        } catch (e) {
        // IE9 may throw "Error: Not implemented"
        }
    }
};
// https://jsbin.com/vafaba/3/edit?html,js,console,output
var result$3 = platform.is.GECKO || platform.is.TRIDENT || platform.is.EDGE;
function tabsequenceAreaAtImgPosition() {
    return result$3;
}
var testCallbacks = {
    cssShadowPiercingDeepCombinator: cssShadowPiercingDeepCombinator,
    focusInZeroDimensionObject: focusInZeroDimensionObject,
    focusObjectSwf: focusObjectSwf,
    focusSvgInIframe: focusSvgInIframe,
    tabsequenceAreaAtImgPosition: tabsequenceAreaAtImgPosition
};
var testDescriptions = {
    focusAreaImgTabindex: focusAreaImgTabindex,
    focusAreaTabindex: focusAreaTabindex,
    focusAreaWithoutHref: focusAreaWithoutHref,
    focusAudioWithoutControls: focusAudioWithoutControls,
    focusBrokenImageMap: focusBrokenImageMap,
    focusChildrenOfFocusableFlexbox: focusChildrenOfFocusableFlexbox,
    focusFieldsetDisabled: focusFieldsetDisabled,
    focusFieldset: focusFieldset,
    focusFlexboxContainer: focusFlexboxContainer,
    focusFormDisabled: focusFormDisabled,
    focusImgIsmap: focusImgIsmap,
    focusImgUsemapTabindex: focusImgUsemapTabindex,
    focusInHiddenIframe: focusInHiddenIframe,
    focusInvalidTabindex: focusInvalidTabindex,
    focusLabelTabindex: focusLabelTabindex,
    focusObjectSvg: focusObjectSvg,
    focusObjectSvgHidden: focusObjectSvgHidden,
    focusRedirectImgUsemap: focusRedirectImgUsemap,
    focusRedirectLegend: focusRedirectLegend,
    focusScrollBody: focusScrollBody,
    focusScrollContainerWithoutOverflow: focusScrollContainerWithoutOverflow,
    focusScrollContainer: focusScrollContainer,
    focusSummary: focusSummary,
    focusSvgFocusableAttribute: focusSvgFocusableAttribute,
    focusSvgTabindexAttribute: focusSvgTabindexAttribute,
    focusSvgNegativeTabindexAttribute: focusSvgNegativeTabindexAttribute,
    focusSvgUseTabindex: focusSvgUseTabindex,
    focusSvgForeignobjectTabindex: focusSvgForeignobjectTabindex,
    focusSvg: focusSvg,
    focusTabindexTrailingCharacters: focusTabindexTrailingCharacters,
    focusTable: focusTable,
    focusVideoWithoutControls: focusVideoWithoutControls
};
function executeTests() {
    var results = detectFocus(testDescriptions);
    Object.keys(testCallbacks).forEach(function(key) {
        results[key] = testCallbacks[key]();
    });
    return results;
}
var supportsCache = null;
function _supports() {
    if (supportsCache) {
        return supportsCache;
    }
    supportsCache = cache$1.get();
    if (!supportsCache.time) {
        cache$1.set(executeTests());
        supportsCache = cache$1.get();
    }
    return supportsCache;
}
var supports = void 0;
// https://www.w3.org/TR/html5/infrastructure.html#rules-for-parsing-integers
// NOTE: all browsers agree to allow trailing spaces as well
var validIntegerPatternNoTrailing = /^\s*(-|\+)?[0-9]+\s*$/;
var validIntegerPatternWithTrailing = /^\s*(-|\+)?[0-9]+.*$/;
function isValidTabindex(context) {
    if (!supports) {
        supports = _supports();
    }
    var validIntegerPattern = supports.focusTabindexTrailingCharacters ? validIntegerPatternWithTrailing : validIntegerPatternNoTrailing;
    var element = contextToElement({
        label: "is/valid-tabindex",
        resolveDocument: true,
        context: context
    });
    // Edge 14 has a capitalization problem on SVG elements,
    // see https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/9282058/
    var hasTabindex = element.hasAttribute("tabindex");
    var hasTabIndex = element.hasAttribute("tabIndex");
    if (!hasTabindex && !hasTabIndex) {
        return false;
    }
    // older Firefox and Internet Explorer don't support tabindex on SVG elements
    var isSvgElement = element.ownerSVGElement || element.nodeName.toLowerCase() === "svg";
    if (isSvgElement && !supports.focusSvgTabindexAttribute) {
        return false;
    }
    // @browser-issue Gecko https://bugzilla.mozilla.org/show_bug.cgi?id=1128054
    if (supports.focusInvalidTabindex) {
        return true;
    }
    // an element matches the tabindex selector even if its value is invalid
    var tabindex = element.getAttribute(hasTabindex ? "tabindex" : "tabIndex");
    // IE11 parses tabindex="" as the value "-32768"
    // @browser-issue Trident https://connect.microsoft.com/IE/feedback/details/1072965
    if (tabindex === "-32768") {
        return false;
    }
    return Boolean(tabindex && validIntegerPattern.test(tabindex));
}
function tabindexValue(element) {
    if (!isValidTabindex(element)) {
        return null;
    }
    // Edge 14 has a capitalization problem on SVG elements,
    // see https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/9282058/
    var hasTabindex = element.hasAttribute("tabindex");
    var attributeName = hasTabindex ? "tabindex" : "tabIndex";
    // @browser-issue Gecko https://bugzilla.mozilla.org/show_bug.cgi?id=1128054
    var tabindex = parseInt(element.getAttribute(attributeName), 10);
    return isNaN(tabindex) ? -1 : tabindex;
}
// this is a shared utility file for focus-relevant.js and tabbable.js
// separate testing of this file's functions is not necessary,
// as they're implicitly tested by way of the consumers
function isUserModifyWritable(style) {
    // https://www.w3.org/TR/1999/WD-css3-userint-19990916#user-modify
    // https://github.com/medialize/ally.js/issues/17
    var userModify = style.webkitUserModify || "";
    return Boolean(userModify && userModify.indexOf("write") !== -1);
}
function hasCssOverflowScroll(style) {
    return [
        style.getPropertyValue("overflow"),
        style.getPropertyValue("overflow-x"),
        style.getPropertyValue("overflow-y")
    ].some(function(overflow) {
        return overflow === "auto" || overflow === "scroll";
    });
}
function hasCssDisplayFlex(style) {
    return style.display.indexOf("flex") > -1;
}
function isScrollableContainer(element, nodeName, parentNodeName, parentStyle) {
    if (nodeName !== "div" && nodeName !== "span") {
        // Internet Explorer advances scrollable containers and bodies to focusable
        // only if the scrollable container is <div> or <span> - this does *not*
        // happen for <section>, <article>, …
        return false;
    }
    if (parentNodeName && parentNodeName !== "div" && parentNodeName !== "span" && !hasCssOverflowScroll(parentStyle)) {
        return false;
    }
    return element.offsetHeight < element.scrollHeight || element.offsetWidth < element.scrollWidth;
}
var supports$1 = void 0;
function isFocusRelevantRules() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, _ref$except = _ref.except, except = _ref$except === undefined ? {
        flexbox: false,
        scrollable: false,
        shadow: false
    } : _ref$except;
    if (!supports$1) {
        supports$1 = _supports();
    }
    var element = contextToElement({
        label: "is/focus-relevant",
        resolveDocument: true,
        context: context
    });
    if (!except.shadow && element.shadowRoot) {
        // a ShadowDOM host receives focus when the focus moves to its content
        return true;
    }
    var nodeName = element.nodeName.toLowerCase();
    if (nodeName === "input" && element.type === "hidden") {
        // input[type="hidden"] supports.cannot be focused
        return false;
    }
    if (nodeName === "input" || nodeName === "select" || nodeName === "button" || nodeName === "textarea") {
        return true;
    }
    if (nodeName === "legend" && supports$1.focusRedirectLegend) {
        // specifics filtered in is/focusable
        return true;
    }
    if (nodeName === "label") {
        // specifics filtered in is/focusable
        return true;
    }
    if (nodeName === "area") {
        // specifics filtered in is/focusable
        return true;
    }
    if (nodeName === "a" && element.hasAttribute("href")) {
        return true;
    }
    if (nodeName === "object" && element.hasAttribute("usemap")) {
        // object[usemap] is not focusable in any browser
        return false;
    }
    if (nodeName === "object") {
        var svgType = element.getAttribute("type");
        if (!supports$1.focusObjectSvg && svgType === "image/svg+xml") {
            // object[type="image/svg+xml"] is not focusable in Internet Explorer
            return false;
        } else if (!supports$1.focusObjectSwf && svgType === "application/x-shockwave-flash") {
            // object[type="application/x-shockwave-flash"] is not focusable in Internet Explorer 9
            return false;
        }
    }
    if (nodeName === "iframe" || nodeName === "object") {
        // browsing context containers
        return true;
    }
    if (nodeName === "embed" || nodeName === "keygen") {
        // embed is considered focus-relevant but not focusable
        // see https://github.com/medialize/ally.js/issues/82
        return true;
    }
    if (element.hasAttribute("contenteditable")) {
        // also see CSS property user-modify below
        return true;
    }
    if (nodeName === "audio" && (supports$1.focusAudioWithoutControls || element.hasAttribute("controls"))) {
        return true;
    }
    if (nodeName === "video" && (supports$1.focusVideoWithoutControls || element.hasAttribute("controls"))) {
        return true;
    }
    if (supports$1.focusSummary && nodeName === "summary") {
        return true;
    }
    var validTabindex = isValidTabindex(element);
    if (nodeName === "img" && element.hasAttribute("usemap")) {
