导航抽屉

概览

link

Web

tanrei-navigation-drawer

schedule

SwiftUI

TanreiNavigationDrawer

schedule

Jetpack Compose

TanreiNavigationDrawer

schedule

Flutter

TanreiNavigationDrawer

schedule

React Native

NavigationDrawer

schedule

生成自 docs/status/status.json, specs/navigation-drawer.spec.json

规格已修订，尚未覆盖所有平台

本页描述的是规格当前所定的导航抽屉。collapsible 的抽屉可以收窄为一列图标，由此取代了导航轨道（navigation rail）：收起的抽屉就是去掉标签的展开抽屉，每一行都在图标之后截断，它的菜单按钮再把它展宽，每个图标都留在原位。目的地的 badge 文本改为 trailingText，画得更低调，另有 trailing 插槽用来放图标；badge 现在指图标上的徽标。group 项用来展开和折叠嵌套的目的地。行高为 48，与菜单项的高度相同。responsive 让窗口的宽度决定抽屉的呈现方式。带 href 的目的地是链接，revealSelected 和 scrollOffset 则让抽屉可以充当网站的侧边栏。Web 组件已经做到了这一切，本页的演示也是如此。SwiftUI、Compose、Flutter 和 React Native 在上方标记为“待跟进”：在跟上之前，它们提供的是上一版——行高 44，badge 是行末的文本，没有收起形态、分组、链接目的地和响应式呈现，另有一个独立的导航轨道；这些平台的示例展示的也是那个版本。 紧凑的 density、同时作为目的地的分组（selectableGroups）和筛选输入框（filterable）更新一些，目前只在 Web 上提供。

带两个分区的标准抽屉

可收起的抽屉：菜单按钮把它收起为一列图标，其中的单元格用工具提示显示名称

menuadd

作为链接的目的地：抽屉的 value 指明当前页面，reveal-selected 展开包含它的分组

可以筛选行的抽屉：在输入框中键入，或者在页面的任何地方按 / 来到输入框

紧凑的抽屉，供用指针操作的工具使用：32 高的行和 16 的字形，每个嵌套图标都对齐到其分组标签的起点

同时作为目的地的分组：设置 selectable-groups 后，分组的行选中它，而它的展开箭头负责展开和折叠

用法

link

导航抽屉有五种项。destination（目的地）是一行，包含可选的图标、标签，以及行末可选的后置内容；带 href 时它是链接。group（分组）也是一行，用来展开和折叠它里面的目的地和分组。section（分区）把目的地和分组归在一个可选的 title（Web 上为 headline） 之下，前面可以加一条可选的 divider；分区不能嵌套，分组里也不能放分区。header-button（第一个是菜单按钮）和 main-action 位于页眉。在 Web 上，它们是 <tanrei-navigation-drawer-item>、<tanrei-navigation-drawer-group> 和 <tanrei-navigation-drawer-section> 子元素，以及放在 header-button 和 main-action 插槽里的纯图标 <tanrei-button> 和一个 <tanrei-main-action-button>。待跟进的平台按各自的惯用方式接收目的地和分区：在 SwiftUI 上是 TanreiNavigationDrawerItem 和 TanreiNavigationDrawerSection 视图，在 Compose 上是同名的调用，在 Flutter 上是 children: 中的 TanreiNavigationDrawerDestination 和 TanreiNavigationDrawerSection 对象，在 React Native 上是 items 数组中的目的地条目和分区条目，其中分区靠它自己的 items 来区分。

选择属于抽屉，以目的地的值来表示，无论这个目的地位于何处。change 和 reselect 的工作方式与导航栏相同。Compose 没有抽屉级别的值：由你把当前项标记为 selected，它的 onClick 同时充当 change 和 reselect。Flutter 按索引选择，索引按阅读顺序跨各个分区连续计数。

带 href 的目的地是链接，而不是按钮。浏览器像跟随任何链接一样跟随它，抽屉不会因为按下而选中它：由到达的页面说明哪个目的地是当前的——把抽屉的 value 设为那个目的地的值；目的地没有值时，设为它原样书写的 href。对链接的普通激活仍会触发 change 和 reselect。它们带着链接的 href，并且可以取消，客户端路由就是这样接管导航的。目前只有 Web 提供链接目的地。

分组的行只负责展开和折叠分组，不选中任何东西。当一个分组本身也是一个地方时（例如网站中某个分区的概览页，或选中后会显示内容的文件夹），请给抽屉设置 selectableGroups，并给分组一个 value 或 href：这样它的行会像目的地的行一样选中它，而它的展开箭头成为单独的控件，负责展开和折叠。两者都没有的分组仍然只展开和折叠。同时作为目的地的分组目前在 Web 上提供。

density 可以是默认的 regular，也可以是 compact：32 高的行、16 的字形和更窄的图标列，供目的地很多、用指针操作的工具使用。紧凑密度目前在 Web 上提供。

filterable 会在行的上方画一个筛选输入框。用户键入的内容会把抽屉缩小到标签中含有它的那些行，包含这些行的分组在筛选期间临时展开；清空输入框，抽屉就恢复原样。filterValue 就是这段文本，用户键入时由抽屉设置，然后触发 filterChange；你也可以设置它，在重新绘制页面时把筛选还原。输入框的文字由你提供：filterLabel 是它的名称，filterPlaceholder、filterCountText（“匹配项：{count}”）、filterEmptyText 和 filterClearLabel 留空时取自你的产品文字。筛选目前在 Web 上提供。

抽屉有两种变体，一个产品通常两种都用：窗口足够宽时用标准，不够宽时用模态。

• 标准抽屉是一块布局区域，不是浮层。打开时它在内容旁边占据自己的宽度，关闭时不占宽度。它不绘制遮罩，也从不把焦点留在自己内部。
• 模态抽屉是供操作的浮层，而且是模态的。它带着遮罩从内容上方滑入，在关闭之前把焦点限制在自己之内，并在用户选择目的地之后自行关闭。

使用 responsive 时，抽屉会根据窗口的宽度自己做出这个选择（见下文“跟随窗口的宽度”）。

open 显示或隐藏任一变体。用户按下遮罩或 Escape、使用平台的返回操作，或把抽屉朝它所在的边缘拖动时，模态抽屉也会关闭，然后触发 close。在 Web 上，抽屉会像对话框一样自己把 open 设回 false。在其他平台上，由你根据关闭事件让它保持同步：Flutter 和 React Native 上是 onClose，SwiftUI 上是 isPresented 绑定，Compose 上是抽屉状态，它的 confirmValueChange 会收到每一次关闭。

<tanrei-button variant="text" id="menu" label="菜单"><span slot="icon">menu</span></tanrei-button>

<!-- 模态：shadow root 中的一个 <dialog>，用 showModal() 打开。标准抽屉是一个由 label 命名的 <nav>。 -->
<tanrei-navigation-drawer variant="modal" label="邮件" value="inbox">
  <tanrei-navigation-drawer-section headline="邮件">
    <tanrei-navigation-drawer-item value="inbox" label="收件箱" icon="inbox" trailing-text="24"></tanrei-navigation-drawer-item>
    <tanrei-navigation-drawer-item value="sent" label="已发送" icon="send"></tanrei-navigation-drawer-item>
  </tanrei-navigation-drawer-section>
  <tanrei-navigation-drawer-section headline="标签" divider>
    <tanrei-navigation-drawer-item value="work" label="工作" icon="label" trailing-text="新"></tanrei-navigation-drawer-item>
  </tanrei-navigation-drawer-section>
</tanrei-navigation-drawer>

<!-- 可收起：第一个页眉按钮是菜单按钮。抽屉自己响应它，并触发 expandedchange。 -->
<tanrei-navigation-drawer collapsible open label="工作区" value="home">
  <tanrei-button slot="header-button" variant="text" label="菜单"><span slot="icon">menu</span></tanrei-button>
  <tanrei-main-action-button slot="main-action" label="新建项目"><span slot="icon">add</span></tanrei-main-action-button>
  <span slot="header">工作区</span>
  <tanrei-navigation-drawer-item value="home" label="首页" icon="home"></tanrei-navigation-drawer-item>
  <!-- 分组：它的行负责展开和折叠它，并触发 toggle。 -->
  <tanrei-navigation-drawer-group label="项目" icon="folder">
    <tanrei-navigation-drawer-item value="atlas" label="Atlas" icon="deployed_code"></tanrei-navigation-drawer-item>
  </tanrei-navigation-drawer-group>
  <!-- 图标上的徽标，两种形态下都显示；后置内容只在展开时显示。 -->
  <tanrei-navigation-drawer-item value="inbox" label="收件箱" icon="inbox" badge badge-count="3" badge-label="3 封未读"></tanrei-navigation-drawer-item>
  <!-- 在新标签页中打开的链接：展开的行以 open_in_new 结尾，target-label 在它的名称之后朗读。 -->
  <tanrei-navigation-drawer-item label="帮助中心" icon="help" href="/help" target="new" target-label="在新标签页中打开"></tanrei-navigation-drawer-item>
</tanrei-navigation-drawer>

<!-- 网站的侧边栏：每个目的地都是链接，每个页面把自己的地址作为 value 交给抽屉。
     responsive 让窗口的宽度决定呈现方式；reveal-selected 展开包含当前页面的分组。 -->
<tanrei-navigation-drawer id="sidebar" label="文档" value="/components/tabs/" reveal-selected responsive open>
  <tanrei-navigation-drawer-item label="开始使用" href="/getting-started/"></tanrei-navigation-drawer-item>
  <tanrei-navigation-drawer-group label="组件">
    <tanrei-navigation-drawer-item label="按钮" href="/components/button/"></tanrei-navigation-drawer-item>
    <tanrei-navigation-drawer-item label="标签页" href="/components/tabs/" trailing-text="新"></tanrei-navigation-drawer-item>
  </tanrei-navigation-drawer-group>
</tanrei-navigation-drawer>

<!-- 可以筛选行的侧边栏：在页面的任何地方按“/”都会来到输入框。文字由你提供。 -->
<tanrei-navigation-drawer id="filtered" label="文档" value="/components/tabs/" reveal-selected open
  filterable filter-label="筛选导航" filter-placeholder="筛选"
  filter-count-text="匹配项：{count}" filter-empty-text="无匹配项" filter-clear-label="清除">
  <tanrei-navigation-drawer-group label="组件">
    <tanrei-navigation-drawer-item label="按钮" href="/components/button/"></tanrei-navigation-drawer-item>
    <tanrei-navigation-drawer-item label="标签页" href="/components/tabs/"></tanrei-navigation-drawer-item>
  </tanrei-navigation-drawer-group>
</tanrei-navigation-drawer>

<script type="module">
  import '@tanrei/web/components/navigation-drawer';
  import '@tanrei/web/components/button';
  const drawer = document.querySelector('tanrei-navigation-drawer');
  document.querySelector('#menu').addEventListener('click', () => (drawer.open = true));
  // 抽屉先设置自己的 value，再触发 change。随后模态抽屉会自行关闭。
  drawer.addEventListener('change', (e) => showFolder(e.detail.value));
  // 模态抽屉每次关闭之后都会触发 close：遮罩、Escape、拖动或选择目的地。
  drawer.addEventListener('close', onDrawerClosed);
  // 此时可收起的抽屉已经变成了菜单按钮所要求的形态。
  document.querySelector('[collapsible]').addEventListener('expandedchange', (e) => savePreference(e.detail.expanded));

  const sidebar = document.querySelector('#sidebar');
  // 链接的 change 可以取消，并带有它的 href：客户端路由在这里接管导航。
  // 由独立文档组成的网站什么都不用监听，由下一个页面给出 value。
  sidebar.addEventListener('change', (e) => {
    e.preventDefault();
    router.navigate(e.detail.href);
  });
  // 响应式抽屉会说明窗口宽度让它变成了什么：standard、column 或 modal。
  sidebar.addEventListener('presentationchange', (e) => showMenuButton(e.detail.presentation === 'modal'));

  // 保存用户留下的筛选文本，留给下一个页面（抽屉自己不保存任何东西）。
  const filtered = document.querySelector('#filtered');
  filtered.addEventListener('filterchange', (e) => sessionStorage.setItem('filter', e.detail.value));
  filtered.filterValue = sessionStorage.getItem('filter') ?? '';
</script>

import {
  NavigationDrawer,
  NavigationDrawerGroup,
  NavigationDrawerItem,
  NavigationDrawerSection,
} from '@tanrei/react';

// 模态抽屉会自行关闭（onClose）：在那里让 open 保持同步。
<NavigationDrawer
  variant="modal"
  label="邮件"
  open={open}
  value={folder}
  onChange={(e) => setFolder(e.detail.value)}
  onClose={() => setOpen(false)}
>
  <NavigationDrawerSection headline="邮件">
    <NavigationDrawerItem value="inbox" label="收件箱" icon="inbox" trailingText="24" />
    <NavigationDrawerItem value="sent" label="已发送" icon="send" />
  </NavigationDrawerSection>
</NavigationDrawer>

// 网站的侧边栏：目的地是链接，由页面说明哪一个是当前的。
<NavigationDrawer
  label="文档"
  open
  responsive
  revealSelected
  value={pathname}
  onChange={(e) => {
    e.preventDefault(); // 客户端路由接管导航
    navigate(e.detail.href);
  }}
  onPresentationChange={(e) => setPresentation(e.detail.presentation)}
>
  <NavigationDrawerGroup label="组件">
    <NavigationDrawerItem label="按钮" href="/components/button/" />
    <NavigationDrawerItem label="标签页" href="/components/tabs/" trailingText="新" />
  </NavigationDrawerGroup>
  <NavigationDrawerItem label="源代码" href="https://example.com/tanrei" target="new" targetLabel="在新标签页中打开" />
</NavigationDrawer>

// 可以筛选行的侧边栏：用户键入时，抽屉自己设置 filterValue。
<NavigationDrawer
  label="文档"
  open
  filterable
  filterLabel="筛选导航"
  filterPlaceholder="筛选"
  filterCountText="匹配项：{count}"
  filterEmptyText="无匹配项"
  filterClearLabel="清除"
  filterValue={filter}
  onFilterChange={(e) => setFilter(e.detail.value)}
>
  <NavigationDrawerGroup label="组件">
    <NavigationDrawerItem label="按钮" href="/components/button/" />
    <NavigationDrawerItem label="标签页" href="/components/tabs/" />
  </NavigationDrawerGroup>
</NavigationDrawer>

import Tanrei

// 标准：位于内容旁边。isPresented 显示和隐藏它；选择目的地时会写入 selection。
HStack(spacing: 0) {
    TanreiNavigationDrawer(variant: .standard, isPresented: $sidebarShown, selection: $folder,
                           accessibilityLabel: "邮件", onReselect: { _ in scrollToTop() }) {
        TanreiNavigationDrawerSection("邮件") {
            TanreiNavigationDrawerItem("收件箱", icon: "inbox", value: "inbox", badge: "24")
            TanreiNavigationDrawerItem("已发送", icon: "send", value: "sent")
        }
        TanreiNavigationDrawerSection("标签", divider: true) {
            TanreiNavigationDrawerItem("工作", icon: "label", value: "work")
        }
    } header: {
        Text("邮件")
    }
    FolderView(folder)
}

// 模态：加在它所覆盖的内容上的修饰符。关闭时会向绑定写入 false。
FolderView(folder)
    .tanreiNavigationDrawer(isPresented: $menuShown, selection: $folder, accessibilityLabel: "邮件") { … }

import io.github.chnotchy.tanrei.components.TanreiNavigationDrawer
import io.github.chnotchy.tanrei.components.TanreiNavigationDrawerItem
import io.github.chnotchy.tanrei.components.TanreiNavigationDrawerSection
import io.github.chnotchy.tanrei.components.rememberTanreiDrawerState
import io.github.chnotchy.tanrei.tokens.TanreiNavigationDrawerVariant

// 抽屉包住整个屏幕。drawerState 对应规格中的 open；confirmValueChange 会收到规格中的 close。
val drawerState = rememberTanreiDrawerState()
TanreiNavigationDrawer(
    variant = if (wide) TanreiNavigationDrawerVariant.Standard else TanreiNavigationDrawerVariant.Modal,
    drawerState = drawerState,
    contentDescription = "邮件",
    drawerContent = {
        // 由你把当前项标记为 selected。模态抽屉在 onClick 之后自行关闭。
        TanreiNavigationDrawerSection(heading = "邮件") {
            TanreiNavigationDrawerItem(selected = folder == "inbox", onClick = { folder = "inbox" }, label = "收件箱", icon = "inbox", badge = "24")
            TanreiNavigationDrawerItem(selected = folder == "sent", onClick = { folder = "sent" }, label = "已发送", icon = "send")
        }
        TanreiNavigationDrawerSection(heading = "标签", divider = true) {
            TanreiNavigationDrawerItem(selected = folder == "work", onClick = { folder = "work" }, label = "工作", icon = "label", badge = "新")
        }
    },
) {
    FolderScreen(folder, onMenu = { drawerState.open() })
}

import 'package:tanrei/tanrei.dart';

// 标准：一块布局区域，放在 Row 的最前面，位于内容旁边。
Row(
  children: <Widget>[
    TanreiNavigationDrawer(
      open: sidebarOpen,
      selectedIndex: current, // 按阅读顺序跨各个分区连续计数
      onDestinationSelected: (int index) => setState(() => current = index), // change 和 reselect
      semanticLabel: '邮件',
      children: const <TanreiNavigationDrawerChild>[
        TanreiNavigationDrawerSection(
          heading: '邮件',
          children: <TanreiNavigationDrawerChild>[
            TanreiNavigationDrawerDestination(icon: 'inbox', label: '收件箱', badge: '24'),
            TanreiNavigationDrawerDestination(icon: 'send', label: '已发送'),
          ],
        ),
        TanreiNavigationDrawerSection(
          heading: '标签',
          divider: true,
          children: <TanreiNavigationDrawerChild>[
            TanreiNavigationDrawerDestination(icon: 'label', label: '工作', badge: '新'),
          ],
        ),
      ],
    ),
    const Expanded(child: Page()),
  ],
),

// 模态：填满窗口的 Stack 的最后一个子项。在 onClose 中把 open 设为 false。
Stack(
  children: <Widget>[
    const Positioned.fill(child: Page()),
    TanreiNavigationDrawer(
      variant: TanreiNavigationDrawerVariant.modal,
      open: menuOpen,
      onClose: () => setState(() => menuOpen = false),
      selectedIndex: current,
      onDestinationSelected: (int index) => setState(() => current = index),
      semanticLabel: '邮件',
      children: destinations,
    ),
  ],
),

import { useState } from 'react';
import { NavigationDrawer } from '@tanrei/react-native';

const [open, setOpen] = useState(false);
const [folder, setFolder] = useState('inbox');

