@spectrum-web-components/underlay

Overview

An <sp-underlay> provides a visual layer between overlay content and the rest of your application. It is commonly used with modal dialogs and other overlay elements to create a visual separation and prevent interaction with the background content while the overlay is active.

Usage

yarn add @spectrum-web-components/underlay

Import the side effectful registration of <sp-underlay> via:

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

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

import { Underlay } from '@spectrum-web-components/underlay';

Examples

Basic Usage

When using an <sp-underlay> with overlay content, place it as a sibling element before your overlay content.

<style>
    sp-underlay:not([open]) + sp-dialog {
        display: none;
    }
    sp-underlay + sp-dialog {
        position: fixed;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        z-index: 1;
        background: var(--spectrum-gray-100);
    }
</style>

<sp-button
    onclick="
        console.log(this.nextElementSibling);
        this.nextElementSibling.open = true;
    "
>
    Open dialog with underlay element
</sp-button>

<sp-underlay></sp-underlay>
<sp-dialog size="s">
    <h1 slot="heading">Hello, I'm an overlay!</h1>
    <p>Enjoy your day...</p>
    <sp-button
        slot="button"
        onclick="
            this.parentElement.previousElementSibling.open = false;
        "
    >
        Close
    </sp-button>
</sp-dialog>

Styling

To ensure proper layering of your overlay content with the underlay, use appropriate CSS:

<style>
    /* Hide overlay content when underlay is closed */
    sp-underlay:not([open]) + sp-dialog {
        display: none;
    }

    /* Position overlay content above the underlay */
    sp-underlay + sp-dialog {
        position: fixed;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        z-index: 1;
    }
</style>

Accessibility

The <sp-underlay> element helps create an accessible modal experience by:

• Providing visual separation between modal content and the rest of the page
• Supporting proper focus management when used with modal dialogs
• Helping communicate the modal state to assistive technologies

Changelog

1.7.0 (2025-06-11)

Minor Changes

sp-overlay: Fixed : Overlays (like pickers and action menus) were incorrectly closing when scrolling occurred within components. The fix ensures the handleScroll method in OverlayStack only responds to document/body scrolling events and ignores component-level scrolling events, which was the original intention.

sp-card: Fixed: On mobile Chrome (both Android and iOS), scrolling on sp-card components would inadvertently trigger click events. This was caused by the timing-based click detection (200ms threshold) in the pointer event handling, which could misinterpret quick scrolls as clicks. This issue did not affect Safari on mobile devices.

sp-action-button: - Fixed : Action buttons with href attributes now properly detects modifier keys and skips the proxy click, allowing only native browser behavior to proceed.

Patch Changes

sp-styles: Remove unnecessary system theme references to reduce complexity for components that don't need the additional mapping layer.

sp-card: - Fixed: sp-card component relies on sp-popover for certain toggle interactive behaviors, but this dependency was missing from its dependency tree.

sp-menu: Fixes: Icons in menu stories weren't properly responding to theme changes when used in functional story components. Switching to class-based LitElement components ensures proper component lifecycle hooks and shadow DOM context for icon initialization and theme integration.

sp-tabs: Added @spectrum-web-components/action-button as a dependency for Tabs as its used in the direction button.

sp-split-view: Added @spectrum-web-components/shared dependency in splitview since it uses ranDomId from the shared package

sp-textfield: Replace deprecated word-break: break-word with overflow-wrap: break-word to align with modern CSS standards and improve cross-browser compatibility. This property was deprecated in Chrome 44 (July 2015) in favor of the standardized overflow-wrap property.