        // Gecko, Trident and Edge do not allow an image with an image map and tabindex to be focused,
        // it appears the tabindex is overruled so focus is still forwarded to the <map>
        return validTabindex && supports$1.focusImgUsemapTabindex || supports$1.focusRedirectImgUsemap;
    }
    if (supports$1.focusTable && (nodeName === "table" || nodeName === "td")) {
        // IE10-11 supports.can focus <table> and <td>
        return true;
    }
    if (supports$1.focusFieldset && nodeName === "fieldset") {
        // IE10-11 supports.can focus <fieldset>
        return true;
    }
    var isSvgElement = nodeName === "svg";
    var isSvgContent = element.ownerSVGElement;
    var focusableAttribute = element.getAttribute("focusable");
    var tabindex = tabindexValue(element);
    if (nodeName === "use" && tabindex !== null && !supports$1.focusSvgUseTabindex) {
        // <use> cannot be made focusable by adding a tabindex attribute anywhere but Blink and WebKit
        return false;
    }
    if (nodeName === "foreignobject") {
        // <use> can only be made focusable in Blink and WebKit
        return tabindex !== null && supports$1.focusSvgForeignobjectTabindex;
    }
    if (elementMatches(element, "svg a") && element.hasAttribute("xlink:href")) {
        return true;
    }
    if ((isSvgElement || isSvgContent) && element.focus && !supports$1.focusSvgNegativeTabindexAttribute && tabindex < 0) {
        // Firefox 51 and 52 treat any natively tabbable SVG element with
        // tabindex="-1" as tabbable and everything else as inert
        // see https://bugzilla.mozilla.org/show_bug.cgi?id=1302340
        return false;
    }
    if (isSvgElement) {
        return validTabindex || supports$1.focusSvg || supports$1.focusSvgInIframe || // Internet Explorer understands the focusable attribute introduced in SVG Tiny 1.2
        Boolean(supports$1.focusSvgFocusableAttribute && focusableAttribute && focusableAttribute === "true");
    }
    if (isSvgContent) {
        if (supports$1.focusSvgTabindexAttribute && validTabindex) {
            return true;
        }
        if (supports$1.focusSvgFocusableAttribute) {
            // Internet Explorer understands the focusable attribute introduced in SVG Tiny 1.2
            return focusableAttribute === "true";
        }
    }
    // https://www.w3.org/TR/html5/editing.html#sequential-focus-navigation-and-the-tabindex-attribute
    if (validTabindex) {
        return true;
    }
    var style = window.getComputedStyle(element, null);
    if (isUserModifyWritable(style)) {
        return true;
    }
    if (supports$1.focusImgIsmap && nodeName === "img" && element.hasAttribute("ismap")) {
        // IE10-11 considers the <img> in <a href><img ismap> focusable
        // https://github.com/medialize/ally.js/issues/20
        var hasLinkParent = getParents({
            context: element
        }).some(function(parent) {
            return parent.nodeName.toLowerCase() === "a" && parent.hasAttribute("href");
        });
        if (hasLinkParent) {
            return true;
        }
    }
    // https://github.com/medialize/ally.js/issues/21
    if (!except.scrollable && supports$1.focusScrollContainer) {
        if (supports$1.focusScrollContainerWithoutOverflow) {
            // Internet Explorer does will consider the scrollable area focusable
            // if the element is a <div> or a <span> and it is in fact scrollable,
            // regardless of the CSS overflow property
            if (isScrollableContainer(element, nodeName)) {
                return true;
            }
        } else if (hasCssOverflowScroll(style)) {
            // Firefox requires proper overflow setting, IE does not necessarily
            // https://developer.mozilla.org/en-US/docs/Web/CSS/overflow
            return true;
        }
    }
    if (!except.flexbox && supports$1.focusFlexboxContainer && hasCssDisplayFlex(style)) {
        // elements with display:flex are focusable in IE10-11
        return true;
    }
    var parent = element.parentElement;
    if (!except.scrollable && parent) {
        var parentNodeName = parent.nodeName.toLowerCase();
        var parentStyle = window.getComputedStyle(parent, null);
        if (supports$1.focusScrollBody && isScrollableContainer(parent, nodeName, parentNodeName, parentStyle)) {
            // scrollable bodies are focusable Internet Explorer
            // https://github.com/medialize/ally.js/issues/21
            return true;
        }
        // Children of focusable elements with display:flex are focusable in IE10-11
        if (supports$1.focusChildrenOfFocusableFlexbox) {
            if (hasCssDisplayFlex(parentStyle)) {
                return true;
            }
        }
    }
    // NOTE: elements marked as inert are not focusable,
    // but that property is not exposed to the DOM
    // https://www.w3.org/TR/html5/editing.html#inert
    return false;
}
// bind exceptions to an iterator callback
isFocusRelevantRules.except = function() {
    var except = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
    var isFocusRelevant = function isFocusRelevant(context) {
        return isFocusRelevantRules({
            context: context,
            except: except
        });
    };
    isFocusRelevant.rules = isFocusRelevantRules;
    return isFocusRelevant;
};
// provide isFocusRelevant(context) as default iterator callback
var isFocusRelevant = isFocusRelevantRules.except({});
function findIndex(array, callback) {
    // attempt to use native or polyfilled Array#findIndex first
    if (array.findIndex) {
        return array.findIndex(callback);
    }
    var length = array.length;
    // shortcut if the array is empty
    if (length === 0) {
        return -1;
    }
    // otherwise loop over array
    for(var i = 0; i < length; i++){
        if (callback(array[i], i, array)) {
            return i;
        }
    }
    return -1;
}
function getContentDocument(node) {
    try {
        // works on <object> and <iframe>
        return node.contentDocument || // works on <object> and <iframe>
        node.contentWindow && node.contentWindow.document || // works on <object> and <iframe> that contain SVG
        node.getSVGDocument && node.getSVGDocument() || null;
    } catch (e) {
        // SecurityError: Failed to read the 'contentDocument' property from 'HTMLObjectElement'
        // also IE may throw member not found exception e.g. on <object type="image/png">
        return null;
    }
}
function getWindow(node) {
    var _document = getDocument(node);
    return _document.defaultView || window;
}
var shadowPrefix = void 0;
function selectInShadows(selector) {
    if (typeof shadowPrefix !== "string") {
        var operator = cssShadowPiercingDeepCombinator();
        if (operator) {
            shadowPrefix = ", html " + operator + " ";
        }
    }
    if (!shadowPrefix) {
        return selector;
    }
    return selector + shadowPrefix + selector.replace(/\s*,\s*/g, ",").split(",").join(shadowPrefix);
}
var selector = void 0;
function findDocumentHostElement(_window) {
    if (!selector) {
        selector = selectInShadows("object, iframe");
    }
    if (_window._frameElement !== undefined) {
        return _window._frameElement;
    }
    _window._frameElement = null;
    var potentialHosts = _window.parent.document.querySelectorAll(selector);
    [].some.call(potentialHosts, function(element) {
        var _document = getContentDocument(element);
        if (_document !== _window.document) {
            return false;
        }
        _window._frameElement = element;
        return true;
    });
    return _window._frameElement;
}
function getFrameElement(element) {
    var _window = getWindow(element);
    if (!_window.parent || _window.parent === _window) {
        // if there is no parent browsing context,
        // we're not going to get a frameElement either way
        return null;
    }
    try {
        // see https://developer.mozilla.org/en-US/docs/Web/API/Window/frameElement
        // does not work within <embed> anywhere, and not within in <object> in IE
        return _window.frameElement || findDocumentHostElement(_window);
    } catch (e) {
        return null;
    }
}
// https://www.w3.org/TR/html5/rendering.html#being-rendered
// <area> is not rendered, but we *consider* it visible to simplfiy this function's usage
var notRenderedElementsPattern = /^(area)$/;
function computedStyle(element, property) {
    return window.getComputedStyle(element, null).getPropertyValue(property);
}
function notDisplayed(_path) {
    return _path.some(function(element) {
        // display:none is not visible (optimized away at layout)
        return computedStyle(element, "display") === "none";
    });
}
function notVisible(_path) {
    // https://github.com/jquery/jquery-ui/blob/master/ui/core.js#L109-L114
    // NOTE: a nested element can reverse visibility:hidden|collapse by explicitly setting visibility:visible
    // NOTE: visibility can be ["", "visible", "hidden", "collapse"]
    var hidden = findIndex(_path, function(element) {
        var visibility = computedStyle(element, "visibility");
        return visibility === "hidden" || visibility === "collapse";
    });
    if (hidden === -1) {
        // there is no hidden element
        return false;
    }
    var visible = findIndex(_path, function(element) {
        return computedStyle(element, "visibility") === "visible";
    });