// 受控：在 onClose 中把 open 设为 false。模态抽屉在一个透明的 Modal 中呈现。
<NavigationDrawer
  variant={wide ? 'standard' : 'modal'}
  open={open}
  onClose={() => setOpen(false)}
  accessibilityLabel="邮件"
  value={folder}
  onValueChange={setFolder}
  items={[
    { heading: '邮件', items: [
      { value: 'inbox', label: '收件箱', icon: 'inbox', badge: '24' },
      { value: 'sent', label: '已发送', icon: 'send' },
    ] },
    { heading: '标签', divider: true, items: [{ value: 'work', label: '工作', icon: 'label', badge: '新' }] },
  ]}
/>

规格

link

不带图标、也不属于任何分区的目的地

构成

构成

绘制在 Web 包所绘的测试样例 standard 之上。

部件	说明
1 container	The panel at the start edge, the full height of its parent: expanded, the full drawer; collapsed, the icon column. Standard: part of the layout. Modal: above the content, its end corners rounded. Its color reaches under the system insets at its start, top and bottom.
2 outline	The end edge of a standard drawer, and of a collapsible modal drawer's column, which sets it apart from the content beside it.
3 scrim · 可选	The modal layer's scrim (MDL-1): it dims everything behind a modal drawer; a press on it closes the drawer.
4 header · 可选	The top of the drawer, which stays in place while the items scroll: the header buttons (a menu button first) stacked in the icon column, the header slot's content beside the first of them while expanded, and the main action below them.
5 header-button · 可选	An icon-only Button in the header (an item of the header-button kind), on the icon column. While the drawer is collapsible, the first one is its menu button: it widens and narrows the drawer, and carries its expanded state. It stays the Button it is in both forms, with the Button's own size and shape (a circle in the default system).
6 main-action · 可选	The screen's main action (an item of the main-action kind), below the header buttons: its icon alone while the drawer is collapsed, its icon and label while expanded, its glyph in the same place in both.
7 filter	The filter field, while filterable is true and the drawer is expanded: a Text input of type search below the header, with the search glyph at its start and, at its end, the key hint while it is empty and does not have focus, or a clear button while it holds text. It stays in place while the items scroll.
8 filter.status	The line at the top of the results while a filter is applied: how many rows match, in the product's filterCountText, unless filterCountHidden; or, where no row matches, the product's filterEmptyText. Takes no focus and no state.
9 section · 可选	A group of items (an item of the section kind) under an optional heading: its divider, its heading and its items, in that order. Not interactive, and never collapsed away.
10 heading · 可选	A section's heading: text that names the items under it. Not interactive. Collapsed, its row keeps its height and its text is not drawn.
11 divider · 可选	A divider component the drawer draws before a section whose divider is true, across the drawer's inner width in either form.
12 group · 可选	An expandable group of destinations (an item of the group kind): a row that opens and closes, and the destinations and groups it holds, whose rows start further in than its own while it is open. Collapsed, one cell.
13 group.chevron · 可选	The icon set's expand_more at the end of a group's row, turned half a turn while the group is open. Hidden from assistive technology.
14 item	One destination (an item of the destination kind), or a group's row: a cell across the drawer's width, which is its hit area and has the same height and place in both forms. A destination is a button, or a link while it has an href; the two are drawn alike.
15 item.container	The destination's box: a row with the corners of a menu's item, never a capsule in the default system. Expanded, the row across the drawer's inner width, a nested one starting further in; collapsed, the same row with its label gone: the box around its icon, as tall as before and with the same corners. It carries hover, focus and press, and is filled as the active indicator while the destination is selected; the fill changes in place and never grows in width.
16 item.icon-indicator	The box behind the icon alone, the icon centered in it. The default system leaves it transparent; a system that marks a collapsed destination behind its glyph only (Material's) fills it there and leaves the collapsed item container clear.
17 item.icon · 可选	The destination's glyph (its icon), centered on the icon column in both forms. Outlined when unselected, filled when selected.
18 item.label	The destination's name: beside the icon while expanded (its label, wrapping). Collapsed, no label is drawn unless collapsedLabels asks for the short label under the icon, on one line. Its label is always its accessible name.
19 item.trailing · 可选	The end of an expanded row: the trailing slot's content (a glyph such as open_in_new) or else the destination's trailing text (a count such as "24", a word such as "New"), quieter than the label. Not interactive; part of the destination's description.
20 item.badge · 可选	A Tanrei badge anchored to the icon in both forms, drawn from the destination's badge, badgeCount and badgeLabel: a dot or a count (the badge component).
21 focus-ring	Gap-then-ring indicator around the item container, shown for keyboard focus.

尺寸

尺寸

长度	令牌	值（px）
container width	tanrei.comp.navigation-drawer.container.width	240
container padding-inline	tanrei.comp.navigation-drawer.container.padding-inline	12

绘制在 Web 包所绘的测试样例 standard 之上。

属性

属性	类型	默认值	说明
variant	standard | modal	"standard"	Standard sits beside the content and takes its width in the layout; modal lays itself over the content with a scrim and holds focus until it closes. One product uses both: standard where the window is wide enough, modal where it is not. A design system may add values. Ignored while responsive is true, when the window's width chooses.
open	boolean	false	Whether the drawer is shown: for a standard drawer, whether it takes its place in the layout (in the form collapsible and expanded choose); for a modal one, whether it is presented over the content (while collapsible, its collapsed column stays in the layout when it is not). While responsive is true it only says whether the drawer is shown over the content in the presentations that are modal, and every change of presentation sets it back to false.
collapsible	boolean	false	Gives the drawer a collapsed form, the icon column. A standard drawer then shows the form expanded chooses; a modal one shows its column in the layout while closed and widens over the content while open. While false the drawer is always expanded and lays its rows out for that form alone.
expanded	boolean	true	The form of a collapsible standard drawer: true for the full drawer, false for the icon column. Ignored while collapsible is false, and by a modal drawer, whose form follows open. It is the user's choice: a change of the window's width never writes it, so a responsive drawer returns to it when the window is wide again.
collapsedLabels	always | selected | never	"never"	Which cells draw their short label under the icon while the drawer is collapsed: none of them (the default: a collapsed drawer is the expanded one with its labels gone), only the selected one's, or all of them, for a product or a design system whose collapsed column is labelled. A label that is not drawn is still the destination's accessible name.
density	regular | compact	"regular"	How much room a row takes, in a tree view's words. regular (a 48 row with a 24 glyph in the default system, a menu item's row) is the drawer of a product used by touch as well as by pointer. compact (a 32 row with a 16 glyph, a tree view's compact row) is for a tool used with a pointer whose drawer lists many places. It sets the rows, the section headings, the paddings, the glyphs, the nesting indent and the collapsed column alike — never the gap between the icon and the label — so both forms follow it; for touch a row is never lower than the touch target in either. A design system may add values.
chevron	start | end | none	"start"	Where a group's chevron is drawn, as the tree view's: start, before its icon (every row then keeps the chevron's room, so the icons of a level stand in one column); end, at the very end of the row, after its trailing content; none, no chevron — the arrow keys still open and close a group, and with a pointer a press on the group's icon does, the icon showing openIcon while the group is open (NVD-68). A collapsible drawer draws start as end, so that every icon keeps its point in both forms.
guides	none | shown | hover	"none"	Whether an open group draws a line down beside what it holds, as the tree view's: none; shown, always; hover, while the pointer is over the drawer or focus is in it, fading in and out (NVD-73).
indent	number	null	How much further a level's rows begin than their group's, as the tree view's: null (auto, the default) lines a row's first part (its chevron, icon or label) up with where its group's label begins, and steps by comp.navigation-drawer.item.nest-indent where the group has neither a start chevron nor an icon; a number steps by that many units of the layout at every level, 0 none (NVD-69). On the web the attribute takes auto or a number.
highlight	indented | full	"indented"	How far the selected fill and the hover and press layers of a nested row reach, as the tree view's: indented, from where the row begins (its indent) to the end; full, across the drawer's whole inner width at every level (NVD-70).
iconSpace	auto | always | never	"auto"	Whether a row without an icon keeps the icon's room, as the tree view's: auto, where another row of its level has an icon, so that the labels of a level line up; always; never (NVD-71).
expandable	boolean	true	Whether groups open and close at all, as the tree view's. While false every group is shown open, draws no chevron, has no toggle and is not exposed as expandable: its row names the list of its items (NVD-72). It is not collapsible, which narrows the drawer itself.
labelWrap	boolean	false	Lets a row's label wrap onto more lines, as the tree view's. While false (the default) a label is one line, cut with an ellipsis, and its full text is shown in a tooltip on hover and keyboard focus wherever it is cut (NVD-75).
supportingWrap	boolean	false	Lets a row's supporting text wrap, as labelWrap lets its label.
responsive	boolean	false	Lets the window's width choose the drawer's presentation (NVD-53): beside the content where the window is wide, its collapsed column beside the content where it is narrower (while collapsible), and over the content alone where it is narrow. While true the drawer ignores variant, shows itself in a wide window whatever open says, and closes whenever the width changes its presentation.
value	string	""	The value of the selected destination (selection is the drawer's, by a destination's value), wherever it stands, in a section, in a group or neither. Empty selects none. The selected destination is the place the product is showing, and it is exposed as the current page: in a product whose pages are separate documents nothing is selected by a press, and each page sets value to the destination that is that page (a link's href stands as its value while it has none, NVD-59).
revealSelected	boolean	false	Opens the groups that hold the selected destination when the drawer first appears and whenever value changes, so that the place the product is showing is drawn and not only the closed group that holds it (NVD-58). A site's sidebar sets it; while false a closed group stays closed and its row shows the selection (NVD-47). The user may still close such a group afterwards.
selectableGroups	boolean	false	Lets a group be a destination as well as a row that opens and closes: a setting of the product's, off by default. While true a group that has a value or an href is a place of its own (NVD-66) — a section's overview page in a site, a folder that is shown when it is chosen — which the drawer's value selects, whose activation emits change or reselect and which an href makes a link; its chevron becomes a control of its own that opens and closes it, and the rest of its row chooses it (NVD-67). A group without either still only opens and closes. While false every group only opens and closes, whatever value or href it has.
scrollOffset	number	0	How far the drawer's items are scrolled from their start, in the units of the layout. The product may set it, before the drawer first appears included, and the drawer scrolls there at once; reading it gives the present distance. It is the handle by which a product keeps a long drawer where the user left it from one page to the next (NVD-61, NVD-62); the drawer stores nothing itself.
stickyParents	boolean	false	Keeps the rows of the open groups that the rows at the top of the drawer belong to pinned there while their items scroll under them, as the tree view's (on by default there, off here) and as VS Code's sticky scroll (NVD-77). Not applied while the drawer is collapsed.
stickyMax	number	2	At most how many group rows are pinned, one per level, the innermost winning, as VS Code keeps its innermost scopes (NVD-77).
loadingLabel	string	""	What the loading row under a group that is fetching its items says ("Loading…"), and its accessible name, as the tree view's: Tanrei ships no words of its own.
filterable	boolean	false	Draws a filter field above the items: what a person types there narrows the drawer to the rows whose label holds it, opening for the time being the groups that hold them, and the drawer comes back as it was when the field is emptied. Off by default: a product that filters on a server, ranks, or matches in another way leaves it off and gives the drawer the items that match, as before.
filterValue	string	""	The filter text: what the filter field holds. The drawer sets it when the person types and emits filterChange; the product may set it too (a filter given back when a page is rendered again). Empty, or only white space, applies no filter.
filterLabel	string	""	Names the filter field for assistive technology, in the product's language: what it narrows ("Filter navigation", "Filter files"). Required while filterable is true. It names this one field, so it is not one of the product's words set once.
filterPlaceholder	string	""	The hint the filter field shows while it is empty ("Filter"), in the product's language. Never a replacement for filterLabel. The product's: Tanrei has no words for it. Empty reads the product's words; with neither, the field shows no hint.
filterEmptyText	string	""	What the drawer draws at the top of the results and says while a filter is applied and no row matches ("No matches"), in the product's language. The product's: Tanrei has no words for it. Empty reads the product's words; with neither, nothing is drawn in its place and it is reported.
filterCountText	string	""	What the drawer draws quietly at the top of the results (NVD-90) and says to assistive technology once the result of a filter has settled (NVD-91), with {count} where the number of rows that match goes ("Matches: {count}"), in the product's language. filterCountHidden leaves it undrawn and still said. The product's: Tanrei has no words for it. Empty reads the product's words; with neither, no count is drawn or said and it is reported.
filterCountHidden	boolean	false	Does not draw the count at the top of the results (NVD-90); it is still said to assistive technology (NVD-91). The words for a filter that matches nothing are drawn either way. A drawer whose results are counted elsewhere on the screen, or where the rows left say enough, turns it on.
filterClearLabel	string	""	The accessible name of the filter field's clear button ("Clear"), in the product's language. Required while the field can hold text. Empty reads the product's words.
filterShortcut	strings	/	The key that moves focus to the filter field from anywhere in the window, in the keyboard shortcut component's key names, one chord (["/"], the default). While filterable is true the drawer draws it as a hint in the empty field, exposes it as the field's keyboard shortcut and answers it itself while it is shown (NVD-87); an app shell answers it for a drawer it has closed over its content (APS-33). Pressed while focus is in a field, or with a key held down, it does nothing. An empty list draws no hint and binds nothing: a product that already gives "/" another meaning sets its own chord or none.
label	string	""	Names the drawer for assistive technology ("Mail"): the navigation landmark on the web, and the modal drawer as a whole on every platform.

插槽

插槽	说明
header	Content the product puts in the header beside the first header button (a title, an account switcher); the drawer does not restyle it. Drawn only while the drawer is expanded; collapsed, its row keeps its height.

事件

事件	说明
change	The user activated a destination that is not the selected one, or a group that is one (NVD-66); carries its value and, for a link, its href. For a link it comes before the link is followed, only for an activation that follows it in place (NVD-60), and a product that cancels it follows the link itself.
reselect	The user activated the destination that is already selected; carries its value and, for a link, its href, as change does.
close	A modal drawer closed, or asks its controlled owner to close it: by the scrim, Escape, the platform's back action, a drag toward its edge, its menu button, or after a destination was activated.
expandedChange	The user asked a collapsible drawer for its other form, with its menu button or a group's cell in the collapsed drawer; carries true to expand and false to collapse. For a collapsible modal drawer, true asks it to open.
presentationChange	A responsive drawer decided its presentation for the first time, or the window's width changed it; carries standard (beside the content), column (its collapsed column beside the content, widening over it) or modal (over the content alone). A product shows its own menu button while the presentation is modal.
filterChange	The person changed the filter text — typing, deleting, pasting, dictating, an input method committing text, the clear button or Escape; carries the new text. Not emitted when the product sets filterValue. It is the product's cue to keep the text where it keeps a page's state.

条目

该组件重复排列的条目种类。测试样例按顺序列出条目；各平台以各自的惯用方式为每个种类命名。

destination

One destination of the drawer: an icon, a label, optional trailing content at the end of its row and an optional badge on its icon. Collapsed, its icon alone. With an href it is a link to that address and not a button.

属性	类型	默认值	说明
value	string	""	What identifies the destination. The drawer's value selects the destination whose value equals it; change and reselect carry it. Unique within the drawer. Empty on a link, its href stands as its value.
href	string	""	The address the destination leads to. Not empty, the destination is a link and not a button (NVD-59): it is followed as the platform follows a link, and the drawer does not select it by itself (NVD-60). Empty, the destination is a button and the product moves on change. As the Button's href (a control with a destination is a link).
target	same | new	"same"	Where a link opens, as the Button's target. same: where the person is. new: a new context — a new tab or window on the web, outside the current screen elsewhere — which the expanded row marks with the glyph open_in_new at its end unless the product put trailing content there, and says through targetLabel (NVD-63). A link that opens elsewhere is never selected by a press (NVD-60). Ignored without href.
targetLabel	string	""	What assistive technology reads after the link's name while target is new ("opens in a new tab"), as the Button's targetLabel: Tanrei ships no words of its own. Required while target is new; ignored otherwise.
label	string	""	Its name, drawn beside the icon while the drawer is expanded and always its accessible name. Required.
supportingText	string	""	A few words about the row ("3 new", "shared with the team"), under its label or after it (supportingPosition), quieter than the label, read as its description after its name. Empty draws none (NVD-74).
supportingPosition	below | inline	"below"	Where the supporting text stands, as the tree view's: below, on a line of its own under the label; inline, after the label on its line (NVD-74).
shortLabel	string	""	What the collapsed drawer draws under the icon, on one line ("Files" for "My files"), where collapsedLabels asks for labels. Empty draws the label, truncated if it does not fit. It should be a part of the label, which stays the accessible name.
icon	string	""	The name of its glyph in the system's icon set, drawn in the destination's own icon style: outlined while unselected, filled while selected. Empty draws no icon; give every destination of a drawer an icon, or none, and every top-level one an icon in a collapsible drawer.
disabled	boolean	false	Makes it unavailable. It keeps its place, draws its disabled look, cannot be activated and leaves the focus order.
trailingText	string	""	Short text at the end of the expanded row, a count or a word ("24", "New"), quieter than the label. Empty draws none; the trailing slot's content, when there is any, is drawn instead.
badge	boolean	false	Draws a Tanrei badge (the badge component) on the icon, in both forms, from badgeCount and badgeLabel.
badgeCount	number	null	The badge's count, as the badge component's count: null draws the dot, 0 draws nothing, above 0 the number (above 999 as 999+). Ignored while badge is false.
badgeLabel	string	""	The badge's label, as the badge component's: what assistive technology reads after the destination's name and state ("3 unread"). A dot needs one. Ignored while badge is false.

插槽	说明
trailing	Content at the end of the expanded row, in place of trailingText: a glyph (open_in_new for a destination that opens elsewhere), a short text. Not interactive. A count belongs in trailingText, and a badge on the icon (badge): a Badge needs an anchor, and the end of the row has none. A fixture item's content is a glyph drawn here.

