3 files changed, 262 insertions, 0 deletions
diff --git a/toolkit/content/widgets/moz-toggle/moz-toggle.css b/toolkit/content/widgets/moz-toggle/moz-toggle.css
new file mode 100644
index 0000000000..af5d9085ae
--- /dev/null
+++ b/toolkit/content/widgets/moz-toggle/moz-toggle.css
@@ -0,0 +1,119 @@
+/* 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/. */
+
+:host {
+  display: grid;
+  gap: 8px;
+  justify-content: space-between;
+  align-items: center;
+}
+
+:host([disabled]) {
+  opacity: 0.4
+}
+
+button,
+label {
+  grid-row: 1;
+}
+
+p {
+  grid-row: 2;
+  font-size: .85em;
+  line-height: 1.25;
+  color: var(--in-content-deemphasized-text);
+  margin: 0;
+  grid-column: 1 / -1;
+}
+
+.toggle-button {
+  --button-height: 16px;
+  --button-half-height: 8px;
+  --button-width: 32px;
+  --button-border-width: 1px;
+  /* dot-size = button-height - 2*dot-margin - 2*button-border-width */
+  --dot-size: 12px;
+  --dot-margin: 1px;
+  /* --dot-transform-x = button-width - 2*dot-margin - dot-size - 2*button-border-width */
+  --dot-transform-x: 16px;
+  --border-color: #8F8F9D;
+}
+
+.toggle-button {
+  appearance: none;
+  padding: 0;
+  margin: 0;
+  border: var(--button-border-width) solid var(--border-color);
+  height: var(--button-height);
+  width: var(--button-width);
+  border-radius: var(--button-half-height);
+  background-color: var(--in-content-button-background);
+  box-sizing: border-box;
+}
+
+.toggle-button:focus-visible {
+  outline: var(--in-content-focus-outline-width) solid var(--in-content-focus-outline-color);
+  outline-offset: var(--in-content-focus-outline-offset);
+}
+
+.toggle-button:enabled:hover {
+  background-color: var(--in-content-button-background-hover);
+  border-color: var(--border-color);
+}
+
+.toggle-button:enabled:active {
+  background-color: var(--in-content-button-background-active);
+  border-color: var(--border-color);
+}
+
+.toggle-button[aria-pressed="true"] {
+  background-color: var(--in-content-primary-button-background);
+  border-color: transparent;
+}
+
+.toggle-button[aria-pressed="true"]:enabled:hover {
+  background-color: var(--in-content-primary-button-background-hover);
+  border-color: transparent;
+}
+
+.toggle-button[aria-pressed="true"]:enabled:active,
+.toggle-button[aria-pressed="true"].toggle-button:checked:enabled:hover:active {
+  background-color: var(--in-content-primary-button-background-active);
+  border-color: transparent;
+}
+
+.toggle-button::before {
+  display: block;
+  content: "";
+  background-color: var(--border-color);
+  height: var(--dot-size);
+  width: var(--dot-size);
+  margin: var(--dot-margin);
+  border-radius: 50%;
+  outline: 1px solid transparent;
+  outline-offset: -1px;
+  translate: 0;
+}
+
+.toggle-button[aria-pressed="true"]::before {
+  translate: var(--dot-transform-x);
+  /* TODO: Bug 1798404 - This color doesn't match the spec in dark mode. This should
+  be re-visited when we're defining tokens. */
+  background-color: var(--in-content-box-background);
+}
+
+.toggle-button[aria-pressed="true"]:-moz-locale-dir(rtl)::before,
+.toggle-button[aria-pressed="true"]:dir(rtl)::before {
+  translate: calc(-1 * var(--dot-transform-x));
+}
+
+.toggle-button[aria-pressed="true"]:not(:active, :hover:active)::before {
+  outline-color: var(--in-content-box-background);
+}
+
+@media (prefers-reduced-motion: no-preference) {
+  .toggle-button::before {
+    transition: translate 100ms;
+  }
+}
diff --git a/toolkit/content/widgets/moz-toggle/moz-toggle.mjs b/toolkit/content/widgets/moz-toggle/moz-toggle.mjs
new file mode 100644
index 0000000000..5aee2a7d42
--- /dev/null
+++ b/toolkit/content/widgets/moz-toggle/moz-toggle.mjs
@@ -0,0 +1,89 @@
+/* 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 htp://mozilla.org/MPL/2.0/. */
+
+import { html, ifDefined } from "../vendor/lit.all.mjs";
+import { MozLitElement } from "../lit-utils.mjs";
+
+export default class MozToggle extends MozLitElement {
+  static properties = {
+    pressed: { type: Boolean, reflect: true },
+    disabled: { type: Boolean, reflect: true },
+    label: { type: String },
+    description: { type: String },
+    ariaLabel: { type: String, attribute: "aria-label" },
+  };
+
+  static get queries() {
+    return {
+      buttonEl: "#moz-toggle-button",
+      labelEl: "#moz-toggle-label",
+      descriptionEl: "#moz-toggle-description",
+    };
+  }
+
+  // Use a relative URL in storybook to get faster reloads on style changes.
