Files
webawesome/src/components/dropdown/dropdown.ts
2024-06-18 13:46:08 -04:00

454 lines
14 KiB
TypeScript

import '../popup/popup.js';
import { animateWithClass } from '../../internal/animate.js';
import { classMap } from 'lit/directives/class-map.js';
import { customElement, property, query } from 'lit/decorators.js';
import { html } from 'lit';
import { ifDefined } from 'lit/directives/if-defined.js';
import { WaAfterHideEvent } from '../../events/after-hide.js';
import { WaAfterShowEvent } from '../../events/after-show.js';
import { WaHideEvent } from '../../events/hide.js';
import { waitForEvent } from '../../internal/event.js';
import { WaShowEvent } from '../../events/show.js';
import { watch } from '../../internal/watch.js';
import componentStyles from '../../styles/component.styles.js';
import styles from './dropdown.styles.js';
import WebAwesomeElement from '../../internal/webawesome-element.js';
import type { CSSResultGroup } from 'lit';
import type { WaSelectEvent } from '../../events/select.js';
import type WaButton from '../button/button.js';
import type WaIconButton from '../icon-button/icon-button.js';
import type WaMenu from '../menu/menu.js';
import type WaPopup from '../popup/popup.js';
/**
* @summary Dropdowns expose additional content that "drops down" in a panel.
* @documentation https://shoelace.style/components/dropdown
* @status stable
* @since 2.0
*
* @dependency wa-popup
*
* @slot - The dropdown's main content.
* @slot trigger - The dropdown's trigger, usually a `<wa-button>` element.
*
* @event wa-show - Emitted when the dropdown opens.
* @event wa-after-show - Emitted after the dropdown opens and all animations are complete.
* @event wa-hide - Emitted when the dropdown closes.
* @event wa-after-hide - Emitted after the dropdown closes and all animations are complete.
*
* @cssproperty --box-shadow - The shadow effects around the dropdown's edges.
*
* @csspart base - The component's base wrapper.
* @csspart trigger - The container that wraps the trigger.
* @csspart panel - The panel that gets shown when the dropdown is open.
*/
@customElement('wa-dropdown')
export default class WaDropdown extends WebAwesomeElement {
static styles: CSSResultGroup = [componentStyles, styles];
@query('.dropdown') popup: WaPopup;
@query('.dropdown__trigger') trigger: HTMLSlotElement;
@query('.dropdown__panel') panel: HTMLSlotElement;
private closeWatcher: CloseWatcher | null;
/**
* Indicates whether or not the dropdown is open. You can toggle this attribute to show and hide the dropdown, or you
* can use the `show()` and `hide()` methods and this attribute will reflect the dropdown's open state.
*/
@property({ type: Boolean, reflect: true }) open = false;
/**
* The preferred placement of the dropdown panel. Note that the actual placement may vary as needed to keep the panel
* inside of the viewport.
*/
@property({ reflect: true }) placement:
| 'top'
| 'top-start'
| 'top-end'
| 'bottom'
| 'bottom-start'
| 'bottom-end'
| 'right'
| 'right-start'
| 'right-end'
| 'left'
| 'left-start'
| 'left-end' = 'bottom-start';
/** Disables the dropdown so the panel will not open. */
@property({ type: Boolean, reflect: true }) disabled = false;
/**
* By default, the dropdown is closed when an item is selected. This attribute will keep it open instead. Useful for
* dropdowns that allow for multiple interactions.
*/
@property({ attribute: 'stay-open-on-select', type: Boolean, reflect: true }) stayOpenOnSelect = false;
/**
* The dropdown will close when the user interacts outside of this element (e.g. clicking). Useful for composing other
* components that use a dropdown internally.
*/
@property({ attribute: false }) containingElement?: HTMLElement;
/** The distance in pixels from which to offset the panel away from its trigger. */
@property({ type: Number }) distance = 0;
/** The distance in pixels from which to offset the panel along its trigger. */
@property({ type: Number }) skidding = 0;
/**
* Enable this option to prevent the panel from being clipped when the component is placed inside a container with
* `overflow: auto|scroll`. Hoisting uses a fixed positioning strategy that works in many, but not all, scenarios.
*/
@property({ type: Boolean }) hoist = false;
/**
* Syncs the popup width or height to that of the trigger element.
