@angular/cdk/fesm5/a11y.js

Angular Material Component Development Kit

import { DOCUMENT, CommonModule } from '@angular/common';
import { Injectable, Inject, ɵɵdefineInjectable, ɵɵinject, QueryList, isDevMode, NgZone, Directive, ElementRef, Input, InjectionToken, Optional, EventEmitter, Output, NgModule } from '@angular/core';
import { __extends, __read } from 'tslib';
import { Subject, Subscription, of } from 'rxjs';
import { hasModifierKey, A, Z, ZERO, NINE, LEFT_ARROW, RIGHT_ARROW, UP_ARROW, DOWN_ARROW, TAB } from '@angular/cdk/keycodes';
import { tap, debounceTime, filter, map, take } from 'rxjs/operators';
import { coerceBooleanProperty, coerceElement } from '@angular/cdk/coercion';
import { Platform, normalizePassiveListenerOptions, PlatformModule } from '@angular/cdk/platform';
import { ContentObserver, ObserversModule } from '@angular/cdk/observers';

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** IDs are deliminated by an empty space, as per the spec. */
var ID_DELIMINATOR = ' ';
/**
 * Adds the given ID to the specified ARIA attribute on an element.
 * Used for attributes such as aria-labelledby, aria-owns, etc.
 */
function addAriaReferencedId(el, attr, id) {
    var ids = getAriaReferenceIds(el, attr);
    if (ids.some(function (existingId) { return existingId.trim() == id.trim(); })) {
        return;
    }
    ids.push(id.trim());
    el.setAttribute(attr, ids.join(ID_DELIMINATOR));
}
/**
 * Removes the given ID from the specified ARIA attribute on an element.
 * Used for attributes such as aria-labelledby, aria-owns, etc.
 */
function removeAriaReferencedId(el, attr, id) {
    var ids = getAriaReferenceIds(el, attr);
    var filteredIds = ids.filter(function (val) { return val != id.trim(); });
    if (filteredIds.length) {
        el.setAttribute(attr, filteredIds.join(ID_DELIMINATOR));
    }
    else {
        el.removeAttribute(attr);
    }
}
/**
 * Gets the list of IDs referenced by the given ARIA attribute on an element.
 * Used for attributes such as aria-labelledby, aria-owns, etc.
 */
function getAriaReferenceIds(el, attr) {
    // Get string array of all individual ids (whitespace deliminated) in the attribute value
    return (el.getAttribute(attr) || '').match(/\S+/g) || [];
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** ID used for the body container where all messages are appended. */
var MESSAGES_CONTAINER_ID = 'cdk-describedby-message-container';
/** ID prefix used for each created message element. */
var CDK_DESCRIBEDBY_ID_PREFIX = 'cdk-describedby-message';
/** Attribute given to each host element that is described by a message element. */
var CDK_DESCRIBEDBY_HOST_ATTRIBUTE = 'cdk-describedby-host';
/** Global incremental identifier for each registered message element. */
var nextId = 0;
/** Global map of all registered message elements that have been placed into the document. */
var messageRegistry = new Map();
/** Container for all registered messages. */
var messagesContainer = null;
/**
 * Utility that creates visually hidden elements with a message content. Useful for elements that
 * want to use aria-describedby to further describe themselves without adding additional visual
 * content.
 */
var AriaDescriber = /** @class */ (function () {
    function AriaDescriber(_document) {
        this._document = _document;
    }
    /**
     * Adds to the host element an aria-describedby reference to a hidden element that contains
     * the message. If the same message has already been registered, then it will reuse the created
     * message element.
     */
    AriaDescriber.prototype.describe = function (hostElement, message) {
        if (!this._canBeDescribed(hostElement, message)) {
            return;
        }
        if (typeof message !== 'string') {
            // We need to ensure that the element has an ID.
            this._setMessageId(message);
            messageRegistry.set(message, { messageElement: message, referenceCount: 0 });
        }
        else if (!messageRegistry.has(message)) {
            this._createMessageElement(message);
        }
        if (!this._isElementDescribedByMessage(hostElement, message)) {
            this._addMessageReference(hostElement, message);
        }
    };
    /** Removes the host element's aria-describedby reference to the message element. */
    AriaDescriber.prototype.removeDescription = function (hostElement, message) {
        if (!this._isElementNode(hostElement)) {
            return;
        }
        if (this._isElementDescribedByMessage(hostElement, message)) {
            this._removeMessageReference(hostElement, message);
        }
        // If the message is a string, it means that it's one that we created for the
        // consumer so we can remove it safely, otherwise we should leave it in place.
        if (typeof message === 'string') {
            var registeredMessage = messageRegistry.get(message);
            if (registeredMessage && registeredMessage.referenceCount === 0) {
                this._deleteMessageElement(message);
            }
        }
        if (messagesContainer && messagesContainer.childNodes.length === 0) {
            this._deleteMessagesContainer();
        }
    };
    /** Unregisters all created message elements and removes the message container. */
    AriaDescriber.prototype.ngOnDestroy = function () {
        var describedElements = this._document.querySelectorAll("[" + CDK_DESCRIBEDBY_HOST_ATTRIBUTE + "]");
        for (var i = 0; i < describedElements.length; i++) {
            this._removeCdkDescribedByReferenceIds(describedElements[i]);
            describedElements[i].removeAttribute(CDK_DESCRIBEDBY_HOST_ATTRIBUTE);
        }
        if (messagesContainer) {
            this._deleteMessagesContainer();
        }
        messageRegistry.clear();
    };
    /**
     * Creates a new element in the visually hidden message container element with the message
     * as its content and adds it to the message registry.
