source: trip-planner-front/node_modules/@angular/cdk/fesm2015/a11y.js@ 6fe77af

import * as i2 from '@angular/common';
import { DOCUMENT } from '@angular/common';
import * as i0 from '@angular/core';
import { Injectable, Inject, QueryList, NgZone, Directive, ElementRef, Input, InjectionToken, Optional, EventEmitter, Output, NgModule } from '@angular/core';
import { Subject, Subscription, BehaviorSubject, of } from 'rxjs';
import { hasModifierKey, A, Z, ZERO, NINE, END, HOME, LEFT_ARROW, RIGHT_ARROW, UP_ARROW, DOWN_ARROW, TAB, ALT, CONTROL, MAC_META, META, SHIFT } from '@angular/cdk/keycodes';
import { tap, debounceTime, filter, map, take, skip, distinctUntilChanged, takeUntil } from 'rxjs/operators';
import { coerceBooleanProperty, coerceElement } from '@angular/cdk/coercion';
import * as i1 from '@angular/cdk/platform';
import { Platform, _getFocusedElementPierceShadowDom, normalizePassiveListenerOptions, _getEventTarget, _getShadowRoot, 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 delimited by an empty space, as per the spec. */
const ID_DELIMITER = ' ';
/**
 * 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) {
    const ids = getAriaReferenceIds(el, attr);
    if (ids.some(existingId => existingId.trim() == id.trim())) {
        return;
    }
    ids.push(id.trim());
    el.setAttribute(attr, ids.join(ID_DELIMITER));
}
/**
 * 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) {
    const ids = getAriaReferenceIds(el, attr);
    const filteredIds = ids.filter(val => val != id.trim());
    if (filteredIds.length) {
        el.setAttribute(attr, filteredIds.join(ID_DELIMITER));
    }
    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 delimited) 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. */
const MESSAGES_CONTAINER_ID = 'cdk-describedby-message-container';
/** ID prefix used for each created message element. */
const CDK_DESCRIBEDBY_ID_PREFIX = 'cdk-describedby-message';
/** Attribute given to each host element that is described by a message element. */
const CDK_DESCRIBEDBY_HOST_ATTRIBUTE = 'cdk-describedby-host';
/** Global incremental identifier for each registered message element. */
let nextId = 0;
/** Global map of all registered message elements that have been placed into the document. */
const messageRegistry = new Map();
/** Container for all registered messages. */
let 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.
 */
class AriaDescriber {
    constructor(_document) {
        this._document = _document;
    }
    describe(hostElement, message, role) {
        if (!this._canBeDescribed(hostElement, message)) {
            return;
        }
        const key = getKey(message, role);
        if (typeof message !== 'string') {
            // We need to ensure that the element has an ID.
            setMessageId(message);
            messageRegistry.set(key, { messageElement: message, referenceCount: 0 });
        }
        else if (!messageRegistry.has(key)) {
            this._createMessageElement(message, role);
        }
        if (!this._isElementDescribedByMessage(hostElement, key)) {
            this._addMessageReference(hostElement, key);
        }
    }
    removeDescription(hostElement, message, role) {
        if (!message || !this._isElementNode(hostElement)) {
            return;
        }
        const key = getKey(message, role);
        if (this._isElementDescribedByMessage(hostElement, key)) {
            this._removeMessageReference(hostElement, key);
        }
        // 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') {
            const registeredMessage = messageRegistry.get(key);
            if (registeredMessage && registeredMessage.referenceCount === 0) {
                this._deleteMessageElement(key);
            }
        }
        if (messagesContainer && messagesContainer.childNodes.length === 0) {
            this._deleteMessagesContainer();
        }
    }
    /** Unregisters all created message elements and removes the message container. */
    ngOnDestroy() {
        const describedElements = this._document.querySelectorAll(`[${CDK_DESCRIBEDBY_HOST_ATTRIBUTE}]`);
        for (let 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.
     */
    _createMessageElement(message, role) {
        const messageElement = this._document.createElement('div');
        setMessageId(messageElement);
        messageElement.textContent = message;
        if (role) {
            messageElement.setAttribute('role', role);
        }
        this._createMessagesContainer();
        messagesContainer.appendChild(messageElement);
        messageRegistry.set(getKey(message, role), { messageElement, referenceCount: 0 });
    }
    /** Deletes the message element from the global messages container. */
    _deleteMessageElement(key) {
        const registeredMessage = messageRegistry.get(key);
        const messageElement = registeredMessage && registeredMessage.messageElement;
        if (messagesContainer && messageElement) {
            messagesContainer.removeChild(messageElement);
        }
        messageRegistry.delete(key);
    }
    /** Creates the global container for all aria-describedby messages. */
    _createMessagesContainer() {
        if (!messagesContainer) {
            const 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) {
                preExistingContainer.parentNode.removeChild(preExistingContainer);
            }
            messagesContainer = this._document.createElement('div');
            messagesContainer.id = MESSAGES_CONTAINER_ID;
            // We add `visibility: hidden` in order to prevent text in this container from
            // being searchable by the browser's Ctrl + F functionality.
            // Screen-readers will still read the description for elements with aria-describedby even
            // when the description element is not visible.
            messagesContainer.style.visibility = 'hidden';
            // Even though we use `visibility: hidden`, we still apply `cdk-visually-hidden` so that
            // the description element doesn't impact page layout.
            messagesContainer.classList.add('cdk-visually-hidden');
            this._document.body.appendChild(messagesContainer);
        }
    }
    /** Deletes the global messages container. */
    _deleteMessagesContainer() {
        if (messagesContainer && messagesContainer.parentNode) {
            messagesContainer.parentNode.removeChild(messagesContainer);
            messagesContainer = null;
        }
    }
    /** Removes all cdk-describedby messages that are hosted through the element. */
    _removeCdkDescribedByReferenceIds(element) {
        // Remove all aria-describedby reference IDs that are prefixed by CDK_DESCRIBEDBY_ID_PREFIX
        const originalReferenceIds = getAriaReferenceIds(element, 'aria-describedby')
            .filter(id => 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.
     */
    _addMessageReference(element, key) {
        const registeredMessage = messageRegistry.get(key);
        // 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.
     */
    _removeMessageReference(element, key) {
        const registeredMessage = messageRegistry.get(key);
        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. */
    _isElementDescribedByMessage(element, key) {
        const referenceIds = getAriaReferenceIds(element, 'aria-describedby');
        const registeredMessage = messageRegistry.get(key);
        const messageId = registeredMessage && registeredMessage.messageElement.id;
        return !!messageId && referenceIds.indexOf(messageId) != -1;
    }
    /** Determines whether a message can be described on a particular element. */
    _canBeDescribed(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;
        }
        const trimmedMessage = message == null ? '' : `${message}`.trim();
        const 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. */
    _isElementNode(element) {
        return element.nodeType === this._document.ELEMENT_NODE;
    }
}
AriaDescriber.ɵprov = i0.ɵɵdefineInjectable({ factory: function AriaDescriber_Factory() { return new AriaDescriber(i0.ɵɵinject(i2.DOCUMENT)); }, token: AriaDescriber, providedIn: "root" });
AriaDescriber.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
AriaDescriber.ctorParameters = () => [
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] }
];
/** Gets a key that can be used to look messages up in the registry. */
function getKey(message, role) {
    return typeof message === 'string' ? `${role || ''}/${message}` : message;
}
/** Assigns a unique ID to an element, if it doesn't have one already. */
function setMessageId(element) {
    if (!element.id) {
        element.id = `${CDK_DESCRIBEDBY_ID_PREFIX}-${nextId++}`;
    }
}