*/
@property({ reflect: true }) sync: 'width' | 'height' | 'both' | undefined = undefined;
connectedCallback() {
super.connectedCallback();
if (!this.containingElement) {
this.containingElement = this;
}
}
firstUpdated() {
this.panel.hidden = !this.open;
// If the dropdown is visible on init, update its position
if (this.open) {
this.addOpenListeners();
this.popup.active = true;
}
}
disconnectedCallback() {
super.disconnectedCallback();
this.removeOpenListeners();
this.hide();
}
focusOnTrigger() {
const trigger = this.trigger.assignedElements({ flatten: true })[0] as HTMLElement | undefined;
if (typeof trigger?.focus === 'function') {
trigger.focus();
}
}
getMenu() {
return this.panel.assignedElements({ flatten: true }).find(el => el.tagName.toLowerCase() === 'wa-menu') as
| WaMenu
| undefined;
}
private handleKeyDown = (event: KeyboardEvent) => {
// Close when escape is pressed inside an open dropdown. We need to listen on the panel itself and stop propagation
// in case any ancestors are also listening for this key.
if (this.open && event.key === 'Escape' && !this.closeWatcher) {
event.stopPropagation();
this.hide();
this.focusOnTrigger();
}
};
private handleDocumentKeyDown = (event: KeyboardEvent) => {
// Close when escape or tab is pressed
if (event.key === 'Escape' && this.open) {
event.stopPropagation();
this.focusOnTrigger();
this.hide();
return;
}
// Handle tabbing
if (event.key === 'Tab') {
// Tabbing within an open menu should close the dropdown and refocus the trigger
if (this.open && document.activeElement?.tagName.toLowerCase() === 'wa-menu-item') {
event.preventDefault();
this.hide();
this.focusOnTrigger();
return;
}
// Tabbing outside of the containing element closes the panel
//
// If the dropdown is used within a shadow DOM, we need to obtain the activeElement within that shadowRoot,
// otherwise `document.activeElement` will only return the name of the parent shadow DOM element.
setTimeout(() => {
const activeElement =
this.containingElement?.getRootNode() instanceof ShadowRoot
? document.activeElement?.shadowRoot?.activeElement
: document.activeElement;
if (
!this.containingElement ||
activeElement?.closest(this.containingElement.tagName.toLowerCase()) !== this.containingElement
) {
this.hide();
}
});
}
};
private handleDocumentMouseDown = (event: MouseEvent) => {
// Close when clicking outside of the containing element
const path = event.composedPath();
if (this.containingElement && !path.includes(this.containingElement)) {
this.hide();
}
};
private handlePanelSelect = (event: WaSelectEvent) => {
const target = event.target as HTMLElement;
// Hide the dropdown when a menu item is selected
if (!this.stayOpenOnSelect && target.tagName.toLowerCase() === 'wa-menu') {
this.hide();
this.focusOnTrigger();
}
};
handleTriggerClick() {
if (this.open) {
this.hide();
} else {
this.show();
this.focusOnTrigger();
}
}
async handleTriggerKeyDown(event: KeyboardEvent) {
// When spacebar/enter is pressed, show the panel but don't focus on the menu. This let's the user press the same
// key again to hide the menu in case they don't want to make a selection.
if ([' ', 'Enter'].includes(event.key)) {
event.preventDefault();
this.handleTriggerClick();
return;
}
const menu = this.getMenu();
if (menu) {
const menuItems = menu.getAllItems();
const firstMenuItem = menuItems[0];
const lastMenuItem = menuItems[menuItems.length - 1];
// When up/down is pressed, we make the assumption that the user is familiar with the menu and plans to make a
// selection. Rather than toggle the panel, we focus on the menu (if one exists) and activate the first item for
// faster navigation.
if (['ArrowDown', 'ArrowUp', 'Home', 'End'].includes(event.key)) {
event.preventDefault();
// Show the menu if it's not already open
if (!this.open) {
this.show();
// Wait for the dropdown to open before focusing, but not the animation
await this.updateComplete;
}
if (menuItems.length > 0) {
// Focus on the first/last menu item after showing
this.updateComplete.then(() => {
if (event.key === 'ArrowDown' || event.key === 'Home') {
menu.setCurrentItem(firstMenuItem);
firstMenuItem.focus();
}
if (event.key === 'ArrowUp' || event.key === 'End') {
menu.setCurrentItem(lastMenuItem);
lastMenuItem.focus();
}
});
}
}
}
}
handleTriggerKeyUp(event: KeyboardEvent) {
// Prevent space from triggering a click event in Firefox
if (event.key === ' ') {
event.preventDefault();
}
}
handleTriggerSlotChange() {
this.updateAccessibleTrigger();
}
updateAccessibleTrigger() {
const assignedElements = this.trigger.assignedElements({ flatten: true }) as HTMLElement[];
const accessibleTrigger = assignedElements[0];
let target: HTMLElement;
if (accessibleTrigger) {
const tagName = accessibleTrigger.tagName.toLowerCase()
switch (tagName) {
// Web Awesome buttons have to update the internal button so it's announced correctly by screen readers
case 'wa-button':
case 'wa-icon-button':
target = (accessibleTrigger as WaButton | WaIconButton).button;
// Either the tag hasn't registered, or it hasn't rendered.