     */
    AriaDescriber.prototype._createMessageElement = function (message) {
        var messageElement = this._document.createElement('div');
        this._setMessageId(messageElement);
        messageElement.textContent = message;
        this._createMessagesContainer();
        messagesContainer.appendChild(messageElement);
        messageRegistry.set(message, { messageElement: messageElement, referenceCount: 0 });
    };
    /** Assigns a unique ID to an element, if it doesn't have one already. */
    AriaDescriber.prototype._setMessageId = function (element) {
        if (!element.id) {
            element.id = CDK_DESCRIBEDBY_ID_PREFIX + "-" + nextId++;
        }
    };
    /** Deletes the message element from the global messages container. */
    AriaDescriber.prototype._deleteMessageElement = function (message) {
        var registeredMessage = messageRegistry.get(message);
        var messageElement = registeredMessage && registeredMessage.messageElement;
        if (messagesContainer && messageElement) {
            messagesContainer.removeChild(messageElement);
        }
        messageRegistry.delete(message);
    };
    /** Creates the global container for all aria-describedby messages. */
    AriaDescriber.prototype._createMessagesContainer = function () {
        if (!messagesContainer) {
            var preExistingContainer = this._document.getElementById(MESSAGES_CONTAINER_ID);
            // When going from the server to the client, we may end up in a situation where there's
            // already a container on the page, but we don't have a reference to it. Clear the
            // old container so we don't get duplicates. Doing this, instead of emptying the previous
            // container, should be slightly faster.
            if (preExistingContainer) {
                preExistingContainer.parentNode.removeChild(preExistingContainer);
            }
            messagesContainer = this._document.createElement('div');
            messagesContainer.id = MESSAGES_CONTAINER_ID;
            messagesContainer.setAttribute('aria-hidden', 'true');
            messagesContainer.style.display = 'none';
            this._document.body.appendChild(messagesContainer);
        }
    };
    /** Deletes the global messages container. */
    AriaDescriber.prototype._deleteMessagesContainer = function () {
        if (messagesContainer && messagesContainer.parentNode) {
            messagesContainer.parentNode.removeChild(messagesContainer);
            messagesContainer = null;
        }
    };
    /** Removes all cdk-describedby messages that are hosted through the element. */
    AriaDescriber.prototype._removeCdkDescribedByReferenceIds = function (element) {
        // Remove all aria-describedby reference IDs that are prefixed by CDK_DESCRIBEDBY_ID_PREFIX
        var originalReferenceIds = getAriaReferenceIds(element, 'aria-describedby')
            .filter(function (id) { return id.indexOf(CDK_DESCRIBEDBY_ID_PREFIX) != 0; });
        element.setAttribute('aria-describedby', originalReferenceIds.join(' '));
    };
    /**
     * Adds a message reference to the element using aria-describedby and increments the registered
     * message's reference count.
     */
    AriaDescriber.prototype._addMessageReference = function (element, message) {
        var registeredMessage = messageRegistry.get(message);
        // Add the aria-describedby reference and set the
        // describedby_host attribute to mark the element.
        addAriaReferencedId(element, 'aria-describedby', registeredMessage.messageElement.id);
        element.setAttribute(CDK_DESCRIBEDBY_HOST_ATTRIBUTE, '');
        registeredMessage.referenceCount++;
    };
    /**
     * Removes a message reference from the element using aria-describedby
     * and decrements the registered message's reference count.
     */
    AriaDescriber.prototype._removeMessageReference = function (element, message) {
        var registeredMessage = messageRegistry.get(message);
        registeredMessage.referenceCount--;
        removeAriaReferencedId(element, 'aria-describedby', registeredMessage.messageElement.id);
        element.removeAttribute(CDK_DESCRIBEDBY_HOST_ATTRIBUTE);
    };
    /** Returns true if the element has been described by the provided message ID. */
    AriaDescriber.prototype._isElementDescribedByMessage = function (element, message) {
        var referenceIds = getAriaReferenceIds(element, 'aria-describedby');
        var registeredMessage = messageRegistry.get(message);
        var messageId = registeredMessage && registeredMessage.messageElement.id;
        return !!messageId && referenceIds.indexOf(messageId) != -1;
    };
    /** Determines whether a message can be described on a particular element. */
    AriaDescriber.prototype._canBeDescribed = function (element, message) {
        if (!this._isElementNode(element)) {
            return false;
        }
        if (message && typeof message === 'object') {
            // We'd have to make some assumptions about the description element's text, if the consumer
            // passed in an element. Assume that if an element is passed in, the consumer has verified
            // that it can be used as a description.
            return true;
        }
        var trimmedMessage = message == null ? '' : ("" + message).trim();
        var ariaLabel = element.getAttribute('aria-label');
        // We shouldn't set descriptions if they're exactly the same as the `aria-label` of the
        // element, because screen readers will end up reading out the same text twice in a row.
        return trimmedMessage ? (!ariaLabel || ariaLabel.trim() !== trimmedMessage) : false;
    };
    /** Checks whether a node is an Element node. */
    AriaDescriber.prototype._isElementNode = function (element) {
        return element.nodeType === this._document.ELEMENT_NODE;
    };
    AriaDescriber.decorators = [
        { type: Injectable, args: [{ providedIn: 'root' },] }
    ];
    /** @nocollapse */
    AriaDescriber.ctorParameters = function () { return [
        { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] }
    ]; };
    AriaDescriber.ɵprov = ɵɵdefineInjectable({ factory: function AriaDescriber_Factory() { return new AriaDescriber(ɵɵinject(DOCUMENT)); }, token: AriaDescriber, providedIn: "root" });
    return AriaDescriber;
}());

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * This class manages keyboard events for selectable lists. If you pass it a query list
 * of items, it will set the active item correctly when arrow events occur.