/**
 * @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.
 */
class ListKeyManager {
    constructor(_items) {
        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 = [];
        this._homeAndEnd = false;
        /**
         * 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 = (item) => 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((newItems) => {
                if (this._activeItem) {
                    const itemArray = newItems.toArray();
                    const 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.
     */
    skipPredicate(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.
     */
    withWrap(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.
     */
    withVerticalOrientation(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.
     */
    withHorizontalOrientation(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.
     */
    withAllowedModifierKeys(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.
     */
    withTypeAhead(debounceInterval = 200) {
        if ((typeof ngDevMode === 'undefined' || ngDevMode) && (this._items.length &&
            this._items.some(item => 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(letter => this._pressedLetters.push(letter)), debounceTime(debounceInterval), filter(() => this._pressedLetters.length > 0), map(() => this._pressedLetters.join(''))).subscribe(inputString => {
            const items = this._getItemsArray();
            // Start at 1 because we want to start searching at the item immediately
            // following the current active item.
            for (let i = 1; i < items.length + 1; i++) {
                const index = (this._activeItemIndex + i) % items.length;
                const item = items[index];
                if (!this._skipPredicateFn(item) &&
                    item.getLabel().toUpperCase().trim().indexOf(inputString) === 0) {
                    this.setActiveItem(index);
                    break;
                }
            }
            this._pressedLetters = [];
        });
        return this;
    }
    /**
     * Configures the key manager to activate the first and last items
     * respectively when the Home or End key is pressed.
     * @param enabled Whether pressing the Home or End key activates the first/last item.
     */
    withHomeAndEnd(enabled = true) {
        this._homeAndEnd = enabled;
        return this;
    }
    setActiveItem(item) {
        const previousActiveItem = this._activeItem;
        this.updateActiveItem(item);
        if (this._activeItem !== previousActiveItem) {
            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.
     */
    onKeydown(event) {
        const keyCode = event.keyCode;
        const modifiers = ['altKey', 'ctrlKey', 'metaKey', 'shiftKey'];
        const isModifierAllowed = modifiers.every(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;
                }
            case HOME:
                if (this._homeAndEnd && isModifierAllowed) {
                    this.setFirstItemActive();
                    break;
                }
                else {
                    return;
                }
            case END:
                if (this._homeAndEnd && isModifierAllowed) {
                    this.setLastItemActive();
                    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();
    }
    /** Index of the currently active item. */
    get activeItemIndex() {
        return this._activeItemIndex;
    }
    /** The active item. */
    get activeItem() {
        return this._activeItem;
    }
    /** Gets whether the user is currently typing into the manager using the typeahead feature. */
    isTyping() {
        return this._pressedLetters.length > 0;
    }
    /** Sets the active item to the first enabled item in the list. */
    setFirstItemActive() {
        this._setActiveItemByIndex(0, 1);
    }
    /** Sets the active item to the last enabled item in the list. */
    setLastItemActive() {
        this._setActiveItemByIndex(this._items.length - 1, -1);
    }
    /** Sets the active item to the next enabled item in the list. */
    setNextItemActive() {
        this._activeItemIndex < 0 ? this.setFirstItemActive() : this._setActiveItemByDelta(1);
    }
    /** Sets the active item to a previous enabled item in the list. */
    setPreviousItemActive() {
        this._activeItemIndex < 0 && this._wrap ? this.setLastItemActive()
            : this._setActiveItemByDelta(-1);
    }
    updateActiveItem(item) {
        const itemArray = this._getItemsArray();
        const index = typeof item === 'number' ? item : itemArray.indexOf(item);
        const 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.
     */
    _setActiveItemByDelta(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.
     */
    _setActiveInWrapMode(delta) {
        const items = this._getItemsArray();
        for (let i = 1; i <= items.length; i++) {
            const index = (this._activeItemIndex + (delta * i) + items.length) % items.length;
            const 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.
     */
    _setActiveInDefaultMode(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.
     */
    _setActiveItemByIndex(index, fallbackDelta) {
        const 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. */
    _getItemsArray() {
        return this._items instanceof QueryList ? this._items.toArray() : this._items;
    }
}

/**
 * @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 ActiveDescendantKeyManager extends ListKeyManager {
    setActiveItem(index) {
        if (this.activeItem) {
            this.activeItem.setInactiveStyles();
        }
        super.setActiveItem(index);
        if (this.activeItem) {
            this.activeItem.setActiveStyles();
        }
    }
}

/**
 * @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 FocusKeyManager extends ListKeyManager {
    constructor() {
        super(...arguments);
        this._origin = 'program';
    }
    /**
     * 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.
     */
    setFocusOrigin(origin) {
        this._origin = origin;
        return this;
    }
    setActiveItem(item) {
        super.setActiveItem(item);
        if (this.activeItem) {
            this.activeItem.focus(this._origin);
        }
    }
}

