iter(g31): 新增 tree 树形组件

2026-10-26 11:42:25 +08:00
parent 4f512b0d6b
commit 4b0dbfecec
13 changed files with 324 additions and 9 deletions
@@ -0,0 +1,98 @@
+import { effect, h, signal } from '@ui-arch/frame';
+import type { TreeProps, TreeNode } from './types.js';
+
+/*** 树形：递归渲染节点，箭头展开/收起，点击标签选中；键盘 Enter 选中、→ 展开、← 收起，被禁用的节点不响应 ***/
+export function tree(props: TreeProps): HTMLElement {
+  // —— 状态集中声明 ——
+  const expanded = props.expanded ?? signal<string[]>([]); // 展开的 key 集合，外部不传则内部维护
+  const selected = props.selected ?? signal(''); // 当前选中 key
+  const rows = new Map<string, HTMLElement>(); // key → 行元素，供响应式同步
+  const toggles = new Map<string, HTMLElement>(); // key → 展开箭头，供响应式同步
+
+  /*** 展开/收起一个节点（写回信号后由 effect 统一刷新 DOM） ***/
+  const toggle = (key: string) => {
+    const cur = expanded();
+    expanded(cur.includes(key) ? cur.filter((k) => k !== key) : [...cur, key]);
+  };
+
+  /*** 选中节点：写信号并回调 ***/
+  const pick = (node: TreeNode) => {
+    selected(node.key);
+    props.onSelect?.(node);
+  };
+
+  /*** 递归构建节点行：父行 + 子容器（子容器缩进一级） ***/
+  const build = (node: TreeNode, depth: number): HTMLElement => {
+    const on = expanded().includes(node.key);
+    const caret = h('span', { class: 'ua-tree-caret', 'aria-hidden': 'true' }, '›');
+    const row = h(
+      'div',
+      {
+        class: 'ua-tree-row',
+        role: 'treeitem',
+        'aria-level': String(depth + 1),
+        'aria-expanded': String(on),
+        tabindex: '0',
+        onClick: (e: Event) => {
+          if (node.disabled) return; // 卫语句：禁用节点不响应
+          if ((e.target as HTMLElement) === caret) toggle(node.key); // 点箭头只展开/收起
+          else pick(node);
+        },
+      },
+      caret,
+      h('span', { class: 'ua-tree-label' }, node.label),
+    );
+    rows.set(node.key, row);
+    toggles.set(node.key, caret);
+    if (!node.children?.length) caret.classList.add('ua-tree-caret-leaf'); // 叶子节点箭头置空位占位
+    const box = h('div', { class: 'ua-tree-children', role: 'group' }, ...(node.children ?? []).map((c) => build(c, depth + 1)));
+    return h('div', { class: 'ua-tree-node' }, row, box);
+  };
+
+  const root = h('div', { class: 'ua-tree', role: 'tree' }, ...props.nodes.map((n) => build(n, 0))) as HTMLElement;
+  if (props.defaultExpandAll) {
+    const all: string[] = [];
+    const walk = (list: TreeNode[]) => list.forEach((n) => { if (n.children?.length) { all.push(n.key); walk(n.children); } });
+    walk(props.nodes);
+    if (!expanded().length) expanded(all); // 仅在外部未给初值时展开全部
+  }
+
+  effect(() => {
+    const open = expanded();
+    const sel = selected();
+    for (const [key, row] of rows) {
+      const on = open.includes(key);
+      row.classList.toggle('ua-tree-open', on);
+      row.classList.toggle('ua-tree-selected', key === sel);
+      row.setAttribute('aria-selected', String(key === sel));
+      row.setAttribute('aria-expanded', String(on));
+      toggles.get(key)?.classList.toggle('ua-tree-caret-open', on); // 箭头随展开态旋转
+      const box = row.nextElementSibling as HTMLElement | null;
+      if (box) box.hidden = !on; // 收起即隐藏子容器
+    }
+  });
+
+  root.addEventListener('keydown', (e: KeyboardEvent) => {
+    const row = (e.target as HTMLElement).closest('.ua-tree-row') as HTMLElement | null;
+    if (!row) return; // 卫语句：焦点不在节点行
+    const key = [...rows.entries()].find(([, el]) => el === row)?.[0];
+    if (!key) return; // 卫语句：找不到对应节点
+    const node = findNode(props.nodes, key);
+    if (!node || node.disabled) return; // 卫语句：禁用节点不接管键盘
+    if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); pick(node); return; }
+    if (e.key === 'ArrowRight' && !expanded().includes(key)) { e.preventDefault(); toggle(key); return; } // → 展开
+    if (e.key === 'ArrowLeft' && expanded().includes(key)) { e.preventDefault(); toggle(key); } // ← 收起
+  });
+
+  return root;
+}
+
+/*** 按 key 深度查找节点（键盘操作需要拿到原始节点对象） ***/
+function findNode(nodes: TreeNode[], key: string): TreeNode | null {
+  for (const n of nodes) {
+    if (n.key === key) return n;
+    const hit = n.children ? findNode(n.children, key) : null;
+    if (hit) return hit;
+  }
+  return null;
+}