 */
var ListKeyManager = /** @class */ (function () {
    function ListKeyManager(_items) {
        var _this = this;
        this._items = _items;
        this._activeItemIndex = -1;
        this._activeItem = null;
        this._wrap = false;
        this._letterKeyStream = new Subject();
        this._typeaheadSubscription = Subscription.EMPTY;
        this._vertical = true;
        this._allowedModifierKeys = [];
        /**
         * Predicate function that can be used to check whether an item should be skipped
         * by the key manager. By default, disabled items are skipped.
         */
        this._skipPredicateFn = function (item) { return item.disabled; };
        // Buffer for the letters that the user has pressed when the typeahead option is turned on.
        this._pressedLetters = [];
        /**
         * Stream that emits any time the TAB key is pressed, so components can react
         * when focus is shifted off of the list.
         */
        this.tabOut = new Subject();
        /** Stream that emits whenever the active item of the list manager changes. */
        this.change = new Subject();
        // We allow for the items to be an array because, in some cases, the consumer may
        // not have access to a QueryList of the items they want to manage (e.g. when the
        // items aren't being collected via `ViewChildren` or `ContentChildren`).
        if (_items instanceof QueryList) {
            _items.changes.subscribe(function (newItems) {
                if (_this._activeItem) {
                    var itemArray = newItems.toArray();
                    var newIndex = itemArray.indexOf(_this._activeItem);
                    if (newIndex > -1 && newIndex !== _this._activeItemIndex) {
                        _this._activeItemIndex = newIndex;
                    }
                }
            });
        }
    }
    /**
     * Sets the predicate function that determines which items should be skipped by the
     * list key manager.
     * @param predicate Function that determines whether the given item should be skipped.
     */
    ListKeyManager.prototype.skipPredicate = function (predicate) {
        this._skipPredicateFn = predicate;
        return this;
    };
    /**
     * Configures wrapping mode, which determines whether the active item will wrap to
     * the other end of list when there are no more items in the given direction.
     * @param shouldWrap Whether the list should wrap when reaching the end.
     */
    ListKeyManager.prototype.withWrap = function (shouldWrap) {
        if (shouldWrap === void 0) { shouldWrap = true; }
        this._wrap = shouldWrap;
        return this;
    };
    /**
     * Configures whether the key manager should be able to move the selection vertically.
     * @param enabled Whether vertical selection should be enabled.
     */
    ListKeyManager.prototype.withVerticalOrientation = function (enabled) {
        if (enabled === void 0) { enabled = true; }
        this._vertical = enabled;
        return this;
    };
    /**
     * Configures the key manager to move the selection horizontally.
     * Passing in `null` will disable horizontal movement.
     * @param direction Direction in which the selection can be moved.
     */
    ListKeyManager.prototype.withHorizontalOrientation = function (direction) {
        this._horizontal = direction;
        return this;
    };
    /**
     * Modifier keys which are allowed to be held down and whose default actions will be prevented
     * as the user is pressing the arrow keys. Defaults to not allowing any modifier keys.
     */
    ListKeyManager.prototype.withAllowedModifierKeys = function (keys) {
        this._allowedModifierKeys = keys;
        return this;
    };
    /**
     * Turns on typeahead mode which allows users to set the active item by typing.
     * @param debounceInterval Time to wait after the last keystroke before setting the active item.
     */
    ListKeyManager.prototype.withTypeAhead = function (debounceInterval) {
        var _this = this;
        if (debounceInterval === void 0) { debounceInterval = 200; }
        if (this._items.length && this._items.some(function (item) { return typeof item.getLabel !== 'function'; })) {
            throw Error('ListKeyManager items in typeahead mode must implement the `getLabel` method.');
        }
        this._typeaheadSubscription.unsubscribe();
        // Debounce the presses of non-navigational keys, collect the ones that correspond to letters
        // and convert those letters back into a string. Afterwards find the first item that starts
        // with that string and select it.
        this._typeaheadSubscription = this._letterKeyStream.pipe(tap(function (letter) { return _this._pressedLetters.push(letter); }), debounceTime(debounceInterval), filter(function () { return _this._pressedLetters.length > 0; }), map(function () { return _this._pressedLetters.join(''); })).subscribe(function (inputString) {
            var items = _this._getItemsArray();
            // Start at 1 because we want to start searching at the item immediately
            // following the current active item.
            for (var i = 1; i < items.length + 1; i++) {
                var index = (_this._activeItemIndex + i) % items.length;
                var item = items[index];
                if (!_this._skipPredicateFn(item) &&
                    item.getLabel().toUpperCase().trim().indexOf(inputString) === 0) {
                    _this.setActiveItem(index);
                    break;
                }
            }
            _this._pressedLetters = [];
        });
        return this;
    };
    ListKeyManager.prototype.setActiveItem = function (item) {
        var previousIndex = this._activeItemIndex;
        this.updateActiveItem(item);
        if (this._activeItemIndex !== previousIndex) {
            this.change.next(this._activeItemIndex);
        }
    };
    /**
     * Sets the active item depending on the key event passed in.