/**
 * @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
 */
/**
 * Configuration for the isFocusable method.
 */
class IsFocusableConfig {
    constructor() {
        /**
         * Whether to count an element as focusable even if it is not currently visible.
         */
        this.ignoreVisibility = false;
    }
}
// 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.
 */
class InteractivityChecker {
    constructor(_platform) {
        this._platform = _platform;
    }
    /**
     * Gets whether an element is disabled.
     *
     * @param element Element to be checked.
     * @returns Whether the element is disabled.
     */
    isDisabled(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.
     */
    isVisible(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.
     */
    isTabbable(element) {
        // Nothing is tabbable on the server 😎
        if (!this._platform.isBrowser) {
            return false;
        }
        const frameElement = getFrameElement(getWindow(element));
        if (frameElement) {
            // Frame elements inherit their tabindex onto all child elements.
            if (getTabIndexValue(frameElement) === -1) {
                return false;
            }
            // Browsers disable tabbing to an element inside of an invisible frame.
            if (!this.isVisible(frameElement)) {
                return false;
            }
        }
        let nodeName = element.nodeName.toLowerCase();
        let tabIndexValue = getTabIndexValue(element);
        if (element.hasAttribute('contenteditable')) {
            return tabIndexValue !== -1;
        }
        if (nodeName === 'iframe' || nodeName === 'object') {
            // The frame or object's content may be tabbable depending on the content, but it's
            // not possibly to reliably detect the content of the frames. We always consider such
            // elements as non-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;
        }
        if (nodeName === 'audio') {
            // Audio elements without controls enabled are never tabbable, regardless
            // of the tabindex attribute explicitly being set.
            if (!element.hasAttribute('controls')) {
                return false;
            }
            // Audio elements with controls are by default tabbable unless the
            // tabindex attribute is set to `-1` explicitly.
            return tabIndexValue !== -1;
        }
        if (nodeName === 'video') {
            // For all video elements, if the tabindex attribute is set to `-1`, the video
            // is not tabbable. Note: We cannot rely on the default `HTMLElement.tabIndex`
            // property as that one is set to `-1` in Chrome, Edge and Safari v13.1. The
            // tabindex attribute is the source of truth here.
            if (tabIndexValue === -1) {
                return false;
            }
            // If the tabindex is explicitly set, and not `-1` (as per check before), the
            // video element is always tabbable (regardless of whether it has controls or not).
            if (tabIndexValue !== null) {
                return true;
            }
            // Otherwise (when no explicit tabindex is set), a video is only tabbable if it
            // has controls enabled. Firefox is special as videos are always tabbable regardless
            // of whether there are controls or not.
            return this._platform.FIREFOX || element.hasAttribute('controls');
        }
        return element.tabIndex >= 0;
    }
    /**
     * Gets whether an element can be focused by the user.
     *
     * @param element Element to be checked.
     * @param config The config object with options to customize this method's behavior
     * @returns Whether the element is focusable.
     */
    isFocusable(element, config) {
        // 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) &&
            ((config === null || config === void 0 ? void 0 : config.ignoreVisibility) || this.isVisible(element));
    }
}
InteractivityChecker.ɵprov = i0.ɵɵdefineInjectable({ factory: function InteractivityChecker_Factory() { return new InteractivityChecker(i0.ɵɵinject(i1.Platform)); }, token: InteractivityChecker, providedIn: "root" });
InteractivityChecker.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
InteractivityChecker.ctorParameters = () => [
    { type: Platform }
];
/**
 * 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) {
    let 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;
    }
    let 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
    const tabIndex = parseInt(element.getAttribute('tabindex') || '', 10);
    return isNaN(tabIndex) ? -1 : tabIndex;
}
/** Checks whether the specified element is potentially tabbable on iOS */
function isPotentiallyTabbableIOS(element) {
    let nodeName = element.nodeName.toLowerCase();
    let 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 the two to be misaligned.
 *
 * @deprecated Use `ConfigurableFocusTrap` instead.
 * @breaking-change 11.0.0
 */
class FocusTrap {
    constructor(_element, _checker, _ngZone, _document, 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 = () => this.focusLastTabbableElement();
        this.endAnchorListener = () => this.focusFirstTabbableElement();
        this._enabled = true;
        if (!deferAnchors) {
            this.attachAnchors();
        }
    }
    /** Whether the focus trap is active. */
    get enabled() { return this._enabled; }
    set enabled(value) {
        this._enabled = value;
        if (this._startAnchor && this._endAnchor) {
            this._toggleAnchorTabIndex(value, this._startAnchor);
            this._toggleAnchorTabIndex(value, this._endAnchor);
        }
    }
    /** Destroys the focus trap by cleaning up the anchors. */
    destroy() {
        const startAnchor = this._startAnchor;
        const 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;
        this._hasAttached = false;
    }
    /**
     * 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 successfully. This may not be the case
     * if the target element isn't currently in the DOM.
     */
    attachAnchors() {
        // If we're not on the browser, there can be no focus to trap.
        if (this._hasAttached) {
            return true;
        }
        this._ngZone.runOutsideAngular(() => {
            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 successfully.
     */
    focusInitialElementWhenReady(options) {
        return new Promise(resolve => {
            this._executeOnStable(() => resolve(this.focusInitialElement(options)));
        });
    }
    /**
     * 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 successfully.
     */
    focusFirstTabbableElementWhenReady(options) {
        return new Promise(resolve => {
            this._executeOnStable(() => resolve(this.focusFirstTabbableElement(options)));
        });
    }
    /**
     * 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 successfully.
     */
    focusLastTabbableElementWhenReady(options) {
        return new Promise(resolve => {
            this._executeOnStable(() => resolve(this.focusLastTabbableElement(options)));
        });
    }
    /**
     * 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.
     */
    _getRegionBoundary(bound) {
        // Contains the deprecated version of selector, for temporary backwards comparability.
        let markers = this._element.querySelectorAll(`[cdk-focus-region-${bound}], ` +
            `[cdkFocusRegion${bound}], ` +
            `[cdk-focus-${bound}]`);
        for (let i = 0; i < markers.length; i++) {
            // @breaking-change 8.0.0
            if (markers[i].hasAttribute(`cdk-focus-${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 successfully.
     */
    focusInitialElement(options) {
        // Contains the deprecated version of selector, for temporary backwards comparability.
        const 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 ((typeof ngDevMode === 'undefined' || ngDevMode) &&
                !this._checker.isFocusable(redirectToElement)) {
                console.warn(`Element matching '[cdkFocusInitial]' is not focusable.`, redirectToElement);
            }
            if (!this._checker.isFocusable(redirectToElement)) {
                const focusableChild = this._getFirstTabbableElement(redirectToElement);
                focusableChild === null || focusableChild === void 0 ? void 0 : focusableChild.focus(options);
                return !!focusableChild;
            }
            redirectToElement.focus(options);
            return true;
        }
        return this.focusFirstTabbableElement(options);
    }
    /**
     * Focuses the first tabbable element within the focus trap region.
     * @returns Whether focus was moved successfully.
     */
    focusFirstTabbableElement(options) {
        const redirectToElement = this._getRegionBoundary('start');
        if (redirectToElement) {
            redirectToElement.focus(options);
        }
        return !!redirectToElement;
    }
    /**
     * Focuses the last tabbable element within the focus trap region.
     * @returns Whether focus was moved successfully.
     */
    focusLastTabbableElement(options) {
        const redirectToElement = this._getRegionBoundary('end');
        if (redirectToElement) {
            redirectToElement.focus(options);
        }
        return !!redirectToElement;
    }
    /**
     * Checks whether the focus trap has successfully been attached.
     */
    hasAttached() {
        return this._hasAttached;
    }
    /** Get the first tabbable element from a DOM subtree (inclusive). */
    _getFirstTabbableElement(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.
        let children = root.children || root.childNodes;
        for (let i = 0; i < children.length; i++) {
            let 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). */
    _getLastTabbableElement(root) {
        if (this._checker.isFocusable(root) && this._checker.isTabbable(root)) {
            return root;
        }
        // Iterate in reverse DOM order.
        let children = root.children || root.childNodes;
        for (let i = children.length - 1; i >= 0; i--) {
            let tabbableChild = children[i].nodeType === this._document.ELEMENT_NODE ?
                this._getLastTabbableElement(children[i]) :
                null;
            if (tabbableChild) {
                return tabbableChild;
            }
        }
        return null;
    }
    /** Creates an anchor element. */
    _createAnchor() {
        const 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.
     */
    _toggleAnchorTabIndex(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');
    }
    /**
     * Toggles the`tabindex` of both anchors to either trap Tab focus or allow it to escape.
     * @param enabled: Whether the anchors should trap Tab.
     */
    toggleAnchors(enabled) {
        if (this._startAnchor && this._endAnchor) {
            this._toggleAnchorTabIndex(enabled, this._startAnchor);
            this._toggleAnchorTabIndex(enabled, this._endAnchor);
        }
    }
    /** Executes a function when the zone is stable. */
    _executeOnStable(fn) {
        if (this._ngZone.isStable) {
            fn();
        }
        else {
            this._ngZone.onStable.pipe(take(1)).subscribe(fn);
        }
    }
}
/**
 * Factory that allows easy instantiation of focus traps.
 * @deprecated Use `ConfigurableFocusTrapFactory` instead.
 * @breaking-change 11.0.0
 */
class FocusTrapFactory {
    constructor(_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.
     */
    create(element, deferCaptureElements = false) {
        return new FocusTrap(element, this._checker, this._ngZone, this._document, deferCaptureElements);
    }
}
FocusTrapFactory.ɵprov = i0.ɵɵdefineInjectable({ factory: function FocusTrapFactory_Factory() { return new FocusTrapFactory(i0.ɵɵinject(InteractivityChecker), i0.ɵɵinject(i0.NgZone), i0.ɵɵinject(i2.DOCUMENT)); }, token: FocusTrapFactory, providedIn: "root" });
FocusTrapFactory.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
FocusTrapFactory.ctorParameters = () => [
    { type: InteractivityChecker },
    { type: NgZone },
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] }
];
/** Directive for trapping focus within a region. */
class CdkTrapFocus {
    constructor(_elementRef, _focusTrapFactory, 
    /**
     * @deprecated No longer being used. To be removed.
     * @breaking-change 13.0.0
     */
    _document) {
        this._elementRef = _elementRef;
        this._focusTrapFactory = _focusTrapFactory;
        /** Previously focused element to restore focus to upon destroy when using autoCapture. */
        this._previouslyFocusedElement = null;
        this.focusTrap = this._focusTrapFactory.create(this._elementRef.nativeElement, true);
    }
    /** Whether the focus trap is active. */
    get enabled() { return this.focusTrap.enabled; }
    set enabled(value) { this.focusTrap.enabled = coerceBooleanProperty(value); }
    /**
     * Whether the directive should automatically move focus into the trapped region upon
     * initialization and return focus to the previous activeElement upon destruction.
     */
    get autoCapture() { return this._autoCapture; }
    set autoCapture(value) { this._autoCapture = coerceBooleanProperty(value); }
    ngOnDestroy() {
        this.focusTrap.destroy();
        // If we stored a previously focused element when using autoCapture, return focus to that
        // element now that the trapped region is being destroyed.
        if (this._previouslyFocusedElement) {
            this._previouslyFocusedElement.focus();
            this._previouslyFocusedElement = null;
        }
    }
    ngAfterContentInit() {
        this.focusTrap.attachAnchors();
        if (this.autoCapture) {
            this._captureFocus();
        }
    }
    ngDoCheck() {
        if (!this.focusTrap.hasAttached()) {
            this.focusTrap.attachAnchors();
        }
    }
    ngOnChanges(changes) {
        const autoCaptureChange = changes['autoCapture'];
        if (autoCaptureChange && !autoCaptureChange.firstChange && this.autoCapture &&
            this.focusTrap.hasAttached()) {
            this._captureFocus();
        }
    }
    _captureFocus() {
        this._previouslyFocusedElement = _getFocusedElementPierceShadowDom();
        this.focusTrap.focusInitialElementWhenReady();
    }
}
CdkTrapFocus.decorators = [
    { type: Directive, args: [{
                selector: '[cdkTrapFocus]',
                exportAs: 'cdkTrapFocus',
            },] }
];
CdkTrapFocus.ctorParameters = () => [
    { type: ElementRef },
    { type: FocusTrapFactory },
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] }
];
CdkTrapFocus.propDecorators = {
    enabled: [{ type: Input, args: ['cdkTrapFocus',] }],
    autoCapture: [{ type: Input, args: ['cdkTrapFocusAutoCapture',] }]
};

/**
 * @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 uses a strategy pattern that determines how it traps focus.
 * See FocusTrapInertStrategy.
 */
class ConfigurableFocusTrap extends FocusTrap {
    constructor(_element, _checker, _ngZone, _document, _focusTrapManager, _inertStrategy, config) {
        super(_element, _checker, _ngZone, _document, config.defer);
        this._focusTrapManager = _focusTrapManager;
        this._inertStrategy = _inertStrategy;
        this._focusTrapManager.register(this);
    }
    /** Whether the FocusTrap is enabled. */
    get enabled() { return this._enabled; }
    set enabled(value) {
        this._enabled = value;
        if (this._enabled) {
            this._focusTrapManager.register(this);
        }
        else {
            this._focusTrapManager.deregister(this);
        }
    }
    /** Notifies the FocusTrapManager that this FocusTrap will be destroyed. */
    destroy() {
        this._focusTrapManager.deregister(this);
        super.destroy();
    }
    /** @docs-private Implemented as part of ManagedFocusTrap. */
    _enable() {
        this._inertStrategy.preventFocus(this);
        this.toggleAnchors(true);
    }
    /** @docs-private Implemented as part of ManagedFocusTrap. */
    _disable() {
        this._inertStrategy.allowFocus(this);
        this.toggleAnchors(false);
    }
}

/**
 * @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
 */

/**
 * @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 injection token used to specify the inert strategy. */
const FOCUS_TRAP_INERT_STRATEGY = new InjectionToken('FOCUS_TRAP_INERT_STRATEGY');