规格	Web	SwiftUI	Jetpack Compose	Flutter	React Native
条目	tanrei-navigation-drawer-item	TanreiNavigationDrawerItem	TanreiNavigationDrawerItem	TanreiNavigationDrawerDestination	NavigationDrawerDestination
value · 属性	value	value	selected	children	value
href · 属性	href	destination	href	href	href
target · 属性	target	target	target	target	target
targetLabel · 属性	targetLabel	targetLabel	targetLabel	targetSemanticLabel	targetLabel
label · 属性	label	title	label	label	label
supportingText · 属性	supportingText	supportingText	supportingText	supportingText	supportingText
supportingPosition · 属性	supportingPosition	supportingPosition	supportingPosition	supportingPosition	supportingPosition
shortLabel · 属性	shortLabel	shortTitle	shortLabel	shortLabel	shortLabel
icon · 属性	icon	icon	icon	icon	icon
disabled · 属性	disabled	disabled	enabled	enabled	disabled
trailingText · 属性	trailingText	trailingText	trailingText	trailingText	trailingText
badge · 属性	badge	badge	badge	badge	badge
badgeCount · 属性	badgeCount	count	count	count	count
badgeLabel · 属性	badgeLabel	label	contentDescription	semanticLabel	label
备注	icon is the glyph's name; none, no icon. short-label, trailing-text, badge-count and badge-label are attributes; the trailing slot is trailing. badge is the boolean of the icon badge; a destination's trailing text is trailing-text. href makes the destination a link: the cell is an <a href> in the item's shadow root. target is the target attribute with the values same and new (the HTML spellings _self and _blank are read as those two), targetLabel the target-label attribute, and rel (to which new adds noopener) and download are web-only and forwarded to the anchor, all as <tanrei-button>'s. Space is not handled on it. With no value attribute the item's value property reads its href attribute as written (not the resolved URL).	TanreiNavigationDrawerItem(_ title: String, shortTitle: String = "", icon: String? = nil, value: Value, trailingText: String = "", badge: TanreiNavigationBadge? = nil) { trailing }, with the bar's TanreiNavigationBadge(count:, label:). disabled follows .disabled(_:). destination: URL? = nil makes it a SwiftUI Link (the link trait), opened by the environment's openURL after the selection callback, which an app that routes addresses itself answers with its own OpenURLAction; target: TanreiLinkTarget = .same and targetLabel (the accessibility hint), as the Button's.	TanreiNavigationDrawerItem(selected, onClick, label, shortLabel = "", icon = null, trailingText = "", badge = null, enabled = true, trailing = null); icon is the glyph's name, null for none; badge is the bar's TanreiNavigationBadge(count, contentDescription); trailing is a composable slot. enabled is the inverse flag. href: String? = null makes it a link: opened through LocalUriHandler.current after onClick (an app that routes addresses itself provides its own UriHandler); Compose has no link role for a clickable element, so the node drops Role.Button and carries no role; target: TanreiLinkTarget = TanreiLinkTarget.Same, and targetLabel is appended to the state description, as the Button's.	TanreiNavigationDrawerDestination(icon:, label:, shortLabel: '', trailingText: '', trailing: null, badge: null, enabled: true); icon is the glyph's name, null for none; badge: TanreiNavigationBadge(count:, semanticLabel:), as the bar's; trailing is a widget. Its value is its index among the destinations of children. href: Uri? = null makes it a link (Semantics(link: true) with the address as its linkUrl), opened by the nearest TanreiLinkOpener after onDestinationSelected; target is a TanreiLinkTarget and targetSemanticLabel the semantics hint, as the Button's.	An entry of items: { value, label, shortLabel?, icon?, trailingText?, trailing?, badge?: { count?, label? }, disabled? }, where icon is the glyph's name and trailing a React node; the badge has the navigation bar's shape. href?: string makes it a link (accessibilityRole="link"); onValueChange receives the value and the href, and Linking.openURL(href) follows it unless the product handles it; target is "same" | "new" and targetLabel the accessibilityHint, as the Button's.

group · 分组 — 包含条目

A group of destinations under a row that opens and closes it: an icon, a label and a chevron. It holds destinations and groups, not sections, and their rows start further in than its own. While the drawer's selectableGroups is true and it has a value or an href, it is a destination as well (NVD-66): its row chooses it and its chevron opens and closes it.

属性	类型	默认值	说明
label	string	""	Its name, drawn in its row and used as the accessible name of its row and of the list of its items. Required.
shortLabel	string	""	What the collapsed drawer draws under its icon where collapsedLabels asks for labels; empty draws the label, as a destination's.
icon	string	""	The name of its glyph in the system's icon set, drawn as a destination's icon.
openIcon	string	""	A second glyph, drawn in the icon's place while the group is open (folder_open beside folder), as the tree view's. Ignored while icon is empty.
supportingText	string	""	A few words about the group ("3 new", "shared with the team"), under its label or after it (supportingPosition), quieter than the label, read as its description after its name. Empty draws none (NVD-74).
supportingPosition	below | inline	"below"	Where the supporting text stands, as the tree view's: below, on a line of its own under the label; inline, after the label on its line (NVD-74).
trailingText	string	""	Short text at the end of the group's expanded row (a count), before an end chevron, as a destination's; the trailing slot's content, when there is any, is drawn instead.
disabled	boolean	false	Makes its row unavailable: it keeps its place and its open state, draws its disabled look, cannot be toggled and leaves the focus order. Its items keep their own disabled.
open	boolean	false	Whether its items are shown under its row while the drawer is expanded.
loading	boolean	false	Says that the product is fetching the group's items: while the group is open a loading row is drawn under it, after any items it already holds, and the list of its items is exposed as busy (NVD-76).
value	string	""	What identifies the group as a destination, read only while the drawer's selectableGroups is true (NVD-66): the drawer's value selects the group whose value equals it, as it selects a destination, and change and reselect carry it. Unique among the drawer's destinations and groups. Empty on a link, its href stands as its value; empty with no href, the group is not a destination and only opens and closes.
href	string	""	The address the group leads to as a destination, read only while the drawer's selectableGroups is true: not empty, its row is a link and not a button (NVD-59, NVD-60), opened where the person is. Ignored while selectableGroups is false.

插槽	说明
trailing	Content at the end of the group's expanded row, before an end chevron, in place of trailingText: a glyph of the icon set, as a destination's trailing slot. Not interactive. A count belongs in trailingText.

事件	说明
toggle	The user opened or closed the group from its row, or from its cell in the collapsed drawer, or the drawer opened it to show the selected destination (NVD-58); carries its new open state.

规格	Web	SwiftUI	Jetpack Compose	Flutter	React Native
条目	tanrei-navigation-drawer-group	TanreiNavigationDrawerGroup	TanreiNavigationDrawerGroup	TanreiNavigationDrawerGroup	NavigationDrawerGroup
label · 属性	label	title	label	label	label
shortLabel · 属性	shortLabel	shortTitle	shortLabel	shortLabel	shortLabel
icon · 属性	icon	icon	icon	icon	icon
openIcon · 属性	openIcon	openIcon	openIcon	openIcon	openIcon
supportingText · 属性	supportingText	supportingText	supportingText	supportingText	supportingText
supportingPosition · 属性	supportingPosition	supportingPosition	supportingPosition	supportingPosition	supportingPosition
trailingText · 属性	trailingText	trailingText	trailingText	trailingText	trailingText
disabled · 属性	disabled	disabled	enabled	enabled	disabled
open · 属性	open	isExpanded	expanded	expanded	open
loading · 属性	loading	loading	loading	loading	loading
value · 属性	value	value	selected	value	value
href · 属性	href	destination	href	href	href
toggle · 事件	toggle	isExpanded	onExpandedChange	onExpansionChanged	onToggle
备注	Holds <tanrei-navigation-drawer-item> and <tanrei-navigation-drawer-group> children. Its row is a <button aria-expanded aria-controls> and its items a nested list labelled by it; open is reflected. toggle bubbles, with detail.open; the drawer's own expandedchange is a different event. While the drawer's selectable-groups is set and the group has a value or an href, its row is the destination — an <a href> or a <button> with aria-current="page" while selected — and its chevron a second <button aria-expanded aria-controls> after it, named by the group's label; a group without either keeps the one row button. The group's value property reads its href attribute while it has no value, as an item's does.	TanreiNavigationDrawerGroup(_ title: String, shortTitle: String = "", icon: String? = nil, isExpanded: Binding<Bool>) { items }, as SwiftUI's DisclosureGroup binds its state; toggling writes the binding. disabled follows .disabled(_:).	TanreiNavigationDrawerGroup(label, expanded, onExpandedChange, shortLabel = "", icon = null, enabled = true) { … }; the row has Modifier.semantics { expand() / collapse() } and the expanded state. enabled is the inverse flag.	TanreiNavigationDrawerGroup(label:, icon:, shortLabel: '', expanded:, onExpansionChanged:, enabled: true, children: [...]), controlled, with ExpansionTile's callback name; its row carries Semantics(expanded:).	An entry { label, shortLabel?, icon?, disabled?, open, onToggle, groupItems: (NavigationDrawerDestination | NavigationDrawerGroup)[] }; its groupItems array tells it from a section's items.

section · 分组 — 包含条目

A group of destinations and groups under an optional heading, with an optional divider before it. It is not interactive and does not nest.

属性	类型	默认值	说明
title	string	""	The text that names the items under it, exposed as a heading. Empty draws no heading row.
divider	boolean	false	Draws a divider (the divider component) before the section, to set it apart from what is above it.

规格	Web	SwiftUI	Jetpack Compose	Flutter	React Native
条目	tanrei-navigation-drawer-section	TanreiNavigationDrawerSection	TanreiNavigationDrawerSection	TanreiNavigationDrawerSection	NavigationDrawerSection
title · 属性	headline	heading	heading	heading	heading
divider · 属性	divider	divider	divider	divider	divider
备注	Holds <tanrei-navigation-drawer-item> and <tanrei-navigation-drawer-group> children. It draws a <tanrei-divider> before itself while divider is set, and its heading as a heading element (role="heading", level 2 unless a web-only heading-level says otherwise).	TanreiNavigationDrawerSection(_ heading: String = "", divider: Bool = false) { items }, as SwiftUI's Section; the heading carries the header trait.	TanreiNavigationDrawerSection(heading = "", divider = false) { … }, a composable whose content lambda holds its items; the heading has Modifier.semantics { heading() } and the divider is a TanreiDivider.	TanreiNavigationDrawerSection(heading: '', divider: false, children: [...]); the heading is wrapped in Semantics(header: true) and the divider is a TanreiDivider.	An entry { heading?, divider?, items: (NavigationDrawerDestination | NavigationDrawerGroup)[] }; its items array tells it from a destination.

header-button

An icon-only Button in the header, on the icon column (a menu button): a Button of the text variant and the medium size with an icon and no label, unless the product sets otherwise, which the drawer lays out and does not restyle, resize or reshape in either form. While the drawer is collapsible the first one is its menu button.

属性	类型	默认值	说明
label	string	""	Its accessible name, as the Button's label. Required.

插槽	说明
icon	Its glyph, as the Button's icon slot. A fixture item's content is this glyph.

事件	说明
click	The button was activated, as the Button's click.

规格	Web	SwiftUI	Jetpack Compose	Flutter	React Native
条目	tanrei-button	TanreiButton	TanreiButton	TanreiButton	Button
label · 属性	label	label	contentDescription	semanticLabel	accessibilityLabel
click · 事件	click	action	onClick	onPressed	onPress
备注	An icon-only <tanrei-button> child with slot="header-button"; the glyph is its content.	An icon-only TanreiButton in the headerButtons view builder; the drawer adds the expanded value to the first.	An icon-only TanreiButton in the headerButtons lambda; the drawer adds the expanded state to the first one's semantics.	An icon-only TanreiButton in headerButtons:; the drawer wraps the first in Semantics(expanded:).	An icon-only Button element in headerButtons; the drawer adds accessibilityState.expanded to the first.

main-action

The screen's main action, below the header buttons: the Main Action Button component, whose extended the drawer sets from its own form (collapsed to its icon while the drawer is collapsed). The drawer lays it out and does not restyle it.

属性	类型	默认值	说明
label	string	""	Its label, drawn while the drawer is expanded and always its accessible name, as the Main Action Button's. Required.

插槽	说明
icon	Its glyph, as the Main Action Button's icon slot. A fixture item's content is this glyph.

事件	说明
click	The button was activated, as the Main Action Button's click.

规格	Web	SwiftUI	Jetpack Compose	Flutter	React Native
条目	tanrei-main-action-button	TanreiMainActionButton	TanreiMainActionButton	TanreiMainActionButton	MainActionButton
label · 属性	label	title	text	label	label
click · 事件	click	action	onClick	onPressed	onPress
备注	A <tanrei-main-action-button> child with slot="main-action"; the glyph is its icon slot. The drawer sets its extended (the inverse collapsed attribute).	A TanreiMainActionButton in the mainAction view builder; the drawer sets its isExtended from its own form.	A TanreiMainActionButton in the mainAction lambda; the drawer passes its form as expanded.	A TanreiMainActionButton as mainAction:; the drawer sets its isExtended from its own form.	A MainActionButton element as mainAction; the drawer sets its extended.