     * @param event Keyboard event to be used for determining which element should be active.
     */
    ListKeyManager.prototype.onKeydown = function (event) {
        var _this = this;
        var keyCode = event.keyCode;
        var modifiers = ['altKey', 'ctrlKey', 'metaKey', 'shiftKey'];
        var isModifierAllowed = modifiers.every(function (modifier) {
            return !event[modifier] || _this._allowedModifierKeys.indexOf(modifier) > -1;
        });
        switch (keyCode) {
            case TAB:
                this.tabOut.next();
                return;
            case DOWN_ARROW:
                if (this._vertical && isModifierAllowed) {
                    this.setNextItemActive();
                    break;
                }
                else {
                    return;
                }
            case UP_ARROW:
                if (this._vertical && isModifierAllowed) {
                    this.setPreviousItemActive();
                    break;
                }
                else {
                    return;
                }
            case RIGHT_ARROW:
                if (this._horizontal && isModifierAllowed) {
                    this._horizontal === 'rtl' ? this.setPreviousItemActive() : this.setNextItemActive();
                    break;
                }
                else {
                    return;
                }
            case LEFT_ARROW:
                if (this._horizontal && isModifierAllowed) {
                    this._horizontal === 'rtl' ? this.setNextItemActive() : this.setPreviousItemActive();
                    break;
                }
                else {
                    return;
                }
            default:
                if (isModifierAllowed || hasModifierKey(event, 'shiftKey')) {
                    // Attempt to use the `event.key` which also maps it to the user's keyboard language,
                    // otherwise fall back to resolving alphanumeric characters via the keyCode.
                    if (event.key && event.key.length === 1) {
                        this._letterKeyStream.next(event.key.toLocaleUpperCase());
                    }
                    else if ((keyCode >= A && keyCode <= Z) || (keyCode >= ZERO && keyCode <= NINE)) {
                        this._letterKeyStream.next(String.fromCharCode(keyCode));
                    }
                }
                // Note that we return here, in order to avoid preventing
                // the default action of non-navigational keys.
                return;
        }
        this._pressedLetters = [];
        event.preventDefault();
    };
    Object.defineProperty(ListKeyManager.prototype, "activeItemIndex", {
        /** Index of the currently active item. */
        get: function () {
            return this._activeItemIndex;
        },
        enumerable: true,
        configurable: true
    });
    Object.defineProperty(ListKeyManager.prototype, "activeItem", {
        /** The active item. */
        get: function () {
            return this._activeItem;
        },
        enumerable: true,
        configurable: true
    });
    /** Gets whether the user is currently typing into the manager using the typeahead feature. */
    ListKeyManager.prototype.isTyping = function () {
        return this._pressedLetters.length > 0;
    };
    /** Sets the active item to the first enabled item in the list. */
    ListKeyManager.prototype.setFirstItemActive = function () {
        this._setActiveItemByIndex(0, 1);
    };
    /** Sets the active item to the last enabled item in the list. */
    ListKeyManager.prototype.setLastItemActive = function () {
        this._setActiveItemByIndex(this._items.length - 1, -1);
    };
    /** Sets the active item to the next enabled item in the list. */
    ListKeyManager.prototype.setNextItemActive = function () {
        this._activeItemIndex < 0 ? this.setFirstItemActive() : this._setActiveItemByDelta(1);
    };
    /** Sets the active item to a previous enabled item in the list. */
    ListKeyManager.prototype.setPreviousItemActive = function () {
        this._activeItemIndex < 0 && this._wrap ? this.setLastItemActive()
            : this._setActiveItemByDelta(-1);
    };
    ListKeyManager.prototype.updateActiveItem = function (item) {
        var itemArray = this._getItemsArray();
        var index = typeof item === 'number' ? item : itemArray.indexOf(item);
        var activeItem = itemArray[index];
        // Explicitly check for `null` and `undefined` because other falsy values are valid.
        this._activeItem = activeItem == null ? null : activeItem;
        this._activeItemIndex = index;
    };
    /**
     * This method sets the active item, given a list of items and the delta between the
     * currently active item and the new active item. It will calculate differently
     * depending on whether wrap mode is turned on.
     */
    ListKeyManager.prototype._setActiveItemByDelta = function (delta) {
        this._wrap ? this._setActiveInWrapMode(delta) : this._setActiveInDefaultMode(delta);
    };
    /**
     * Sets the active item properly given "wrap" mode. In other words, it will continue to move
     * down the list until it finds an item that is not disabled, and it will wrap if it
     * encounters either end of the list.
     */
    ListKeyManager.prototype._setActiveInWrapMode = function (delta) {
        var items = this._getItemsArray();
        for (var i = 1; i <= items.length; i++) {
            var index = (this._activeItemIndex + (delta * i) + items.length) % items.length;
            var item = items[index];
            if (!this._skipPredicateFn(item)) {
                this.setActiveItem(index);
                return;
            }
        }
    };
    /**
     * Sets the active item properly given the default mode. In other words, it will
     * continue to move down the list until it finds an item that is not disabled. If
     * it encounters either end of the list, it will stop and not wrap.