/**
 * @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
 */
/** IE 11 compatible closest implementation that is able to start from non-Element Nodes. */
function closest(element, selector) {
    if (!(element instanceof Node)) {
        return null;
    }
    let curr = element;
    while (curr != null && !(curr instanceof Element)) {
        curr = curr.parentNode;
    }
    return curr && (hasNativeClosest ?
        curr.closest(selector) : polyfillClosest(curr, selector));
}
/** Polyfill for browsers without Element.closest. */
function polyfillClosest(element, selector) {
    let curr = element;
    while (curr != null && !(curr instanceof Element && matches(curr, selector))) {
        curr = curr.parentNode;
    }
    return (curr || null);
}
const hasNativeClosest = typeof Element != 'undefined' && !!Element.prototype.closest;
/** IE 11 compatible matches implementation. */
function matches(element, selector) {
    return element.matches ?
        element.matches(selector) :
        element['msMatchesSelector'](selector);
}

/**
 * @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
 */
/**
 * Lightweight FocusTrapInertStrategy that adds a document focus event
 * listener to redirect focus back inside the FocusTrap.
 */
class EventListenerFocusTrapInertStrategy {
    constructor() {
        /** Focus event handler. */
        this._listener = null;
    }
    /** Adds a document event listener that keeps focus inside the FocusTrap. */
    preventFocus(focusTrap) {
        // Ensure there's only one listener per document
        if (this._listener) {
            focusTrap._document.removeEventListener('focus', this._listener, true);
        }
        this._listener = (e) => this._trapFocus(focusTrap, e);
        focusTrap._ngZone.runOutsideAngular(() => {
            focusTrap._document.addEventListener('focus', this._listener, true);
        });
    }
    /** Removes the event listener added in preventFocus. */
    allowFocus(focusTrap) {
        if (!this._listener) {
            return;
        }
        focusTrap._document.removeEventListener('focus', this._listener, true);
        this._listener = null;
    }
    /**
     * Refocuses the first element in the FocusTrap if the focus event target was outside
     * the FocusTrap.
     *
     * This is an event listener callback. The event listener is added in runOutsideAngular,
     * so all this code runs outside Angular as well.
     */
    _trapFocus(focusTrap, event) {
        const target = event.target;
        const focusTrapRoot = focusTrap._element;
        // Don't refocus if target was in an overlay, because the overlay might be associated
        // with an element inside the FocusTrap, ex. mat-select.
        if (!focusTrapRoot.contains(target) && closest(target, 'div.cdk-overlay-pane') === null) {
            // Some legacy FocusTrap usages have logic that focuses some element on the page
            // just before FocusTrap is destroyed. For backwards compatibility, wait
            // to be sure FocusTrap is still enabled before refocusing.
            setTimeout(() => {
                // Check whether focus wasn't put back into the focus trap while the timeout was pending.
                if (focusTrap.enabled && !focusTrapRoot.contains(focusTrap._document.activeElement)) {
                    focusTrap.focusFirstTabbableElement();
                }
            });
        }
    }
}

/**
 * @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
 */
/** Injectable that ensures only the most recently enabled FocusTrap is active. */
class FocusTrapManager {
    constructor() {
        // A stack of the FocusTraps on the page. Only the FocusTrap at the
        // top of the stack is active.
        this._focusTrapStack = [];
    }
    /**
     * Disables the FocusTrap at the top of the stack, and then pushes
     * the new FocusTrap onto the stack.
     */
    register(focusTrap) {
        // Dedupe focusTraps that register multiple times.
        this._focusTrapStack = this._focusTrapStack.filter((ft) => ft !== focusTrap);
        let stack = this._focusTrapStack;
        if (stack.length) {
            stack[stack.length - 1]._disable();
        }
        stack.push(focusTrap);
        focusTrap._enable();
    }
    /**
     * Removes the FocusTrap from the stack, and activates the
     * FocusTrap that is the new top of the stack.
     */
    deregister(focusTrap) {
        focusTrap._disable();
        const stack = this._focusTrapStack;
        const i = stack.indexOf(focusTrap);
        if (i !== -1) {
            stack.splice(i, 1);
            if (stack.length) {
                stack[stack.length - 1]._enable();
            }
        }
    }
}
FocusTrapManager.ɵprov = i0.ɵɵdefineInjectable({ factory: function FocusTrapManager_Factory() { return new FocusTrapManager(); }, token: FocusTrapManager, providedIn: "root" });
FocusTrapManager.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];

/**
 * @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
 */
/** Factory that allows easy instantiation of configurable focus traps. */
class ConfigurableFocusTrapFactory {
    constructor(_checker, _ngZone, _focusTrapManager, _document, _inertStrategy) {
        this._checker = _checker;
        this._ngZone = _ngZone;
        this._focusTrapManager = _focusTrapManager;
        this._document = _document;
        // TODO split up the strategies into different modules, similar to DateAdapter.
        this._inertStrategy = _inertStrategy || new EventListenerFocusTrapInertStrategy();
    }
    create(element, config = { defer: false }) {
        let configObject;
        if (typeof config === 'boolean') {
            configObject = { defer: config };
        }
        else {
            configObject = config;
        }
        return new ConfigurableFocusTrap(element, this._checker, this._ngZone, this._document, this._focusTrapManager, this._inertStrategy, configObject);
    }
}
ConfigurableFocusTrapFactory.ɵprov = i0.ɵɵdefineInjectable({ factory: function ConfigurableFocusTrapFactory_Factory() { return new ConfigurableFocusTrapFactory(i0.ɵɵinject(InteractivityChecker), i0.ɵɵinject(i0.NgZone), i0.ɵɵinject(FocusTrapManager), i0.ɵɵinject(i2.DOCUMENT), i0.ɵɵinject(FOCUS_TRAP_INERT_STRATEGY, 8)); }, token: ConfigurableFocusTrapFactory, providedIn: "root" });
ConfigurableFocusTrapFactory.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
ConfigurableFocusTrapFactory.ctorParameters = () => [
    { type: InteractivityChecker },
    { type: NgZone },
    { type: FocusTrapManager },
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] },
    { type: undefined, decorators: [{ type: Optional }, { type: Inject, args: [FOCUS_TRAP_INERT_STRATEGY,] }] }
];

/**
 * @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
 */
/** Gets whether an event could be a faked `mousedown` event dispatched by a screen reader. */
function isFakeMousedownFromScreenReader(event) {
    // Some screen readers will dispatch a fake `mousedown` event when pressing enter or space on
    // a clickable element. We can distinguish these events when both `offsetX` and `offsetY` are
    // zero. Note that there's an edge case where the user could click the 0x0 spot of the screen
    // themselves, but that is unlikely to contain interaction elements. Historially we used to check
    // `event.buttons === 0`, however that no longer works on recent versions of NVDA.
    return event.offsetX === 0 && event.offsetY === 0;
}
/** Gets whether an event could be a faked `touchstart` event dispatched by a screen reader. */
function isFakeTouchstartFromScreenReader(event) {
    const touch = (event.touches && event.touches[0]) ||
        (event.changedTouches && event.changedTouches[0]);
    // A fake `touchstart` can be distinguished from a real one by looking at the `identifier`
    // which is typically >= 0 on a real device versus -1 from a screen reader. Just to be safe,
    // we can also look at `radiusX` and `radiusY`. This behavior was observed against a Windows 10
    // device with a touch screen running NVDA v2020.4 and Firefox 85 or Chrome 88.
    return !!touch && touch.identifier === -1 && (touch.radiusX == null || touch.radiusX === 1) &&
        (touch.radiusY == null || touch.radiusY === 1);
}