    if (visible === -1) {
        // there is no visible element (but a hidden element)
        return true;
    }
    if (hidden < visible) {
        // there is a hidden element and it's closer than the first visible element
        return true;
    }
    // there may be a hidden element, but the closest element is visible
    return false;
}
function collapsedParent(_path) {
    var offset = 1;
    if (_path[0].nodeName.toLowerCase() === "summary") {
        offset = 2;
    }
    return _path.slice(offset).some(function(element) {
        // "content children" of a closed details element are not visible
        return element.nodeName.toLowerCase() === "details" && element.open === false;
    });
}
function isVisibleRules() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, _ref$except = _ref.except, except = _ref$except === undefined ? {
        notRendered: false,
        cssDisplay: false,
        cssVisibility: false,
        detailsElement: false,
        browsingContext: false
    } : _ref$except;
    var element = contextToElement({
        label: "is/visible",
        resolveDocument: true,
        context: context
    });
    var nodeName = element.nodeName.toLowerCase();
    if (!except.notRendered && notRenderedElementsPattern.test(nodeName)) {
        return true;
    }
    var _path = getParents({
        context: element
    });
    // in Internet Explorer <audio> has a default display: none, where others have display: inline
    // but IE allows focusing <audio style="display:none">, but not <div display:none><audio>
    // this is irrelevant to other browsers, as the controls attribute is required to make <audio> focusable
    var isAudioWithoutControls = nodeName === "audio" && !element.hasAttribute("controls");
    if (!except.cssDisplay && notDisplayed(isAudioWithoutControls ? _path.slice(1) : _path)) {
        return false;
    }
    if (!except.cssVisibility && notVisible(_path)) {
        return false;
    }
    if (!except.detailsElement && collapsedParent(_path)) {
        return false;
    }
    if (!except.browsingContext) {
        // elements within a browsing context are affected by the
        // browsing context host element's visibility and tabindex
        var frameElement = getFrameElement(element);
        var _isVisible = isVisibleRules.except(except);
        if (frameElement && !_isVisible(frameElement)) {
            return false;
        }
    }
    return true;
}
// bind exceptions to an iterator callback
isVisibleRules.except = function() {
    var except = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
    var isVisible = function isVisible(context) {
        return isVisibleRules({
            context: context,
            except: except
        });
    };
    isVisible.rules = isVisibleRules;
    return isVisible;
};
// provide isVisible(context) as default iterator callback
var isVisible = isVisibleRules.except({});
function getMapByName(name, _document) {
    // apparently getElementsByName() also considers id attribute in IE & opera
    // https://developer.mozilla.org/en-US/docs/Web/API/Document/getElementsByName
    var map = _document.querySelector('map[name="' + cssEscape(name) + '"]');
    return map || null;
}
function getImageOfArea(element) {
    var map = element.parentElement;
    if (!map.name || map.nodeName.toLowerCase() !== "map") {
        return null;
    }
    // NOTE: image maps can also be applied to <object> with image content,
    // but no browser supports this at the moment
    // HTML5 specifies HTMLMapElement.images to be an HTMLCollection of all
    // <img> and <object> referencing the <map> element, but no browser implements this
    //   https://www.w3.org/TR/html5/embedded-content-0.html#the-map-element
    //   https://developer.mozilla.org/en-US/docs/Web/API/HTMLMapElement
    // the image must be valid and loaded for the map to take effect
    var _document = getDocument(element);
    return _document.querySelector('img[usemap="#' + cssEscape(map.name) + '"]') || null;
}
var supports$2 = void 0;
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/map
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-usemap
// https://github.com/jquery/jquery-ui/blob/master/ui/core.js#L88-L107
function isValidArea(context) {
    if (!supports$2) {
        supports$2 = _supports();
    }
    var element = contextToElement({
        label: "is/valid-area",
        context: context
    });
    var nodeName = element.nodeName.toLowerCase();
    if (nodeName !== "area") {
        return false;
    }
    var hasTabindex = element.hasAttribute("tabindex");
    if (!supports$2.focusAreaTabindex && hasTabindex) {
        // Blink and WebKit do not consider <area tabindex="-1" href="#void"> focusable
        return false;
    }
    var img = getImageOfArea(element);
    if (!img || !isVisible(img)) {
        return false;
    }
    // Firefox only allows fully loaded images to reference image maps
    // https://stereochro.me/ideas/detecting-broken-images-js
    if (!supports$2.focusBrokenImageMap && (!img.complete || !img.naturalHeight || img.offsetWidth <= 0 || img.offsetHeight <= 0)) {
        return false;
    }
    // Firefox supports.can focus area elements even if they don't have an href attribute
    if (!supports$2.focusAreaWithoutHref && !element.href) {
        // Internet explorer supports.can focus area elements without href if either
        // the area element or the image element has a tabindex attribute
        return supports$2.focusAreaTabindex && hasTabindex || supports$2.focusAreaImgTabindex && img.hasAttribute("tabindex");
    }
    // https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-usemap
    var childOfInteractive = getParents({
        context: img
    }).slice(1).some(function(_element) {
        var name = _element.nodeName.toLowerCase();
        return name === "button" || name === "a";
    });
    if (childOfInteractive) {
        return false;
    }
    return true;
}
var supports$3 = void 0;
// https://www.w3.org/TR/html5/disabled-elements.html#concept-element-disabled
var disabledElementsPattern = void 0;
var disabledElements = {
    input: true,
    select: true,
    textarea: true,
    button: true,
    fieldset: true,
    form: true
};
function isNativeDisabledSupported(context) {
    if (!supports$3) {
        supports$3 = _supports();
        if (supports$3.focusFieldsetDisabled) {
            delete disabledElements.fieldset;
        }
        if (supports$3.focusFormDisabled) {
            delete disabledElements.form;
        }
        disabledElementsPattern = new RegExp("^(" + Object.keys(disabledElements).join("|") + ")$");
    }
    var element = contextToElement({
        label: "is/native-disabled-supported",
        context: context
    });
    var nodeName = element.nodeName.toLowerCase();
    return Boolean(disabledElementsPattern.test(nodeName));
}
var supports$4 = void 0;
function isDisabledFieldset(element) {
    var nodeName = element.nodeName.toLowerCase();
    return nodeName === "fieldset" && element.disabled;
}
function isDisabledForm(element) {
    var nodeName = element.nodeName.toLowerCase();
    return nodeName === "form" && element.disabled;
}
function isDisabled(context) {
    if (!supports$4) {
        supports$4 = _supports();
    }
    var element = contextToElement({
        label: "is/disabled",
        context: context
    });
    if (element.hasAttribute("data-ally-disabled")) {
        // treat ally's element/disabled like the DOM native element.disabled
        return true;
    }
    if (!isNativeDisabledSupported(element)) {
        // non-form elements do not support the disabled attribute
        return false;
    }
    if (element.disabled) {
        // the element itself is disabled
        return true;
    }
    var parents = getParents({
        context: element
    });
    if (parents.some(isDisabledFieldset)) {
        // a parental <fieldset> is disabld and inherits the state onto this element
        return true;
    }
    if (!supports$4.focusFormDisabled && parents.some(isDisabledForm)) {
        // a parental <form> is disabld and inherits the state onto this element
        return true;
    }
    return false;
}
function isOnlyTabbableRules() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, _ref$except = _ref.except, except = _ref$except === undefined ? {
        onlyFocusableBrowsingContext: false,
        visible: false
    } : _ref$except;
    var element = contextToElement({
        label: "is/only-tabbable",
        resolveDocument: true,
        context: context
    });
    if (!except.visible && !isVisible(element)) {
        return false;
    }
    if (!except.onlyFocusableBrowsingContext && (platform.is.GECKO || platform.is.TRIDENT || platform.is.EDGE)) {
        var frameElement = getFrameElement(element);
        if (frameElement) {
            if (tabindexValue(frameElement) < 0) {
                // iframe[tabindex="-1"] and object[tabindex="-1"] inherit the
                // tabbable demotion onto elements of their browsing contexts
                return false;
            }
        }
    }
    var nodeName = element.nodeName.toLowerCase();
    var tabindex = tabindexValue(element);
    if (nodeName === "label" && platform.is.GECKO) {
        // Firefox cannot focus, but tab to: label[tabindex=0]
        return tabindex !== null && tabindex >= 0;
    }
    // SVG Elements were keyboard focusable but not script focusable before Firefox 51.