     */
    ListKeyManager.prototype._setActiveInDefaultMode = function (delta) {
        this._setActiveItemByIndex(this._activeItemIndex + delta, delta);
    };
    /**
     * Sets the active item to the first enabled item starting at the index specified. If the
     * item is disabled, it will move in the fallbackDelta direction until it either
     * finds an enabled item or encounters the end of the list.
     */
    ListKeyManager.prototype._setActiveItemByIndex = function (index, fallbackDelta) {
        var items = this._getItemsArray();
        if (!items[index]) {
            return;
        }
        while (this._skipPredicateFn(items[index])) {
            index += fallbackDelta;
            if (!items[index]) {
                return;
            }
        }
        this.setActiveItem(index);
    };
    /** Returns the items as an array. */
    ListKeyManager.prototype._getItemsArray = function () {
        return this._items instanceof QueryList ? this._items.toArray() : this._items;
    };
    return ListKeyManager;
}());

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
var ActiveDescendantKeyManager = /** @class */ (function (_super) {
    __extends(ActiveDescendantKeyManager, _super);
    function ActiveDescendantKeyManager() {
        return _super !== null && _super.apply(this, arguments) || this;
    }
    ActiveDescendantKeyManager.prototype.setActiveItem = function (index) {
        if (this.activeItem) {
            this.activeItem.setInactiveStyles();
        }
        _super.prototype.setActiveItem.call(this, index);
        if (this.activeItem) {
            this.activeItem.setActiveStyles();
        }
    };
    return ActiveDescendantKeyManager;
}(ListKeyManager));

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
var FocusKeyManager = /** @class */ (function (_super) {
    __extends(FocusKeyManager, _super);
    function FocusKeyManager() {
        var _this = _super !== null && _super.apply(this, arguments) || this;
        _this._origin = 'program';
        return _this;
    }
    /**
     * Sets the focus origin that will be passed in to the items for any subsequent `focus` calls.
     * @param origin Focus origin to be used when focusing items.
     */
    FocusKeyManager.prototype.setFocusOrigin = function (origin) {
        this._origin = origin;
        return this;
    };
    FocusKeyManager.prototype.setActiveItem = function (item) {
        _super.prototype.setActiveItem.call(this, item);
        if (this.activeItem) {
            this.activeItem.focus(this._origin);
        }
    };
    return FocusKeyManager;
}(ListKeyManager));

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
// The InteractivityChecker leans heavily on the ally.js accessibility utilities.
// Methods like `isTabbable` are only covering specific edge-cases for the browsers which are
// supported.
/**
 * Utility for checking the interactivity of an element, such as whether is is focusable or
 * tabbable.
 */
var InteractivityChecker = /** @class */ (function () {
    function InteractivityChecker(_platform) {
        this._platform = _platform;
    }
    /**
     * Gets whether an element is disabled.
     *
     * @param element Element to be checked.
     * @returns Whether the element is disabled.
     */
    InteractivityChecker.prototype.isDisabled = function (element) {
        // This does not capture some cases, such as a non-form control with a disabled attribute or
        // a form control inside of a disabled form, but should capture the most common cases.
        return element.hasAttribute('disabled');
    };
    /**
     * Gets whether an element is visible for the purposes of interactivity.
     *
     * This will capture states like `display: none` and `visibility: hidden`, but not things like
     * being clipped by an `overflow: hidden` parent or being outside the viewport.
     *
     * @returns Whether the element is visible.
     */
    InteractivityChecker.prototype.isVisible = function (element) {
        return hasGeometry(element) && getComputedStyle(element).visibility === 'visible';
    };
    /**
     * Gets whether an element can be reached via Tab key.
     * Assumes that the element has already been checked with isFocusable.
     *
     * @param element Element to be checked.
     * @returns Whether the element is tabbable.
     */
    InteractivityChecker.prototype.isTabbable = function (element) {
        // Nothing is tabbable on the server 😎
        if (!this._platform.isBrowser) {
            return false;
        }
        var frameElement = getFrameElement(getWindow(element));
        if (frameElement) {
            var frameType = frameElement && frameElement.nodeName.toLowerCase();
            // Frame elements inherit their tabindex onto all child elements.
            if (getTabIndexValue(frameElement) === -1) {
                return false;
            }
            // Webkit and Blink consider anything inside of an <object> element as non-tabbable.
            if ((this._platform.BLINK || this._platform.WEBKIT) && frameType === 'object') {
                return false;
            }
            // Webkit and Blink disable tabbing to an element inside of an invisible frame.
            if ((this._platform.BLINK || this._platform.WEBKIT) && !this.isVisible(frameElement)) {
                return false;
            }
        }
        var nodeName = element.nodeName.toLowerCase();
        var tabIndexValue = getTabIndexValue(element);
        if (element.hasAttribute('contenteditable')) {
            return tabIndexValue !== -1;
        }
        if (nodeName === 'iframe') {
            // The frames may be tabbable depending on content, but it's not possibly to reliably
            // investigate the content of the frames.
            return false;
        }
        if (nodeName === 'audio') {
            if (!element.hasAttribute('controls')) {
                // By default an <audio> element without the controls enabled is not tabbable.
                return false;
            }
            else if (this._platform.BLINK) {
                // In Blink <audio controls> elements are always tabbable.
                return true;
            }
        }
        if (nodeName === 'video') {
            if (!element.hasAttribute('controls') && this._platform.TRIDENT) {
                // In Trident a <video> element without the controls enabled is not tabbable.
                return false;
            }
            else if (this._platform.BLINK || this._platform.FIREFOX) {
                // In Chrome and Firefox <video controls> elements are always tabbable.
                return true;
            }
        }
        if (nodeName === 'object' && (this._platform.BLINK || this._platform.WEBKIT)) {
            // In all Blink and WebKit based browsers <object> elements are never tabbable.
            return false;
        }
        // In iOS the browser only considers some specific elements as tabbable.
        if (this._platform.WEBKIT && this._platform.IOS && !isPotentiallyTabbableIOS(element)) {
            return false;
        }
        return element.tabIndex >= 0;
    };
    /**
     * Gets whether an element can be focused by the user.