状态

行为

以 EARS 形式写成的需求。每个平台的实现都按这些 ID 逐条测试。需求原文取自规格文件，原样以英文呈现。

ID	需求
NVD-1	WHEN the user activates a destination by pointer, touch, Enter or Space (Enter only for a destination that is a link, and for a link only an activation that NVD-60 counts) THE navigation drawer SHALL emit change exactly once with the destination's value WHILE it is not the selected destination, and reselect exactly once with its value WHILE it is.
NVD-2	WHILE a destination's disabled is true THE navigation drawer SHALL NOT emit change or reselect for it, SHALL NOT make it focusable and SHALL expose it as disabled to assistive technology.
NVD-3	THE navigation drawer SHALL draw the destination whose value equals the drawer's value, in a section, in a group or neither, from the selected parts and every other destination from the unselected parts: WHILE the drawer is expanded, from selected (comp.navigation-drawer.selected.item.container.color, comp.navigation-drawer.selected.item.icon-indicator.color, comp.navigation-drawer.selected.item.icon.color, comp.navigation-drawer.selected.item.label.color, comp.navigation-drawer.selected.item.trailing-text.color, comp.navigation-drawer.selected.item.trailing-icon.color) and unselected; WHILE it is collapsed, from collapsed-selected (comp.navigation-drawer.collapsed-selected.item.container.color, comp.navigation-drawer.collapsed-selected.item.icon-indicator.color, comp.navigation-drawer.collapsed-selected.item.icon.color, comp.navigation-drawer.collapsed-selected.item.label.color) and collapsed-unselected. IF no destination's value equals a value that is not empty THE navigation drawer SHALL draw every destination unselected, and in debug builds report the value.
NVD-4	WHILE a destination or a group's row is hovered, keyboard-focused or pressed THE navigation drawer SHALL render its item container, icon indicator, icon, label, trailing content and opacity from the component tokens of its condition in the highest-precedence active state, with precedence pressed over focused over hovered; focus gained by pointer or touch SHALL NOT select the focused state.
NVD-5	WHEN a destination or a group's row receives keyboard focus THE navigation drawer SHALL show the focus ring around its item container without animation; focus gained by pointer or touch SHALL NOT show it.
NVD-6	THE navigation drawer SHALL make each cell (a destination's or a group's row) its hit area, across the drawer's full width inside its insets, however deep it is nested (NVD-13), and the cell's height with half of comp.navigation-drawer.container.gap.regular above and below it, in both forms, and SHALL NOT let it fall below sys.target.pointer high for a fine pointer WHILE density is regular, nor below sys.target.touch for touch; a system whose geometry gives less SHALL still extend the hit area without changing the drawn cell. WHILE density is compact, for a fine pointer the hit area SHALL be the cell and half of the gap above and below it, the one place where a cell of the drawer is lower than the pointer target (still above the 24 of WCAG 2.5.8); WHERE input is touch, or the platform cannot tell the input type, a compact cell SHALL be drawn at least sys.target.touch high, because cells whose hit areas touch cannot extend them over each other. Hover and press over any part of the hit area SHALL answer on the item container.
NVD-7	WHILE a destination's or a group's disabled is true THE navigation drawer SHALL render its item container, icon indicator, icon, label, trailing content and opacity from the disabled component tokens of its condition.
NVD-8	WHEN a destination or a group's row is pressed by pointer, touch, Enter or Space THE navigation drawer SHALL show its pressed state without delay and SHALL keep it visible for at least sys.motion.duration.press-hold, even when the press ends sooner.
NVD-9	WHILE a destination or a group's row is pressed THE navigation drawer SHALL answer as sys.behavior.pressed-feedback names: overlay applies the pressed tokens to the whole item container at once; ripple grows the pressed state layer, clipped to the item container, from the point of contact (from the center for keyboard activation); dim applies the pressed opacity to the whole destination and draws no state layer; none draws no answer to the press. Under ripple and dim only the item container color stays with the state under the press; icon indicator, icon, label, trailing content and opacity still come from the pressed tokens. Under none every part stays with the state under the press. The ripple grows over comp.navigation-drawer.motion.feedback-duration with comp.navigation-drawer.motion.state-easing, fades over comp.navigation-drawer.motion.state-duration with comp.navigation-drawer.motion.state-easing once the press has ended and press-hold has passed, and appears whole where motion is reduced.
NVD-10	THE navigation drawer SHALL ease its item container and icon indicator corners and a modal drawer's end corners by sys.shape.corner-smoothing (0 is a quarter circle, 0.6 the iOS continuous corner; a platform with only the OS curve draws it for any amount above 0) and show its keyboard focus as sys.behavior.focus-style names (ring or glow); a platform that cannot draw a choice SHALL fall back to the first value and state that in its README.
NVD-11	THE navigation drawer SHALL be comp.navigation-drawer.container.width wide while expanded and comp.navigation-drawer.collapsed.container.width.regular wide while collapsed, beside the start inset, and the full height of its parent, filled with its variant's container color (comp.navigation-drawer.container.color.standard or comp.navigation-drawer.container.color.modal), raised by its variant's elevation (comp.navigation-drawer.container.elevation.standard, comp.navigation-drawer.container.elevation.modal), with its end corners rounded by its variant's shape (comp.navigation-drawer.container.shape.standard, comp.navigation-drawer.container.shape.modal) and square start corners, and edged at its end by comp.navigation-drawer.outline.width of its variant's outline color (comp.navigation-drawer.outline.color.standard, comp.navigation-drawer.outline.color.modal); right-to-left layouts SHALL put it at the right edge, mirrored.
NVD-12	THE navigation drawer SHALL lay out, comp.navigation-drawer.container.padding-inline from its start and end and comp.navigation-drawer.container.padding-block from its top and bottom (measured to the first and last cell, not to their hit areas), its header (NVD-38) and then, comp.navigation-drawer.header.gap below it (at the padding WHILE the header is empty), its items in reading order: destinations, groups and sections, a section laying out its divider, its heading and its items in that order, and an open group its row and then its items; it SHALL put comp.navigation-drawer.container.gap.regular between two cells, and WHILE the items are taller than the space below the header it SHALL scroll them and keep the header in place, in both forms.
NVD-13	WHILE the drawer is expanded THE navigation drawer SHALL draw each destination as an item container that ends comp.navigation-drawer.container.padding-inline inside the drawer's end edge and starts comp.navigation-drawer.container.padding-inline inside its start edge, further in by the row's indent (NVD-69) WHILE highlight is indented and at that same place at every level WHILE highlight is full (NVD-70), its content starting the row's indent further in either way; comp.navigation-drawer.item.container.height.regular high unless its label's lines need more, with corners comp.navigation-drawer.item.container.shape, holding in reading order: its icon, centered on the icon column's center line (half of comp.navigation-drawer.collapsed.container.width.regular from the drawer's start edge, the row's indent further, and a chevron's room and comp.navigation-drawer.item.gap further WHILE chevron is start) and on the cell's icon line (NVD-31), with its icon indicator centered behind it and taking no space; a group's start chevron before it WHILE chevron is start (NVD-68); its label in comp.navigation-drawer.item.label.typescale.regular, comp.navigation-drawer.item.gap after the icon or the icon's room (NVD-71), or comp.navigation-drawer.item.padding-inline.regular from where the row's content starts WHILE it has neither, on one line unless labelWrap is true (NVD-75), and its supporting text (NVD-74); and its trailing content (NVD-43) at the end, before an end chevron, comp.navigation-drawer.item.gap after the label and comp.navigation-drawer.item.padding-inline.regular from the item container's end. Right-to-left layouts SHALL mirror it.
NVD-14	THE navigation drawer SHALL draw each icon at comp.navigation-drawer.item.icon.size.regular with the family and fill of its condition (selected for the selected destination, unselected for every other), sys.icon.weight, and an optical size clamped between sys.icon.optical-size.min and sys.icon.optical-size.max.
NVD-15	WHILE a destination has trailing content (its trailingText, or its trailing slot's content) THE navigation drawer SHALL expose it as part of the destination's description, after its name, its state and its badge's description, and not as an element of its own, and SHALL keep drawing it WHILE the destination is disabled.
NVD-16	WHILE a section's title is not empty THE navigation drawer SHALL draw it as the section's heading in comp.navigation-drawer.heading.typescale and comp.navigation-drawer.heading.color, in a row at least comp.navigation-drawer.heading.height.regular high with the text vertically centered and starting where the destinations' labels start WHILE they have no icon (comp.navigation-drawer.item.padding-inline.regular inside the drawer's inner edge), and SHALL expose it as a heading that is not focusable; WHILE the drawer is collapsed it SHALL keep the row at its height, draw no text in it and hide it from assistive technology; WHILE the title is empty the section SHALL draw no heading row. THE navigation drawer SHALL set the heading's letter-spacing by the script of its text, as every title is set (PRS-20): no negative letter-spacing WHERE its language is Chinese, Japanese or Korean, and none WHERE its script joins its letters or stacks marks on them.
NVD-17	WHILE a section's divider is true THE navigation drawer SHALL draw a divider component before the section, across the drawer's inner width in either form, and leave it as the divider component draws it; IF a section holds a section, or a group holds a section, THE navigation drawer SHALL render the inner section's items in its place, and in debug builds report that sections do not nest and do not go inside a group.
NVD-18	WHILE variant is standard THE navigation drawer SHALL take its width in the layout, in its current form (NVD-30), WHILE open is true and no width and no presence to assistive technology or focus WHILE open is false; WHEN open changes it SHALL slide in or out while the content beside it resizes, over comp.navigation-drawer.motion.enter-duration with comp.navigation-drawer.motion.enter-easing when opening and comp.navigation-drawer.motion.exit-duration with comp.navigation-drawer.motion.exit-easing when closing, and at once where motion is reduced. A standard drawer SHALL draw no scrim, SHALL NOT keep focus inside it and SHALL NOT emit close.
NVD-19	WHEN open becomes true WHILE variant is modal THE navigation drawer SHALL, WHILE collapsible is false, slide in from its start edge over the content and fade its modal layer's scrim in comp.navigation-drawer.scrim.color and comp.navigation-drawer.scrim.blur in over the rest of the window in step (MDL-1, MDL-7), over comp.navigation-drawer.motion.enter-duration with comp.navigation-drawer.motion.enter-easing (at once where motion is reduced), and WHILE collapsible is true widen from its column as NVD-40 says; in both cases it SHALL move focus to the selected destination (or the group row that shows it, NVD-47) or else to its first focusable element, SHALL keep focus inside the drawer while it is open, and SHALL make everything behind it inert to pointer, touch, keyboard and assistive technology, as its modal layer does (MDL-2, MDL-3, MDL-4).
NVD-20	WHEN the user presses the scrim, presses Escape, uses the platform's back action (as its modal layer answers them, MDL-6), activates the menu button (NVD-37), or drags the drawer toward its start edge past half its width or flings it that way, WHILE variant is modal and open is true, THE navigation drawer SHALL close and emit close exactly once; on the web it SHALL set open to false itself, as a dialog does, and a controlled platform SHALL leave open to the caller, who sets it from close. A fling is a release faster than the platform's minimum fling velocity (Android's ViewConfiguration.getScaledMinimumFlingVelocity, Flutter's kMinFlingVelocity) or, where the platform names none (the web, SwiftUI, React Native), 0.5 points per millisecond, and the drawer follows a drag only beyond the platform's touch slop (Android's ViewConfiguration.getScaledTouchSlop, Flutter's kTouchSlop) or, where the platform names none, 8 points, as BSH-9 says for the bottom sheet. A release's velocity is the pointer's over its last moves: WHERE the pointer has not moved for longer than the time after which the platform's velocity tracker takes a pointer as stopped (40 milliseconds in Android's VelocityTracker, Jetpack Compose's VelocityTracker and Flutter's VelocityTracker) or, where the platform names none (the web, SwiftUI, React Native), 40 milliseconds before the release THE navigation drawer SHALL take the release as having no velocity, so that a drag that stops where it is wanted and is let go there is no fling, however fast it moved before it stopped.
NVD-21	WHEN the user activates a destination WHILE variant is modal THE navigation drawer SHALL emit change or reselect as NVD-1 says, and then close and emit close as NVD-20 says; an activation of a link that NVD-60 does not count, which opens the link somewhere else, SHALL leave the drawer open.
NVD-22	WHEN a modal drawer closes THE navigation drawer SHALL, WHILE collapsible is false, slide out and fade its scrim out over comp.navigation-drawer.motion.exit-duration with comp.navigation-drawer.motion.exit-easing, and WHILE collapsible is true narrow back to its column as NVD-40 says (at once where motion is reduced), and SHALL return focus to the element that had it when the drawer opened, or, WHERE that element is gone, to where the platform puts focus by default, as its modal layer does (MDL-5).
NVD-23	THE navigation drawer SHALL expose each destination as one element named by its label in both forms, with its selected state and its position among the items of its level, and its icon hidden: a link WHILE its href is not empty (NVD-59) and a button otherwise. On the web it is an anchor or a button inside a navigation landmark named by the drawer's label, the selected destination carrying aria-current="page"; on Apple platforms, Android, Flutter and React Native a button, or a link, with the selected state. The selected destination is the place the product is showing, in a product of one screen and in a site of many pages alike: THE navigation drawer SHALL have no second state and no second mark for a current page, and SHALL expose exactly one destination, or none, as current. It SHALL expose groups as NVD-46 says. WHILE variant is modal and open is true THE navigation drawer SHALL also be a modal dialog named by the drawer's label (the web's dialog element; the modal trait or pane title elsewhere).
NVD-24	WHILE a destination's label is not empty THE navigation drawer SHALL expose it as the destination's accessible name, over a name the product gives the destination on the element (aria-label or aria-labelledby); WHILE a destination's label is empty and the product gives the destination a name of its own on the element — aria-label, or aria-labelledby naming an element — THE navigation drawer SHALL expose that name as its accessible name; WHILE a destination's label is empty and the product gives it none THE navigation drawer SHALL still render it, and in debug builds report that it has no accessible name; WHILE the drawer's label is empty, variant is modal and the product gives the drawer no name of its own on the element — aria-label, or aria-labelledby naming an element — it SHALL report that the dialog has no name.
NVD-25	THE navigation drawer SHALL extend its container under the system insets at its start, top and bottom and SHALL place its header, destinations and sections inside them.
NVD-26	WHEN variant or density names a value that the active design system does not have THE navigation drawer SHALL render with that axis's default value's tokens, and in debug builds report the unknown value.
NVD-27	WHILE the text size is enlarged THE navigation drawer SHALL keep both its widths, grow each cell and section heading with its text in both forms alike (their heights are minimums, NVD-31), keep one-line labels, one-line supporting text and short labels on one line and cut them (NVD-75), and SHALL NOT scale its icons, icon indicators or trailing glyphs; WHERE the platform offers a large-content viewer for bar items (iOS) a long press on a collapsed destination SHALL show its icon and label enlarged.
NVD-28	WHEN open changes from false to true WHILE variant is standard THE navigation drawer SHALL move focus to the selected destination or else to its first focusable element, and WHEN open then changes to false while focus is inside it SHALL return focus to the element that had it when the drawer opened, or, WHERE that element is gone, to where the platform puts focus by default; Tab and Shift+Tab SHALL move focus out of an open standard drawer without closing it (a standard drawer is a layout region, not an overlay).
NVD-29	IF two destinations have the same value THE navigation drawer SHALL treat the first of them in reading order as the one the drawer's value selects, and in debug builds report the repeated value.
NVD-30	WHILE collapsible is false THE navigation drawer SHALL be expanded and ignore expanded; WHILE collapsible is true and variant is standard it SHALL be expanded WHILE expanded is true and collapsed WHILE expanded is false; WHILE collapsible is true and variant is modal it SHALL be collapsed, in the layout, WHILE open is false, and expanded over the content WHILE open is true (NVD-40), ignoring expanded.
NVD-31	WHILE collapsible is true THE navigation drawer SHALL give every cell the same height and the same place in both forms, so that each icon, each header button and the main action's glyph is drawn at exactly the same point expanded, collapsed and while moving between them: a cell's icon line SHALL lie below its top by the larger of half the expanded row's height (NVD-13) and comp.navigation-drawer.collapsed.item.container.padding-block.regular plus half of comp.navigation-drawer.item.icon-indicator.height.regular, and the cell SHALL reach below that line by the larger of half the expanded row's height and half of comp.navigation-drawer.item.icon-indicator.height.regular plus, WHILE collapsedLabels is not never, comp.navigation-drawer.collapsed.item.gap and one line of comp.navigation-drawer.collapsed.item.label.typescale, plus comp.navigation-drawer.collapsed.item.container.padding-block.regular; both forms SHALL center the icon on that line. A section heading's row, and the header slot's row, SHALL keep their heights in both forms. The one exception is an open group, whose items the collapsed drawer does not draw (NVD-47): the cells after it move up while the drawer collapses and back while it expands. WHILE collapsible is false a cell SHALL be the expanded row alone.
NVD-32	WHILE the drawer is collapsed THE navigation drawer SHALL draw only the cells that are not inside a group (top-level destinations and groups, in a section or not), each as an item container comp.navigation-drawer.collapsed.item.container.width.regular wide, centered in the icon column, with corners comp.navigation-drawer.collapsed.item.container.shape, each at most half its height, holding, comp.navigation-drawer.collapsed.item.container.padding-block.regular below its top, the icon indicator, comp.navigation-drawer.item.icon-indicator.width.regular wide and comp.navigation-drawer.item.icon-indicator.height.regular high with corners comp.navigation-drawer.item.icon-indicator.shape, its icon centered in it on the cell's icon line; and WHILE its short label is drawn (NVD-33), comp.navigation-drawer.collapsed.item.gap below the icon indicator, the short label centered on one line in comp.navigation-drawer.collapsed.item.label.typescale, truncated at its end with an ellipsis inside comp.navigation-drawer.collapsed.item.container.padding-inline, and comp.navigation-drawer.collapsed.item.container.padding-block.regular below it. It SHALL draw no trailing content. Every part is laid out in every system; a transparent color hides a part without changing the layout.
NVD-33	WHILE the drawer is collapsed and collapsedLabels is never THE navigation drawer SHALL draw no short label, so that a collapsed cell is its expanded row with the label and trailing content gone; WHILE it is selected it SHALL draw only the short label of the cell drawn selected (the selected destination, or the group that shows it, NVD-47); WHILE it is always it SHALL draw every cell's short label. Every destination's label SHALL remain its accessible name.
NVD-34	THE navigation drawer SHALL draw a collapsed cell's shortLabel, or its label WHILE shortLabel is empty, and SHALL keep its label as its accessible name in both forms; IF shortLabel is not empty and is not a part of label (ignoring case) THE navigation drawer SHALL still draw it, and in debug builds report that the visible name is not part of the accessible name.
NVD-35	WHEN the drawer changes form (NVD-30) THE navigation drawer SHALL, over comp.navigation-drawer.motion.expand-duration with comp.navigation-drawer.motion.expand-easing: move its end edge between comp.navigation-drawer.collapsed.container.width.regular and comp.navigation-drawer.container.width, a standard drawer's content beside it resizing with it; keep every icon, header button and the main action's glyph in place (NVD-31); change each item container between its two sizes and corners as one shape around the same icon line (WHERE the two forms give it the same height and corners, as the default system does, its end edge alone moves), and cross-fade its color and those of its icon indicator, icon and label from one form's condition to the other's; clip the expanded labels, trailing content, headings' text and the header slot at the moving edge and fade them out over the first half of the change when collapsing, and in over the second half when expanding; and fade the short labels in over the second half when collapsing, and out over the first half when expanding. It SHALL NOT stretch, reshape or recolor a header button on the way (NVD-38). WHERE motion is reduced it SHALL change form at once.
NVD-36	WHEN the drawer changes form THE navigation drawer SHALL keep focus where it is, and SHALL take what the collapsed form does not draw (the header slot's content, the headings' text, trailing content, the chevron of a group that is a destination, the items inside groups) out of the focus order and away from assistive technology WHILE it is collapsed; IF focus is on such content when the drawer collapses THE navigation drawer SHALL move it to the menu button (NVD-37), or else to the first focusable element of the drawer. A destination's role, name and state SHALL be the same in both forms.
NVD-37	WHILE collapsible is true THE navigation drawer SHALL treat its first header button as its menu button and expose it as expanded or collapsed, controlling the drawer (aria-expanded and aria-controls on the web; the expanded state elsewhere); WHEN the user activates it, after the button's own click, THE navigation drawer SHALL emit expandedChange exactly once with the form asked for (true to expand, false to collapse) WHILE variant is standard or the drawer is not open, and on the web apply it itself (expanded for a standard drawer, open for a modal one); WHILE a modal drawer is open it SHALL close as NVD-20 says instead. WHILE collapsible is true and the drawer has no header button it SHALL report in debug builds that its user cannot change its form.
NVD-38	THE navigation drawer SHALL lay out its header from the top: its header buttons stacked in the icon column, each centered on its center line, comp.navigation-drawer.header.item-gap apart, and each drawn as the Button it is in both forms and while the drawer moves between them: the Button's own size, shape (a circle in the default system) and colors, never stretched to a row's width, never given an item container's shape and never filled as an active indicator; WHILE expanded, the header slot's content in the first header button's row, comp.navigation-drawer.item.gap after it (from comp.navigation-drawer.container.padding-inline WHILE there is no header button), vertically centered, the row as tall as the taller of the two, the slot's box giving what it holds comp.navigation-drawer.header.typescale and comp.navigation-drawer.header.color as an inherited text style, so that plain text placed there is drawn in the system's title style and an element that sets its own style keeps it; and then the main action (NVD-39), comp.navigation-drawer.header.item-gap below. A header-button or main-action item SHALL go to the header wherever it stands among the items, and the header's content SHALL come first in reading and focus order and keep its own semantics.
NVD-39	WHILE the drawer holds a main-action item THE navigation drawer SHALL draw it as the Main Action Button it is, collapsed to its icon (extended false) WHILE the drawer is collapsed and extended with its label WHILE the drawer is expanded, changing with the drawer over comp.navigation-drawer.motion.expand-duration; it SHALL place the button so that the center of its glyph lies on the icon column's center line, the line the destinations' icons are centered on (NVD-13, NVD-31), in both forms, at every size of the button, in every density and design system and in either layout direction: the icon column's center line lying a chevron's room and comp.navigation-drawer.item.gap further from the start WHILE chevron is start (NVD-68): WHILE the drawer is collapsed the button's start SHALL lie half the column's width less half the button's height (the side of its collapsed square, comp.main-action-button.container.height.medium for medium, and so on) from the drawer's start edge, and WHILE it is expanded half the column's width less the button's padding before a leading glyph and half that glyph (comp.main-action-button.container.padding-inline-start-with-icon.medium and comp.main-action-button.icon.size.medium for medium, and so on), each read from the button's own tokens for its size and never measured or written as a number; WHEN the drawer changes form the button's start SHALL move between the two over comp.main-action-button.motion.resize-duration with comp.main-action-button.motion.resize-easing, the motion with which the button moves its glyph between the middle and its side (MAB-14), at once where motion is reduced. A button whose collapsed square is wider than the icon column (a large one in the default system's columns) SHALL still be placed so, reaching past the column's start edge, and in debug builds THE navigation drawer SHALL report it; a button whose glyph is trailing SHALL be placed so while collapsed and, while expanded, start where it starts collapsed, and in debug builds THE navigation drawer SHALL report that its glyph leaves the column while expanded. Its label SHALL remain its accessible name in both forms. IF the drawer holds more than one main-action item THE navigation drawer SHALL draw the first, and in debug builds report the rest.