    // Firefox 51 added the focus management DOM API (.focus and .blur) to SVGElement,
    // see https://bugzilla.mozilla.org/show_bug.cgi?id=778654
    if (platform.is.GECKO && element.ownerSVGElement && !element.focus) {
        if (nodeName === "a" && element.hasAttribute("xlink:href")) {
            // any focusable child of <svg> cannot be focused, but tabbed to
            if (platform.is.GECKO) {
                return true;
            }
        }
    }
    return false;
}
// bind exceptions to an iterator callback
isOnlyTabbableRules.except = function() {
    var except = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
    var isOnlyTabbable = function isOnlyTabbable(context) {
        return isOnlyTabbableRules({
            context: context,
            except: except
        });
    };
    isOnlyTabbable.rules = isOnlyTabbableRules;
    return isOnlyTabbable;
};
// provide isOnlyTabbable(context) as default iterator callback
var isOnlyTabbable = isOnlyTabbableRules.except({});
var supports$5 = void 0;
function isOnlyFocusRelevant(element) {
    var nodeName = element.nodeName.toLowerCase();
    if (nodeName === "embed" || nodeName === "keygen") {
        // embed is considered focus-relevant but not focusable
        // see https://github.com/medialize/ally.js/issues/82
        return true;
    }
    var _tabindex = tabindexValue(element);
    if (element.shadowRoot && _tabindex === null) {
        // ShadowDOM host elements *may* receive focus
        // even though they are not considered focuable
        return true;
    }
    if (nodeName === "label") {
        // <label tabindex="0"> is only tabbable in Firefox, not script-focusable
        // there's no way to make an element focusable other than by adding a tabindex,
        // and focus behavior of the label element seems hard-wired to ignore tabindex
        // in some browsers (like Gecko, Blink and WebKit)
        return !supports$5.focusLabelTabindex || _tabindex === null;
    }
    if (nodeName === "legend") {
        return _tabindex === null;
    }
    if (supports$5.focusSvgFocusableAttribute && (element.ownerSVGElement || nodeName === "svg")) {
        // Internet Explorer understands the focusable attribute introduced in SVG Tiny 1.2
        var focusableAttribute = element.getAttribute("focusable");
        return focusableAttribute && focusableAttribute === "false";
    }
    if (nodeName === "img" && element.hasAttribute("usemap")) {
        // Gecko, Trident and Edge do not allow an image with an image map and tabindex to be focused,
        // it appears the tabindex is overruled so focus is still forwarded to the <map>
        return _tabindex === null || !supports$5.focusImgUsemapTabindex;
    }
    if (nodeName === "area") {
        // all <area>s are considered relevant,
        // but only the valid <area>s are focusable
        return !isValidArea(element);
    }
    return false;
}
function isFocusableRules() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, _ref$except = _ref.except, except = _ref$except === undefined ? {
        disabled: false,
        visible: false,
        onlyTabbable: false
    } : _ref$except;
    if (!supports$5) {
        supports$5 = _supports();
    }
    var _isOnlyTabbable = isOnlyTabbable.rules.except({
        onlyFocusableBrowsingContext: true,
        visible: except.visible
    });
    var element = contextToElement({
        label: "is/focusable",
        resolveDocument: true,
        context: context
    });
    var focusRelevant = isFocusRelevant.rules({
        context: element,
        except: except
    });
    if (!focusRelevant || isOnlyFocusRelevant(element)) {
        return false;
    }
    if (!except.disabled && isDisabled(element)) {
        return false;
    }
    if (!except.onlyTabbable && _isOnlyTabbable(element)) {
        // some elements may be keyboard focusable, but not script focusable
        return false;
    }
    // elements that are not rendered, cannot be focused
    if (!except.visible) {
        var visibilityOptions = {
            context: element,
            except: {}
        };
        if (supports$5.focusInHiddenIframe) {
            // WebKit and Blink can focus content in hidden <iframe> and <object>
            visibilityOptions.except.browsingContext = true;
        }
        if (supports$5.focusObjectSvgHidden) {
            // Blink allows focusing the object element, even if it has visibility: hidden;
            // @browser-issue Blink https://code.google.com/p/chromium/issues/detail?id=586191
            var _nodeName2 = element.nodeName.toLowerCase();
            if (_nodeName2 === "object") {
                visibilityOptions.except.cssVisibility = true;
            }
        }
        if (!isVisible.rules(visibilityOptions)) {
            return false;
        }
    }
    var frameElement = getFrameElement(element);
    if (frameElement) {
        var _nodeName = frameElement.nodeName.toLowerCase();
        if (_nodeName === "object" && !supports$5.focusInZeroDimensionObject) {
            if (!frameElement.offsetWidth || !frameElement.offsetHeight) {
                // WebKit can not focus content in <object> if it doesn't have dimensions
                return false;
            }
        }
    }
    var nodeName = element.nodeName.toLowerCase();
    if (nodeName === "svg" && supports$5.focusSvgInIframe && !frameElement && element.getAttribute("tabindex") === null) {
        return false;
    }
    return true;
}
// bind exceptions to an iterator callback
isFocusableRules.except = function() {
    var except = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
    var isFocusable = function isFocusable(context) {
        return isFocusableRules({
            context: context,
            except: except
        });
    };
    isFocusable.rules = isFocusableRules;
    return isFocusable;
};
// provide isFocusRelevant(context) as default iterator callback
var isFocusable = isFocusableRules.except({});
function createFilter(condition) {
    // see https://developer.mozilla.org/en-US/docs/Web/API/NodeFilter
    var filter = function filter(node) {
        if (node.shadowRoot) {
            // return ShadowRoot elements regardless of them being focusable,
            // so they can be walked recursively later
            return NodeFilter.FILTER_ACCEPT;
        }
        if (condition(node)) {
            // finds elements that could have been found by document.querySelectorAll()
            return NodeFilter.FILTER_ACCEPT;
        }
        return NodeFilter.FILTER_SKIP;
    };
    // IE requires a function, Browsers require {acceptNode: function}
    // see http://www.bennadel.com/blog/2607-finding-html-comment-nodes-in-the-dom-using-treewalker.htm
    filter.acceptNode = filter;
    return filter;
}
var PossiblyFocusableFilter = createFilter(isFocusRelevant);
function queryFocusableStrict() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, includeContext = _ref.includeContext, includeOnlyTabbable = _ref.includeOnlyTabbable, strategy = _ref.strategy;
    if (!context) {
        context = document.documentElement;
    }
    var _isFocusable = isFocusable.rules.except({
        onlyTabbable: includeOnlyTabbable
    });
    var _document = getDocument(context);
    // see https://developer.mozilla.org/en-US/docs/Web/API/Document/createTreeWalker
    var walker = _document.createTreeWalker(// root element to start search in
    context, // element type filter
    NodeFilter.SHOW_ELEMENT, // custom NodeFilter filter
    strategy === "all" ? PossiblyFocusableFilter : createFilter(_isFocusable), // deprecated, but IE requires it
    false);
    var list = [];
    while(walker.nextNode()){
        if (walker.currentNode.shadowRoot) {
            if (_isFocusable(walker.currentNode)) {
                list.push(walker.currentNode);
            }
            list = list.concat(queryFocusableStrict({
                context: walker.currentNode.shadowRoot,
                includeOnlyTabbable: includeOnlyTabbable,
                strategy: strategy
            }));
        } else {
            list.push(walker.currentNode);
        }
    }
    // add context if requested and focusable
    if (includeContext) {
        if (strategy === "all") {
            if (isFocusRelevant(context)) {
                list.unshift(context);
            }
        } else if (_isFocusable(context)) {
            list.unshift(context);
        }
    }
    return list;
}
// NOTE: this selector MUST *never* be used directly,
var supports$6 = void 0;
var selector$1 = void 0;
function selector$2() {
    if (!supports$6) {
        supports$6 = _supports();
    }
    if (typeof selector$1 === "string") {
        return selector$1;
    }
    // https://www.w3.org/TR/html5/editing.html#sequential-focus-navigation-and-the-tabindex-attribute
    selector$1 = "" + // IE11 supports.can focus <table> and <td>
    (supports$6.focusTable ? "table, td," : "") + // IE11 supports.can focus <fieldset>
    (supports$6.focusFieldset ? "fieldset," : "") + // Namespace problems of [xlink:href] explained in https://stackoverflow.com/a/23047888/515124
    // svg a[*|href] does not match in IE9, but since we're filtering
    // through is/focusable we can include all <a> from SVG
    "svg a," + // may behave as 'svg, svg *,' in chrome as *every* svg element with a focus event listener is focusable
    // navigational elements
    "a[href]," + // validity determined by is/valid-area.js
    "area[href]," + // validity determined by is/disabled.js
    "input, select, textarea, button," + // browsing context containers
