gecko-dev/toolkit/content/widgets/moz-button/moz-button.mjs

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

import { html, ifDefined, classMap } from "../vendor/lit.all.mjs";
import { MozLitElement } from "../lit-utils.mjs";

/**
 * A button with multiple types and two sizes.
 *
 * @tagname moz-button
 * @property {string} label - The button's label, will be overridden by slotted content.
 * @property {string} type - The button type.
 *   Options: default, primary, destructive, icon, icon ghost, ghost.
 * @property {string} size - The button size.
 *   Options: default, small.
 * @property {boolean} disabled - The disabled state.
 * @property {string} title - The button's title attribute, used in shadow DOM and therefore not as an attribute on moz-button.
 * @property {string} titleAttribute - Internal, map title attribute to the title JS property.
 * @property {string} tooltipText - Set the title property, the title attribute will be used first.
 * @property {string} ariaLabel - The button's arial-label attribute, used in shadow DOM and therefore not as an attribute on moz-button.
 * @property {string} iconSrc - Path to the icon that should be displayed in the button.
 * @property {string} ariaLabelAttribute - Internal, map aria-label attribute to the ariaLabel JS property.
 * @property {string} hasVisibleLabel - Internal, tracks whether or not the button has a visible label.
 * @property {HTMLButtonElement} buttonEl - The internal button element in the shadow DOM.
 * @property {HTMLButtonElement} slotEl - The internal slot element in the shadow DOM.
 * @slot default - The button's content, overrides label property.
 * @fires click - The click event.
 */
export default class MozButton extends MozLitElement {
  static shadowRootOptions = {
    ...MozLitElement.shadowRootOptions,
    delegatesFocus: true,
  };

  static properties = {
    label: { type: String, reflect: true },
    type: { type: String, reflect: true },
    size: { type: String, reflect: true },
    disabled: { type: Boolean, reflect: true },
    title: { type: String, state: true },
    titleAttribute: { type: String, attribute: "title", reflect: true },
    tooltipText: { type: String },
    ariaLabelAttribute: {
      type: String,
      attribute: "aria-label",
      reflect: true,
    },
    ariaLabel: { type: String, state: true },
    iconSrc: { type: String },
    hasVisibleLabel: { type: Boolean, state: true },
  };

  static queries = {
    buttonEl: "button",
    slotEl: "slot",
  };

  constructor() {
    super();
    this.type = "default";
    this.size = "default";
    this.disabled = false;
    this.hasVisibleLabel = !!this.label;
  }

  willUpdate(changes) {
    if (changes.has("titleAttribute")) {
      this.title = this.titleAttribute;
      this.titleAttribute = null;
    }
    if (changes.has("ariaLabelAttribute")) {
      this.ariaLabel = this.ariaLabelAttribute;
      this.ariaLabelAttribute = null;
    }
  }

  // Delegate clicks on host to the button element.
  click() {
    this.buttonEl.click();
  }

  checkForLabelText() {
    this.hasVisibleLabel = this.slotEl
      ?.assignedNodes()
      .some(node => node.textContent.trim());
  }

  labelTemplate() {
    if (this.label) {
      return this.label;
    }
    return html`<slot @slotchange=${this.checkForLabelText}></slot>`;
  }

  render() {
    return html`
      <link
        rel="stylesheet"
        href="chrome://global/content/elements/moz-button.css"
      />
      <button
        type=${this.type}
        size=${this.size}
        ?disabled=${this.disabled}
        title=${ifDefined(this.title || this.tooltipText)}
        aria-label=${ifDefined(this.ariaLabel)}
        part="button"
        class=${classMap({ labelled: this.label || this.hasVisibleLabel })}
      >
        ${this.iconSrc
          ? html`<img src=${this.iconSrc} role="presentation" />`
          : ""}
        ${this.labelTemplate()}
      </button>
    `;
  }
}
customElements.define("moz-button", MozButton);