sp-theme applies a Spectrum theme by using CSS custom properties to set default sizes & colors for all of the components in its scope. The Spectrum design system provides four color themes (lightest, light, dark, and darkest) and two different scales (medium and large) to support desktop & mobile UI.

yarn add @spectrum-web-components/theme

import '@spectrum-web-components/theme/sp-theme.js';
import '@spectrum-web-components/theme/src/themes.js';

The above import statements do two things: the first will get you started using the <sp-theme> wrapper element, and the second includes all four (4) color options (lightest, light, dark, and darkest) and both (2) scale options (medium and large) for the Spectrum Classic theme. Having all of these options available together is the easiest way to get a handle on the theming possibilities offered by the package and empowers you to prototype and test various deliveries of your application. However, reserving the download and parse time for all of the variants may not be required for all applications. See the "Advanced usage" section below for instructions on tuning the performance of an application that leverages this package.

Below are more ways to import the different scale and color options individually, in case you didn't want to import all of them as we did above. You'll use these statements in combination with the side effectful registration import statement import '@spectrum-web-components/theme/sp-theme.js'.

The various Classic themes can be imported en masse, as in the example above:

import '@spectrum-web-components/theme/src/themes.js';

The various Spectrum Express themes can also be imported en masse:

import '@spectrum-web-components/theme/src/express/themes.js';

Or you can import the themes and scales individually:

import '@spectrum-web-components/theme/theme-darkest.js';
import '@spectrum-web-components/theme/theme-dark.js';
import '@spectrum-web-components/theme/theme-light.js';
import '@spectrum-web-components/theme/theme-lightest.js';
import '@spectrum-web-components/theme/scale-medium.js';
import '@spectrum-web-components/theme/scale-large.js';
import '@spectrum-web-components/theme/express/theme-darkest.js';
import '@spectrum-web-components/theme/express/theme-dark.js';
import '@spectrum-web-components/theme/express/theme-light.js';
import '@spectrum-web-components/theme/express/theme-lightest.js';
import '@spectrum-web-components/theme/express/scale-medium.js';
import '@spectrum-web-components/theme/express/scale-large.js';

When looking to leverage the Theme base class as a type and/or for extension purposes, do so via:

import { Theme } from '@spectrum-web-components/theme';

Visually, all Spectrum Web Components are an expression of the design tokens specified by Spectrum, Adobe's design system. On the web, these tokens are made available as CSS Custom Properties. Using sp-theme as a parent element for your components ensures that those CSS Custom Properties can be leveraged by the elements within your application. This ensures consistent delivery of not only the color and scale you've specified in your particular instance, but for all the other color, scale, and content direction specifications across Spectrum.

Additionally, the sp-theme element manages the content direction applied to the elements in its DOM scope. By default, an sp-theme element resolves its initial content direction from the value specified by its first sp-theme or document ancestor; otherwise, it uses the value dir="ltr" if a content direction isn't present in those elements. When a value for dir is manually supplied to sp-theme, the default value is overridden. In all cases, though, sp-theme manages the dir value of its SpectrumElement descendents, unless another sp-theme element is placed into its scope and overrides that management.

To make the above concepts a little more concrete, take a look at the table below. Try selecting another color in the picker, and notice how that changes the values of the colors. The token names for the variables persist, but the RGB values under the hood change! Considering that sp-theme also manages all the other theme and size options, sp-theme reveals itself to be a pretty powerful component.

When you're ready to look into more advanced usage of the components and themes in your application, there are vanilla CSS implementations of these tokens available in the @spectrum-web-components/styles package.

An <sp-theme> element expects a value for each of its color and scale attributes to be provided on the element. While not required, you can also use the system attribute to specify whether the theme you're using is Spectrum Classic (the default), Spectrum 2 (upcoming release) or Spectrum Express.

<sp-theme
    system="spectrum"
    color="light"
    scale="medium"
    style="background-color: var(--spectrum-gray-100)"
>
    <sp-button onclick="spAlert(this, 'Themed <sp-button> clicked!')">
        Click me!
    </sp-button>
</sp-theme>

Once you've moved beyond the prototype phase of an application, it is likely that you will only use one combination of color and scale in your application, and even if not, you'll likely benefit from lazily loading the variants you don't leverage by default. For single combination applications, or to power a default theme, the following imports can be used to ensure only the code your application requires is loaded:

/**
 * Power a site using
 *
 * <sp-theme
 *      system="spectrum"
 *      color="darkest"
 *      scale="large"
 * >
 **/
import '@spectrum-web-components/theme/theme-darkest.js';
import '@spectrum-web-components/theme/scale-large.js';

import '@spectrum-web-components/theme/sp-theme.js';

/**
 * Power a site using
 *
 * <sp-theme
 *      system="express"
 *      color="light"
 *      scale="medium"
 * >
 **/
import '@spectrum-web-components/theme/express/theme-light.js';
import '@spectrum-web-components/theme/express/scale-medium.js';

import '@spectrum-web-components/theme/sp-theme.js';

When subsequent theme variants are needed, you can ensure those are lazily loaded by leveraging dynamic imports via something like:

const themeElement = document.querySelector('sp-theme');

const updateTheme = async (color, scale) => {
    Promise.all([
        import(`@spectrum-web-components/theme/theme-${color}.js`),
        import(`@spectrum-web-components/theme/scale-${scale}.js`),
    ]).then(() => {
        themeElement.color = color;
        themeElement.scale = scale;
    });
};

updateTheme('light', 'medium');

When bundling your application, be sure to consult the documentation of your bundler for the correct way to ensure proper packaging of the programatic dependency graph that this will create.