    "iframe, object, embed," + // interactive content
    "keygen," + (supports$6.focusAudioWithoutControls ? "audio," : "audio[controls],") + (supports$6.focusVideoWithoutControls ? "video," : "video[controls],") + (supports$6.focusSummary ? "summary," : "") + // validity determined by is/valid-tabindex.js
    "[tabindex]," + // editing hosts
    "[contenteditable]";
    // where ShadowDOM is supported, we also want the shadowed focusable elements (via ">>>" or "/deep/")
    selector$1 = selectInShadows(selector$1);
    return selector$1;
}
function queryFocusableQuick() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, includeContext = _ref.includeContext, includeOnlyTabbable = _ref.includeOnlyTabbable;
    var _selector = selector$2();
    var elements = context.querySelectorAll(_selector);
    // the selector potentially matches more than really is focusable
    var _isFocusable = isFocusable.rules.except({
        onlyTabbable: includeOnlyTabbable
    });
    var result = [].filter.call(elements, _isFocusable);
    // add context if requested and focusable
    if (includeContext && _isFocusable(context)) {
        result.unshift(context);
    }
    return result;
}
function queryFocusable() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, includeContext = _ref.includeContext, includeOnlyTabbable = _ref.includeOnlyTabbable, _ref$strategy = _ref.strategy, strategy = _ref$strategy === undefined ? "quick" : _ref$strategy;
    var element = contextToElement({
        label: "query/focusable",
        resolveDocument: true,
        defaultToDocument: true,
        context: context
    });
    var options = {
        context: element,
        includeContext: includeContext,
        includeOnlyTabbable: includeOnlyTabbable,
        strategy: strategy
    };
    if (strategy === "quick") {
        return queryFocusableQuick(options);
    } else if (strategy === "strict" || strategy === "all") {
        return queryFocusableStrict(options);
    }
    throw new TypeError('query/focusable requires option.strategy to be one of ["quick", "strict", "all"]');
}
var supports$7 = void 0;
// Internet Explorer 11 considers fieldset, table, td focusable, but not tabbable
// Internet Explorer 11 considers body to have [tabindex=0], but does not allow tabbing to it
var focusableElementsPattern = /^(fieldset|table|td|body)$/;
function isTabbableRules() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, _ref$except = _ref.except, except = _ref$except === undefined ? {
        flexbox: false,
        scrollable: false,
        shadow: false,
        visible: false,
        onlyTabbable: false
    } : _ref$except;
    if (!supports$7) {
        supports$7 = _supports();
    }
    var element = contextToElement({
        label: "is/tabbable",
        resolveDocument: true,
        context: context
    });
    if (platform.is.BLINK && platform.is.ANDROID && platform.majorVersion > 42) {
        // External keyboard support worked fine in CHrome 42, but stopped working in Chrome 45.
        // The on-screen keyboard does not provide a way to focus the next input element (like iOS does).
        // That leaves us with no option to advance focus by keyboard, ergo nothing is tabbable (keyboard focusable).
        return false;
    }
    var frameElement = getFrameElement(element);
    if (frameElement) {
        if (platform.is.WEBKIT && platform.is.IOS) {
            // iOS only does not consider anything from another browsing context keyboard focusable
            return false;
        }
        // iframe[tabindex="-1"] and object[tabindex="-1"] inherit the
        // tabbable demotion onto elements of their browsing contexts
        if (tabindexValue(frameElement) < 0) {
            return false;
        }
        if (!except.visible && (platform.is.BLINK || platform.is.WEBKIT) && !isVisible(frameElement)) {
            // Blink and WebKit consider elements in hidden browsing contexts focusable, but not tabbable
            return false;
        }
        // Webkit and Blink don't consider anything in <object> tabbable
        // Blink fixed that fixed in Chrome 54, Opera 41
        var frameNodeName = frameElement.nodeName.toLowerCase();
        if (frameNodeName === "object") {
            var isFixedBlink = platform.name === "Chrome" && platform.majorVersion >= 54 || platform.name === "Opera" && platform.majorVersion >= 41;
            if (platform.is.WEBKIT || platform.is.BLINK && !isFixedBlink) {
                return false;
            }
        }
    }
    var nodeName = element.nodeName.toLowerCase();
    var _tabindex = tabindexValue(element);
    var tabindex = _tabindex === null ? null : _tabindex >= 0;
    if (platform.is.EDGE && platform.majorVersion >= 14 && frameElement && element.ownerSVGElement && _tabindex < 0) {
        // Edge 14+ considers <a xlink:href="…" tabindex="-1"> keyboard focusable
        // if the element is in a nested browsing context
        return true;
    }
    var hasTabbableTabindexOrNone = tabindex !== false;
    var hasTabbableTabindex = _tabindex !== null && _tabindex >= 0;
    // NOTE: Firefox 31 considers [contenteditable] to have [tabindex=-1], but allows tabbing to it
    // fixed in Firefox 40 the latest - https://bugzilla.mozilla.org/show_bug.cgi?id=1185657
    if (element.hasAttribute("contenteditable")) {
        // tabbing can still be disabled by explicitly providing [tabindex="-1"]
        return hasTabbableTabindexOrNone;
    }
    if (focusableElementsPattern.test(nodeName) && tabindex !== true) {
        return false;
    }
    if (platform.is.WEBKIT && platform.is.IOS) {
        // iOS only considers a hand full of elements tabbable (keyboard focusable)
        // this holds true even with external keyboards
        var potentiallyTabbable = nodeName === "input" && element.type === "text" || element.type === "password" || nodeName === "select" || nodeName === "textarea" || element.hasAttribute("contenteditable");
        if (!potentiallyTabbable) {
            var style = window.getComputedStyle(element, null);
            potentiallyTabbable = isUserModifyWritable(style);
        }
        if (!potentiallyTabbable) {
            return false;
        }
    }
    if (nodeName === "use" && _tabindex !== null) {
        if (platform.is.BLINK || platform.is.WEBKIT && platform.majorVersion === 9) {
            // In Chrome and Safari 9 the <use> element is keyboard focusable even for tabindex="-1"
            return true;
        }
    }
    if (elementMatches(element, "svg a") && element.hasAttribute("xlink:href")) {
        if (hasTabbableTabindexOrNone) {
            // in Trident and Gecko SVGElement does not handle the tabIndex property properly
            return true;
        }
        if (element.focus && !supports$7.focusSvgNegativeTabindexAttribute) {
            // Firefox 51 and 52 treat any natively tabbable SVG element with
            // tabindex="-1" as tabbable and everything else as inert
            // see https://bugzilla.mozilla.org/show_bug.cgi?id=1302340
            return true;
        }
    }
    if (nodeName === "svg" && supports$7.focusSvgInIframe && hasTabbableTabindexOrNone) {
        return true;
    }
    if (platform.is.TRIDENT || platform.is.EDGE) {
        if (nodeName === "svg") {
            if (supports$7.focusSvg) {
                // older Internet Explorers consider <svg> keyboard focusable
                // unless they have focsable="false", but then they wouldn't
                // be focusable and thus not even reach this filter
                return true;
            }
            // elements that have [focusable] are automatically keyboard focusable regardless of the attribute's value
            return element.hasAttribute("focusable") || hasTabbableTabindex;
        }
        if (element.ownerSVGElement) {
            if (supports$7.focusSvgTabindexAttribute && hasTabbableTabindex) {
                return true;
            }
            // elements that have [focusable] are automatically keyboard focusable regardless of the attribute's value
            return element.hasAttribute("focusable");
        }
    }
    if (element.tabIndex === undefined) {
        return Boolean(except.onlyTabbable);
    }
    if (nodeName === "audio") {
        if (!element.hasAttribute("controls")) {
            // In Internet Explorer the <audio> element is focusable, but not tabbable, and tabIndex property is wrong
            return false;
        } else if (platform.is.BLINK) {
            // In Chrome <audio controls tabindex="-1"> remains keyboard focusable
            return true;
        }
    }
    if (nodeName === "video") {
        if (!element.hasAttribute("controls")) {
            if (platform.is.TRIDENT || platform.is.EDGE) {
                // In Internet Explorer and Edge the <video> element is focusable, but not tabbable, and tabIndex property is wrong
                return false;
            }
        } else if (platform.is.BLINK || platform.is.GECKO) {
            // In Chrome and Firefox <video controls tabindex="-1"> remains keyboard focusable
            return true;
        }
    }
    if (nodeName === "object") {
        if (platform.is.BLINK || platform.is.WEBKIT) {
            // In all Blink and WebKit based browsers <embed> and <object> are never keyboard focusable, even with tabindex="0" set
            return false;
        }
    }
    if (nodeName === "iframe") {
        // In Internet Explorer all iframes are only focusable
        // In WebKit, Blink and Gecko iframes may be tabbable depending on content.
