overlay-trigger
NPM 1.9.0
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triggered-by performance optimization triggered-by attribute to declare which types of overlays your implementation will use. This improves performance by avoiding unnecessary DOM operations and preventing race conditions during rendering. For more information, read the Overview
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.
Usage
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';
Example
In this example, a default <overlay-trigger> manages content that is triggered by "click" and "hover" interactions.
<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 <overlay-trigger> 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> <sp-tooltip slot="hover-content">Hover content</sp-tooltip> </overlay-trigger>
Options
Placement
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.
Type
The type of an Overlay outlines a number of things about the interaction model within which it works:
Note: The type attribute only affects click-triggered overlays. Hover overlays always use hint type behavior, and longpress overlays always use auto type behavior. For more control over hover and longpress overlay types, use <sp-overlay> directly.
'modal' Overlays create a modal context that traps focus within the content and prevents interaction with the rest of the page. The overlay manages focus trapping and accessibility features like aria-modal="true" to ensure proper screen reader behavior.
They should be used when you need to ensure that the user has interacted with the content of the Overlay before continuing with their work. This is commonly used for dialogs that require a user to confirm or cancel an action before continuing.
<overlay-trigger type="modal" triggered-by="click"> <sp-button slot="trigger">Open modal</sp-button> <sp-dialog-wrapper slot="click-content" headline="Signin form" dismissable underlay > <p>I am a modal type overlay.</p> <sp-field-label>Enter your email</sp-field-label> <sp-textfield placeholder="test@gmail.com"></sp-textfield> <sp-action-button onClick=" this.dispatchEvent( new Event('close', { bubbles: true, composed: true, }) ); " > Sign in </sp-action-button> </sp-dialog-wrapper> </overlay-trigger>
'page' Overlays behave similarly to 'modal' Overlays by creating a modal context and trapping focus, but they will not be allowed to close via the "light dismiss" algorithm (e.g. the Escape key).
A page overlay could be used for a full-screen menu on a mobile website. When the user clicks on the menu button, the entire screen is covered with the menu options.
<overlay-trigger type="page" triggered-by="click"> <sp-button slot="trigger">Open page</sp-button> <sp-dialog-wrapper slot="click-content" headline="Full screen menu" mode="fullscreenTakeover" cancel-label="Close" > <p>I am a page type overlay.</p> </sp-dialog-wrapper> </overlay-trigger>
'hint' Overlays are much like tooltips so they are not just ephemeral, but they are delivered primarily as a visual helper and exist outside of the tab order. In this way, be sure not to place interactive content within this type of Overlay.
This overlay type does not accept focus and does not interfere with the user's interaction with the rest of the page.
<overlay-trigger type="hint" triggered-by="hover"> <sp-button slot="trigger">Open hint</sp-button> <sp-tooltip slot="click-content"> I am a hint type overlay. I am not interactive and will close when the user interacts with the page. </sp-tooltip> </overlay-trigger>
'auto' Overlays provide a place for content that is ephemeral and interactive. These Overlays can accept focus and remain open while interacting with their content. They will close when focus moves outside the overlay or when clicking elsewhere on the page.
<overlay-trigger type="auto" triggered-by="click" placement="bottom"> <sp-button slot="trigger">Open overlay</sp-button> <sp-popover slot="click-content" dialog> <p> My slider in overlay element: <sp-slider label="Slider Label - Editable" editable></sp-slider> </p> </sp-popover> </overlay-trigger>
'manual' Overlays act much like 'auto' Overlays, but do not close when losing focus or interacting with other parts of the page.
Note: When a 'manual' Overlay is at the top of the "overlay stack", it will still respond to the Escape key and close.
<style> .chat-container { position: fixed; bottom: 1em; left: 1em; } </style> <overlay-trigger type="manual" triggered-by="click"> <sp-button slot="trigger">Open manual</sp-button> <sp-popover slot="click-content" class="chat-container"> <sp-dialog dismissable> <span slot="heading">Chat Window</span> <sp-textfield placeholder="Enter your message"></sp-textfield> <sp-action-button>Send</sp-action-button> </sp-dialog> </sp-popover> </overlay-trigger>
Performance optimization
The triggered-by attribute (triggeredBy property) allows you to explicitly declare which types of overlays your implementation will use. This can help optimize performance by avoiding unnecessary DOM operations and preventing race conditions during rendering.
<!-- Only using click and hover overlays --> <overlay-trigger triggered-by="click hover"> <sp-button slot="trigger">Click and hover trigger</sp-button> <sp-popover slot="click-content" direction="bottom" tip> Click content </sp-popover> <sp-tooltip slot="hover-content">Hover content</sp-tooltip> </overlay-trigger> <!-- Only using longpress overlay --> <overlay-trigger triggered-by="longpress"> <sp-button slot="trigger">Longpress trigger</sp-button> <sp-popover slot="longpress-content" direction="bottom" tip> Longpress content </sp-popover> <div slot="longpress-describedby-descriptor"> Press and hold to reveal more options </div> </overlay-trigger>
The triggered-by attribute accepts a space-separated string of overlay types:
click- For click-triggered contenthover- For hover/focus-triggered contentlongpress- For longpress-triggered content
When not specified, the component will automatically detect which content types are present, but this may result in additional rendering cycles. For optimal performance, especially in applications with many overlay triggers, explicitly declaring the content types you plan to use is recommended.
Accessibility
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
API
Attributes and Properties
disabled disabled boolean false offset offset number 6 open open OverlayContentTypes | undefined placement placement "top" | "top-start" | "top-end" | "right" | "right-start" | "right-end" | "bottom" | "bottom-start" | "bottom-end" | "left" | "left-start" | "left-end" receivesFocus receives-focus 'true' | 'false' | 'auto' 'auto' triggeredBy triggered-by TriggeredByType | undefined By explicitly declaring which content types are used (e.g. "click", "longpress hover"), we can avoid:
- Extra renders from unnecessary slot reparenting
- Potential infinite render loops during content detection
- Race conditions during slot assignment
By only returning overlay wrappers for explicitly declared content types, we minimize unecessary DOM nodes, operations and ensure a more stable rendering behavior.
type type OverlayTypes | undefined Slots
click-content hover-content longpress-content longpress-describedby-descriptor trigger Events
sp-closed Event Announces that the overlay has been closed sp-opened Event Announces that the overlay has been opened