<style type="text/css">
    #example {
        max-width: 500px;
        padding: 3em;
        background-color: var(--spectrum-gray-100);
        color: var(--spectrum-gray-800);
    }

    #buttons {
        margin-top: 2em;
    }
</style>
<sp-theme system="express" color="light" scale="medium">
    <hzn-app-stuff></hzn-app-stuff>
</sp-theme>

<express-app>
    <hzn-app-stuff></hzn-app-stuff>
</express-app>

<style type="text/css">
    #example {
        max-width: 500px;
        padding: 3em;
        background-color: var(--spectrum-gray-100);
        color: var(--spectrum-gray-800);
    }

    #buttons {
        margin-top: 2em;
    }
</style>
<sp-theme system="express" color="dark" scale="large">
    <hzn-app-stuff></hzn-app-stuff>
</sp-theme>

<express-app>
    <hzn-app-stuff></hzn-app-stuff>
</express-app>

The large scale of <sp-theme> will switch to using Spectrum's larger mobile Platform Scale

<style type="text/css">
    #example {
        max-width: 500px;
        padding: 1em;
        background-color: var(--spectrum-gray-100);
        color: var(--spectrum-gray-800);
    }

    #buttons {
        margin-top: 2em;
    }
</style>
<sp-theme color="darkest" scale="large">
    <div id="example">
        <div>
            <sp-slider
                value="5"
                step="1"
                min="1"
                max="11"
                label="Volume"
                id="volume-slider"
            ></sp-slider>
        </div>
        <div><sp-switch>Overdrive</sp-switch></div>
        <sp-button-group id="buttons">
            <sp-button variant="primary">Cancel</sp-button>
            <sp-button variant="accent">Continue</sp-button>
        </sp-button-group>
    </div>
</sp-theme>

There are a few cases where it is necessary to embed one theme within another. For example, if you have an application that is using a dark theme with a left to right text direction that is previewing or editing content that will be displayed in a light theme with a right to left text direction.

<style type="text/css">
    #outer {
        max-width: 500px;
        padding: 1em;
        background-color: var(--spectrum-gray-100);
        color: var(--spectrum-gray-800);
    }

    #inner {
        margin-top: 2em;
        padding: 1em;
        background-color: var(--spectrum-gray-100);
        color: var(--spectrum-gray-800);
    }

    #buttons {
        margin-top: 2em;
    }
</style>
<sp-theme color="dark" dir="ltr">
    <div id="outer">
        <div>
            <sp-slider
                value="5"
                step="1"
                min="1"
                max="11"
                label="Volume"
                id="volume-slider"
            ></sp-slider>
        </div>
        <div><sp-switch>Overdrive</sp-switch></div>
        <sp-button-group id="buttons">
            <sp-button variant="primary">Cancel</sp-button>
            <sp-button variant="accent">Continue</sp-button>
        </sp-button-group>
        <sp-theme color="light" dir="rtl">
            <div id="inner">
                <div>
                    <sp-slider
                        value="5"
                        step="1"
                        min="1"
                        max="11"
                        label="Volume"
                        id="volume-slider"
                    ></sp-slider>
                </div>
                <div><sp-switch>Overdrive</sp-switch></div>
                <sp-button-group id="buttons">
                    <sp-button variant="primary">Cancel</sp-button>
                    <sp-button variant="accent">Continue</sp-button>
                </sp-button-group>
            </div>
        </sp-theme>
    </div>
</sp-theme>

The <sp-theme> element provides a language context for its descendents in the DOM. Descendents can resolve this context by dispatching an sp-language-context DOM event and supplying a callback(lang: string) => void method in the detail entry of the Custom Event. These callbacks will be reactively envoked when the lang attribute on the <sp-theme> element is updated. This way, you can control the resolved language in <sp-number-field>, <sp-slider>, and other elements in one centralized place.

The element provides a "system" context to its descendants in the DOM. This context indicates the Spectrum design system variant currently in use (e.g., 'spectrum', 'express', or 'spectrum-two').

Components can consume the system context by using the SystemResolutionController. This controller encapsulates the logic for resolving the system context, allowing it to be integrated into any component in few steps.