        // Since we can't reliably investigate iframe documents because of the
        // SameOriginPolicy, we're declaring everything only focusable.
        return false;
    }
    if (!except.scrollable && platform.is.GECKO) {
        // Firefox considers scrollable containers keyboard focusable,
        // even though their tabIndex property is -1
        var _style = window.getComputedStyle(element, null);
        if (hasCssOverflowScroll(_style)) {
            return hasTabbableTabindexOrNone;
        }
    }
    if (platform.is.TRIDENT || platform.is.EDGE) {
        // IE and Edge degrade <area> to script focusable, if the image
        // using the <map> has been given tabindex="-1"
        if (nodeName === "area") {
            var img = getImageOfArea(element);
            if (img && tabindexValue(img) < 0) {
                return false;
            }
        }
        var _style2 = window.getComputedStyle(element, null);
        if (isUserModifyWritable(_style2)) {
            // prevent being swallowed by the overzealous isScrollableContainer() below
            return element.tabIndex >= 0;
        }
        if (!except.flexbox && hasCssDisplayFlex(_style2)) {
            if (_tabindex !== null) {
                return hasTabbableTabindex;
            }
            return isFocusRelevantWithoutFlexbox(element) && isTabbableWithoutFlexbox(element);
        }
        // IE considers scrollable containers script focusable only,
        // even though their tabIndex property is 0
        if (isScrollableContainer(element, nodeName)) {
            return false;
        }
        var parent = element.parentElement;
        if (parent) {
            var parentNodeName = parent.nodeName.toLowerCase();
            var parentStyle = window.getComputedStyle(parent, null);
            // IE considers scrollable bodies script focusable only,
            if (isScrollableContainer(parent, nodeName, parentNodeName, parentStyle)) {
                return false;
            }
            // Children of focusable elements with display:flex are focusable in IE10-11,
            // even though their tabIndex property suggests otherwise
            if (hasCssDisplayFlex(parentStyle)) {
                // value of tabindex takes precedence
                return hasTabbableTabindex;
            }
        }
    }
    // https://www.w3.org/WAI/PF/aria-practices/#focus_tabindex
    return element.tabIndex >= 0;
}
// bind exceptions to an iterator callback
isTabbableRules.except = function() {
    var except = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
    var isTabbable = function isTabbable(context) {
        return isTabbableRules({
            context: context,
            except: except
        });
    };
    isTabbable.rules = isTabbableRules;
    return isTabbable;
};
var isFocusRelevantWithoutFlexbox = isFocusRelevant.rules.except({
    flexbox: true
});
var isTabbableWithoutFlexbox = isTabbableRules.except({
    flexbox: true
});
// provide isTabbable(context) as default iterator callback
var isTabbable = isTabbableRules.except({});
function queryTabbable() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, includeContext = _ref.includeContext, includeOnlyTabbable = _ref.includeOnlyTabbable, strategy = _ref.strategy;
    var _isTabbable = isTabbable.rules.except({
        onlyTabbable: includeOnlyTabbable
    });
    return queryFocusable({
        context: context,
        includeContext: includeContext,
        includeOnlyTabbable: includeOnlyTabbable,
        strategy: strategy
    }).filter(_isTabbable);
}
// sorts a list of elements according to their order in the DOM
function compareDomPosition(a, b) {
    return a.compareDocumentPosition(b) & Node.DOCUMENT_POSITION_FOLLOWING ? -1 : 1;
}
function sortDomOrder(elements) {
    return elements.sort(compareDomPosition);
}
function getFirstSuccessorOffset(list, target) {
    // find the first element that comes AFTER the target element
    return findIndex(list, function(element) {
        return target.compareDocumentPosition(element) & Node.DOCUMENT_POSITION_FOLLOWING;
    });
}
function findInsertionOffsets(list, elements, resolveElement) {
    // instead of mutating the elements list directly, remember position and map
    // to inject later, when we can do this more efficiently
    var insertions = [];
    elements.forEach(function(element) {
        var replace = true;
        var offset = list.indexOf(element);
        if (offset === -1) {
            // element is not in target list
            offset = getFirstSuccessorOffset(list, element);
            replace = false;
        }
        if (offset === -1) {
            // there is no successor in the tabsequence,
            // meaning the image must be the last element
            offset = list.length;
        }
        // allow the consumer to replace the injected element
        var injections = nodeArray(resolveElement ? resolveElement(element) : element);
        if (!injections.length) {
            // we can't inject zero elements
            return;
        }
        insertions.push({
            offset: offset,
            replace: replace,
            elements: injections
        });
    });
    return insertions;
}
function insertElementsAtOffsets(list, insertions) {
    // remember the number of elements we have already injected
    // so we account for the caused index offset
    var inserted = 0;
    // make sure that we insert the elements in sequence,
    // otherwise the offset compensation won't work
    insertions.sort(function(a, b) {
        return a.offset - b.offset;
    });
    insertions.forEach(function(insertion) {
        // array.splice has an annoying function signature :(
        var remove = insertion.replace ? 1 : 0;
        var args = [
            insertion.offset + inserted,
            remove
        ].concat(insertion.elements);
        list.splice.apply(list, args);
        inserted += insertion.elements.length - remove;
    });
}
function mergeInDomOrder() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, list = _ref.list, elements = _ref.elements, resolveElement = _ref.resolveElement;
    // operate on a copy so we don't mutate the original array
    var _list = list.slice(0);
    // make sure the elements we're injecting are provided in DOM order
    var _elements = nodeArray(elements).slice(0);
    sortDomOrder(_elements);
    // find the offsets within the target array (list) at which to inject
    // each individual element (from elements)
    var insertions = findInsertionOffsets(_list, _elements, resolveElement);
    // actually inject the elements into the target array at the identified positions
    insertElementsAtOffsets(_list, insertions);
    return _list;
}
var _createClass = function() {
    function defineProperties(target, props) {
        for(var i = 0; i < props.length; i++){
            var descriptor = props[i];
            descriptor.enumerable = descriptor.enumerable || false;
            descriptor.configurable = true;
            if ("value" in descriptor) descriptor.writable = true;
            Object.defineProperty(target, descriptor.key, descriptor);
        }
    }
    return function(Constructor, protoProps, staticProps) {
        if (protoProps) defineProperties(Constructor.prototype, protoProps);
        if (staticProps) defineProperties(Constructor, staticProps);
        return Constructor;
    };
}();
function _classCallCheck(instance, Constructor) {
    if (!(instance instanceof Constructor)) {
        throw new TypeError("Cannot call a class as a function");
    }
}
var Maps = function() {
    function Maps(context) {
        _classCallCheck(this, Maps);
        this._document = getDocument(context);
        this.maps = {};
    }
    _createClass(Maps, [
        {
            key: "getAreasFor",
            value: function getAreasFor(name) {
                if (!this.maps[name]) {
                    // the map is not defined within the context, so we
                    // have to go find it elsewhere in the document
                    this.addMapByName(name);
                }
                return this.maps[name];
            }
        },
        {
            key: "addMapByName",
            value: function addMapByName(name) {
                var map = getMapByName(name, this._document);
                if (!map) {
                    // if there is no map, the img[usemap] wasn't doing anything anyway
                    return;
                }
                this.maps[map.name] = queryTabbable({
                    context: map
                });
            }
        },
        {
            key: "extractAreasFromList",
            value: function extractAreasFromList(elements) {
                // remove all <area> elements from the elements list,
                // but put them the map for later retrieval
                return elements.filter(function(element) {
                    var nodeName = element.nodeName.toLowerCase();
                    if (nodeName !== "area") {
                        return true;
                    }
                    var map = element.parentNode;
                    if (!this.maps[map.name]) {
                        this.maps[map.name] = [];
                    }
                    this.maps[map.name].push(element);
                    return false;
                }, this);
            }
        }
    ]);
    return Maps;
}();
function sortArea(elements, context) {
    // images - unless they are focusable themselves, likely not
    // part of the elements list, so we'll have to find them and
    // sort them into the elements list manually
    var usemaps = context.querySelectorAll("img[usemap]");
    var maps = new Maps(context);
    // remove all <area> elements from the elements list,
    // but put them the map for later retrieval
