Files
UI/packages/skin/ui/src/autoComplete.ts
T

123 lines
5.5 KiB
TypeScript

import { effect, h, signal } from '@ui-arch/frame';
import type { Signal } from '@ui-arch/frame';
import { bindOutside, pushOverlay } from './overlay.js';
import { flip, trackShift } from './position.js';
import type { AutoCompleteOption, AutoCompleteProps } from './types.js';
let seq = 0; // 实例序号:给弹层列表一个稳定 id,供 aria-controls 关联
/*** 自动补全:输入即过滤候选项,↑↓ 高亮 / Enter 选中 / Esc 收起,value 信号双向绑定 ***/
export function autoComplete(props: AutoCompleteProps): HTMLElement {
// —— 状态集中声明 ——
const value: Signal<string> = props.value ?? signal(''); // 输入值
const open = signal(false); // 弹层开合
const query = signal(''); // 当前过滤关键字(与 value 同步,独立信号便于受控写入)
const active = signal(-1); // 键盘高亮下标,-1 表示无高亮
const place = signal<'top' | 'bottom'>('bottom'); // 实际方位
let releaseEsc: (() => void) | null = null; // Esc 栈注销函数
const max = props.maxItems ?? 8;
/*** 按关键字取候选:函数式入参交给调用方计算(可远程联想),结果截断到 maxItems ***/
const candidates = (): AutoCompleteOption[] => {
const all = typeof props.options === 'function' ? props.options(query()) : props.options;
const q = query().trim().toLowerCase();
const hit = q ? all.filter((o) => o.value.toLowerCase().includes(q)) : all; // 包含匹配,大小写不敏感
return hit.slice(0, max);
};
const input = h('input', {
type: 'text',
class: 'ua-autocomplete-input',
placeholder: props.placeholder ?? '',
'aria-label': props.placeholder ?? '自动补全',
role: 'combobox',
'aria-expanded': () => String(open()),
'aria-autocomplete': 'list',
disabled: props.disabled,
value: () => value(), // 外部写入信号时回填输入框
oninput: (e: Event) => {
const v = (e.target as HTMLInputElement).value;
value(v);
query(v);
active(-1);
open(v.trim().length > 0); // 空串收起,避免开屏就弹
props.onInput?.(v);
},
}) as HTMLInputElement;
const list = h('ul', { class: 'ua-autocomplete-list', role: 'listbox', id: `ua-ac-${(seq += 1)}` }) as HTMLElement;
input.setAttribute('aria-controls', list.id);
const pop = h('div', { class: () => `ua-autocomplete-pop${open() ? ' ua-open' : ''}${place() === 'top' ? ' is-flip' : ''}` }, list) as HTMLElement;
const root = h('div', { class: 'ua-autocomplete' }, input, pop) as HTMLElement;
/*** 选中候选:写值 + 收起 + 回调,焦点回到输入框便于继续输入 ***/
const pick = (opt: AutoCompleteOption): void => {
value(opt.value);
query(opt.value);
open(false);
active(-1);
props.onSelect?.(opt);
input.focus();
};
/*** 重绘候选行:高亮项由 active 决定,空结果渲染提示行 ***/
const render = (): void => {
const opts = candidates();
if (!opts.length) {
list.replaceChildren(h('li', { class: 'ua-autocomplete-empty' }, props.emptyText ?? '无匹配项'));
input.removeAttribute('aria-activedescendant');
return;
}
const rows = opts.map((opt, i) => {
const row = h(
'li',
{
class: () => `ua-autocomplete-opt${active() === i ? ' is-active' : ''}`,
role: 'option',
id: `${list.id}-${i}`,
'aria-selected': String(active() === i),
onmousedown: (e: Event) => { e.preventDefault(); pick(opt); }, // 阻止默认:保住输入框焦点,blur 后仍能选中
},
h('span', { class: 'ua-autocomplete-value' }, opt.value),
opt.hint ? h('span', { class: 'ua-autocomplete-hint' }, opt.hint) : null,
);
return row;
});
list.replaceChildren(...rows);
const cur = rows[active()];
if (cur) input.setAttribute('aria-activedescendant', cur.id); // 读屏跟随高亮
else input.removeAttribute('aria-activedescendant');
};
root.addEventListener('keydown', (e: KeyboardEvent) => {
const opts = candidates();
if (e.key === 'ArrowDown' || e.key === 'ArrowUp') {
e.preventDefault(); // 阻止光标跳行
if (!open() && opts.length) { open(true); active(0); return; } // 未展开:先展开并高亮首项
const dir = e.key === 'ArrowDown' ? 1 : -1;
active((active() + dir + opts.length) % opts.length); // 环形移动
return;
}
if (e.key === 'Enter' && open() && active() >= 0) { e.preventDefault(); pick(opts[active()]); return; } // 有高亮才回车选中
if (e.key === 'Tab') { open(false); return; } // 失焦前收起,避免残留浮层
});
bindOutside(root, open, () => open(false)); // 点外部收起:仅展开期间挂监听,收起即摘
effect(render); // 依赖 query / active / options,任一变化即重绘
effect(() => {
if (open()) releaseEsc ??= pushOverlay(() => { open(false); input.focus(); }); // 入栈逐层关闭
else { releaseEsc?.(); releaseEsc = null; }
});
let releaseShift: (() => void) | null = null; // 展开期间的位移跟随释放函数(滚动 / 缩放重算翻转)
effect(() => {
if (!open()) { // 收起即摘监听:弹层不在,重算方位没有意义
releaseShift?.();
releaseShift = null;
return;
}
place(flip(input, pop, 'bottom')); // 打开先算一次:空间不足自动翻转
releaseShift ??= trackShift(() => place(flip(input, pop, 'bottom'))); // 展开期间跟着滚动重算:视口空间会变
}); // 空间不足自动翻转
return root;
}