     *
     * @param element Element to be checked.
     * @returns Whether the element is focusable.
     */
    InteractivityChecker.prototype.isFocusable = function (element) {
        // Perform checks in order of left to most expensive.
        // Again, naive approach that does not capture many edge cases and browser quirks.
        return isPotentiallyFocusable(element) && !this.isDisabled(element) && this.isVisible(element);
    };
    InteractivityChecker.decorators = [
        { type: Injectable, args: [{ providedIn: 'root' },] }
    ];
    /** @nocollapse */
    InteractivityChecker.ctorParameters = function () { return [
        { type: Platform }
    ]; };
    InteractivityChecker.ɵprov = ɵɵdefineInjectable({ factory: function InteractivityChecker_Factory() { return new InteractivityChecker(ɵɵinject(Platform)); }, token: InteractivityChecker, providedIn: "root" });
    return InteractivityChecker;
}());
/**
 * Returns the frame element from a window object. Since browsers like MS Edge throw errors if
 * the frameElement property is being accessed from a different host address, this property
 * should be accessed carefully.
 */
function getFrameElement(window) {
    try {
        return window.frameElement;
    }
    catch (_a) {
        return null;
    }
}
/** Checks whether the specified element has any geometry / rectangles. */
function hasGeometry(element) {
    // Use logic from jQuery to check for an invisible element.
    // See https://github.com/jquery/jquery/blob/master/src/css/hiddenVisibleSelectors.js#L12
    return !!(element.offsetWidth || element.offsetHeight ||
        (typeof element.getClientRects === 'function' && element.getClientRects().length));
}
/** Gets whether an element's  */
function isNativeFormElement(element) {
    var nodeName = element.nodeName.toLowerCase();
    return nodeName === 'input' ||
        nodeName === 'select' ||
        nodeName === 'button' ||
        nodeName === 'textarea';
}
/** Gets whether an element is an `<input type="hidden">`. */
function isHiddenInput(element) {
    return isInputElement(element) && element.type == 'hidden';
}
/** Gets whether an element is an anchor that has an href attribute. */
function isAnchorWithHref(element) {
    return isAnchorElement(element) && element.hasAttribute('href');
}
/** Gets whether an element is an input element. */
function isInputElement(element) {
    return element.nodeName.toLowerCase() == 'input';
}
/** Gets whether an element is an anchor element. */
function isAnchorElement(element) {
    return element.nodeName.toLowerCase() == 'a';
}
/** Gets whether an element has a valid tabindex. */
function hasValidTabIndex(element) {
    if (!element.hasAttribute('tabindex') || element.tabIndex === undefined) {
        return false;
    }
    var tabIndex = element.getAttribute('tabindex');
    // IE11 parses tabindex="" as the value "-32768"
    if (tabIndex == '-32768') {
        return false;
    }
    return !!(tabIndex && !isNaN(parseInt(tabIndex, 10)));
}
/**
 * Returns the parsed tabindex from the element attributes instead of returning the
 * evaluated tabindex from the browsers defaults.
 */
function getTabIndexValue(element) {
    if (!hasValidTabIndex(element)) {
        return null;
    }
    // See browser issue in Gecko https://bugzilla.mozilla.org/show_bug.cgi?id=1128054
    var tabIndex = parseInt(element.getAttribute('tabindex') || '', 10);
    return isNaN(tabIndex) ? -1 : tabIndex;
}
/** Checks whether the specified element is potentially tabbable on iOS */
function isPotentiallyTabbableIOS(element) {
    var nodeName = element.nodeName.toLowerCase();
    var inputType = nodeName === 'input' && element.type;
    return inputType === 'text'
        || inputType === 'password'
        || nodeName === 'select'
        || nodeName === 'textarea';
}
/**
 * Gets whether an element is potentially focusable without taking current visible/disabled state
 * into account.
 */
function isPotentiallyFocusable(element) {
    // Inputs are potentially focusable *unless* they're type="hidden".
    if (isHiddenInput(element)) {
        return false;
    }
    return isNativeFormElement(element) ||
        isAnchorWithHref(element) ||
        element.hasAttribute('contenteditable') ||
        hasValidTabIndex(element);
}
/** Gets the parent window of a DOM node with regards of being inside of an iframe. */
function getWindow(node) {
    // ownerDocument is null if `node` itself *is* a document.
    return node.ownerDocument && node.ownerDocument.defaultView || window;
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Class that allows for trapping focus within a DOM element.
 *
 * This class currently uses a relatively simple approach to focus trapping.
 * It assumes that the tab order is the same as DOM order, which is not necessarily true.
 * Things like `tabIndex > 0`, flex `order`, and shadow roots can cause to two to misalign.