    var _elements = maps.extractAreasFromList(elements);
    if (!usemaps.length) {
        // the context does not contain any <area>s so no need
        // to replace anything, just remove any maps
        return _elements;
    }
    return mergeInDomOrder({
        list: _elements,
        elements: usemaps,
        resolveElement: function resolveElement(image) {
            var name = image.getAttribute("usemap").slice(1);
            return maps.getAreasFor(name);
        }
    });
}
var _createClass$1 = function() {
    function defineProperties(target, props) {
        for(var i = 0; i < props.length; i++){
            var descriptor = props[i];
            descriptor.enumerable = descriptor.enumerable || false;
            descriptor.configurable = true;
            if ("value" in descriptor) descriptor.writable = true;
            Object.defineProperty(target, descriptor.key, descriptor);
        }
    }
    return function(Constructor, protoProps, staticProps) {
        if (protoProps) defineProperties(Constructor.prototype, protoProps);
        if (staticProps) defineProperties(Constructor, staticProps);
        return Constructor;
    };
}();
function _classCallCheck$1(instance, Constructor) {
    if (!(instance instanceof Constructor)) {
        throw new TypeError("Cannot call a class as a function");
    }
}
var Shadows = function() {
    function Shadows(context, sortElements) {
        _classCallCheck$1(this, Shadows);
        // document context we're working with
        this.context = context;
        // callback that sorts an array of elements
        this.sortElements = sortElements;
        // reference to create unique IDs for each ShadowHost
        this.hostCounter = 1;
        // reference map for child-ShadowHosts of a ShadowHost
        this.inHost = {};
        // reference map for child-ShadowHost of the document
        this.inDocument = [];
        // reference map for ShadowHosts
        this.hosts = {};
        // reference map for tabbable elements of a ShadowHost
        this.elements = {};
    }
    // remember which hosts we have to sort within later
    _createClass$1(Shadows, [
        {
            key: "_registerHost",
            value: function _registerHost(host) {
                if (host._sortingId) {
                    return;
                }
                // make the ShadowHost identifiable (see cleanup() for undo)
                host._sortingId = "shadow-" + this.hostCounter++;
                this.hosts[host._sortingId] = host;
                // hosts may contain other hosts
                var parentHost = getShadowHost({
                    context: host
                });
                if (parentHost) {
                    this._registerHost(parentHost);
                    this._registerHostParent(host, parentHost);
                } else {
                    this.inDocument.push(host);
                }
            }
        },
        {
            key: "_registerHostParent",
            value: function _registerHostParent(host, parent) {
                if (!this.inHost[parent._sortingId]) {
                    this.inHost[parent._sortingId] = [];
                }
                this.inHost[parent._sortingId].push(host);
            }
        },
        {
            key: "_registerElement",
            value: function _registerElement(element, host) {
                if (!this.elements[host._sortingId]) {
                    this.elements[host._sortingId] = [];
                }
                this.elements[host._sortingId].push(element);
            }
        },
        {
            key: "extractElements",
            value: function extractElements(elements) {
                return elements.filter(function(element) {
                    var host = getShadowHost({
                        context: element
                    });
                    if (!host) {
                        return true;
                    }
                    this._registerHost(host);
                    this._registerElement(element, host);
                    return false;
                }, this);
            }
        },
        {
            key: "sort",
            value: function sort(elements) {
                var _elements = this._injectHosts(elements);
                _elements = this._replaceHosts(_elements);
                this._cleanup();
                return _elements;
            }
        },
        {
            key: "_injectHosts",
            value: function _injectHosts(elements) {
                Object.keys(this.hosts).forEach(function(_sortingId) {
                    var _list = this.elements[_sortingId];
                    var _elements = this.inHost[_sortingId];
                    var _context = this.hosts[_sortingId].shadowRoot;
                    this.elements[_sortingId] = this._merge(_list, _elements, _context);
                }, this);
                return this._merge(elements, this.inDocument, this.context);
            }
        },
        {
            key: "_merge",
            value: function _merge(list, elements, context) {
                var merged = mergeInDomOrder({
                    list: list,
                    elements: elements
                });
                return this.sortElements(merged, context);
            }
        },
        {
            key: "_replaceHosts",
            value: function _replaceHosts(elements) {
                return mergeInDomOrder({
                    list: elements,
                    elements: this.inDocument,
                    resolveElement: this._resolveHostElement.bind(this)
                });
            }
        },
        {
            key: "_resolveHostElement",
            value: function _resolveHostElement(host) {
                var merged = mergeInDomOrder({
                    list: this.elements[host._sortingId],
                    elements: this.inHost[host._sortingId],
                    resolveElement: this._resolveHostElement.bind(this)
                });
                var _tabindex = tabindexValue(host);
                if (_tabindex !== null && _tabindex > -1) {
                    return [
                        host
                    ].concat(merged);
                }
                return merged;
            }
        },
        {
            key: "_cleanup",
            value: function _cleanup() {
                // remove those identifers we put on the ShadowHost to avoid using Map()
                Object.keys(this.hosts).forEach(function(key) {
                    delete this.hosts[key]._sortingId;
                }, this);
            }
        }
    ]);
    return Shadows;
}();
function sortShadowed(elements, context, sortElements) {
    var shadows = new Shadows(context, sortElements);
    var _elements = shadows.extractElements(elements);
    if (_elements.length === elements.length) {
        // no shadowed content found, no need to continue
        return sortElements(elements);
    }
    return shadows.sort(_elements);
}
function sortTabindex(elements) {
    // https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement.tabIndex
    // elements with tabIndex "0" (including tabbableElements without tabIndex) should be navigated in the order they appear.
    // elements with a positive tabIndex:
    //   Elements that have identical tabIndexes should be navigated in the order they appear.
    //   Navigation proceeds from the lowest tabIndex to the highest tabIndex.
    // NOTE: sort implementation may be unstable and thus mess up DOM order,
    // that's why we build a map that's being sorted instead. If we were able to rely
    // on a stable sorting algorithm, sortTabindex() could be as simple as
    // elements.sort(function(a, b) { return a.tabIndex - b.tabIndex; });
    // at this time Chrome does not use a stable sorting algorithm
    // see http://blog.rodneyrehm.de/archives/14-Sorting-Were-Doing-It-Wrong.html#stability
    // NOTE: compareDocumentPosition seemed like more overhead than just sorting this with buckets
    // https://developer.mozilla.org/en-US/docs/Web/API/Node.compareDocumentPosition
    var map = {};
    var indexes = [];
    var normal = elements.filter(function(element) {
        // in Trident and Gecko SVGElement does not know about the tabIndex property
        var tabIndex = element.tabIndex;
        if (tabIndex === undefined) {
            tabIndex = tabindexValue(element);
        }
        // extract elements that don't need sorting
        if (tabIndex <= 0 || tabIndex === null || tabIndex === undefined) {
            return true;
        }
        if (!map[tabIndex]) {
            // create sortable bucket for dom-order-preservation of elements with the same tabIndex
            map[tabIndex] = [];
            // maintain a list of unique tabIndexes
            indexes.push(tabIndex);
        }
        // sort element into the proper bucket
        map[tabIndex].push(element);
        // element moved to sorting map, so not "normal" anymore
        return false;
    });
    // sort the tabindex ascending,
    // then resolve them to their appropriate buckets,
    // then flatten the array of arrays to an array
    var _elements = indexes.sort().map(function(tabIndex) {
        return map[tabIndex];
    }).reduceRight(function(previous, current) {
        return current.concat(previous);
    }, normal);
    return _elements;
}
var supports$8 = void 0;
function moveContextToBeginning(elements, context) {
    var pos = elements.indexOf(context);
    if (pos > 0) {
        var tmp = elements.splice(pos, 1);
        return tmp.concat(elements);
    }
    return elements;
}
function sortElements(elements, _context) {
    if (supports$8.tabsequenceAreaAtImgPosition) {
        // Some browsers sort <area> in DOM order, some place the <area>s
        // where the <img> referecing them would've been in DOM order.