/**
 * @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
 */
/**
 * Injectable options for the InputModalityDetector. These are shallowly merged with the default
 * options.
 */
const INPUT_MODALITY_DETECTOR_OPTIONS = new InjectionToken('cdk-input-modality-detector-options');
/**
 * Default options for the InputModalityDetector.
 *
 * Modifier keys are ignored by default (i.e. when pressed won't cause the service to detect
 * keyboard input modality) for two reasons:
 *
 * 1. Modifier keys are commonly used with mouse to perform actions such as 'right click' or 'open
 *    in new tab', and are thus less representative of actual keyboard interaction.
 * 2. VoiceOver triggers some keyboard events when linearly navigating with Control + Option (but
 *    confusingly not with Caps Lock). Thus, to have parity with other screen readers, we ignore
 *    these keys so as to not update the input modality.
 *
 * Note that we do not by default ignore the right Meta key on Safari because it has the same key
 * code as the ContextMenu key on other browsers. When we switch to using event.key, we can
 * distinguish between the two.
 */
const INPUT_MODALITY_DETECTOR_DEFAULT_OPTIONS = {
    ignoreKeys: [ALT, CONTROL, MAC_META, META, SHIFT],
};
/**
 * The amount of time needed to pass after a touchstart event in order for a subsequent mousedown
 * event to be attributed as mouse and not touch.
 *
 * This is the value used by AngularJS Material. Through trial and error (on iPhone 6S) they found
 * that a value of around 650ms seems appropriate.
 */
const TOUCH_BUFFER_MS = 650;
/**
 * Event listener options that enable capturing and also mark the listener as passive if the browser
 * supports it.
 */
const modalityEventListenerOptions = normalizePassiveListenerOptions({
    passive: true,
    capture: true,
});
/**
 * Service that detects the user's input modality.
 *
 * This service does not update the input modality when a user navigates with a screen reader
 * (e.g. linear navigation with VoiceOver, object navigation / browse mode with NVDA, virtual PC
 * cursor mode with JAWS). This is in part due to technical limitations (i.e. keyboard events do not
 * fire as expected in these modes) but is also arguably the correct behavior. Navigating with a
 * screen reader is akin to visually scanning a page, and should not be interpreted as actual user
 * input interaction.
 *
 * When a user is not navigating but *interacting* with a screen reader, this service attempts to
 * update the input modality to keyboard, but in general this service's behavior is largely
 * undefined.
 */
class InputModalityDetector {
    constructor(_platform, ngZone, document, options) {
        this._platform = _platform;
        /**
         * The most recently detected input modality event target. Is null if no input modality has been
         * detected or if the associated event target is null for some unknown reason.
         */
        this._mostRecentTarget = null;
        /** The underlying BehaviorSubject that emits whenever an input modality is detected. */
        this._modality = new BehaviorSubject(null);
        /**
         * The timestamp of the last touch input modality. Used to determine whether mousedown events
         * should be attributed to mouse or touch.
         */
        this._lastTouchMs = 0;
        /**
         * Handles keydown events. Must be an arrow function in order to preserve the context when it gets
         * bound.
         */
        this._onKeydown = (event) => {
            var _a, _b;
            // If this is one of the keys we should ignore, then ignore it and don't update the input
            // modality to keyboard.
            if ((_b = (_a = this._options) === null || _a === void 0 ? void 0 : _a.ignoreKeys) === null || _b === void 0 ? void 0 : _b.some(keyCode => keyCode === event.keyCode)) {
                return;
            }
            this._modality.next('keyboard');
            this._mostRecentTarget = _getEventTarget(event);
        };
        /**
         * Handles mousedown events. Must be an arrow function in order to preserve the context when it
         * gets bound.
         */
        this._onMousedown = (event) => {
            // Touches trigger both touch and mouse events, so we need to distinguish between mouse events
            // that were triggered via mouse vs touch. To do so, check if the mouse event occurs closely
            // after the previous touch event.
            if (Date.now() - this._lastTouchMs < TOUCH_BUFFER_MS) {
                return;
            }
            // Fake mousedown events are fired by some screen readers when controls are activated by the
            // screen reader. Attribute them to keyboard input modality.
            this._modality.next(isFakeMousedownFromScreenReader(event) ? 'keyboard' : 'mouse');
            this._mostRecentTarget = _getEventTarget(event);
        };
        /**
         * Handles touchstart events. Must be an arrow function in order to preserve the context when it
         * gets bound.
         */
        this._onTouchstart = (event) => {
            // Same scenario as mentioned in _onMousedown, but on touch screen devices, fake touchstart
            // events are fired. Again, attribute to keyboard input modality.
            if (isFakeTouchstartFromScreenReader(event)) {
                this._modality.next('keyboard');
                return;
            }
            // Store the timestamp of this touch event, as it's used to distinguish between mouse events
            // triggered via mouse vs touch.
            this._lastTouchMs = Date.now();
            this._modality.next('touch');
            this._mostRecentTarget = _getEventTarget(event);
        };
        this._options = Object.assign(Object.assign({}, INPUT_MODALITY_DETECTOR_DEFAULT_OPTIONS), options);
        // Skip the first emission as it's null.
        this.modalityDetected = this._modality.pipe(skip(1));
        this.modalityChanged = this.modalityDetected.pipe(distinctUntilChanged());
        // If we're not in a browser, this service should do nothing, as there's no relevant input
        // modality to detect.
        if (_platform.isBrowser) {
            ngZone.runOutsideAngular(() => {
                document.addEventListener('keydown', this._onKeydown, modalityEventListenerOptions);
                document.addEventListener('mousedown', this._onMousedown, modalityEventListenerOptions);
                document.addEventListener('touchstart', this._onTouchstart, modalityEventListenerOptions);
            });
        }
    }
    /** The most recently detected input modality. */
    get mostRecentModality() {
        return this._modality.value;
    }
    ngOnDestroy() {
        this._modality.complete();
        if (this._platform.isBrowser) {
            document.removeEventListener('keydown', this._onKeydown, modalityEventListenerOptions);
            document.removeEventListener('mousedown', this._onMousedown, modalityEventListenerOptions);
            document.removeEventListener('touchstart', this._onTouchstart, modalityEventListenerOptions);
        }
    }
}
InputModalityDetector.ɵprov = i0.ɵɵdefineInjectable({ factory: function InputModalityDetector_Factory() { return new InputModalityDetector(i0.ɵɵinject(i1.Platform), i0.ɵɵinject(i0.NgZone), i0.ɵɵinject(i2.DOCUMENT), i0.ɵɵinject(INPUT_MODALITY_DETECTOR_OPTIONS, 8)); }, token: InputModalityDetector, providedIn: "root" });
InputModalityDetector.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
InputModalityDetector.ctorParameters = () => [
    { type: Platform },
    { type: NgZone },
    { type: Document, decorators: [{ type: Inject, args: [DOCUMENT,] }] },
    { type: undefined, decorators: [{ type: Optional }, { type: Inject, args: [INPUT_MODALITY_DETECTOR_OPTIONS,] }] }
];

/**
 * @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
 */
const LIVE_ANNOUNCER_ELEMENT_TOKEN = new InjectionToken('liveAnnouncerElement', {
    providedIn: 'root',
    factory: LIVE_ANNOUNCER_ELEMENT_TOKEN_FACTORY,
});
/** @docs-private */
function LIVE_ANNOUNCER_ELEMENT_TOKEN_FACTORY() {
    return null;
}
/** Injection token that can be used to configure the default options for the LiveAnnouncer. */
const LIVE_ANNOUNCER_DEFAULT_OPTIONS = new InjectionToken('LIVE_ANNOUNCER_DEFAULT_OPTIONS');