NVD-40	WHILE variant is modal and collapsible is true THE navigation drawer SHALL take its column's width in the layout and draw the column as a standard drawer's (comp.navigation-drawer.container.color.standard, comp.navigation-drawer.container.elevation.standard, comp.navigation-drawer.outline.color.standard) WHILE open is false; WHEN open becomes true it SHALL widen over the content, without resizing it, from the column to comp.navigation-drawer.container.width in the modal variant's container, elevation, shape and outline, and fade its modal layer's scrim in comp.navigation-drawer.scrim.color and comp.navigation-drawer.scrim.blur in over the rest of the window (MDL-1), both over comp.navigation-drawer.motion.expand-duration with comp.navigation-drawer.motion.expand-easing, changing its parts as NVD-35 says; WHEN it closes it SHALL narrow back to the column and fade the scrim out over the same time; WHERE motion is reduced it SHALL do both at once. While it widens and while it narrows its container color, elevation, end corners and outline SHALL change between the column's and the modal variant's over the same motion, in step with its width, so that no frame changes its look at once: its first frame opening is drawn as the column at rest, and its last frame closing as the column at rest, which then stays where it is. WHEN it first appears with open true it SHALL draw itself open in its first frame, at comp.navigation-drawer.container.width over its full scrim, without widening from a column it never showed. NVD-19 to NVD-22 apply to it while it is open.
NVD-41	WHEN the selected destination changes THE navigation drawer SHALL change the new destination's item container to its selected color and the previous one's to its unselected color in place, each at its full size and shape throughout, and change icon, label and trailing content colors and icon fill, over comp.navigation-drawer.motion.state-duration with comp.navigation-drawer.motion.state-easing, in either form; it SHALL NOT grow, shrink, slide or otherwise resize an item container to show a selection. THE icon indicator, which the default system leaves transparent, SHALL grow in width from its center to its full width, at its full height throughout, on the new destination and fade out on the previous one, over comp.navigation-drawer.motion.selection-duration with comp.navigation-drawer.motion.selection-easing; WHILE the drawer is collapsed and collapsedLabels is selected the short labels SHALL appear and disappear over the same time without moving any cell (NVD-31); WHERE motion is reduced it SHALL show the new selection at once.
NVD-42	WHILE a destination's badge is true THE navigation drawer SHALL draw a Tanrei badge anchored to its icon in both forms, above the icon indicator, as the badge component draws one whose count is the destination's badgeCount and whose label is its badgeLabel, SHALL keep it while the destination is disabled, and SHALL expose the badge's description (badgeLabel, or the displayed count when it is empty) as part of the destination's own description, after its name and state.
NVD-43	WHILE a destination's trailing slot holds content THE navigation drawer SHALL draw it at the end of the expanded row: a glyph at comp.navigation-drawer.item.trailing-icon.size.regular in its condition's trailing icon color (comp.navigation-drawer.unselected.item.trailing-icon.color, comp.navigation-drawer.selected.item.trailing-icon.color), anything else as it draws itself; WHILE the slot is empty and trailingText is not empty it SHALL draw trailingText there, on one line and never truncated, in comp.navigation-drawer.item.trailing-text.typescale and its condition's trailing text color (comp.navigation-drawer.unselected.item.trailing-text.color, comp.navigation-drawer.selected.item.trailing-text.color); IF both are given it SHALL draw the slot's content and in debug builds report trailingText. IF the slot holds a focusable element THE navigation drawer SHALL keep it out of the focus order, and in debug builds report that trailing content is not interactive.
NVD-44	THE navigation drawer SHALL draw a group's row as a destination's in either form (NVD-13, NVD-32), with its icon, label and short label, its trailing content (NVD-43, a group's trailing slot and trailingText as a destination's), and its chevron where chevron puts it (NVD-68): the icon set's expand_more at comp.navigation-drawer.item.trailing-icon.size.regular in its condition's trailing icon color, turned half a turn WHILE the group is open; WHILE the group is open and the drawer expanded it SHALL draw the group's items below its row, each one's row starting one step of indent further in (NVD-69, NVD-70); WHEN open changes it SHALL reveal or hide those items, moving the cells below, and turn the chevron, over comp.navigation-drawer.motion.disclosure-duration with comp.navigation-drawer.motion.disclosure-easing, at once where motion is reduced. A group's row SHALL answer hover, focus and press, show its focus ring, and follow press-hold, pressed-feedback, corner smoothing and focus style exactly as a destination does (NVD-4 to NVD-10), from the unselected condition unless NVD-47 says otherwise.
NVD-45	WHEN the user activates, WHILE expandable is true and the drawer is expanded, a group's row by pointer, touch, Enter or Space and the group is not a destination (NVD-66), or activates the chevron of a group that is one (NVD-67), or the icon of a group while chevron is none (NVD-68), THE navigation drawer SHALL emit the group's toggle exactly once with its new open state, SHALL NOT emit change, reselect or close, and on the web SHALL set the group's open itself (a controlled platform leaves it to the caller); WHEN focus is on a closed group's row and the user presses the arrow key toward the end of the line (Right in a left-to-right layout) it SHALL open the group, and on an open group's row the arrow key toward the start SHALL close it; WHEN focus is on an item inside an open group and the user presses the arrow key toward the start, it SHALL move focus to that group's row. WHILE a group's disabled is true THE navigation drawer SHALL NOT emit toggle, change or reselect for it, SHALL NOT make its row or its chevron focusable and SHALL expose it as disabled.
NVD-46	THE navigation drawer SHALL expose a group's row as one button named by its label, with its expanded or collapsed state and its icon and chevron hidden, controlling its items, and its items as a list named by the group's label inside the drawer's list: on the web a button with aria-expanded and aria-controls and a nested list labelled by it; on Apple platforms a button whose value is expanded or collapsed, as a disclosure group reads; on Android the expanded state with the expand and collapse actions; in Flutter the expanded semantics flag; in React Native accessibilityState.expanded. WHILE a group is a destination (NVD-66) THE navigation drawer SHALL instead expose its row as that destination, as NVD-23 says (a link while it has an href and a button otherwise, named by its label, with its selected state), and its chevron as one more button, named by the group's label, with the group's expanded or collapsed state and controlling its items, which stay a list named by the group's label: on the web the row is the link or button with aria-current and the chevron a button with aria-expanded and aria-controls, each its own Tab stop, as the disclosure navigation menu with top-level links of the WAI-ARIA Authoring Practices is; on the other platforms the row carries the selected state and the chevron the expanded state with the expand and collapse actions. WHILE expandable is false, NVD-72 says instead what a group's row is. WHILE a group is closed, or the drawer collapsed, its items SHALL be neither exposed nor focusable. WHILE a group's label is not empty THE navigation drawer SHALL expose it as its row's accessible name, over a name the product gives the group on the element (aria-label or aria-labelledby); WHILE a group's label is empty and the product gives the group a name of its own on the element — aria-label, or aria-labelledby naming an element — THE navigation drawer SHALL expose that name as its row's accessible name; WHILE a group's label is empty and the product gives it none THE navigation drawer SHALL still render it, and in debug builds report that it has no accessible name.
NVD-47	WHILE the selected destination is inside a closed group, or inside a group WHILE the drawer is collapsed, THE navigation drawer SHALL draw the row that shows it (the outermost closed group that holds it; collapsed, its top-level group) from its form's selected condition; WHILE the drawer is collapsed it SHALL draw each top-level group as one cell and none of its items; WHEN the user activates the cell of a group that is not a destination (NVD-66) WHILE the drawer is collapsed THE navigation drawer SHALL emit expandedChange with true, and the group's toggle with true WHILE it is closed, SHALL on the web apply both itself, and SHALL move focus to the group's row once the drawer is expanded.
NVD-48	IF groups nest more than three levels deep THE navigation drawer SHALL still render them, indenting each level's content by comp.navigation-drawer.item.nest-indent.regular, and in debug builds report the depth.
NVD-49	WHILE the drawer is collapsed and a top-level destination or group has no icon THE navigation drawer SHALL still draw its cell, with an empty icon indicator and, WHERE NVD-33 draws one, its short label, and in debug builds report that a collapsible drawer needs an icon on every top-level destination and group.
NVD-50	THE navigation drawer SHALL take its layout direction from where it is used — the direction of the nearest ancestor that sets one, and the platform's own where none does — and SHALL have no direction setting of its own; WHEN that direction changes while the navigation drawer is shown THE navigation drawer SHALL draw itself for the new direction at once, without a motion of its own, keeping its expanded or collapsed form, its open state, the selected destination and its focus.
NVD-51	WHERE the layout direction is right-to-left THE navigation drawer SHALL draw a destination's and a group's icon mirrored left to right exactly when the system's icon set marks that glyph's name as mirrored or the product forces mirroring for that use, and unmirrored when the product forbids it: the icon helper mirrors the glyph inside its own box, about the box's vertical centre line, changing neither its place, size, color and fill nor the order NVD-13 gives. THE navigation drawer SHALL NOT mirror a glyph itself, and SHALL NOT mirror content the product gives as an image or a view of its own rather than by a glyph's name. A group's chevron (expand_more, NVD-44) is not marked and is never mirrored; the product's own content in a trailing slot is the product's to mirror, and a header button's and the main action's glyphs are mirrored by those components (BTN-19, MAB-22).
NVD-52	THE navigation drawer SHALL lay out a destination's and a group's label and short label, a section's heading, a destination's trailing text and the header's text as text of its own direction, isolated from the text around it: each takes the base direction of its first strong character, or the layout direction where it has none, so that a left-to-right word, a number with its sign or unit, a telephone number and an address keep their own order in a right-to-left layout and reorder nothing beside them; THE navigation drawer SHALL still place each and align its lines by the layout direction, not by the text's own, and SHALL cut a short label that does not fit (NVD-32) at the end of its own direction, so that a left-to-right label in a right-to-left layout loses its right end and never its beginning.
NVD-53	WHILE responsive is true THE navigation drawer SHALL choose its presentation from the width of the window it is in, and SHALL ignore variant: WHILE the window is at least comp.navigation-drawer.breakpoint.expanded wide it SHALL be a standard drawer that is shown whatever open says (the standard presentation: NVD-18's place in the layout, in the form NVD-30 gives a standard drawer); WHILE the window is narrower than that, at least comp.navigation-drawer.breakpoint.collapsed wide, and collapsible is true, it SHALL be a collapsible modal drawer (the column presentation: its column in the layout, widening over the content WHILE open is true, NVD-40); and otherwise it SHALL be a modal drawer that is not collapsible (the modal presentation: nothing in the layout, shown over the content WHILE open is true, NVD-19 to NVD-22). In each presentation THE navigation drawer SHALL draw and behave exactly as the drawer whose variant and collapsible it stands for, from that variant's tokens. WHILE responsive is false THE navigation drawer SHALL NOT read the window's width.
NVD-54	WHEN the window's width takes a responsive drawer from one presentation to another THE navigation drawer SHALL draw the new presentation at once, without the motions of NVD-18, NVD-35 and NVD-40; SHALL enter it closed — WHERE open is true it SHALL emit close exactly once, the web setting open to false itself and a controlled platform leaving it to the caller (NVD-20); SHALL keep expanded, which only the user's request (NVD-37) and the product change, so that the standard presentation returns in the form it was left in; SHALL keep value and every group's open; and SHALL emit presentationChange exactly once with the new presentation (standard, column or modal). It SHALL also emit presentationChange exactly once WHEN the presentation is first decided. IF keyboard focus is on something the new presentation does not show THE navigation drawer SHALL move it to the menu button (NVD-37), or else to the first focusable element it still shows, and WHERE it shows nothing SHALL leave focus to the platform; focus that an open modal presentation kept inside the drawer SHALL be free to leave once the drawer is standard.
NVD-55	THE navigation drawer SHALL hold three things apart WHILE responsive is true: the presentation, which it derives from the window's width alone, never stores, never writes into variant, open or expanded, and exposes read-only; open, which is transient, false unless the product or the menu button has just asked, and false again after every change of presentation and every close (NVD-20, NVD-21); and expanded, the user's choice of form for the standard presentation, which THE navigation drawer SHALL NOT persist beyond its own lifetime — a product that wants the choice remembered stores what expandedChange carries and sets expanded from it. WHEN a responsive drawer first appears THE navigation drawer SHALL draw the presentation of the current width in its first frame, without motion and without emitting close; WHERE it is rendered before the width is known (a page rendered on a server) it SHALL render no modal presentation open, SHALL make nothing inert, and SHALL decide both only once the width is known.
NVD-56	WHILE the drawer is collapsed and a cell draws no short label (NVD-33), and WHILE it is expanded and a row's label or supporting text is cut (NVD-75), THE navigation drawer SHALL show that cell's label (and, where its supporting text is cut, its supporting text after it), WHEN the cell is hovered with a fine pointer or receives keyboard focus, as the platform shows the name of a control that is an icon alone (a plain tooltip beside the cell, toward the content, on the web and on desktop; nothing more than the large-content viewer of NVD-27 on a touch platform), and SHALL NOT add it to the cell's accessible name or description, which already hold it.
NVD-57	WHEN the navigation drawer first appears in the layout with a selected destination, and WHEN value changes while it is shown, THE navigation drawer SHALL bring the row that shows the selection (the selected destination, or the group's row NVD-47 names) into view: IF that row is not wholly inside the space its items scroll in THE navigation drawer SHALL scroll them so that the row is centered in that space, as far as the scroll range allows, and otherwise it SHALL NOT scroll at all, so that a drawer whose selection is already in view stays where it is from one page to the next. It SHALL do so at once, without motion, WHEN the drawer first appears in its first frame (in the order NVD-62 gives), and SHALL NOT move keyboard focus. A modal presentation is brought there WHEN it opens, by the focus NVD-19 gives.
NVD-58	WHILE revealSelected is true THE navigation drawer SHALL, WHEN it first appears with a selected destination and WHEN value changes to a destination, draw every closed group that holds that destination open — and, WHERE the selected destination is a group (NVD-66), that group as well, so that a site's sidebar shows the pages of the section whose page is shown — whatever its open said (a state the product gave back included, NVD-62), and SHALL emit each such group's toggle exactly once with true, the web setting the group's open itself and a controlled platform leaving its open to the caller, as NVD-45 says; WHEN the drawer first appears it SHALL draw them open in its first frame, without the motion of NVD-44, and afterwards with it. It SHALL NOT emit change, reselect or close for it, and SHALL NOT open again a group the user closes afterwards until value changes: that group's row then shows the selection (NVD-47). WHILE the drawer is collapsed it SHALL open them all the same, for the form in which they are drawn. WHILE revealSelected is false THE navigation drawer SHALL leave every group as its open says.
NVD-59	WHILE a destination's href is not empty THE navigation drawer SHALL make it a link to that address and not a button. On the web it SHALL be an anchor element with that address, whose behaviours are the browser's own — following it on a plain click, a touch or Enter; opening it in another tab or window by a modified click or a middle click; the link's context menu; dragging it; copying its address; showing its address on hover — and THE navigation drawer SHALL NOT prevent, replace or imitate any of them; Space SHALL NOT activate a link. On other platforms it SHALL be the platform's own link (SwiftUI's Link; on Compose, Flutter and React Native an element with the platform's link semantics whose address is opened by the platform's opener), as BTN-22 says for a link button. THE navigation drawer SHALL draw a link exactly as it draws a button destination, from the same tokens in every state and both forms (NVD-3, NVD-4, NVD-7 to NVD-9, NVD-13, NVD-32), SHALL draw no look of its own for a link the user has visited, and SHALL give its hit area (NVD-6) to the link. WHILE a link's value is empty THE navigation drawer SHALL take its href as its value, for value, change, reselect and NVD-29. WHILE a link's disabled is true it SHALL keep the link role with the disabled state and no destination, and SHALL open nothing by any means the platform gives a link (NVD-2; on the web the anchor carries no address).
NVD-60	WHEN the user activates a link destination THE navigation drawer SHALL count it as an activation (NVD-1, NVD-21) only WHILE it follows the link in the place where the product is shown: a click with the primary button and no modifier key, a touch, Enter, or the default action of assistive technology, on a link whose target is same and that asks for no download. It SHALL then emit change or reselect exactly once, carrying the destination's value and its href, before the link is followed, and SHALL NOT hold the link back for sys.motion.duration.press-hold; SHALL NOT write value itself on any platform, because where the product is, is the product's to say, and the page or the route shown next sets value; and SHALL let the link be followed unless the product cancels the event (preventDefault on the web), as a product does that moves between its pages without loading a document. For every other activation of a link — a modified or a middle click, a link whose target is new, a download — THE navigation drawer SHALL emit neither change nor reselect, SHALL NOT close, and SHALL keep value and the drawn selection as they are.
NVD-61	THE navigation drawer SHALL hold how far its items are scrolled from their start as scrollOffset, in the units of its layout: it SHALL give the present distance whenever the product reads it, and WHEN the product sets it, before the drawer first appears included, SHALL scroll there at once and without motion, held inside the scroll range, the header staying in place (NVD-12). Scrolling by the user SHALL emit no event. WHILE the items can scroll, a scroll that reaches either end of them SHALL NOT go on to scroll what is beside or behind the drawer. WHEN a group opens or closes (NVD-44) THE navigation drawer SHALL keep that group's row where it is in view and move only the cells after it; WHEN keyboard focus moves to a cell that is not wholly in view it SHALL scroll that cell into view by the least distance that shows it whole.
NVD-62	THE navigation drawer SHALL treat scrollOffset and every group's open as the state of one view, as NVD-55 treats expanded: it SHALL keep neither beyond its own lifetime and SHALL write neither to any storage. A product whose pages are separate documents keeps what each group's toggle carries, and what scrollOffset reads when a page is left, and gives them back as the groups' open and the drawer's scrollOffset when the next page is rendered. WHEN the drawer first appears THE navigation drawer SHALL build its first frame in this order — every group as its open says; then the groups NVD-58 opens; then the items at scrollOffset; then the selection brought into view (NVD-57) — and SHALL draw it without the motions of NVD-41 and NVD-44 and without emitting change, reselect or close.
NVD-63	WHILE a destination is a link and its target is new THE navigation drawer SHALL open its href in a new context, as BTN-24 says for a link button (on the web a new tab or window that is given no handle to the page that opened it), and, WHILE the drawer is expanded and the destination has neither trailing slot content nor trailingText, SHALL draw the glyph open_in_new of the system's icon set as its trailing content, as NVD-43 draws a glyph: at comp.navigation-drawer.item.trailing-icon.size.regular, in its condition's trailing icon color (comp.navigation-drawer.unselected.item.trailing-icon.color, comp.navigation-drawer.selected.item.trailing-icon.color), through the icon helper, which mirrors it in a right-to-left layout because the icon set marks its name, and hidden from assistive technology; WHILE the product has put trailing content there THE navigation drawer SHALL draw no mark of its own. Whether a mark is drawn or not, and in both forms, it SHALL expose targetLabel as part of the destination's description, after its badge's description and its trailing content (NVD-15), and WHILE targetLabel is empty SHALL still render and in debug builds report that a link that opens a new context does not say so. WHILE target is same THE navigation drawer SHALL draw no mark and SHALL ignore targetLabel.
NVD-64	WHEN a destination's target names a value the navigation drawer does not define THE navigation drawer SHALL treat it as same, and in debug builds report the unknown value. IF a destination's href is only white space, or names a script to run rather than a place to go (the web's javascript: scheme), or cannot be read as an address by the platform, THE navigation drawer SHALL make the destination a button without a destination, and in the last two cases report it in debug builds, as BTN-26 says for a button. WHILE a destination's href is empty THE navigation drawer SHALL ignore its target and targetLabel.
NVD-65	THE navigation drawer SHALL draw its cells, its section headings, the gaps between its cells, its nesting indent and its collapsed column from the tokens of its density: WHILE density is regular from comp.navigation-drawer.container.gap.regular, comp.navigation-drawer.item.container.height.regular, comp.navigation-drawer.item.padding-inline.regular, comp.navigation-drawer.item.padding-block.regular, comp.navigation-drawer.item.nest-indent.regular, comp.navigation-drawer.item.icon.size.regular, comp.navigation-drawer.item.icon-indicator.width.regular, comp.navigation-drawer.item.icon-indicator.height.regular, comp.navigation-drawer.item.label.typescale.regular, comp.navigation-drawer.item.trailing-icon.size.regular, comp.navigation-drawer.collapsed.container.width.regular, comp.navigation-drawer.collapsed.item.container.width.regular, comp.navigation-drawer.collapsed.item.container.padding-block.regular and comp.navigation-drawer.heading.height.regular, and WHILE density is compact from comp.navigation-drawer.container.gap.compact, comp.navigation-drawer.item.container.height.compact, comp.navigation-drawer.item.padding-inline.compact, comp.navigation-drawer.item.padding-block.compact, comp.navigation-drawer.item.nest-indent.compact, comp.navigation-drawer.item.icon.size.compact, comp.navigation-drawer.item.icon-indicator.width.compact, comp.navigation-drawer.item.icon-indicator.height.compact, comp.navigation-drawer.item.label.typescale.compact, comp.navigation-drawer.item.trailing-icon.size.compact, comp.navigation-drawer.collapsed.container.width.compact, comp.navigation-drawer.collapsed.item.container.width.compact, comp.navigation-drawer.collapsed.item.container.padding-block.compact and comp.navigation-drawer.heading.height.compact. No density SHALL change comp.navigation-drawer.item.gap, the room between the icon (or its room), the label and the trailing content, as no density changes the tree view's. Wherever another behaviour names one of these tokens by its regular value, THE navigation drawer SHALL read the value of its density instead, in both forms and while moving between them, so that every icon keeps one point in both forms (NVD-31) in each density and a nested destination's icon stands where its group's label starts in each. WHEN density changes while the drawer is shown THE navigation drawer SHALL draw the new density at once, without the motions of NVD-35, NVD-41 and NVD-44, keeping its form, its selection, every group's open, its scroll offset where the range allows, and focus, and SHALL emit nothing for it.
NVD-66	WHILE selectableGroups is true THE navigation drawer SHALL treat each group whose value or href is not empty as a destination as well as a group: the drawer's value SHALL select it as it selects a destination, its href standing as its value while its value is empty (NVD-59), and NVD-29 SHALL count it among the destinations in reading order, before the items it holds; its row SHALL be drawn from the selected parts in its form while it is selected (NVD-3, NVD-41) and from the parts NVD-47 names while it is not and a destination it holds is shown by it; its activation SHALL emit change or reselect as NVD-1 says and close a modal drawer as NVD-21 says; and WHILE its href is not empty its row SHALL be a link as NVD-59, NVD-60 and NVD-64 say, opened where the person is. WHILE selectableGroups is false, and for a group whose value and href are both empty, THE navigation drawer SHALL ignore the group's value and href, the group SHALL only open and close (NVD-45), and in debug builds it SHALL report once a group that has a value or an href while selectableGroups is false. WHEN selectableGroups changes while the drawer is shown THE navigation drawer SHALL draw the new form of each group at once, keeping value, every group's open and focus where the element that had it is still drawn, and SHALL emit nothing for it.