        // https://github.com/medialize/ally.js/issues/5
        elements = sortArea(elements, _context);
    }
    elements = sortTabindex(elements);
    return elements;
}
function queryTabsequence() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, context = _ref.context, includeContext = _ref.includeContext, includeOnlyTabbable = _ref.includeOnlyTabbable, strategy = _ref.strategy;
    if (!supports$8) {
        supports$8 = _supports();
    }
    var _context = nodeArray(context)[0] || document.documentElement;
    var elements = queryTabbable({
        context: _context,
        includeContext: includeContext,
        includeOnlyTabbable: includeOnlyTabbable,
        strategy: strategy
    });
    if (document.body.createShadowRoot && platform.is.BLINK) {
        // sort tabindex localized to shadow dom
        // see https://github.com/medialize/ally.js/issues/6
        elements = sortShadowed(elements, _context, sortElements);
    } else {
        elements = sortElements(elements, _context);
    }
    if (includeContext) {
        // if we include the context itself, it has to be the first
        // element of the sequence
        elements = moveContextToBeginning(elements, _context);
    }
    return elements;
}
// codes mostly cloned from https://github.com/keithamus/jwerty/blob/master/jwerty.js
// deliberately not exposing characters like <,.-#* because they vary *wildly*
// across keyboard layouts and may cause various problems
// (e.g. "*" is "Shift +" on a German Mac keyboard)
// (e.g. "@" is "Alt L" on a German Mac keyboard)
var keycode = {
    // Element Focus
    tab: 9,
    // Navigation
    left: 37,
    up: 38,
    right: 39,
    down: 40,
    pageUp: 33,
    "page-up": 33,
    pageDown: 34,
    "page-down": 34,
    end: 35,
    home: 36,
    // Action
    enter: 13,
    escape: 27,
    space: 32,
    // Modifier
    shift: 16,
    capsLock: 20,
    "caps-lock": 20,
    ctrl: 17,
    alt: 18,
    meta: 91,
    // in firefox: 224
    // on mac (chrome): meta-left=91, meta-right=93
    // on win (IE11): meta-left=91, meta-right=92
    pause: 19,
    // Content Manipulation
    insert: 45,
    delete: 46,
    backspace: 8,
    // the same logical key may be identified through different keyCodes
    _alias: {
        91: [
            92,
            93,
            224
        ]
    }
};
// Function keys (112 - 137)
// NOTE: not every keyboard knows F13+
for(var n = 1; n < 26; n++){
    keycode["f" + n] = n + 111;
}
// Number keys (48-57, numpad 96-105)
// NOTE: not every keyboard knows num-0+
for(var _n = 0; _n < 10; _n++){
    var code = _n + 48;
    var numCode = _n + 96;
    keycode[_n] = code;
    keycode["num-" + _n] = numCode;
    keycode._alias[code] = [
        numCode
    ];
}
// Latin characters (65 - 90)
for(var _n2 = 0; _n2 < 26; _n2++){
    var _code = _n2 + 65;
    var name$1 = String.fromCharCode(_code).toLowerCase();
    keycode[name$1] = _code;
}
var modifier = {
    alt: "altKey",
    ctrl: "ctrlKey",
    meta: "metaKey",
    shift: "shiftKey"
};
var modifierSequence = Object.keys(modifier).map(function(name) {
    return modifier[name];
});
function createExpectedModifiers(ignoreModifiers) {
    var value = ignoreModifiers ? null : false;
    return {
        altKey: value,
        ctrlKey: value,
        metaKey: value,
        shiftKey: value
    };
}
function resolveModifiers(modifiers) {
    var ignoreModifiers = modifiers.indexOf("*") !== -1;
    var expected = createExpectedModifiers(ignoreModifiers);
    modifiers.forEach(function(token) {
        if (token === "*") {
            // we've already covered the all-in operator
            return;
        }
        // we want the modifier pressed
        var value = true;
        var operator = token.slice(0, 1);
        if (operator === "?") {
            // we don't care if the modifier is pressed
            value = null;
        } else if (operator === "!") {
            // we do not want the modifier pressed
            value = false;
        }
        if (value !== true) {
            // compensate for the modifier's operator
            token = token.slice(1);
        }
        var propertyName = modifier[token];
        if (!propertyName) {
            throw new TypeError('Unknown modifier "' + token + '"');
        }
        expected[propertyName] = value;
    });
    return expected;
}
function resolveKey(key) {
    var code = keycode[key] || parseInt(key, 10);
    if (!code || typeof code !== "number" || isNaN(code)) {
        throw new TypeError('Unknown key "' + key + '"');
    }
    return [
        code
    ].concat(keycode._alias[code] || []);
}
function matchModifiers(expected, event) {
    // returns true on match
    return !modifierSequence.some(function(prop) {
        // returns true on mismatch
        return typeof expected[prop] === "boolean" && Boolean(event[prop]) !== expected[prop];
    });
}
function keyBinding(text) {
    return text.split(/\s+/).map(function(_text) {
        var tokens = _text.split("+");
        var _modifiers = resolveModifiers(tokens.slice(0, -1));
        var _keyCodes = resolveKey(tokens.slice(-1));
        return {
            keyCodes: _keyCodes,
            modifiers: _modifiers,
            matchModifiers: matchModifiers.bind(null, _modifiers)
        };
    });
}
// Node.compareDocumentPosition is available since IE9
// see https://developer.mozilla.org/en-US/docs/Web/API/Node.compareDocumentPosition
// callback returns true when element is contained by parent or is the parent suited for use with Array.some()
/*
  USAGE:
    var isChildOf = getParentComparator({parent: someNode});
    listOfElements.some(isChildOf)
*/ function getParentComparator() {
    var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {}, parent = _ref.parent, element = _ref.element, includeSelf = _ref.includeSelf;
    if (parent) {
        return function isChildOf(node) {
            return Boolean(includeSelf && node === parent || parent.compareDocumentPosition(node) & Node.DOCUMENT_POSITION_CONTAINED_BY);
        };
    } else if (element) {
        return function isParentOf(node) {
            return Boolean(includeSelf && element === node || node.compareDocumentPosition(element) & Node.DOCUMENT_POSITION_CONTAINED_BY);
        };
    }
    throw new TypeError("util/compare-position#getParentComparator required either options.parent or options.element");
}
// Bug 286933 - Key events in the autocomplete popup should be hidden from page scripts
// @browser-issue Gecko https://bugzilla.mozilla.org/show_bug.cgi?id=286933
function whenKey() {
    var map = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
    var bindings = {};
    var context = nodeArray(map.context)[0] || document.documentElement;
    delete map.context;
    var filter = nodeArray(map.filter);
    delete map.filter;
    var mapKeys = Object.keys(map);
    if (!mapKeys.length) {
        throw new TypeError("when/key requires at least one option key");
    }
    var registerBinding = function registerBinding(event) {
        event.keyCodes.forEach(function(code) {
            if (!bindings[code]) {
                bindings[code] = [];
            }
            bindings[code].push(event);
        });
    };
    mapKeys.forEach(function(text) {
        if (typeof map[text] !== "function") {
            throw new TypeError('when/key requires option["' + text + '"] to be a function');
        }
        var addCallback = function addCallback(event) {
            event.callback = map[text];
            return event;
        };
        keyBinding(text).map(addCallback).forEach(registerBinding);
    });
    var handleKeyDown = function handleKeyDown(event) {
        if (event.defaultPrevented) {
            return;
        }
        if (filter.length) {
            // ignore elements within the exempted sub-trees
            var isParentOfElement = getParentComparator({
                element: event.target,
                includeSelf: true
            });
            if (filter.some(isParentOfElement)) {
                return;
            }
        }
        var key = event.keyCode || event.which;
        if (!bindings[key]) {
            return;
        }
        bindings[key].forEach(function(_event) {
            if (!_event.matchModifiers(event)) {
                return;
            }
            _event.callback.call(context, event, disengage);
        });
    };
    context.addEventListener("keydown", handleKeyDown, false);
    var disengage = function disengage() {
        context.removeEventListener("keydown", handleKeyDown, false);
    };
    return {
        disengage: disengage
    };
}
export default function(param) {
    let { context  } = param === void 0 ? {} : param;
    if (!context) {
        context = document.documentElement;
    }
    // Make sure the supports tests are run before intercepting the Tab key,
    // or IE10 and IE11 will fail to process the first Tab key event. Not
    // limiting this warm-up to IE because it may be a problem elsewhere, too.
    queryTabsequence();
    return whenKey({
        // Safari on OSX may require ALT+TAB to reach links,
        // see https://github.com/medialize/ally.js/issues/146
        "?alt+?shift+tab": function altShiftTab(event) {
            // we're completely taking over the Tab key handling
            event.preventDefault();
            var sequence = queryTabsequence({
                context: context
            });
            var backward = event.shiftKey;
            var first = sequence[0];
            var last = sequence[sequence.length - 1];
            // wrap around first to last, last to first
            var source = backward ? first : last;
            var target = backward ? last : first;
            if (isActiveElement(source)) {
                target.focus();
                return;
            }
            // find current position in tabsequence
            var currentIndex = void 0;
            var found = sequence.some(function(element, index) {
                if (!isActiveElement(element)) {
                    return false;
                }
                currentIndex = index;
                return true;
            });
            if (!found) {
                // redirect to first as we're not in our tabsequence
                first.focus();
                return;
            }
            // shift focus to previous/next element in the sequence
            var offset = backward ? -1 : 1;
            sequence[currentIndex + offset].focus();
        }
    });
}

//# sourceMappingURL=maintain--tab-focus.js.map