 */
var FocusTrap = /** @class */ (function () {
    function FocusTrap(_element, _checker, _ngZone, _document, deferAnchors) {
        var _this = this;
        if (deferAnchors === void 0) { deferAnchors = false; }
        this._element = _element;
        this._checker = _checker;
        this._ngZone = _ngZone;
        this._document = _document;
        this._hasAttached = false;
        // Event listeners for the anchors. Need to be regular functions so that we can unbind them later.
        this.startAnchorListener = function () { return _this.focusLastTabbableElement(); };
        this.endAnchorListener = function () { return _this.focusFirstTabbableElement(); };
        this._enabled = true;
        if (!deferAnchors) {
            this.attachAnchors();
        }
    }
    Object.defineProperty(FocusTrap.prototype, "enabled", {
        /** Whether the focus trap is active. */
        get: function () { return this._enabled; },
        set: function (value) {
            this._enabled = value;
            if (this._startAnchor && this._endAnchor) {
                this._toggleAnchorTabIndex(value, this._startAnchor);
                this._toggleAnchorTabIndex(value, this._endAnchor);
            }
        },
        enumerable: true,
        configurable: true
    });
    /** Destroys the focus trap by cleaning up the anchors. */
    FocusTrap.prototype.destroy = function () {
        var startAnchor = this._startAnchor;
        var endAnchor = this._endAnchor;
        if (startAnchor) {
            startAnchor.removeEventListener('focus', this.startAnchorListener);
            if (startAnchor.parentNode) {
                startAnchor.parentNode.removeChild(startAnchor);
            }
        }
        if (endAnchor) {
            endAnchor.removeEventListener('focus', this.endAnchorListener);
            if (endAnchor.parentNode) {
                endAnchor.parentNode.removeChild(endAnchor);
            }
        }
        this._startAnchor = this._endAnchor = null;
    };
    /**
     * Inserts the anchors into the DOM. This is usually done automatically
     * in the constructor, but can be deferred for cases like directives with `*ngIf`.
     * @returns Whether the focus trap managed to attach successfuly. This may not be the case
     * if the target element isn't currently in the DOM.
     */
    FocusTrap.prototype.attachAnchors = function () {
        var _this = this;
        // If we're not on the browser, there can be no focus to trap.
        if (this._hasAttached) {
            return true;
        }
        this._ngZone.runOutsideAngular(function () {
            if (!_this._startAnchor) {
                _this._startAnchor = _this._createAnchor();
                _this._startAnchor.addEventListener('focus', _this.startAnchorListener);
            }
            if (!_this._endAnchor) {
                _this._endAnchor = _this._createAnchor();
                _this._endAnchor.addEventListener('focus', _this.endAnchorListener);
            }
        });
        if (this._element.parentNode) {
            this._element.parentNode.insertBefore(this._startAnchor, this._element);
            this._element.parentNode.insertBefore(this._endAnchor, this._element.nextSibling);
            this._hasAttached = true;
        }
        return this._hasAttached;
    };
    /**
     * Waits for the zone to stabilize, then either focuses the first element that the
     * user specified, or the first tabbable element.
     * @returns Returns a promise that resolves with a boolean, depending
     * on whether focus was moved successfuly.
     */
    FocusTrap.prototype.focusInitialElementWhenReady = function () {
        var _this = this;
        return new Promise(function (resolve) {
            _this._executeOnStable(function () { return resolve(_this.focusInitialElement()); });
        });
    };
    /**
     * Waits for the zone to stabilize, then focuses
     * the first tabbable element within the focus trap region.
     * @returns Returns a promise that resolves with a boolean, depending
     * on whether focus was moved successfuly.
     */
    FocusTrap.prototype.focusFirstTabbableElementWhenReady = function () {
        var _this = this;
        return new Promise(function (resolve) {
            _this._executeOnStable(function () { return resolve(_this.focusFirstTabbableElement()); });
        });
    };
    /**
     * Waits for the zone to stabilize, then focuses
     * the last tabbable element within the focus trap region.
     * @returns Returns a promise that resolves with a boolean, depending
     * on whether focus was moved successfuly.
     */
    FocusTrap.prototype.focusLastTabbableElementWhenReady = function () {
        var _this = this;
        return new Promise(function (resolve) {
            _this._executeOnStable(function () { return resolve(_this.focusLastTabbableElement()); });
        });
    };
    /**
     * Get the specified boundary element of the trapped region.
     * @param bound The boundary to get (start or end of trapped region).
     * @returns The boundary element.
     */
    FocusTrap.prototype._getRegionBoundary = function (bound) {
        // Contains the deprecated version of selector, for temporary backwards comparability.
        var markers = this._element.querySelectorAll("[cdk-focus-region-" + bound + "], " +
            ("[cdkFocusRegion" + bound + "], ") +
            ("[cdk-focus-" + bound + "]"));
        for (var i = 0; i < markers.length; i++) {
            // @breaking-change 8.0.0
            if (markers[i].hasAttribute("cdk-focus-" + bound)) {
                console.warn("Found use of deprecated attribute 'cdk-focus-" + bound + "', " +
                    ("use 'cdkFocusRegion" + bound + "' instead. The deprecated ") +
                    "attribute will be removed in 8.0.0.", markers[i]);
            }
            else if (markers[i].hasAttribute("cdk-focus-region-" + bound)) {
                console.warn("Found use of deprecated attribute 'cdk-focus-region-" + bound + "', " +
                    ("use 'cdkFocusRegion" + bound + "' instead. The deprecated attribute ") +
                    "will be removed in 8.0.0.", markers[i]);
            }
        }
        if (bound == 'start') {
            return markers.length ? markers[0] : this._getFirstTabbableElement(this._element);
        }
        return markers.length ?
            markers[markers.length - 1] : this._getLastTabbableElement(this._element);
    };
    /**
     * Focuses the element that should be focused when the focus trap is initialized.