/**
 * @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 LiveAnnouncer {
    constructor(elementToken, _ngZone, _document, _defaultOptions) {
        this._ngZone = _ngZone;
        this._defaultOptions = _defaultOptions;
        // We inject the live element and document as `any` because the constructor signature cannot
        // reference browser globals (HTMLElement, Document) on non-browser environments, since having
        // a class decorator causes TypeScript to preserve the constructor signature types.
        this._document = _document;
        this._liveElement = elementToken || this._createLiveElement();
    }
    announce(message, ...args) {
        const defaultOptions = this._defaultOptions;
        let politeness;
        let duration;
        if (args.length === 1 && typeof args[0] === 'number') {
            duration = args[0];
        }
        else {
            [politeness, duration] = args;
        }
        this.clear();
        clearTimeout(this._previousTimeout);
        if (!politeness) {
            politeness =
                (defaultOptions && defaultOptions.politeness) ? defaultOptions.politeness : 'polite';
        }
        if (duration == null && defaultOptions) {
            duration = defaultOptions.duration;
        }
        // TODO: ensure changing the politeness works on all environments we support.
        this._liveElement.setAttribute('aria-live', politeness);
        // This 100ms timeout is necessary for some browser + screen-reader combinations:
        // - Both JAWS and NVDA over IE11 will not announce anything without a non-zero timeout.
        // - With Chrome and IE11 with NVDA or JAWS, a repeated (identical) message won't be read a
        //   second time without clearing and then using a non-zero delay.
        // (using JAWS 17 at time of this writing).
        return this._ngZone.runOutsideAngular(() => {
            return new Promise(resolve => {
                clearTimeout(this._previousTimeout);
                this._previousTimeout = setTimeout(() => {
                    this._liveElement.textContent = message;
                    resolve();
                    if (typeof duration === 'number') {
                        this._previousTimeout = setTimeout(() => this.clear(), duration);
                    }
                }, 100);
            });
        });
    }
    /**
     * Clears the current text from the announcer element. Can be used to prevent
     * screen readers from reading the text out again while the user is going
     * through the page landmarks.
     */
    clear() {
        if (this._liveElement) {
            this._liveElement.textContent = '';
        }
    }
    ngOnDestroy() {
        clearTimeout(this._previousTimeout);
        if (this._liveElement && this._liveElement.parentNode) {
            this._liveElement.parentNode.removeChild(this._liveElement);
            this._liveElement = null;
        }
    }
    _createLiveElement() {
        const elementClass = 'cdk-live-announcer-element';
        const previousElements = this._document.getElementsByClassName(elementClass);
        const liveEl = this._document.createElement('div');
        // Remove any old containers. This can happen when coming in from a server-side-rendered page.
        for (let i = 0; i < previousElements.length; i++) {
            previousElements[i].parentNode.removeChild(previousElements[i]);
        }
        liveEl.classList.add(elementClass);
        liveEl.classList.add('cdk-visually-hidden');
        liveEl.setAttribute('aria-atomic', 'true');
        liveEl.setAttribute('aria-live', 'polite');
        this._document.body.appendChild(liveEl);
        return liveEl;
    }
}
LiveAnnouncer.ɵprov = i0.ɵɵdefineInjectable({ factory: function LiveAnnouncer_Factory() { return new LiveAnnouncer(i0.ɵɵinject(LIVE_ANNOUNCER_ELEMENT_TOKEN, 8), i0.ɵɵinject(i0.NgZone), i0.ɵɵinject(i2.DOCUMENT), i0.ɵɵinject(LIVE_ANNOUNCER_DEFAULT_OPTIONS, 8)); }, token: LiveAnnouncer, providedIn: "root" });
LiveAnnouncer.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
LiveAnnouncer.ctorParameters = () => [
    { type: undefined, decorators: [{ type: Optional }, { type: Inject, args: [LIVE_ANNOUNCER_ELEMENT_TOKEN,] }] },
    { type: NgZone },
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] },
    { type: undefined, decorators: [{ type: Optional }, { type: Inject, args: [LIVE_ANNOUNCER_DEFAULT_OPTIONS,] }] }
];
/**
 * A directive that works similarly to aria-live, but uses the LiveAnnouncer to ensure compatibility
 * with a wider range of browsers and screen readers.
 */
class CdkAriaLive {
    constructor(_elementRef, _liveAnnouncer, _contentObserver, _ngZone) {
        this._elementRef = _elementRef;
        this._liveAnnouncer = _liveAnnouncer;
        this._contentObserver = _contentObserver;
        this._ngZone = _ngZone;
        this._politeness = 'polite';
    }
    /** The aria-live politeness level to use when announcing messages. */
    get politeness() { return this._politeness; }
    set politeness(value) {
        this._politeness = value === 'off' || value === 'assertive' ? value : 'polite';
        if (this._politeness === 'off') {
            if (this._subscription) {
                this._subscription.unsubscribe();
                this._subscription = null;
            }
        }
        else if (!this._subscription) {
            this._subscription = this._ngZone.runOutsideAngular(() => {
                return this._contentObserver
                    .observe(this._elementRef)
                    .subscribe(() => {
                    // Note that we use textContent here, rather than innerText, in order to avoid a reflow.
                    const elementText = this._elementRef.nativeElement.textContent;
                    // The `MutationObserver` fires also for attribute
                    // changes which we don't want to announce.
                    if (elementText !== this._previousAnnouncedText) {
                        this._liveAnnouncer.announce(elementText, this._politeness);
                        this._previousAnnouncedText = elementText;
                    }
                });
            });
        }
    }
    ngOnDestroy() {
        if (this._subscription) {
            this._subscription.unsubscribe();
        }
    }
}
CdkAriaLive.decorators = [
    { type: Directive, args: [{
                selector: '[cdkAriaLive]',
                exportAs: 'cdkAriaLive',
            },] }
];
CdkAriaLive.ctorParameters = () => [
    { type: ElementRef },
    { type: LiveAnnouncer },
    { type: ContentObserver },
    { type: NgZone }
];
CdkAriaLive.propDecorators = {
    politeness: [{ type: Input, args: ['cdkAriaLive',] }]
};

