Toast.ts

/*
Copyright 2020 Adobe. All rights reserved.
This file is licensed to you under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License. You may obtain a copy
of the License at http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under
the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
OF ANY KIND, either express or implied. See the License for the specific language
governing permissions and limitations under the License.
*/

import {
    CSSResultArray,
    html,
    PropertyValues,
    SpectrumElement,
    TemplateResult,
} from '@spectrum-web-components/base';
import { property } from '@spectrum-web-components/base/src/decorators.js';
import '@spectrum-web-components/button/sp-close-button.js';
import '@spectrum-web-components/icons-workflow/icons/sp-icon-alert.js';
import '@spectrum-web-components/icons-workflow/icons/sp-icon-info.js';
import '@spectrum-web-components/icons-workflow/icons/sp-icon-checkmark-circle.js';
import { FocusVisiblePolyfillMixin } from '@spectrum-web-components/shared/src/focus-visible.js';

import toastStyles from './toast.css.js';

export const toastVariants: ToastVariants[] = [
    'negative',
    'positive',
    'info',
    'error',
    'warning',
];

export type ToastVariants =
    | 'negative'
    | 'positive'
    | 'info'
    | 'error'
    | 'warning'
    | '';

/**
 * @element sp-toast
 *
 * @slot - The toast content
 * @slot action - button element surfacing an action in the Toast
 *
 * @fires close - Announces that the Toast has been closed by the user or by its timeout.
 */

export class Toast extends FocusVisiblePolyfillMixin(SpectrumElement) {
    public static override get styles(): CSSResultArray {
        return [toastStyles];
    }

    @property({ type: Boolean, reflect: true })
    public open = false;

    /**
     * When a timeout is provided it represents the number of milliseconds from when
     * the Toast was placed on the page before it will automatically dismiss itself.
     * Accessibility concerns require that a Toast is available for at least 6000ms
     * before being dismissed, so any timeout of less than 6000ms will be raised to
     * that baseline. It is suggested that messages longer than 120 words should
     * receive another 1000ms in their timeout for each additional 120 words in the
     * message. E.G. 240 words = 7000ms, 360 words = 8000ms, etc.
     *
     * @param {Number} timeout
     */
    @property({ type: Number })
    public set timeout(timeout: number | null) {
        const hasTimeout = typeof timeout !== null && (timeout as number) > 0;
        const newTimeout = hasTimeout
            ? Math.max(6000, timeout as number)
            : null;
        const oldValue = this.timeout;
        if (newTimeout && this.countdownStart) {
            this.countdownStart = performance.now();
        }
        this._timeout = newTimeout;
        this.requestUpdate('timeout', oldValue);
    }

    public get timeout(): number | null {
        return this._timeout;
    }

    public _timeout: number | null = null;

    /**
     * The variant applies specific styling when set to `negative`, `positive`, `info`, `error`, or `warning`.
     * `variant` attribute is removed when not matching one of the above.
     *
     * @param {String} variant
     */
    @property({ type: String })
    public set variant(variant: ToastVariants) {
        if (variant === this.variant) {
            return;
        }
        const oldValue = this.variant;
        if (toastVariants.includes(variant)) {
            this.setAttribute('variant', variant);
            this._variant = variant;
        } else {
            this.removeAttribute('variant');
            this._variant = '';
        }
        this.requestUpdate('variant', oldValue);
    }

    public get variant(): ToastVariants {
        return this._variant;
    }

    private _variant: ToastVariants = '';

    private renderIcon(variant: string): TemplateResult {
        switch (variant) {
            case 'info':
                return html`
                    <sp-icon-info
                        label="Information"
                        class="type"
                    ></sp-icon-info>
                `;
            case 'negative':
            case 'error': // deprecated
            case 'warning': // deprecated
                return html`
                    <sp-icon-alert label="Error" class="type"></sp-icon-alert>
                `;
            case 'positive':
            case 'success': // deprecated
                return html`
                    <sp-icon-checkmark-circle
                        label="Success"
                        class="type"
                    ></sp-icon-checkmark-circle>
                `;
            default:
                return html``;
        }
    }

    private countdownStart = 0;
    private nextCount = -1;

    private doCountdown = (time: number): void => {
        if (!this.countdownStart) {
            this.countdownStart = performance.now();
        }
        if (time - this.countdownStart > (this._timeout as number)) {
            this.shouldClose();
            this.countdownStart = 0;
        } else {
            this.countdown();
        }
    };

    private countdown = (): void => {
        cancelAnimationFrame(this.nextCount);
        this.nextCount = requestAnimationFrame(this.doCountdown);
    };

    private holdCountdown = (): void => {
        this.stopCountdown();
        this.addEventListener('focusout', this.resumeCountdown);
    };

    private resumeCountdown = (): void => {
        this.removeEventListener('focusout', this.holdCountdown);
        this.countdown();
    };

    private startCountdown(): void {
        this.countdown();
        this.addEventListener('focusin', this.holdCountdown);
    }

    private stopCountdown(): void {
        cancelAnimationFrame(this.nextCount);
        this.countdownStart = 0;
    }

    private shouldClose(): void {
        const applyDefault = this.dispatchEvent(
            new CustomEvent('close', {
                composed: true,
                bubbles: true,
                cancelable: true,
            })
        );
        if (applyDefault) {
            this.close();
        }
    }

    public close(): void {
        this.open = false;
    }

    protected override render(): TemplateResult {
        return html`
            ${this.renderIcon(this.variant)}
            <div class="body" role="alert">
                <div class="content">
                    <slot></slot>
                </div>
                <slot name="action"></slot>
            </div>
            <div class="buttons">
                <sp-close-button
                    @click=${this.shouldClose}
                    label="Close"
                    static-color="white"
                ></sp-close-button>
            </div>
        `;
    }

    protected override updated(changes: PropertyValues): void {
        super.updated(changes);
        if (changes.has('open')) {
            if (this.open) {
                if (this.timeout) {
                    this.startCountdown();
                }
            } else {
                if (this.timeout) {
                    this.stopCountdown();
                }
            }
        }
        if (changes.has('timeout')) {
            if (this.timeout !== null && this.open) {
                this.startCountdown();
            } else {
                this.stopCountdown();
            }
        }
    }
}