An <overlay-trigger> element supports the delivery of temporary overlay content based on interaction with a persistent trigger element. An element prepared to receive accessible interactions (e.g. an <sp-button>, or <button>, etc.) is addressed to slot="trigger", and the content to display (either via click or hover/focus interactions) is addressed to slot="click-content" or slot="hover-content", respectively. A trigger element can be linked to the delivery of content, intended for a single interaction, or both. Content addressed to slot="hover-content" is made available when the mouse enters or leaves the target element. Keyboard navigation will make this content available when focus enters or leaves the target element. Be thoughtful with what content you address to slot="hover-content", as the content available via "hover" will be transient and non-interactive.

yarn add @spectrum-web-components/overlay

Import the side-effectful registration of <overlay-trigger> via:

import '@spectrum-web-components/overlay/overlay-trigger.js';

The default of <overlay-trigger> will load dependencies in @spectrum-web-components/overlay asynchronously via a dynamic import. In the case that you would like to import those tranverse dependencies statically, import the side effectful registration of <overlay-trigger> as follows:

import '@spectrum-web-components/overlay/sync/overlay-trigger.js';

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

import { OverlayTrigger } from '@spectrum-web-components/overlay';

When using the placement attribute of an <overlay-trigger> ("top" |"top-start" | "top-end" | "bottom" | "bottom-start" | "bottom-end" | "right" | "right-start" | "right-end" | "left" | "left-start" | "left-end"), you can suggest to the overlay in which direction relative to the trigger that the content should display. When there is adequate room for the content to display in the specified direction, it will do so. When adequate room is not available, the overlaid content will calculate the direction in which it has the most room to be displayed and use that direction.

The type attribute of an <overlay-trigger> element outlines how the element's "click" content should appear in the tab order. inline will insert the overlay after the trigger; from here, forward tabbing targets the next logical element, and backward/shift tabbing returns to the target. replace will insert the overlay into the page as if it were the trigger; from here, forward tabbing targets the next logical element, and backward/shift tabbing targets the logical element prior to the target. Finally, modal will open the content in a tab order fully separate from the original content flow and trap the tab order within that content until the required interaction is complete.

Here a default <overlay-trigger> manages content that is triggered by click and "hover" interactions.

<overlay-trigger id="trigger" placement="bottom" offset="6">
    <sp-button variant="primary" slot="trigger">Button popover</sp-button>
    <sp-popover slot="click-content" direction="bottom" tip>
        <sp-dialog no-divider class="options-popover-content">
            <sp-slider
                value="5"
                step="0.5"
                min="0"
                max="20"
                label="Awesomeness"
            ></sp-slider>
            <sp-button>Press me</sp-button>
        </sp-dialog>
    </sp-popover>
    <sp-tooltip slot="hover-content" delayed>Tooltip</sp-tooltip>
    <sp-popover slot="longpress-content" tip>
        <sp-action-group
            selects="single"
            vertical
            style="margin: calc(var(--spectrum-spacing-100) / 2);"
        >
            <sp-action-button>
                <sp-icon-magnify slot="icon"></sp-icon-magnify>
            </sp-action-button>
            <sp-action-button>
                <sp-icon-magnify slot="icon"></sp-icon-magnify>
            </sp-action-button>
            <sp-action-button>
                <sp-icon-magnify slot="icon"></sp-icon-magnify>
            </sp-action-button>
        </sp-action-group>
    </sp-popover>
</overlay-trigger>

This example only delivers content via the "click" interaction and leverages both placement and type attributes to customize the visual relationship of the content to the page and its position in the tab order.

<overlay-trigger placement="top" type="replace">
    <sp-button slot="trigger">Overlay Trigger</sp-button>
    <sp-popover slot="click-content" open>
        <sp-dialog size="s">
            <h2 slot="heading">Click content</h2>
            An &lt;overlay-trigger&gt; can be used to manage either or both of
            the "click" and "hover" content slots that are made available. Here,
            content is only addressed to
            <code>slot="click-content"</code>
            ...
            <sp-button
                slot="button"
                onclick="javascript: this.dispatchEvent(new Event('close', {bubbles: true, composed: true}));"
            >
                I understand
            </sp-button>
        </sp-dialog>
    </sp-popover>
</overlay-trigger>

The delivery of hover content can be customized via the placement attribute. However, this content can not be interacted with, so the type attribute will not customize its delivery in any way.

<overlay-trigger placement="right">
    <sp-button slot="trigger">Overlay Trigger</sp-button>
    <sp-tooltip slot="hover-content" open placement="right">
        Hover Content
    </sp-tooltip>
</overlay-trigger>

When using an <overlay-trigger> element, it is important to be sure the that content you project into slot="trigger" is "interactive". This means that an element within that branch of DOM will be able to receive focus, and said element will appropriately convert keyboard interactions to click events, similar to what you'd find with <a href="#">Anchors</a>, <button>Buttons</button>, etc. You can find further reading on the subject of accessible keyboard interactions at https://www.w3.org/WAI/WCAG21/Understanding/keyboard.