/**
 * @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
 */
/** InjectionToken for FocusMonitorOptions. */
const FOCUS_MONITOR_DEFAULT_OPTIONS = new InjectionToken('cdk-focus-monitor-default-options');
/**
 * Event listener options that enable capturing and also
 * mark the listener as passive if the browser supports it.
 */
const captureEventListenerOptions = normalizePassiveListenerOptions({
    passive: true,
    capture: true
});
/** Monitors mouse and keyboard events to determine the cause of focus events. */
class FocusMonitor {
    constructor(_ngZone, _platform, _inputModalityDetector, 
    /** @breaking-change 11.0.0 make document required */
    document, options) {
        this._ngZone = _ngZone;
        this._platform = _platform;
        this._inputModalityDetector = _inputModalityDetector;
        /** The focus origin that the next focus event is a result of. */
        this._origin = null;
        /** Whether the window has just been focused. */
        this._windowFocused = false;
        /**
         * Whether the origin was determined via a touch interaction. Necessary as properly attributing
         * focus events to touch interactions requires special logic.
         */
        this._originFromTouchInteraction = false;
        /** Map of elements being monitored to their info. */
        this._elementInfo = new Map();
        /** The number of elements currently being monitored. */
        this._monitoredElementCount = 0;
        /**
         * Keeps track of the root nodes to which we've currently bound a focus/blur handler,
         * as well as the number of monitored elements that they contain. We have to treat focus/blur
         * handlers differently from the rest of the events, because the browser won't emit events
         * to the document when focus moves inside of a shadow root.
         */
        this._rootNodeFocusListenerCount = new Map();
        /**
         * Event listener for `focus` events on the window.
         * Needs to be an arrow function in order to preserve the context when it gets bound.
         */
        this._windowFocusListener = () => {
            // Make a note of when the window regains focus, so we can
            // restore the origin info for the focused element.
            this._windowFocused = true;
            this._windowFocusTimeoutId = setTimeout(() => this._windowFocused = false);
        };
        /** Subject for stopping our InputModalityDetector subscription. */
        this._stopInputModalityDetector = new Subject();
        /**
         * Event listener for `focus` and 'blur' events on the document.
         * Needs to be an arrow function in order to preserve the context when it gets bound.
         */
        this._rootNodeFocusAndBlurListener = (event) => {
            const target = _getEventTarget(event);
            const handler = event.type === 'focus' ? this._onFocus : this._onBlur;
            // We need to walk up the ancestor chain in order to support `checkChildren`.
            for (let element = target; element; element = element.parentElement) {
                handler.call(this, event, element);
            }
        };
        this._document = document;
        this._detectionMode = (options === null || options === void 0 ? void 0 : options.detectionMode) || 0 /* IMMEDIATE */;
    }
    monitor(element, checkChildren = false) {
        const nativeElement = coerceElement(element);
        // Do nothing if we're not on the browser platform or the passed in node isn't an element.
        if (!this._platform.isBrowser || nativeElement.nodeType !== 1) {
            return of(null);
        }
        // If the element is inside the shadow DOM, we need to bind our focus/blur listeners to
        // the shadow root, rather than the `document`, because the browser won't emit focus events
        // to the `document`, if focus is moving within the same shadow root.
        const rootNode = _getShadowRoot(nativeElement) || this._getDocument();
        const cachedInfo = this._elementInfo.get(nativeElement);
        // Check if we're already monitoring this element.
        if (cachedInfo) {
            if (checkChildren) {
                // TODO(COMP-318): this can be problematic, because it'll turn all non-checkChildren
                // observers into ones that behave as if `checkChildren` was turned on. We need a more
                // robust solution.
                cachedInfo.checkChildren = true;
            }
            return cachedInfo.subject;
        }
        // Create monitored element info.
        const info = {
            checkChildren: checkChildren,
            subject: new Subject(),
            rootNode
        };
        this._elementInfo.set(nativeElement, info);
        this._registerGlobalListeners(info);
        return info.subject;
    }
    stopMonitoring(element) {
        const nativeElement = coerceElement(element);
        const elementInfo = this._elementInfo.get(nativeElement);
        if (elementInfo) {
            elementInfo.subject.complete();
            this._setClasses(nativeElement);
            this._elementInfo.delete(nativeElement);
            this._removeGlobalListeners(elementInfo);
        }
    }
    focusVia(element, origin, options) {
        const nativeElement = coerceElement(element);
        const focusedElement = this._getDocument().activeElement;
        // If the element is focused already, calling `focus` again won't trigger the event listener
        // which means that the focus classes won't be updated. If that's the case, update the classes
        // directly without waiting for an event.
        if (nativeElement === focusedElement) {
            this._getClosestElementsInfo(nativeElement)
                .forEach(([currentElement, info]) => this._originChanged(currentElement, origin, info));
        }
        else {
            this._setOrigin(origin);
            // `focus` isn't available on the server
            if (typeof nativeElement.focus === 'function') {
                nativeElement.focus(options);
            }
        }
    }
    ngOnDestroy() {
        this._elementInfo.forEach((_info, element) => this.stopMonitoring(element));
    }
    /** Access injected document if available or fallback to global document reference */
    _getDocument() {
        return this._document || document;
    }
    /** Use defaultView of injected document if available or fallback to global window reference */
    _getWindow() {
        const doc = this._getDocument();
        return doc.defaultView || window;
    }
    _toggleClass(element, className, shouldSet) {
        if (shouldSet) {
            element.classList.add(className);
        }
        else {
            element.classList.remove(className);
        }
    }
    _getFocusOrigin(focusEventTarget) {
        if (this._origin) {
            // If the origin was realized via a touch interaction, we need to perform additional checks
            // to determine whether the focus origin should be attributed to touch or program.
            if (this._originFromTouchInteraction) {
                return this._shouldBeAttributedToTouch(focusEventTarget) ? 'touch' : 'program';
            }
            else {
                return this._origin;
            }
        }
        // If the window has just regained focus, we can restore the most recent origin from before the
        // window blurred. Otherwise, we've reached the point where we can't identify the source of the
        // focus. This typically means one of two things happened:
        //
        // 1) The element was programmatically focused, or
        // 2) The element was focused via screen reader navigation (which generally doesn't fire
        //    events).
        //
        // Because we can't distinguish between these two cases, we default to setting `program`.
        return (this._windowFocused && this._lastFocusOrigin) ? this._lastFocusOrigin : 'program';
    }
    /**
     * Returns whether the focus event should be attributed to touch. Recall that in IMMEDIATE mode, a
     * touch origin isn't immediately reset at the next tick (see _setOrigin). This means that when we
     * handle a focus event following a touch interaction, we need to determine whether (1) the focus
     * event was directly caused by the touch interaction or (2) the focus event was caused by a
     * subsequent programmatic focus call triggered by the touch interaction.
     * @param focusEventTarget The target of the focus event under examination.
     */
    _shouldBeAttributedToTouch(focusEventTarget) {
        // Please note that this check is not perfect. Consider the following edge case:
        //
        // <div #parent tabindex="0">
        //   <div #child tabindex="0" (click)="#parent.focus()"></div>
        // </div>
        //
        // Suppose there is a FocusMonitor in IMMEDIATE mode attached to #parent. When the user touches
        // #child, #parent is programmatically focused. This code will attribute the focus to touch
        // instead of program. This is a relatively minor edge-case that can be worked around by using
        // focusVia(parent, 'program') to focus #parent.
        return (this._detectionMode === 1 /* EVENTUAL */) ||
            !!(focusEventTarget === null || focusEventTarget === void 0 ? void 0 : focusEventTarget.contains(this._inputModalityDetector._mostRecentTarget));
    }
    /**
     * Sets the focus classes on the element based on the given focus origin.
     * @param element The element to update the classes on.
     * @param origin The focus origin.
     */
    _setClasses(element, origin) {
        this._toggleClass(element, 'cdk-focused', !!origin);
        this._toggleClass(element, 'cdk-touch-focused', origin === 'touch');
        this._toggleClass(element, 'cdk-keyboard-focused', origin === 'keyboard');
        this._toggleClass(element, 'cdk-mouse-focused', origin === 'mouse');
        this._toggleClass(element, 'cdk-program-focused', origin === 'program');
    }
    /**
     * Updates the focus origin. If we're using immediate detection mode, we schedule an async
     * function to clear the origin at the end of a timeout. The duration of the timeout depends on
     * the origin being set.
     * @param origin The origin to set.
     * @param isFromInteraction Whether we are setting the origin from an interaction event.
     */
    _setOrigin(origin, isFromInteraction = false) {
        this._ngZone.runOutsideAngular(() => {
            this._origin = origin;
            this._originFromTouchInteraction = (origin === 'touch') && isFromInteraction;
            // If we're in IMMEDIATE mode, reset the origin at the next tick (or in `TOUCH_BUFFER_MS` ms
            // for a touch event). We reset the origin at the next tick because Firefox focuses one tick
            // after the interaction event. We wait `TOUCH_BUFFER_MS` ms before resetting the origin for
            // a touch event because when a touch event is fired, the associated focus event isn't yet in
            // the event queue. Before doing so, clear any pending timeouts.
            if (this._detectionMode === 0 /* IMMEDIATE */) {
                clearTimeout(this._originTimeoutId);
                const ms = this._originFromTouchInteraction ? TOUCH_BUFFER_MS : 1;
                this._originTimeoutId = setTimeout(() => this._origin = null, ms);
            }
        });
    }
    /**
     * Handles focus events on a registered element.
     * @param event The focus event.
     * @param element The monitored element.
     */
    _onFocus(event, element) {
        // NOTE(mmalerba): We currently set the classes based on the focus origin of the most recent
        // focus event affecting the monitored element. If we want to use the origin of the first event
        // instead we should check for the cdk-focused class here and return if the element already has
        // it. (This only matters for elements that have includesChildren = true).
        // If we are not counting child-element-focus as focused, make sure that the event target is the
        // monitored element itself.
        const elementInfo = this._elementInfo.get(element);
        const focusEventTarget = _getEventTarget(event);
        if (!elementInfo || (!elementInfo.checkChildren && element !== focusEventTarget)) {
            return;
        }
        this._originChanged(element, this._getFocusOrigin(focusEventTarget), elementInfo);
    }
    /**
     * Handles blur events on a registered element.
     * @param event The blur event.
     * @param element The monitored element.
     */
    _onBlur(event, element) {
        // If we are counting child-element-focus as focused, make sure that we aren't just blurring in
        // order to focus another child of the monitored element.
        const elementInfo = this._elementInfo.get(element);
        if (!elementInfo || (elementInfo.checkChildren && event.relatedTarget instanceof Node &&
            element.contains(event.relatedTarget))) {
            return;
        }
        this._setClasses(element);
        this._emitOrigin(elementInfo.subject, null);
    }
    _emitOrigin(subject, origin) {
        this._ngZone.run(() => subject.next(origin));
    }
    _registerGlobalListeners(elementInfo) {
        if (!this._platform.isBrowser) {
            return;
        }
        const rootNode = elementInfo.rootNode;
        const rootNodeFocusListeners = this._rootNodeFocusListenerCount.get(rootNode) || 0;
        if (!rootNodeFocusListeners) {
            this._ngZone.runOutsideAngular(() => {
                rootNode.addEventListener('focus', this._rootNodeFocusAndBlurListener, captureEventListenerOptions);
                rootNode.addEventListener('blur', this._rootNodeFocusAndBlurListener, captureEventListenerOptions);
            });
        }
        this._rootNodeFocusListenerCount.set(rootNode, rootNodeFocusListeners + 1);
        // Register global listeners when first element is monitored.
        if (++this._monitoredElementCount === 1) {
            // Note: we listen to events in the capture phase so we
            // can detect them even if the user stops propagation.
            this._ngZone.runOutsideAngular(() => {
                const window = this._getWindow();
                window.addEventListener('focus', this._windowFocusListener);
            });
            // The InputModalityDetector is also just a collection of global listeners.
            this._inputModalityDetector.modalityDetected
                .pipe(takeUntil(this._stopInputModalityDetector))
                .subscribe(modality => { this._setOrigin(modality, true /* isFromInteraction */); });
        }
    }
    _removeGlobalListeners(elementInfo) {
        const rootNode = elementInfo.rootNode;
        if (this._rootNodeFocusListenerCount.has(rootNode)) {
            const rootNodeFocusListeners = this._rootNodeFocusListenerCount.get(rootNode);
            if (rootNodeFocusListeners > 1) {
                this._rootNodeFocusListenerCount.set(rootNode, rootNodeFocusListeners - 1);
            }
            else {
                rootNode.removeEventListener('focus', this._rootNodeFocusAndBlurListener, captureEventListenerOptions);
                rootNode.removeEventListener('blur', this._rootNodeFocusAndBlurListener, captureEventListenerOptions);
                this._rootNodeFocusListenerCount.delete(rootNode);
            }
        }
        // Unregister global listeners when last element is unmonitored.
        if (!--this._monitoredElementCount) {
            const window = this._getWindow();
            window.removeEventListener('focus', this._windowFocusListener);
            // Equivalently, stop our InputModalityDetector subscription.
            this._stopInputModalityDetector.next();
            // Clear timeouts for all potentially pending timeouts to prevent the leaks.
            clearTimeout(this._windowFocusTimeoutId);
            clearTimeout(this._originTimeoutId);
        }
    }
    /** Updates all the state on an element once its focus origin has changed. */
    _originChanged(element, origin, elementInfo) {
        this._setClasses(element, origin);
        this._emitOrigin(elementInfo.subject, origin);
        this._lastFocusOrigin = origin;
    }
    /**
     * Collects the `MonitoredElementInfo` of a particular element and
     * all of its ancestors that have enabled `checkChildren`.
     * @param element Element from which to start the search.
     */
    _getClosestElementsInfo(element) {
        const results = [];
        this._elementInfo.forEach((info, currentElement) => {
            if (currentElement === element || (info.checkChildren && currentElement.contains(element))) {
                results.push([currentElement, info]);
            }
        });
        return results;
    }
}
FocusMonitor.ɵprov = i0.ɵɵdefineInjectable({ factory: function FocusMonitor_Factory() { return new FocusMonitor(i0.ɵɵinject(i0.NgZone), i0.ɵɵinject(i1.Platform), i0.ɵɵinject(InputModalityDetector), i0.ɵɵinject(i2.DOCUMENT, 8), i0.ɵɵinject(FOCUS_MONITOR_DEFAULT_OPTIONS, 8)); }, token: FocusMonitor, providedIn: "root" });
FocusMonitor.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
FocusMonitor.ctorParameters = () => [
    { type: NgZone },
    { type: Platform },
    { type: InputModalityDetector },
    { type: undefined, decorators: [{ type: Optional }, { type: Inject, args: [DOCUMENT,] }] },
    { type: undefined, decorators: [{ type: Optional }, { type: Inject, args: [FOCUS_MONITOR_DEFAULT_OPTIONS,] }] }
];
/**
 * Directive that determines how a particular element was focused (via keyboard, mouse, touch, or
 * programmatically) and adds corresponding classes to the element.
 *
 * There are two variants of this directive:
 * 1) cdkMonitorElementFocus: does not consider an element to be focused if one of its children is
 *    focused.
 * 2) cdkMonitorSubtreeFocus: considers an element focused if it or any of its children are focused.
 */
class CdkMonitorFocus {
    constructor(_elementRef, _focusMonitor) {
        this._elementRef = _elementRef;
        this._focusMonitor = _focusMonitor;
        this.cdkFocusChange = new EventEmitter();
    }
    ngAfterViewInit() {
        const element = this._elementRef.nativeElement;
        this._monitorSubscription = this._focusMonitor.monitor(element, element.nodeType === 1 && element.hasAttribute('cdkMonitorSubtreeFocus'))
            .subscribe(origin => this.cdkFocusChange.emit(origin));
    }
    ngOnDestroy() {
        this._focusMonitor.stopMonitoring(this._elementRef);
        if (this._monitorSubscription) {
            this._monitorSubscription.unsubscribe();
        }
    }
}
CdkMonitorFocus.decorators = [
    { type: Directive, args: [{
                selector: '[cdkMonitorElementFocus], [cdkMonitorSubtreeFocus]',
            },] }
];
CdkMonitorFocus.ctorParameters = () => [
    { type: ElementRef },
    { type: FocusMonitor }
];
CdkMonitorFocus.propDecorators = {
    cdkFocusChange: [{ type: Output }]
};