// So, wait for the tag to register, and then try again.
if (target === undefined) {
customElements.whenDefined(tagName).then(async () => {
await (target as WaButton | WaIconButton).updateComplete
this.updateAccessibleTrigger()
})
return
}
break;
default:
target = accessibleTrigger;
}
target.setAttribute('aria-haspopup', 'true');
target.setAttribute('aria-expanded', this.open ? 'true' : 'false');
}
}
/** Shows the dropdown panel. */
async show() {
if (this.open) {
return undefined;
}
this.open = true;
return waitForEvent(this, 'wa-after-show');
}
/** Hides the dropdown panel */
async hide() {
if (!this.open) {
return undefined;
}
this.open = false;
return waitForEvent(this, 'wa-after-hide');
}
/**
* Instructs the dropdown menu to reposition. Useful when the position or size of the trigger changes when the menu
* is activated.
*/
reposition() {
this.popup.reposition();
}
addOpenListeners() {
this.panel.addEventListener('wa-select', this.handlePanelSelect);
if ('CloseWatcher' in window) {
this.closeWatcher?.destroy();
this.closeWatcher = new CloseWatcher();
this.closeWatcher.onclose = () => {
this.hide();
this.focusOnTrigger();
};
} else {
this.panel.addEventListener('keydown', this.handleKeyDown);
}
document.addEventListener('keydown', this.handleDocumentKeyDown);
document.addEventListener('mousedown', this.handleDocumentMouseDown);
}
removeOpenListeners() {
if (this.panel) {
this.panel.removeEventListener('wa-select', this.handlePanelSelect);
this.panel.removeEventListener('keydown', this.handleKeyDown);
}
document.removeEventListener('keydown', this.handleDocumentKeyDown);
document.removeEventListener('mousedown', this.handleDocumentMouseDown);
this.closeWatcher?.destroy();
}
@watch('open', { waitUntilFirstUpdate: true })
async handleOpenChange() {
if (this.disabled) {
this.open = false;
return;
}
this.updateAccessibleTrigger();
if (this.open) {
// Show
const waShowEvent = new WaShowEvent();
this.dispatchEvent(waShowEvent);
if (waShowEvent.defaultPrevented) {
this.open = false;
return;
}
this.addOpenListeners();
this.panel.hidden = false;
this.popup.active = true;
await animateWithClass(this.popup.popup, 'show-with-scale');
this.dispatchEvent(new WaAfterShowEvent());
} else {
// Hide
const waHideEvent = new WaHideEvent();
this.dispatchEvent(waHideEvent);
if (waHideEvent.defaultPrevented) {
this.open = true;
return;
}
this.removeOpenListeners();
await animateWithClass(this.popup.popup, 'hide-with-scale');
this.panel.hidden = true;
this.popup.active = false;
this.dispatchEvent(new WaAfterHideEvent());
}
}
render() {
return html`
<wa-popup
part="base"
id="dropdown"
placement=${this.placement}
distance=${this.distance}
skidding=${this.skidding}
strategy=${this.hoist ? 'fixed' : 'absolute'}
flip
shift
auto-size="vertical"
auto-size-padding="10"
sync=${ifDefined(this.sync ? this.sync : undefined)}
class=${classMap({
dropdown: true,
'dropdown--open': this.open
})}
>
<slot
name="trigger"
slot="anchor"
part="trigger"
class="dropdown__trigger"
@click=${this.handleTriggerClick}
@keydown=${this.handleTriggerKeyDown}
@keyup=${this.handleTriggerKeyUp}
@slotchange=${this.handleTriggerSlotChange}
></slot>
<div aria-hidden=${this.open ? 'false' : 'true'} aria-labelledby="dropdown">
<slot part="panel" class="dropdown__panel"></slot>
</div>
</wa-popup>
`;
}
}
declare global {
interface HTMLElementTagNameMap {
'wa-dropdown': WaDropdown;
}
}