NVD-67	WHILE a group is a destination (NVD-66) and the drawer is expanded THE navigation drawer SHALL split its row in two: its chevron SHALL be a control of its own, which opens and closes the group as NVD-45 says and SHALL NOT change the selection, and the rest of the row SHALL be the destination, which a press, Enter or Space (Enter alone for a link) activates as NVD-1 says and which SHALL NOT open or close the group: the chevron opens and the row chooses, and one press never does both. The chevron's hit area SHALL be the part of the cell's hit area from the middle of the gap before the chevron's box to the cell's end edge, at least sys.target.pointer wide for a fine pointer and sys.target.touch wide for touch, reaching over the end of the label where the row gives less; the rest of the cell's hit area SHALL be the row's. A hover anywhere on the cell SHALL show on the item container, a press on the chevron SHALL show the pressed state on the item container as a press on the row does (NVD-8, NVD-9), and keyboard focus on the chevron SHALL show the focus ring around the chevron's own box, at the corners of the item container, and not around the row. With focus on the row the arrow keys SHALL open, close and leave the group as NVD-45 says. WHILE the drawer is collapsed the group's cell SHALL be the destination alone: its activation SHALL emit change or reselect, and SHALL NOT expand the drawer or open the group; its items are reached by expanding the drawer.
NVD-68	THE navigation drawer SHALL draw a group's chevron where chevron says, as the tree view does. WHILE chevron is start THE navigation drawer SHALL keep a box of comp.navigation-drawer.item.trailing-icon.size.regular at the start of every expanded row's content, comp.navigation-drawer.item.gap before its icon, the icon's room or its label, draw the chevron in it on a group's row and nothing on a destination's, so that the icons and labels of a level each stand in one column, and turn it a quarter turn from pointing toward the end of the line WHILE the group is closed to pointing down WHILE it is open. WHILE chevron is end it SHALL draw expand_more at the very end of the row, after its trailing content, turned half a turn WHILE open. WHILE chevron is none it SHALL draw no chevron and keep no room for one: the arrow keys SHALL still open and close a group (NVD-45); a press on a group's icon SHALL open and close it and choose nothing; WHILE the group is open its icon SHALL be drawn as its openIcon where it has one; a group without an icon SHALL open and close by a press anywhere on its row, unless it is a destination (NVD-66), whose row then chooses it and which the pointer cannot open or close. WHILE the drawer is collapsible THE navigation drawer SHALL draw start as end, so that every icon keeps one point in both forms (NVD-31). WHEN chevron names a value it does not define it SHALL draw start, and in debug builds report the value.
NVD-69	THE navigation drawer SHALL begin each row's content, and WHILE highlight is indented its item container, one step of indent further from the start than its group's row for each group that holds it, as the tree view does. WHILE indent is null (auto) a step SHALL be what the group's row draws before its label — its start chevron's room and comp.navigation-drawer.item.gap WHILE chevron is start, and its icon (or the icon's room, NVD-71) and comp.navigation-drawer.item.gap — so that a row's first part (its start chevron, its icon or its label) lines up with where its group's label begins, and comp.navigation-drawer.item.nest-indent.regular WHERE the group's row draws neither. WHILE indent is a number a step SHALL be that many units of the layout, and 0 SHALL begin every row where its group's row begins. WHILE the steps of a row's levels would begin its label past half of the drawer's width THE navigation drawer SHALL begin the row so that its label begins there, as the tree view does, so that a deep row keeps room for its name, at 200 % text too. A step SHALL NOT change a row's height, its hit area (NVD-6), which stays the drawer's width, or the collapsed form, which draws no nested row (NVD-32). WHEN indent is negative or not a number THE navigation drawer SHALL draw auto, and in debug builds report the value.
NVD-70	WHILE highlight is indented THE navigation drawer SHALL draw a nested row's item container — its selected fill, its hover and press layers and its focus indicator — from where the row begins (NVD-69) to the drawer's padding at its end, and WHILE highlight is full from the drawer's padding at its start to its padding at its end at every level, the content starting where the row begins either way; WHEN highlight names a value it does not define it SHALL draw indented, and in debug builds report the value.
NVD-71	WHILE iconSpace is auto THE navigation drawer SHALL keep an icon's room, empty, on a row without an icon WHERE another row of its level (the same group's rows, or the drawer's top-level rows) has an icon, so that the labels of the level start on one line; WHILE it is always on every row without an icon; and WHILE it is never on none, the label then starting comp.navigation-drawer.item.padding-inline.regular from where the row's content starts. The room is the icon's box and and counts toward the next level's step (NVD-69).
NVD-72	WHILE expandable is false THE navigation drawer SHALL draw every group open whatever its open says, draw no chevron and keep no room for one, emit no toggle, and SHALL expose no group as expandable: a group that is a destination (NVD-66) SHALL be that destination alone, and every other group's row SHALL be drawn, take no focus, answer no pointer and be hidden from assistive technology, its label naming the list of its items, which stays a list inside the drawer's list. WHILE the drawer is collapsed it SHALL still draw each top-level group as one cell, whose activation expands the drawer (NVD-47).
NVD-73	WHILE guides is shown THE navigation drawer SHALL draw, for each open group that shows at least one row under it while the drawer is expanded, one line comp.navigation-drawer.guide.width wide in comp.navigation-drawer.guide.color from the lower edge of the group's row to the lower edge of the last row shown under it, centred under the group's first part — its start chevron, else its icon or the icon's room, else at the start of its label — as the tree view does; WHILE guides is hover it SHALL draw the same lines only while the pointer is over the drawer or focus is in it, fading them in and out over comp.navigation-drawer.motion.state-duration with comp.navigation-drawer.motion.state-easing (at once where motion is reduced); WHILE guides is none it SHALL draw none. The lines SHALL take no space, keep their color and full opacity in every state of the rows beside them, be hidden from assistive technology, and continue under a pinned group row (NVD-77); WHILE indent is 0 no line SHALL be drawn. In forced colors they SHALL be drawn in the system's line color.
NVD-74	WHILE a destination's or a group's supportingText is not empty THE navigation drawer SHALL draw it in comp.navigation-drawer.item.supporting-text.typescale and its condition's supporting-text color (comp.navigation-drawer.unselected.item.supporting-text.color, comp.navigation-drawer.selected.item.supporting-text.color): WHILE supportingPosition is below on a line of its own under the label, the row growing to hold it with comp.navigation-drawer.item.padding-block.regular above and below its text, and WHILE it is inline after the label on its line, comp.navigation-drawer.item.gap after it; it SHALL be one line unless supportingWrap is true (NVD-75), SHALL be read as the row's description after its name and state, and SHALL NOT be drawn while the drawer is collapsed.
NVD-75	WHILE labelWrap is false THE navigation drawer SHALL draw each row's label on one line, cut with an ellipsis at the end of its own direction where it does not fit, and WHILE supportingWrap is false the same for its supporting text, below or inline; WHILE either is true that text SHALL wrap and the row grow with it. THE row's accessible name SHALL be its full label, and its description its full supporting text, whatever is drawn. WHEN a row whose label or supporting text is cut is hovered with a fine pointer, after the tooltip's show delay, or receives keyboard focus, THE navigation drawer SHALL show the full text in a plain tooltip beside the row, toward the content (NVD-56), which Escape dismisses, which stays while the pointer is over the row or focus is on it, and which SHALL NOT be shown for a row whose text is drawn whole.
NVD-76	WHILE an open group's loading is true THE navigation drawer SHALL draw one loading row under it, after the rows of any items it already holds, one step of indent further in (NVD-69): a Loading indicator component of the small size in the place of a row's icon, and after it loadingLabel in comp.navigation-drawer.item.supporting-text.typescale and comp.navigation-drawer.unselected.item.supporting-text.color, in a row of comp.navigation-drawer.item.container.height.regular. It is not a destination: it SHALL take no focus and answer no pointer, SHALL be counted among no items, and SHALL be named by loadingLabel; THE navigation drawer SHALL expose the list of the group's items as busy WHILE loading is true, and announce nothing itself. WHILE loadingLabel is empty it SHALL draw the indicator alone and in debug builds report that the loading row has no name.
NVD-77	WHILE stickyParents is true and the drawer is expanded THE navigation drawer SHALL keep pinned at the top of the space its items scroll in the rows of the open groups that hold the first row shown below the pinned rows, at most stickyMax of them, the innermost winning as VS Code keeps its innermost scopes, one per level and each directly under the one above: each pinned row SHALL be the row itself (no copy is drawn or exposed), keep its own fill, state and focus ring, stay interactive as its row is, be drawn over the rows scrolling under it on comp.navigation-drawer.sticky.container.color (a modal drawer's on its own container color), and leave as its group's last row scrolls past, as the platform's sticky position does; the last pinned row SHALL draw an edge comp.navigation-drawer.sticky.divider.width wide in comp.navigation-drawer.sticky.divider.color at its lower side. WHEN keyboard focus moves to a row hidden under the pinned rows THE navigation drawer SHALL scroll it into view below them (NVD-61's least distance, measured from their lower edge), and bring the selection into view below them (NVD-57). Nothing is animated beyond the scroll itself. WHILE the drawer is collapsed, or stickyParents is false, no row SHALL be pinned. WHEN stickyMax is not a positive whole number it SHALL pin 2, and in debug builds report the value.
NVD-78	WHERE the platform has ARIA attributes (the web), WHEN the product sets an aria- attribute on the drawer's own host, by the attribute or by the ARIA property that reflects it, THE navigation drawer SHALL move it to the data-aria- attribute of the same name, so that the host is no second node with its name, description or state, and SHALL expose it on the element that carries the drawer's role — its dialog WHILE it is shown as a modal dialog (NVD-23), its navigation landmark otherwise — an id reference by the elements it names in the host's tree or a tree around it, a description after its own; WHILE label is not empty, label is the drawer's name, over a name given so; WHILE label is empty, a name given so is the drawer's name. WHEN the product sets an aria- attribute on an item's host — a destination's or a group's — THE navigation drawer SHALL move it to the data-aria- attribute of the same name, so that the host is no second node with its name, description or state, and SHALL expose it on the element that carries the row's role (its link or its button), in both forms of the drawer — an id reference by the elements it names in the host's tree or a tree around it, an error message as part of the description while the item is invalid — except those an item owns (aria-current, aria-disabled, and for a group aria-expanded and aria-controls), which it SHALL move and not expose. WHEN the product removes the aria- attribute or its data-aria- twin, or sets the ARIA property that reflects it (ariaLabel, ariaDescribedByElements…) to null, THE navigation drawer SHALL take it off that element. WHEN the product sets an aria- attribute an item owns THE navigation drawer SHALL report it in debug builds.
NVD-79	WHILE filterable is true and the drawer is expanded THE navigation drawer SHALL draw a filter field after its header (NVD-38: its header buttons, its header slot and its main action) and comp.navigation-drawer.header.gap below it (at the padding WHILE the header is empty), across the drawer's width inside comp.navigation-drawer.container.padding-inline, and SHALL lay out what stands under the field — the status line of NVD-90 while there is one, then the items — comp.navigation-drawer.filter.gap below it; the field SHALL stay in place while the items scroll, as the header does (NVD-12). The field SHALL be a Text input component of type search in its default variant, of the medium size WHILE density is regular and the small size WHILE density is compact, showing the glyph search of the system's icon set in its leading-icon slot, filterPlaceholder as its placeholder and filterValue as its value, drawn and answering as that text input draws and answers (its own sentences hold, its tokens are its own). WHILE the drawer is collapsed it SHALL draw no field, SHALL keep filterValue, and SHALL draw its cells as though no filter were applied; WHEN it is expanded again the filter SHALL apply again.
NVD-80	WHEN the person changes the filter field's text — by typing, deleting, pasting, cutting, dictating, an input method committing text, the clear button (NVD-89) or Escape (NVD-86) — THE navigation drawer SHALL emit filterChange exactly once per change with the new text, setting filterValue itself first on the web (a controlled platform leaves filterValue to the caller), and SHALL apply the filter to the new text at once. WHEN the product sets filterValue THE navigation drawer SHALL show that text in the field and apply it, and SHALL NOT emit filterChange. WHILE an input method is composing THE navigation drawer SHALL filter by the text the field reports, and SHALL leave the composition, Enter, Escape and the arrow keys to the input method (TXI-4).
NVD-81	THE navigation drawer SHALL apply a filter WHILE filterable is true and filterValue holds a character that is not white space, and SHALL read the filter text as words: the runs of characters between white space. A destination or a group SHALL match WHILE its label contains every word, each anywhere in it and in any order, compared without regard to case, to the width of a character or to the marks on a letter, as the label's language compares (as the combobox compares, CMB-25). THE navigation drawer SHALL compare nothing else of a row — not its short label, its supporting text, its trailing text, its badge, its value or its href — and not a section's title. A disabled row SHALL match as any other row and stay disabled. It SHALL match only the items it holds: the items of a group that loads them when it opens (NVD-76) are not searched until they are given. THE navigation drawer SHALL NOT fetch, wait, debounce, rank or reorder anything for a filter.
NVD-82	WHILE a filter is applied THE navigation drawer SHALL show, in the order given: each row that matches; each group's row that holds a row that matches, at any depth; and every item inside a group whose own row matches, so that a group found by its name is shown whole. Every other row SHALL be hidden — not drawn, taking no space, not focusable and not exposed to assistive technology — together with what it holds. A section with no row shown SHALL be hidden with its heading and its divider; a section with a row shown SHALL keep both. A hidden row SHALL keep its open, its disabled state and its selection, and WHEN no filter is applied any more every row SHALL be shown as it was.
NVD-84	WHILE a filter is applied THE navigation drawer SHALL draw open, for the filter, each closed group that holds a row that matches and is shown, at any depth, so that every match is in view without the person opening anything, and SHALL draw every other group as its open says. Opening a group for the filter SHALL write nothing to the group's open, SHALL emit no toggle, and SHALL be drawn at once, without the motion of NVD-44; the group's row SHALL be exposed as expanded while it is drawn open. WHEN the person opens or closes a group while a filter is applied THE navigation drawer SHALL answer as NVD-45 says — setting open itself on the web and emitting toggle exactly once where open changes — and SHALL stop opening that group for the filter until the filter text changes. WHEN no filter is applied any more THE navigation drawer SHALL draw every group as its open says: the groups the filter opened close again, at once, and a group the person opened or closed stays as the person left it.
NVD-85	WHILE a filter is applied THE navigation drawer SHALL draw each row it shows as it draws that row without a filter, and SHALL NOT mark, in a label, the characters that a word of the filter text matched: no color, weight, fill or element of their own. What the filter leaves is the answer, as in a file tree's filter and a site's sidebar filter; a row SHALL be told from the others only by its own states — selected, disabled, hovered, pressed and focused — and as the active match (NVD-86). THE navigation drawer SHALL expose each label to assistive technology as the one text it is without a filter.
NVD-86	WHILE keyboard focus is in the filter field, a filter is applied and a row shown matches and is not disabled, THE navigation drawer SHALL make the first such row, in reading order, the active match — as soon as there is one, and the new first one whenever the result changes — and SHALL draw it as it draws that row while the row has keyboard focus, its focused tokens and its focus ring (NVD-10), without animation, while focus stays in the field, so that typing goes on editing the filter text; a pointer over a row SHALL NOT make it the active match, and WHILE focus is not in the field no row SHALL be drawn as one. WHILE no input method is composing, WHEN the person presses Enter THE navigation drawer SHALL take the active match as Enter on that row takes it — a destination activated (NVD-1, NVD-60), a group's row opened or closed (NVD-45) — and SHALL keep focus in the field unless the activation moves it (a link followed, a modal drawer closed, NVD-21); WHEN the person presses Down Arrow THE navigation drawer SHALL move focus to the active match and do nothing more. WHILE there is no active match the two keys SHALL do nothing of the drawer's own. WHEN the person presses Escape WHILE the field holds text THE navigation drawer SHALL empty it, emit filterChange once with the empty text, and keep focus in the field, as a native search field does; WHEN the person presses Escape WHILE the field is empty THE navigation drawer SHALL return focus to the element that had it before the filter shortcut moved it to the field (NVD-87), and otherwise SHALL do nothing of its own and let the key pass on, so that a modal drawer closes (NVD-20). Up Arrow, Home, End and the arrow keys along the line SHALL stay the field's.
NVD-87	WHILE filterable is true and filterShortcut holds exactly one chord THE navigation drawer SHALL draw that chord at the end of the filter field with the keyboard shortcut component, hosted as KBS-13 says — in its plain form, at size small, with convention auto, its legends and separators in comp.navigation-drawer.filter.shortcut.typescale and comp.navigation-drawer.filter.shortcut.color, and no cap, fill or edge (KBS-7) — only while the field is empty and does not have focus, SHALL expose it as the field's keyboard shortcut (KBS-12: aria-keyshortcuts on the web) with the drawn keys hidden from assistive technology, and SHALL give the hint no press of its own. WHEN the person presses that chord anywhere in the window, read as SRC-38 reads a chord and with its exceptions (a press something else has taken, a key repeating while held, an input-method composition and, for a chord without mod, ctrl or alt, focus in an element that takes text), THE navigation drawer SHALL keep the press from doing anything else and SHALL: WHILE it is expanded and shown, move focus to the field with its text selected; WHILE it is collapsed (a collapsible standard drawer, or the column of a collapsible modal drawer), emit expandedChange with true, apply it itself on the web as NVD-37 does, and move focus to the field once it is expanded. WHILE it is not shown (a standard drawer whose open is false, or a modal drawer that is closed and not collapsible) it SHALL NOT take the press: what opens it is the product's, or the app shell's (APS-33). THE navigation drawer SHALL listen only while it is part of what is shown and filterable is true, and SHALL stop when it is removed. IF another shown navigation drawer, tree view or search binds the same chord, the one shown first SHALL keep it and the others SHALL bind nothing and report it in debug builds, as SRC-39 says. WHILE filterShortcut is empty or holds more than one chord THE navigation drawer SHALL draw no hint and bind nothing, reporting more than one chord in debug builds.
NVD-88	WHEN the product asks the navigation drawer to focus its filter (the platform's method for it) WHILE filterable is true THE navigation drawer SHALL do what its chord does (NVD-87), whether or not filterShortcut is empty; WHILE it is a modal drawer that is closed it SHALL instead move focus to the field the next time it opens, in place of the destination NVD-19 would give focus to — so that an app shell, or a key of the product's own, can open the drawer and land in its field.
NVD-89	WHILE the filter field holds text THE navigation drawer SHALL draw, in the field's trailing-icon slot, an icon-only Tanrei Button of the text variant and the small size showing the glyph close of the system's icon set, not mirrored, named by filterClearLabel. WHEN it is activated THE navigation drawer SHALL empty the field, emit filterChange once with the empty text, and move focus to the field. WHILE filterClearLabel is empty and the product's words give none THE navigation drawer SHALL still draw the button, and in debug builds report that it has no accessible name. The hint of NVD-87 and the clear button SHALL never be drawn together.
NVD-90	WHILE a filter is applied THE navigation drawer SHALL draw a status line at the top of the results, where its first item would stand, the items following it: filterCountText with its place {count} filled by the number of rows that match WHILE a row matches and filterCountHidden is false, and filterEmptyText WHILE no row matches, in place of the items, all of them hidden. It SHALL draw the line in comp.navigation-drawer.filter.status.typescale and comp.navigation-drawer.filter.status.color, inset as a row's content is (comp.navigation-drawer.item.padding-inline.regular for regular and comp.navigation-drawer.item.padding-inline.compact for compact), wrapping and growing with enlarged text, as text of its own direction (NVD-52), taking no focus and no state, and hidden from assistive technology, which NVD-91 tells the same words. WHILE a row matches and filterCountHidden is true it SHALL draw no line. WHILE the words it would draw are empty and the product's words give none THE navigation drawer SHALL draw nothing in their place and in debug builds report it.
NVD-91	WHEN the result of a filter changes — the filter text or the items change while a filter is applied — and has then stayed as it is for one second (the pause that ends a type-ahead run, TRV-23), THE navigation drawer SHALL tell assistive technology once, politely and without moving focus, filterCountText with its place {count} filled by the number of rows that match, or filterEmptyText WHILE no row matches; WHEN no filter is applied any more it SHALL say nothing. It SHALL say them whether or not filterCountHidden is true, through one status of its own that is not drawn (the line of NVD-90 is what is drawn) — on the web an element with the status role and aria-atomic true, inside the drawer — and never through the field's name or description. WHILE filterCountText is empty and the product's words give none THE navigation drawer SHALL say no count and in debug builds report it.
NVD-92	THE navigation drawer SHALL change nothing but what it draws for a filter: value, expanded, open, every group's open (except where the person opens or closes one, NVD-84) and the distance scrollOffset measures SHALL stay as they were, and it SHALL keep filterValue no longer than its own lifetime and write it to no storage, as NVD-62 says of a group's open. WHEN a filter begins to be applied THE navigation drawer SHALL remember how far its items are scrolled, and WHEN the filter text changes while a filter is applied it SHALL scroll its items to their start; WHEN no filter is applied any more it SHALL, WHILE keyboard focus is on a row, keep that row where it is in the view as far as the scrolling allows, and otherwise scroll back to where the items stood when the filter began. A selected destination that the filter hides SHALL stay selected and SHALL be brought into view (NVD-57) only once it is shown again.
NVD-93	WHEN a filter comes to hide the row that has keyboard focus (the product sets filterValue, or changes the items) THE navigation drawer SHALL move focus to the filter field. WHILE a filter is applied and keyboard focus is on a destination, a group's row or a group's chevron, WHEN the person presses Escape THE navigation drawer SHALL, WHILE variant is standard, open, as the person would (open set and toggle emitted for each, NVD-45), the groups the filter had opened around that row, so that it stays shown, then empty the filter as NVD-86 does and keep focus on that row, which NVD-92 keeps in view, so that a person who found a place by the filter sees it among its neighbours; WHILE the drawer is modal, Escape SHALL close it as NVD-20 says and leave the filter as it is.
NVD-94	THE navigation drawer SHALL draw every change a filter makes — rows hidden and shown, groups opened for the filter and closed again — at once, without the motions of NVD-41 and NVD-44, whether or not motion is reduced; a group the person opens or closes during a filter moves as NVD-44 says.
NVD-95	THE navigation drawer SHALL expose the filter field as a search field — on the web an input of type search, which has the searchbox role — named by filterLabel, with filterPlaceholder as its placeholder, controlling the drawer's list of items (aria-controls on the web), after the header and before the items in reading and focus order; each shown destination and group with its position among the shown items of its level and their number, so that a person is told the size of what the filter left; and the rows the filter hides not at all. WHILE filterable is true and filterLabel is empty THE navigation drawer SHALL still draw the field, and in debug builds report that it has no accessible name.