1. Import the SystemResolutionController and the necessary types:

import {
    SystemResolutionController,
    systemResolverUpdatedSymbol,
} from './SystemResolutionController.js';
import type { SystemVariant } from '@spectrum-web-components/theme';

2. Instantiate the SystemResolutionController:

   In your component class, create an instance of SystemResolutionController, passing this as the host element.

export class MyComponent extends LitElement {
    private systemResolver = new SystemResolutionController(this);

    // Rest of your component code...
}

3. Respond to system context changes:

   Override the update lifecycle method to detect changes in the system context using the systemResolverUpdatedSymbol.

protected update(changes: Map<PropertyKey, unknown>): void {
  super.update(changes);
  if (changes.has(systemResolverUpdatedSymbol)) {
    this.handleSystemChange();
  }
}

4. Implement the handler for system changes:

   Create a method that will be called whenever the system context changes. Use this.systemResolver.system to access the current system variant.

private handleSystemChange(): void {
  const currentSystem: SystemVariant = this.systemResolver.system;
  // Implement logic based on the current system variant.
  // For example, update styles, states or re-render parts of the component.
}

5. Use the system context in other parts of your component logic and/or template:

   You can now use this.systemResolver.system anywhere in your component to adjust behavior or rendering based on the system variant.

render() {
  return html`
    <div>
      <!-- Use the system context in your rendering logic -->
      Current system variant: ${this.systemResolver.system}
    </div>
  `;
}

API

Changelog

Note: Version bump only for package @spectrum-web-components/theme

• remove 'theme' attribute from sp-theme (#4765)

• add static-color to replace static (#4808) (43cf086)

• add file extension to Theme imports and respective eslint rule (#4771) (a2b6bea)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• breadcrumbs: add Breadcrumbs component (#4578) (acd4b5e)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• styles,theme: add S2 tokens and theme (#4241) (a29e4a2), closes #4232 #4228
• theme: deprecate theme property for system (#4230) (ac26168)

• theme: deprecate theme property for system (#4230) (ac26168)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• styles, theme: surface exports that omit Spectrum Vars proactively (#4142) (5b524c1)
• theme: deprecate lightest and darkest color stops (#4179) (0c01a66)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• theme: expose version property (#3978) (d42bb71)
• theme: include custom Spectrum color tokens in Express color tokens (370a1f1)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• theme: stop language resolution propagation and demo using local languages (6b81391)

• styles: update typography to leverage Core Tokens (2f86560)

• styles: update typography to leverage Core Tokens (2f86560)

• theme: stop language resolution propagation and demo using local languages (6b81391)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• convert the langage resolution workflow to a Reactive Controller (b7781db)
• correct theme calculation for triggering warnings (5576329)

• add docs and address PR comments (568062a)

Note: Version bump only for package @spectrum-web-components/theme

• include all Dev Mode files in side effects (f70817c)

• delivery dev mode messages in various packages (62370a1)

• support Spectrum Token consumption and update Action Button to use them (743ab16)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• ensure all theme data is exported and listed for side effects (14efdc7)

• add support for Spectrum Express (12bfe99)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• leverage latest Spectrum button API (9caf2f6)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• use local declaration of ShadowRoot.adoptedStyleSheets (43f1c63)

• update lit-* dependencies, wip (377f3c8)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• correct @element jsDoc listing across library (c97a632)

• resolve "updateComplete" with a boolean like LitElement (2ebcd44)

Note: Version bump only for package @spectrum-web-components/theme

• manage "lang" via context provided by "sp-theme" (b1e3457)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• use latest exports specification (a7ecf4b)

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

Note: Version bump only for package @spectrum-web-components/theme

• include the "types" entry in package.json files (b432f59)
• use latest @spectrum-css/* versions (c35eb86)

• include the "types" entry in package.json files (b432f59)
• use latest @spectrum-css/* versions (c35eb86)

Note: Version bump only for package @spectrum-web-components/theme

• include default export in the "exports" fields (f32407d)

• update side effect listings (8160d3a)

• allow dir management by sp-theme elements (2d10158)

• ensure browser understandable extensions (f4e59f7)

• theme: Use correct filename in exports field (d5da506)

• leverage "exports" field in package.json (321abd7)

• theme: prevent property sets attribute set property stack overflow (28d8a07)
• theme: support lazily loading theme fragments (3c3b634)

• ensure themes are registered before adopting (a7ffb84)

• rule: add Spectrum rule pattern and apply to docs (f4c52ae)

• use "sideEffects" listing in package.json (7271614)

Note: Version bump only for package @spectrum-web-components/theme

• theme: make typescript happy (a9aa377)
• theme: track default theme values dynamically (a0c306c)

• add "darkest" theme styles (fe38025)

• theme: include "large" scale (67577e7)

• rework overlays to use popper (e17d1bb)

• factor theme to use a single DOM node (7641228), closes #154
• get theme element working in storybook (4c5e478)

Note: Version bump only for package @spectrum-web-components/themes

• include "type" in package.json, generate custom-elements.json (1a8d716)

Note: Version bump only for package @spectrum-web-components/themes

• use @adobe/spectrum-css@2.15.1 (3918888)

• use imported TypeScript helpers instead of inlining them (cc2bd0a)

Note: Version bump only for package @spectrum-web-components/themes