Files
astrolabe/src/app/components/SelectControl.tsx
T

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TypeScript

/**
* SelectControl — the app's value picker: a disclosure trigger showing the current
* choice plus a portaled, non-modal popover listing the options as plain buttons.
*
* This replaces native `<select>` elements wherever a control is part of a designed
* surface: a native select's popup can't be token-styled and renders differently on
* every browser/OS, which reads as a foreign object inside an otherwise consistent
* UI (arch 10 §5 records the resolution). It is the same APG **disclosure**
* primitive as SortControl/SettingsPopover — deliberately NOT an ARIA menu and not
* a combobox; a short list of buttons needs neither's contract.
*
* Behaviour (the shared `usePopover` machinery): at most one popover is open
* app-wide (`PopoverStore`); Esc closes and refocuses the trigger; an outside
* pointer press closes; opening focuses the selected option (or the first);
* Arrow/Home/End move focus through the options; choosing one fires `onSelect`,
* closes, and refocuses the trigger. The panel is portaled to <body> and positioned
* fixed so it escapes pane/modal overflow clipping, flipping above the trigger when
* the viewport below is too short.
*
* The same control doubles as an **action picker** (e.g. "Add field to which
* channel?"): pass no `value` and a custom `triggerContent`; `beforeOpen` lets the
* caller intercept the click entirely (the armed-channel fast path).
*/
import { Fragment, type ReactNode } from 'react';
import { createPortal } from 'react-dom';
import { usePopover } from '../hooks/usePopover';
import styles from './SelectControl.module.css';
/** Land on the selected option (falling back to the first). */
const INITIAL_FOCUS = ['[aria-current="true"]', 'button'] as const;
export interface SelectControlOption<V extends string> {
value: V;
label: string;
/** Optional secondary line (e.g. "replaces Ship Mode" on an occupied channel). */
detail?: string;
/**
* Draw a group separator above this option (purely visual, `role="presentation"`;
* keyboard order is untouched) — e.g. the chart-theme picker's boundary between
* the user's themes and the preset roster.
*/
dividerBefore?: boolean;
}
export interface SelectControlProps<V extends string> {
/** Unique id — popover registry key and the panel's DOM id. */
id: string;
/** Accessible name for the control ("Aggregate for Y", "Add Region to…"). */
label: string;
options: ReadonlyArray<SelectControlOption<V>>;
/** Current value; omit for an action picker (no option reads as selected). */
value?: V;
onSelect: (value: V) => void;
/** Trigger body; defaults to the current option's label plus a caret. */
triggerContent?: ReactNode;
/** Replaces (not extends) the default trigger styling — for chip-styled triggers. */
triggerClassName?: string;
triggerTitle?: string;
disabled?: boolean;
/** Popover heading; defaults to `label`. */
heading?: string;
/** Return false to swallow the trigger click without opening (fast paths). */
beforeOpen?: () => boolean;
}
export function SelectControl<V extends string>({
id,
label,
options,
value,
onSelect,
triggerContent,
triggerClassName,
triggerTitle,
disabled,
heading,
beforeOpen,
}: SelectControlProps<V>) {
const { open, toggle, closeAndRefocus, triggerRef, popRef, setPopNode } = usePopover({
id,
align: 'left',
flip: true,
initialFocus: INITIAL_FOCUS,
});
const current = value !== undefined ? options.find((o) => o.value === value) : undefined;
// Arrow/Home/End roving among the option buttons — a convenience on top of the
// natural Tab order, matching what a native select's popup offers.
const onPopKeyDown = (e: React.KeyboardEvent) => {
const pop = popRef.current;
if (!pop) return;
// Tab closes the popup and resumes tabbing from the trigger (the native-select
// convention) — also keeps focus inside a host modal's trap, since the panel is
// portaled outside it.
if (e.key === 'Tab') {
closeAndRefocus();
return;
}
const items = Array.from(pop.querySelectorAll<HTMLButtonElement>('button'));
const i = items.indexOf(document.activeElement as HTMLButtonElement);
let next = -1;
if (e.key === 'ArrowDown') next = i < 0 ? 0 : Math.min(i + 1, items.length - 1);
else if (e.key === 'ArrowUp') next = i < 0 ? items.length - 1 : Math.max(i - 1, 0);
else if (e.key === 'Home') next = 0;
else if (e.key === 'End') next = items.length - 1;
if (next >= 0) {
e.preventDefault();
items[next]?.focus();
}
};
const choose = (v: V) => {
onSelect(v);
closeAndRefocus();
};
return (
<>
<button
ref={triggerRef}
type="button"
className={triggerClassName ?? styles.trigger}
aria-expanded={open}
aria-controls={open ? id : undefined}
aria-label={current ? `${label}: ${current.label}` : label}
title={triggerTitle}
disabled={disabled}
onClick={() => {
if (beforeOpen && !beforeOpen()) return;
toggle();
}}
>
{triggerContent ?? (
<>
<span className={styles.triggerLabel}>{current?.label ?? '—'}</span>
<span className={styles.caret} aria-hidden="true">
</span>
</>
)}
</button>
{open &&
createPortal(
<div
ref={setPopNode}
id={id}
className={styles.pop}
role="group"
aria-label={label}
onKeyDown={onPopKeyDown}
>
<h4 className={styles.heading}>{heading ?? label}</h4>
<div className={styles.list}>
{options.map((o) => {
const selected = value !== undefined && o.value === value;
return (
<Fragment key={o.value}>
{o.dividerBefore && <div className={styles.divider} role="presentation" />}
<button
type="button"
className={`${styles.option} ${selected ? styles.selected : ''}`}
aria-current={selected || undefined}
onClick={() => choose(o.value)}
>
<span className={styles.optionLabel}>
{o.label}
{o.detail !== undefined && (
<span className={styles.detail}>{o.detail}</span>
)}
</span>
{selected && <span aria-hidden="true"></span>}
</button>
</Fragment>
);
})}
</div>
</div>,
document.body,
)}
</>
);
}