     * @returns Whether focus was moved successfuly.
     */
    FocusTrap.prototype.focusInitialElement = function () {
        // Contains the deprecated version of selector, for temporary backwards comparability.
        var redirectToElement = this._element.querySelector("[cdk-focus-initial], " +
            "[cdkFocusInitial]");
        if (redirectToElement) {
            // @breaking-change 8.0.0
            if (redirectToElement.hasAttribute("cdk-focus-initial")) {
                console.warn("Found use of deprecated attribute 'cdk-focus-initial', " +
                    "use 'cdkFocusInitial' instead. The deprecated attribute " +
                    "will be removed in 8.0.0", redirectToElement);
            }
            // Warn the consumer if the element they've pointed to
            // isn't focusable, when not in production mode.
            if (isDevMode() && !this._checker.isFocusable(redirectToElement)) {
                console.warn("Element matching '[cdkFocusInitial]' is not focusable.", redirectToElement);
            }
            redirectToElement.focus();
            return true;
        }
        return this.focusFirstTabbableElement();
    };
    /**
     * Focuses the first tabbable element within the focus trap region.
     * @returns Whether focus was moved successfuly.
     */
    FocusTrap.prototype.focusFirstTabbableElement = function () {
        var redirectToElement = this._getRegionBoundary('start');
        if (redirectToElement) {
            redirectToElement.focus();
        }
        return !!redirectToElement;
    };
    /**
     * Focuses the last tabbable element within the focus trap region.
     * @returns Whether focus was moved successfuly.
     */
    FocusTrap.prototype.focusLastTabbableElement = function () {
        var redirectToElement = this._getRegionBoundary('end');
        if (redirectToElement) {
            redirectToElement.focus();
        }
        return !!redirectToElement;
    };
    /**
     * Checks whether the focus trap has successfuly been attached.
     */
    FocusTrap.prototype.hasAttached = function () {
        return this._hasAttached;
    };
    /** Get the first tabbable element from a DOM subtree (inclusive). */
    FocusTrap.prototype._getFirstTabbableElement = function (root) {
        if (this._checker.isFocusable(root) && this._checker.isTabbable(root)) {
            return root;
        }
        // Iterate in DOM order. Note that IE doesn't have `children` for SVG so we fall
        // back to `childNodes` which includes text nodes, comments etc.
        var children = root.children || root.childNodes;
        for (var i = 0; i < children.length; i++) {
            var tabbableChild = children[i].nodeType === this._document.ELEMENT_NODE ?
                this._getFirstTabbableElement(children[i]) :
                null;
            if (tabbableChild) {
                return tabbableChild;
            }
        }
        return null;
    };
    /** Get the last tabbable element from a DOM subtree (inclusive). */
    FocusTrap.prototype._getLastTabbableElement = function (root) {
        if (this._checker.isFocusable(root) && this._checker.isTabbable(root)) {
            return root;
        }
        // Iterate in reverse DOM order.
        var children = root.children || root.childNodes;
        for (var i = children.length - 1; i >= 0; i--) {
            var tabbableChild = children[i].nodeType === this._document.ELEMENT_NODE ?
                this._getLastTabbableElement(children[i]) :
                null;
            if (tabbableChild) {
                return tabbableChild;
            }
        }
        return null;
    };
    /** Creates an anchor element. */
    FocusTrap.prototype._createAnchor = function () {
        var anchor = this._document.createElement('div');
        this._toggleAnchorTabIndex(this._enabled, anchor);
        anchor.classList.add('cdk-visually-hidden');
        anchor.classList.add('cdk-focus-trap-anchor');
        anchor.setAttribute('aria-hidden', 'true');
        return anchor;
    };
    /**
     * Toggles the `tabindex` of an anchor, based on the enabled state of the focus trap.
     * @param isEnabled Whether the focus trap is enabled.
     * @param anchor Anchor on which to toggle the tabindex.
     */
    FocusTrap.prototype._toggleAnchorTabIndex = function (isEnabled, anchor) {
        // Remove the tabindex completely, rather than setting it to -1, because if the
        // element has a tabindex, the user might still hit it when navigating with the arrow keys.
        isEnabled ? anchor.setAttribute('tabindex', '0') : anchor.removeAttribute('tabindex');
    };
    /** Executes a function when the zone is stable. */
    FocusTrap.prototype._executeOnStable = function (fn) {
        if (this._ngZone.isStable) {
            fn();
        }
        else {
            this._ngZone.onStable.asObservable().pipe(take(1)).subscribe(fn);
        }
    };
    return FocusTrap;
}());
/** Factory that allows easy instantiation of focus traps. */
var FocusTrapFactory = /** @class */ (function () {
    function FocusTrapFactory(_checker, _ngZone, _document) {
        this._checker = _checker;
        this._ngZone = _ngZone;
        this._document = _document;
    }
    /**
     * Creates a focus-trapped region around the given element.
     * @param element The element around which focus will be trapped.
     * @param deferCaptureElements Defers the creation of focus-capturing elements to be done
     *     manually by the user.
     * @returns The created focus trap instance.