各平台名称对照

对等并不意味着 API 完全相同。同一份契约，由各平台以自己的惯用方式表达。

规格	Web	SwiftUI	Jetpack Compose	Flutter	React Native
组件	tanrei-navigation-drawer	TanreiNavigationDrawer	TanreiNavigationDrawer	TanreiNavigationDrawer	NavigationDrawer
variant · 属性	variant	variant	variant	variant	variant
open · 属性	open	isPresented	drawerState	open	open
collapsible · 属性	collapsible	isCollapsible	collapsible	collapsible	collapsible
expanded · 属性	expanded	isExpanded	expanded	extended	expanded
collapsedLabels · 属性	collapsedLabels	collapsedLabelVisibility	collapsedLabelVisibility	labelType	collapsedLabelVisibility
density · 属性	density	density	density	density	density
chevron · 属性	chevron	chevron	chevron	chevron	chevron
guides · 属性	guides	guides	guides	guides	guides
indent · 属性	indent	indent	indent	indent	indent
highlight · 属性	highlight	highlight	highlight	highlight	highlight
iconSpace · 属性	iconSpace	iconSpace	iconSpace	iconSpace	iconSpace
expandable · 属性	expandable	expandable	expandable	expandable	expandable
labelWrap · 属性	labelWrap	labelWrap	labelWrap	labelWrap	labelWrap
supportingWrap · 属性	supportingWrap	supportingWrap	supportingWrap	supportingWrap	supportingWrap
responsive · 属性	responsive	isResponsive	responsive	responsive	responsive
value · 属性	value	selection	selected	selectedIndex	value
revealSelected · 属性	revealSelected	revealsSelection	revealSelected	revealSelected	revealSelected
selectableGroups · 属性	selectableGroups	selectableGroups	selectableGroups	selectableGroups	selectableGroups
scrollOffset · 属性	scrollOffset	scrollOffset	scrollState	scrollController	scrollOffset
stickyParents · 属性	stickyParents	stickyParents	stickyParents	stickyParents	stickyParents
stickyMax · 属性	stickyMax	stickyMax	stickyMax	stickyMax	stickyMax
loadingLabel · 属性	loadingLabel	loadingLabel	loadingLabel	loadingLabel	loadingLabel
filterable · 属性	filterable	isFilterable	filterable	filterable	filterable
filterValue · 属性	filterValue	filterText	filterValue	filterValue	filterValue
filterLabel · 属性	filterLabel	filterLabel	filterLabel	filterLabel	filterLabel
filterPlaceholder · 属性	filterPlaceholder	filterPrompt	filterPlaceholder	filterPlaceholder	filterPlaceholder
filterEmptyText · 属性	filterEmptyText	filterEmptyText	filterEmptyText	filterEmptyText	filterEmptyText
filterCountText · 属性	filterCountText	filterCountText	filterCountText	filterCountText	filterCountText
filterCountHidden · 属性	filterCountHidden	isFilterCountHidden	filterCountHidden	filterCountHidden	filterCountHidden
filterClearLabel · 属性	filterClearLabel	filterClearLabel	filterClearLabel	filterClearLabel	filterClearLabel
filterShortcut · 属性	filterShortcut	filterShortcut	filterShortcut	filterShortcut	filterShortcut
label · 属性	label	accessibilityLabel	contentDescription	semanticLabel	accessibilityLabel
change · 事件	change	selection	onClick	onDestinationSelected	onValueChange
reselect · 事件	reselect	onReselect	onClick	onDestinationSelected	onReselect
close · 事件	close	isPresented	drawerState	onClose	onClose
expandedChange · 事件	expandedchange	isExpanded	onExpandedChange	onExtendedChanged	onExpandedChange
presentationChange · 事件	presentationchange	onPresentationChange	onPresentationChange	onPresentationChanged	onPresentationChange
filterChange · 事件	filterchange	filterText	onFilterValueChange	onFilterChanged	onFilterChange
备注	Children are <tanrei-navigation-drawer-item>, <tanrei-navigation-drawer-group> and <tanrei-navigation-drawer-section> elements, in order; header buttons (icon-only <tanrei-button>s) and the main action (<tanrei-main-action-button>) are children with slot="header-button" and slot="main-action", and the header slot is header. collapsedLabels is the collapsed-labels attribute; expanded is reflected, and so is a read-only collapsed state attribute for styling. Modal: a <dialog> in the shadow root opened with showModal(), its ::backdrop the scrim; Escape and a press on the backdrop close it, the host sets open to false and fires close; a collapsible modal drawer keeps its column in the host's layout box and widens the dialog from it. Standard: a <nav> named by label. The drawer selects the activated destination itself (sets value) before firing change, sets expanded (or open) before firing expandedchange, and sets a group's open before the group fires toggle. It sets aria-expanded and aria-controls on its first header button's inner button through the Button's ariaExpanded / ariaControlsElements element properties, and the Main Action Button's extended from its own form. responsive is an attribute: the element reads its system's breakpoint.expanded and breakpoint.collapsed custom properties from its computed style, listens to the two widths with matchMedia, exposes the result as the read-only presentation property (reflected as a state attribute for styling) and fires presentationchange with detail.presentation; nothing about the presentation is written to variant, open or expanded, and nothing is kept in storage. Before the element is upgraded, and in the React wrapper on a server, no dialog is open and nothing is inert. A collapsed cell that draws no label shows its name in a plain tooltip. Insets are env(safe-area-inset-*). It lags the spec: it ships an earlier form of the drawer, with a separate rail element beside it. It does not yet follow NVD-57 to NVD-64, nor the parts of NVD-1, NVD-21 and NVD-23 that go with them. reveal-selected is an attribute. scroll-offset is an attribute read once, for the first frame, and scrollOffset a property whose getter returns the scroller's present scrollTop and whose setter writes it; the scroller has overscroll-behavior: contain and scroll-behavior: auto, and bringing the selection into view is a write to scrollTop, never scrollIntoView (which would also scroll the page). For a link destination change and reselect are cancelable, carry detail.href beside detail.value, and are fired from the anchor's click only when event.button is 0, no modifier key is down, the click was not already cancelled, and the item's target is same and it has no download; cancelling one calls preventDefault() on that click. The drawer does not set value for a link. Nothing is read from or written to sessionStorage or localStorage: a site keeps the groups' open and scrollOffset itself (on toggle and on pagehide) and writes them back as attributes in the page's markup, or in an inline script placed after the drawer's markup, before the elements are upgraded. density is reflected; a value a design system added is read from its own tokens, falling back to regular's. selectableGroups is the selectable-groups attribute. The attributes are chevron, guides, indent (auto or a number), highlight, icon-space, expandable (expandable="false" turns it off), label-wrap, supporting-wrap, sticky-parents, sticky-max and loading-label; on the items supporting-text, supporting-position, and on a group open-icon, trailing-text, loading and the trailing slot. Filter (NVD-79 to NVD-95): the attributes are filterable, filter-value, filter-label, filter-placeholder, filter-empty-text, filter-count-text, filter-count-hidden, filter-clear-label and filter-shortcut (a space-separated list of chords); filterchange carries detail.value. The field is a <tanrei-text-input type="search" variant="stacked"> in the shadow root between the header and the items (part filter), its leading glyph and its clear button (a <tanrei-button>) slotted into it; the drawer sets aria-controls (the drawer's list, through ariaControlsElements) and aria-keyshortcuts on its native input. The status line (part filter-status) stands first in the list of items, hidden from assistive technology; the status is a visually hidden element with role="status" and aria-atomic="true" in the shadow root. A row the filter hides takes display: none from a state attribute it writes on its own host (data-filter-hidden), a section with no row shown likewise, and a group opened for the filter draws its items open without writing open. The active match is drawn by a state attribute on its host (data-filter-active). focusFilter() is the method of NVD-88. The chord is read as the search reads its own (SRC-38), and the drawer, the search and the tree view share one registry of the chords that are bound (SRC-39).	TanreiNavigationDrawer(variant:, isPresented: Binding<Bool>, selection: Binding<Value>, isCollapsible:, isExpanded: Binding<Bool>, collapsedLabelVisibility:, onReselect:) { TanreiNavigationDrawerItem(…); TanreiNavigationDrawerGroup(…) { … }; TanreiNavigationDrawerSection(…) { … } } header: { … } headerButtons: { … } mainAction: { … }, and for a modal drawer the modifier .tanreiNavigationDrawer(isPresented:…) on the content it covers. Closing writes false to isPresented (close); the menu button writes isExpanded (expandedChange). The modal drawer carries the modal trait and answers the escape gesture (accessibilityAction(.escape)). It lags the spec: it ships an earlier form of the drawer (no collapsed form, groups or trailing slot; its badge: string is the trailing text), with a separate rail component beside it. Not built on this platform yet: the 48 row with the menu item's corners in both forms, a collapsed cell that is the row without its label (collapsedLabels defaults to never), nested rows whose content alone starts further in while their item containers keep the full width (NVD-13), the header slot's inherited text style and color (NVD-38), a selection that changes color in place, and responsive with its event (NVD-53 to NVD-55): the width comes from a GeometryReader on the window's scene, or horizontalSizeClass where the product prefers Apple's own classes; onPresentationChange is a closure. Also not built yet (NVD-57 to NVD-64): revealsSelection: Bool, and scrollOffset: Binding<CGFloat> over the items' ScrollView (a ScrollPosition where the deployment target has it), which the product may keep in @SceneStorage. Not yet: the heading's letter-spacing by the script of its text (NVD-16, PRS-20). Not built yet: density (NVD-65), a density parameter as the tree view's on this platform; and this platform's drawer still reads the tokens that the density axis made per density (the row height, paddings, gap, nesting indent, icon sizes, label style, the collapsed column and the heading height), each now one value per density in the generated tokens, so it does not build against them until it catches up. Not built yet: selectableGroups (NVD-66, NVD-67) — a group that is a destination, with its row choosing it and its chevron a control of its own that opens and closes it. Not built yet: the row model shared with the tree view (chevron, guides, indent, highlight, iconSpace, expandable, labelWrap and supportingWrap, supporting text, one-line labels with a tooltip where cut, a group's trailing content, openIcon and loading row, stickyParents and stickyMax; NVD-68 to NVD-77). Filter (NVD-79 to NVD-95), not built yet: filterText: Binding<String>; the chord is a .keyboardShortcut on hardware keyboards; the status is an AccessibilityNotification.Announcement with the polite priority; focusFilter() is a FocusState the product can set.	Compose idiom (as ModalNavigationDrawer and DismissibleNavigationDrawer, and Material 3 Expressive's WideNavigationRail for the collapsed form): TanreiNavigationDrawer(variant, drawerState, collapsible, expanded, onExpandedChange, collapsedLabelVisibility, header = { … }, headerButtons = { … }, mainAction = { … }, drawerContent = { TanreiNavigationDrawerItem(…); TanreiNavigationDrawerGroup(…) { … }; TanreiNavigationDrawerSection(…) { … } }, content = { … }). drawerState (rememberTanreiDrawerState) is open or closed; the drawer closes it itself on the scrim, back and drag, and its confirmValueChange sees the close. As for the bar, the drawer's value and a destination's value both map to the item's selected, and one onClick covers change and reselect. The modal sheet sets a pane title from contentDescription and is drawn in a window of its own (a Dialog), as TanreiDialog is, which traps focus, handles back and hides the content behind from TalkBack. It lags the spec: it ships an earlier form of the drawer, with a separate rail component beside it. Not built on this platform yet: the 48 row with the menu item's corners in both forms, a collapsed cell that is the row without its label (collapsedLabels defaults to never), nested rows whose content alone starts further in while their item containers keep the full width (NVD-13), the header slot's inherited text style and color (NVD-38), a selection that changes color in place, and responsive with its event (NVD-53 to NVD-55): the width comes from LocalWindowInfo.current.containerSize (or currentWindowAdaptiveInfo() where the product has it); onPresentationChange is a lambda and drawerState is closed by the drawer when the presentation changes. Also not built yet (NVD-57 to NVD-64): revealSelected: Boolean, and a hoisted scrollState: ScrollState = rememberScrollState(), which is saved and restored by rememberSaveable as any scroll state is; the drawer writes nothing itself. Not yet: the heading's letter-spacing by the script of its text (NVD-16, PRS-20). Not built yet: density (NVD-65), a density parameter as the tree view's on this platform; and this platform's drawer still reads the tokens that the density axis made per density (the row height, paddings, gap, nesting indent, icon sizes, label style, the collapsed column and the heading height), each now one value per density in the generated tokens, so it does not build against them until it catches up. Not built yet: selectableGroups (NVD-66, NVD-67) — a group that is a destination, with its row choosing it and its chevron a control of its own that opens and closes it. Not built yet: the row model shared with the tree view (chevron, guides, indent, highlight, iconSpace, expandable, labelWrap and supportingWrap, supporting text, one-line labels with a tooltip where cut, a group's trailing content, openIcon and loading row, stickyParents and stickyMax; NVD-68 to NVD-77). Filter (NVD-79 to NVD-95), not built yet: filterValue with onFilterValueChange; the status is a polite liveRegion node; the chord is read from hardware keys (onPreviewKeyEvent); focusFilter is a FocusRequester in the drawer's state.	Flutter idiom (as NavigationDrawer, with the rail widget's extended and labelType for the collapsed form): TanreiNavigationDrawer(variant:, collapsible:, extended:, onExtendedChanged:, labelType:, selectedIndex:, onDestinationSelected:, headerButtons: [...], mainAction:, header:, children: [TanreiNavigationDrawerDestination(…), TanreiNavigationDrawerGroup(…), TanreiNavigationDrawerSection(…), …]). A destination's value is its index among the destinations, counted in reading order through sections and groups, open or not, as NavigationDrawer counts its destinations. labelType is all, selected or none. open shows or hides the drawer in both variants. A modal drawer is a controlled overlay in a Stack over the page — not Scaffold.drawer, which would need Material — with its own scrim and motion, a FocusScope that keeps focus in, and the page's semantics blocked; Escape, back (PopScope), a drag or fling, the menu button and choosing a destination call onClose once. It lags the spec: it ships an earlier form of the drawer, with a separate rail component beside it. Not built on this platform yet: the 48 row with the menu item's corners in both forms, a collapsed cell that is the row without its label (collapsedLabels defaults to never), nested rows whose content alone starts further in while their item containers keep the full width (NVD-13), the header slot's inherited text style and color (NVD-38), a selection that changes color in place, and responsive with its event (NVD-53 to NVD-55): the width comes from MediaQuery.sizeOf(context).width; onPresentationChanged is a ValueChanged<TanreiNavigationDrawerPresentation> and onClose is called when a change of presentation closes the drawer. Also not built yet (NVD-57 to NVD-64): revealSelected: bool, and scrollController: ScrollController? (its initialScrollOffset is the first frame's offset); a PageStorageKey or a restorationId on the product's side keeps the offset, the drawer writes nothing itself. Not yet: the heading's letter-spacing by the script of its text (NVD-16, PRS-20). Not built yet: density (NVD-65), a density parameter as the tree view's on this platform; and this platform's drawer still reads the tokens that the density axis made per density (the row height, paddings, gap, nesting indent, icon sizes, label style, the collapsed column and the heading height), each now one value per density in the generated tokens, so it does not build against them until it catches up. Not built yet: selectableGroups (NVD-66, NVD-67) — a group that is a destination, with its row choosing it and its chevron a control of its own that opens and closes it. Not built yet: the row model shared with the tree view (chevron, guides, indent, highlight, iconSpace, expandable, labelWrap and supportingWrap, supporting text, one-line labels with a tooltip where cut, a group's trailing content, openIcon and loading row, stickyParents and stickyMax; NVD-68 to NVD-77). Filter (NVD-79 to NVD-95), not built yet: filterValue with onFilterChanged; the chord is a Shortcuts entry; the status is SemanticsService.announce with the polite assertiveness; focusFilter is a FocusNode the product may pass.	Controlled: open, expanded, value, onValueChange, onExpandedChange, onClose, an items data array, headerButtons and mainAction elements and a header node. A modal drawer is presented in a transparent Modal with its own motion and scrim; onRequestClose (Android back) calls onClose. Destinations have the button role with accessibilityState.selected; group rows the button role with accessibilityState.expanded; headings the header role. Insets come from its own insets prop, falling back to TanreiProvider's. It lags the spec: it ships an earlier form of the drawer, with a separate rail component beside it. Not built on this platform yet: the 48 row with the menu item's corners in both forms, a collapsed cell that is the row without its label (collapsedLabels defaults to never), nested rows whose content alone starts further in while their item containers keep the full width (NVD-13), the header slot's inherited text style and color (NVD-38), a selection that changes color in place, and responsive with its event (NVD-53 to NVD-55): the width comes from useWindowDimensions(); onPresentationChange receives 'standard' | 'column' | 'modal', and onClose is called when a change of presentation closes the drawer. Also not built yet (NVD-57 to NVD-64): revealSelected, and scrollOffset as the first frame's offset with a ref method getScrollOffset() for reading it; the drawer writes to no storage. Not yet: the heading's letter-spacing by the script of its text (NVD-16, PRS-20). Not built yet: density (NVD-65), a density parameter as the tree view's on this platform; and this platform's drawer still reads the tokens that the density axis made per density (the row height, paddings, gap, nesting indent, icon sizes, label style, the collapsed column and the heading height), each now one value per density in the generated tokens, so it does not build against them until it catches up. Not built yet: selectableGroups (NVD-66, NVD-67) — a group that is a destination, with its row choosing it and its chevron a control of its own that opens and closes it. Not built yet: the row model shared with the tree view (chevron, guides, indent, highlight, iconSpace, expandable, labelWrap and supportingWrap, supporting text, one-line labels with a tooltip where cut, a group's trailing content, openIcon and loading row, stickyParents and stickyMax; NVD-68 to NVD-77). Filter (NVD-79 to NVD-95), not built yet: controlled filterValue with onFilterChange; the status is AccessibilityInfo.announceForAccessibilityWithOptions with queue: true; focusFilter() is on the component's ref.

