ngx-bootstrap/focus-trap/esm2015/focus-trap.js

/**
 * @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
 */
/* eslint-disable */
import { coerceBooleanProperty } from './boolean-property';
import { DOCUMENT } from '@angular/common';
import { Directive, ElementRef, Inject, Injectable, Input, NgZone } from '@angular/core';
import { take } from 'rxjs/operators';
import { InteractivityChecker } from './interactivity-checker';
import * as i0 from "@angular/core";
import * as i1 from "./interactivity-checker";
import * as i2 from "@angular/common";
/**
 * 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 misalign.
 *
 * @deprecated Use `ConfigurableFocusTrap` instead.
 * @breaking-change for 11.0.0 Remove this class.
 */
export 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 successfuly. 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() {
        return new Promise(resolve => {
            this._executeOnStable(() => resolve(this.focusInitialElement()));
        });
    }
    /**
     * Waits for the zone to stabilize, then focuses
     * the first tabbable element within the focus trap region.
     * @returns Returns a promise that resolves with a boolean, depending
     * on whether focus was moved successfully.
     */
    focusFirstTabbableElementWhenReady() {
        return new Promise(resolve => {
            this._executeOnStable(() => resolve(this.focusFirstTabbableElement()));
        });
    }
    /**
     * Waits for the zone to stabilize, then focuses
     * the last tabbable element within the focus trap region.
     * @returns Returns a promise that resolves with a boolean, depending
     * on whether focus was moved successfully.
     */
    focusLastTabbableElementWhenReady() {
        return new Promise(resolve => {
            this._executeOnStable(() => resolve(this.focusLastTabbableElement()));
        });
    }
    /**
     * Get the specified boundary element of the trapped region.
     * @param bound The boundary to get (start or end of trapped region).
     * @returns The boundary element.
     */
    _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() {
        // 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 (!this._checker.isFocusable(redirectToElement)) {
                const focusableChild = this._getFirstTabbableElement(redirectToElement);
                focusableChild === null || focusableChild === void 0 ? void 0 : focusableChild.focus();
                return !!focusableChild;
            }
            redirectToElement.focus();
            return true;
        }
        return this.focusFirstTabbableElement();
    }
    /**
     * Focuses the first tabbable element within the focus trap region.
     * @returns Whether focus was moved successfully.
     */
    focusFirstTabbableElement() {
        const redirectToElement = this._getRegionBoundary('start');
        if (redirectToElement) {
            redirectToElement.focus();
        }
        return !!redirectToElement;
    }
    /**
     * Focuses the last tabbable element within the focus trap region.
     * @returns Whether focus was moved successfully.
     */
    focusLastTabbableElement() {
        const redirectToElement = this._getRegionBoundary('end');
        if (redirectToElement) {
            redirectToElement.focus();
        }
        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 for 11.0.0 Remove this class.
 */
export 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(i1.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. */
export class FocusTrapDirective {
    constructor(_elementRef, _focusTrapFactory, _document) {
        this._elementRef = _elementRef;
        this._focusTrapFactory = _focusTrapFactory;
        /** Previously focused element to restore focus to upon destroy when using autoCapture. */
        this._previouslyFocusedElement = null;
        this._autoCapture = false;
        this._document = _document;
        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 = this._document.activeElement;
        this.focusTrap.focusInitialElementWhenReady();
    }
}
FocusTrapDirective.decorators = [
    { type: Directive, args: [{
                selector: '[focusTrap]',
                exportAs: 'focusTrap'
            },] }
];
FocusTrapDirective.ctorParameters = () => [
    { type: ElementRef },
    { type: FocusTrapFactory },
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] }
];
FocusTrapDirective.propDecorators = {
    enabled: [{ type: Input, args: ['cdkTrapFocus',] }],
    autoCapture: [{ type: Input, args: ['cdkTrapFocusAutoCapture',] }]
};
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