+  static stylesheetUrl = window.IS_STORYBOOK
+    ? "./moz-toggle/moz-toggle.css"
+    : "chrome://global/content/elements/moz-toggle.css";
+
+  constructor() {
+    super();
+    this.pressed = false;
+    this.disabled = false;
+  }
+
+  handleClick() {
+    this.pressed = !this.pressed;
+    this.dispatchOnUpdateComplete(
+      new CustomEvent("toggle", {
+        bubbles: true,
+        composed: true,
+      })
+    );
+  }
+
+  labelTemplate() {
+    if (this.label) {
+      return html`
+        <label id="moz-toggle-label" part="label" for="moz-toggle-button">
+          ${this.label}
+        </label>
+      `;
+    }
+    return "";
+  }
+
+  descriptionTemplate() {
+    if (this.description) {
+      return html`
+        <p id="moz-toggle-description" part="description">
+          ${this.description}
+        </p>
+      `;
+    }
+    return "";
+  }
+
+  render() {
+    const { pressed, disabled, description, ariaLabel, handleClick } = this;
+    return html`
+      <link rel="stylesheet" href=${this.constructor.stylesheetUrl} />
+      ${this.labelTemplate()} ${this.descriptionTemplate()}
+      <button
+        id="moz-toggle-button"
+        part="button"
+        type="button"
+        class="toggle-button"
+        ?disabled=${disabled}
+        aria-pressed=${pressed}
+        aria-label=${ifDefined(ariaLabel ?? undefined)}
+        aria-describedby=${ifDefined(
+          description ? "moz-toggle-description" : undefined
+        )}
+        @click=${handleClick}
+      ></button>
+    `;
+  }
+}
+customElements.define("moz-toggle", MozToggle);
diff --git a/toolkit/content/widgets/moz-toggle/moz-toggle.stories.mjs b/toolkit/content/widgets/moz-toggle/moz-toggle.stories.mjs
new file mode 100644
index 0000000000..7441cad91b
--- /dev/null
+++ b/toolkit/content/widgets/moz-toggle/moz-toggle.stories.mjs
@@ -0,0 +1,54 @@
+/* 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 } from "../vendor/lit.all.mjs";
+// eslint-disable-next-line import/no-unassigned-import
+import "./moz-toggle.mjs";
+
+export default {
+  title: "Design System/Experiments/MozToggle",
+  parameters: {
+    actions: {
+      handles: ["toggle"],
+    },
+  },
+};
+
+const Template = ({ pressed, disabled, label, description, ariaLabel }) => html`
+  <div style="max-width: 400px">
+    <moz-toggle
+      ?pressed=${pressed}
+      ?disabled=${disabled}
+      label=${ifDefined(label)}
+      description=${ifDefined(description)}
+      aria-label=${ifDefined(ariaLabel)}
+    ></moz-toggle>
+  </div>
+`;
+
+export const Default = Template.bind({});
+Default.args = {
+  pressed: true,
+  disabled: false,
+  ariaLabel: "This is the aria-label",
+};
+
+export const Disabled = Template.bind({});
+Disabled.args = {
+  ...Default.args,
+  disabled: true,
+};
+
+export const WithLabel = Template.bind({});
+WithLabel.args = {
+  pressed: true,
+  disabled: false,
+  label: "This is the label",
+};
+
+export const WithDescription = Template.bind({});
+WithDescription.args = {
+  ...WithLabel.args,
+  description: "This is the description",
+};