/**
 * @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
 */
/** CSS class applied to the document body when in black-on-white high-contrast mode. */
const BLACK_ON_WHITE_CSS_CLASS = 'cdk-high-contrast-black-on-white';
/** CSS class applied to the document body when in white-on-black high-contrast mode. */
const WHITE_ON_BLACK_CSS_CLASS = 'cdk-high-contrast-white-on-black';
/** CSS class applied to the document body when in high-contrast mode. */
const HIGH_CONTRAST_MODE_ACTIVE_CSS_CLASS = 'cdk-high-contrast-active';
/**
 * Service to determine whether the browser is currently in a high-contrast-mode environment.
 *
 * Microsoft Windows supports an accessibility feature called "High Contrast Mode". This mode
 * changes the appearance of all applications, including web applications, to dramatically increase
 * contrast.
 *
 * IE, Edge, and Firefox currently support this mode. Chrome does not support Windows High Contrast
 * Mode. This service does not detect high-contrast mode as added by the Chrome "High Contrast"
 * browser extension.
 */
class HighContrastModeDetector {
    constructor(_platform, document) {
        this._platform = _platform;
        this._document = document;
    }
    /** Gets the current high-contrast-mode for the page. */
    getHighContrastMode() {
        if (!this._platform.isBrowser) {
            return 0 /* NONE */;
        }
        // Create a test element with an arbitrary background-color that is neither black nor
        // white; high-contrast mode will coerce the color to either black or white. Also ensure that
        // appending the test element to the DOM does not affect layout by absolutely positioning it
        const testElement = this._document.createElement('div');
        testElement.style.backgroundColor = 'rgb(1,2,3)';
        testElement.style.position = 'absolute';
        this._document.body.appendChild(testElement);
        // Get the computed style for the background color, collapsing spaces to normalize between
        // browsers. Once we get this color, we no longer need the test element. Access the `window`
        // via the document so we can fake it in tests. Note that we have extra null checks, because
        // this logic will likely run during app bootstrap and throwing can break the entire app.
        const documentWindow = this._document.defaultView || window;
        const computedStyle = (documentWindow && documentWindow.getComputedStyle) ?
            documentWindow.getComputedStyle(testElement) : null;
        const computedColor = (computedStyle && computedStyle.backgroundColor || '').replace(/ /g, '');
        this._document.body.removeChild(testElement);
        switch (computedColor) {
            case 'rgb(0,0,0)': return 2 /* WHITE_ON_BLACK */;
            case 'rgb(255,255,255)': return 1 /* BLACK_ON_WHITE */;
        }
        return 0 /* NONE */;
    }
    /** Applies CSS classes indicating high-contrast mode to document body (browser-only). */
    _applyBodyHighContrastModeCssClasses() {
        if (!this._hasCheckedHighContrastMode && this._platform.isBrowser && this._document.body) {
            const bodyClasses = this._document.body.classList;
            // IE11 doesn't support `classList` operations with multiple arguments
            bodyClasses.remove(HIGH_CONTRAST_MODE_ACTIVE_CSS_CLASS);
            bodyClasses.remove(BLACK_ON_WHITE_CSS_CLASS);
            bodyClasses.remove(WHITE_ON_BLACK_CSS_CLASS);
            this._hasCheckedHighContrastMode = true;
            const mode = this.getHighContrastMode();
            if (mode === 1 /* BLACK_ON_WHITE */) {
                bodyClasses.add(HIGH_CONTRAST_MODE_ACTIVE_CSS_CLASS);
                bodyClasses.add(BLACK_ON_WHITE_CSS_CLASS);
            }
            else if (mode === 2 /* WHITE_ON_BLACK */) {
                bodyClasses.add(HIGH_CONTRAST_MODE_ACTIVE_CSS_CLASS);
                bodyClasses.add(WHITE_ON_BLACK_CSS_CLASS);
            }
        }
    }
}
HighContrastModeDetector.ɵprov = i0.ɵɵdefineInjectable({ factory: function HighContrastModeDetector_Factory() { return new HighContrastModeDetector(i0.ɵɵinject(i1.Platform), i0.ɵɵinject(i2.DOCUMENT)); }, token: HighContrastModeDetector, providedIn: "root" });
HighContrastModeDetector.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
HighContrastModeDetector.ctorParameters = () => [
    { type: Platform },
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] }
];

/**
 * @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 A11yModule {
    constructor(highContrastModeDetector) {
        highContrastModeDetector._applyBodyHighContrastModeCssClasses();
    }
}
A11yModule.decorators = [
    { type: NgModule, args: [{
                imports: [PlatformModule, ObserversModule],
                declarations: [CdkAriaLive, CdkTrapFocus, CdkMonitorFocus],
                exports: [CdkAriaLive, CdkTrapFocus, CdkMonitorFocus],
            },] }
];
A11yModule.ctorParameters = () => [
    { type: HighContrastModeDetector }
];

/**
 * @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
 */

/**
 * Generated bundle index. Do not edit.
 */

export { A11yModule, ActiveDescendantKeyManager, AriaDescriber, CDK_DESCRIBEDBY_HOST_ATTRIBUTE, CDK_DESCRIBEDBY_ID_PREFIX, CdkAriaLive, CdkMonitorFocus, CdkTrapFocus, ConfigurableFocusTrap, ConfigurableFocusTrapFactory, EventListenerFocusTrapInertStrategy, FOCUS_MONITOR_DEFAULT_OPTIONS, FOCUS_TRAP_INERT_STRATEGY, FocusKeyManager, FocusMonitor, FocusTrap, FocusTrapFactory, HighContrastModeDetector, INPUT_MODALITY_DETECTOR_DEFAULT_OPTIONS, INPUT_MODALITY_DETECTOR_OPTIONS, InputModalityDetector, InteractivityChecker, IsFocusableConfig, LIVE_ANNOUNCER_DEFAULT_OPTIONS, LIVE_ANNOUNCER_ELEMENT_TOKEN, LIVE_ANNOUNCER_ELEMENT_TOKEN_FACTORY, ListKeyManager, LiveAnnouncer, MESSAGES_CONTAINER_ID, isFakeMousedownFromScreenReader, isFakeTouchstartFromScreenReader, FocusTrapManager as ɵangular_material_src_cdk_a11y_a11y_a };
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