令牌

令牌	引用	解析值（浅色）
--tanrei-comp-navigation-drawer-breakpoint-collapsed	sys.breakpoint.medium	600px
--tanrei-comp-navigation-drawer-breakpoint-expanded	sys.breakpoint.expanded	1024px
--tanrei-comp-navigation-drawer-collapsed-selected-disabled-item-container-color	—	#262626 · 16%
--tanrei-comp-navigation-drawer-collapsed-selected-disabled-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-selected-disabled-item-icon-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-selected-disabled-item-label-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-selected-disabled-item-state-layer-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-selected-disabled-item-supporting-text-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-selected-disabled-item-trailing-icon-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-selected-disabled-item-trailing-text-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-selected-focused-item-container-color	—	#262626 · 24.4%
--tanrei-comp-navigation-drawer-collapsed-selected-focused-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-selected-focused-item-icon-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-focused-item-label-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-focused-item-state-layer-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-focused-item-supporting-text-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-focused-item-trailing-icon-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-focused-item-trailing-text-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-hovered-item-container-color	—	#262626 · 22.7%
--tanrei-comp-navigation-drawer-collapsed-selected-hovered-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-selected-hovered-item-icon-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-hovered-item-label-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-hovered-item-state-layer-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-hovered-item-supporting-text-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-hovered-item-trailing-icon-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-hovered-item-trailing-text-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-item-container-color	comp.navigation-drawer.selected.item.container.color	#262626 · 16%
--tanrei-comp-navigation-drawer-collapsed-selected-item-icon-indicator-color	comp.navigation-drawer.selected.item.icon-indicator.color	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-selected-item-icon-color	comp.navigation-drawer.selected.item.icon.color	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-item-label-color	comp.navigation-drawer.selected.item.label.color	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-item-state-layer-color	comp.navigation-drawer.collapsed-selected.item.icon.color	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-item-supporting-text-color	comp.navigation-drawer.selected.item.supporting-text.color	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-item-trailing-icon-color	comp.navigation-drawer.selected.item.trailing-icon.color	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-item-trailing-text-color	comp.navigation-drawer.selected.item.trailing-text.color	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-pressed-item-container-color	—	#262626 · 24.4%
--tanrei-comp-navigation-drawer-collapsed-selected-pressed-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-selected-pressed-item-icon-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-pressed-item-label-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-pressed-item-state-layer-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-pressed-item-supporting-text-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-pressed-item-trailing-icon-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-selected-pressed-item-trailing-text-color	—	#262626
--tanrei-comp-navigation-drawer-collapsed-unselected-disabled-item-container-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-unselected-disabled-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-unselected-disabled-item-icon-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-unselected-disabled-item-label-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-unselected-disabled-item-state-layer-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-unselected-disabled-item-supporting-text-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-unselected-disabled-item-trailing-icon-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-unselected-disabled-item-trailing-text-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-collapsed-unselected-focused-item-container-color	—	#4b4b4b · 10%
--tanrei-comp-navigation-drawer-collapsed-unselected-focused-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-unselected-focused-item-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-focused-item-label-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-focused-item-state-layer-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-focused-item-supporting-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-focused-item-trailing-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-focused-item-trailing-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-hovered-item-container-color	—	#4b4b4b · 8%
--tanrei-comp-navigation-drawer-collapsed-unselected-hovered-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-unselected-hovered-item-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-hovered-item-label-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-hovered-item-state-layer-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-hovered-item-supporting-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-hovered-item-trailing-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-hovered-item-trailing-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-item-container-color	comp.navigation-drawer.unselected.item.container.color	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-unselected-item-icon-indicator-color	comp.navigation-drawer.unselected.item.icon-indicator.color	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-unselected-item-icon-color	comp.navigation-drawer.unselected.item.icon.color	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-item-label-color	comp.navigation-drawer.unselected.item.label.color	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-item-state-layer-color	comp.navigation-drawer.collapsed-unselected.item.icon.color	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-item-supporting-text-color	comp.navigation-drawer.unselected.item.supporting-text.color	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-item-trailing-icon-color	comp.navigation-drawer.unselected.item.trailing-icon.color	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-item-trailing-text-color	comp.navigation-drawer.unselected.item.trailing-text.color	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-pressed-item-container-color	—	#4b4b4b · 10%
--tanrei-comp-navigation-drawer-collapsed-unselected-pressed-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-collapsed-unselected-pressed-item-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-pressed-item-label-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-pressed-item-state-layer-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-pressed-item-supporting-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-pressed-item-trailing-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-unselected-pressed-item-trailing-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-container-width-compact	—	56px
--tanrei-comp-navigation-drawer-collapsed-container-width-regular	—	72px
--tanrei-comp-navigation-drawer-collapsed-item-container-padding-block-compact	sys.space.space100	8px
--tanrei-comp-navigation-drawer-collapsed-item-container-padding-block-regular	sys.space.space150	12px
--tanrei-comp-navigation-drawer-collapsed-item-container-padding-inline	sys.space.space50	4px
--tanrei-comp-navigation-drawer-collapsed-item-container-shape	comp.navigation-drawer.item.container.shape	6px
--tanrei-comp-navigation-drawer-collapsed-item-container-width-compact	—	32px
--tanrei-comp-navigation-drawer-collapsed-item-container-width-regular	—	48px
--tanrei-comp-navigation-drawer-collapsed-item-gap	sys.space.space50	4px
--tanrei-comp-navigation-drawer-container-color-modal	sys.color.surface-container-low	#f9f9f9
--tanrei-comp-navigation-drawer-container-color-standard	sys.color.surface	#ffffff
--tanrei-comp-navigation-drawer-container-elevation-modal	sys.elevation.level2	0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 2px 0px rgb(0 0 0 / 0.04)
--tanrei-comp-navigation-drawer-container-elevation-standard	sys.elevation.level0
--tanrei-comp-navigation-drawer-container-gap-compact	—	2px
--tanrei-comp-navigation-drawer-container-gap-regular	—	4px
--tanrei-comp-navigation-drawer-container-padding-block	sys.space.space150	12px
--tanrei-comp-navigation-drawer-container-padding-inline	sys.space.space150	12px
--tanrei-comp-navigation-drawer-container-shape-modal	sys.shape.corner.large	12px
--tanrei-comp-navigation-drawer-container-shape-standard	sys.shape.corner.none	0px
--tanrei-comp-navigation-drawer-container-width	—	240px
--tanrei-comp-navigation-drawer-disabled-opacity	—	1
--tanrei-comp-navigation-drawer-filter-gap	sys.space.space150	12px
--tanrei-comp-navigation-drawer-filter-shortcut-color	sys.color.on-surface-variant	#4b4b4b
--tanrei-comp-navigation-drawer-filter-status-color	sys.color.on-surface-variant	#4b4b4b
--tanrei-comp-navigation-drawer-focused-opacity	—	1
--tanrei-comp-navigation-drawer-guide-color	sys.color.outline-variant	#000000 · 8%
--tanrei-comp-navigation-drawer-guide-width	sys.border.hairline	1px
--tanrei-comp-navigation-drawer-header-color	sys.color.on-surface	#1b1b1b
--tanrei-comp-navigation-drawer-header-gap	sys.space.space300	24px
--tanrei-comp-navigation-drawer-header-item-gap	sys.space.space100	8px
--tanrei-comp-navigation-drawer-heading-color	sys.color.on-surface-variant	#4b4b4b
--tanrei-comp-navigation-drawer-heading-height-compact	—	28px
--tanrei-comp-navigation-drawer-heading-height-regular	—	36px
--tanrei-comp-navigation-drawer-hovered-opacity	—	1
--tanrei-comp-navigation-drawer-item-container-height-compact	—	32px
--tanrei-comp-navigation-drawer-item-container-height-regular	—	48px
--tanrei-comp-navigation-drawer-item-container-shape	sys.shape.corner.small	6px
--tanrei-comp-navigation-drawer-item-gap	sys.space.space150	12px
--tanrei-comp-navigation-drawer-item-icon-indicator-height-compact	comp.navigation-drawer.item.icon.size.compact	16px
--tanrei-comp-navigation-drawer-item-icon-indicator-height-regular	comp.navigation-drawer.item.icon.size.regular	24px
--tanrei-comp-navigation-drawer-item-icon-indicator-shape	sys.shape.corner.full	9999px
--tanrei-comp-navigation-drawer-item-icon-indicator-width-compact	comp.navigation-drawer.item.icon.size.compact	16px
--tanrei-comp-navigation-drawer-item-icon-indicator-width-regular	comp.navigation-drawer.item.icon.size.regular	24px
--tanrei-comp-navigation-drawer-item-icon-size-compact	sys.icon.extra-small	16px
--tanrei-comp-navigation-drawer-item-icon-size-regular	sys.icon.medium	24px
--tanrei-comp-navigation-drawer-item-nest-indent-compact	sys.space.space300	24px
--tanrei-comp-navigation-drawer-item-nest-indent-regular	sys.space.space450	36px
--tanrei-comp-navigation-drawer-item-padding-block-compact	—	2px
--tanrei-comp-navigation-drawer-item-padding-block-regular	—	4px
--tanrei-comp-navigation-drawer-item-padding-inline-compact	sys.space.space100	8px
--tanrei-comp-navigation-drawer-item-padding-inline-regular	sys.space.space150	12px
--tanrei-comp-navigation-drawer-item-trailing-icon-size-compact	sys.icon.extra-small	16px
--tanrei-comp-navigation-drawer-item-trailing-icon-size-regular	sys.icon.small	20px
--tanrei-comp-navigation-drawer-motion-disclosure-duration	sys.motion.role.disclosure	400ms
--tanrei-comp-navigation-drawer-motion-disclosure-easing	sys.motion.easing.spatial	cubic-bezier(0.2, 0, 0, 1)
--tanrei-comp-navigation-drawer-motion-enter-duration	sys.motion.role.appear.sheet.enter	400ms
--tanrei-comp-navigation-drawer-motion-enter-easing	sys.motion.easing.enter	cubic-bezier(0.2, 0, 0, 1)
--tanrei-comp-navigation-drawer-motion-exit-duration	sys.motion.role.appear.sheet.exit	350ms
--tanrei-comp-navigation-drawer-motion-exit-easing	sys.motion.easing.exit	cubic-bezier(0.3, 0, 1, 1)
--tanrei-comp-navigation-drawer-motion-expand-duration	sys.motion.role.resize.large	400ms
--tanrei-comp-navigation-drawer-motion-expand-easing	sys.motion.easing.spatial	cubic-bezier(0.2, 0, 0, 1)
--tanrei-comp-navigation-drawer-motion-feedback-duration	sys.motion.role.feedback	450ms
--tanrei-comp-navigation-drawer-motion-selection-duration	sys.motion.role.selection.mark	250ms
--tanrei-comp-navigation-drawer-motion-selection-easing	sys.motion.easing.spatial	cubic-bezier(0.2, 0, 0, 1)
--tanrei-comp-navigation-drawer-motion-state-duration	sys.motion.role.state.large	250ms
--tanrei-comp-navigation-drawer-motion-state-easing	sys.motion.easing.state	cubic-bezier(0.2, 0, 0, 1)
--tanrei-comp-navigation-drawer-outline-color-modal	—	#000000 · 0%
--tanrei-comp-navigation-drawer-outline-color-standard	sys.color.outline-variant	#000000 · 8%
--tanrei-comp-navigation-drawer-outline-width	sys.border.hairline	1px
--tanrei-comp-navigation-drawer-pressed-opacity	—	1
--tanrei-comp-navigation-drawer-scrim-blur	comp.modal-layer.scrim.blur	0px
--tanrei-comp-navigation-drawer-scrim-color	comp.modal-layer.scrim.color	#000000 · 40%
--tanrei-comp-navigation-drawer-selected-disabled-item-container-color	—	#262626 · 16%
--tanrei-comp-navigation-drawer-selected-disabled-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-selected-disabled-item-icon-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-selected-disabled-item-label-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-selected-disabled-item-state-layer-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-selected-disabled-item-supporting-text-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-selected-disabled-item-trailing-icon-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-selected-disabled-item-trailing-text-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-selected-focused-item-container-color	—	#262626 · 24.4%
--tanrei-comp-navigation-drawer-selected-focused-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-selected-focused-item-icon-color	—	#262626
--tanrei-comp-navigation-drawer-selected-focused-item-label-color	—	#262626
--tanrei-comp-navigation-drawer-selected-focused-item-state-layer-color	—	#262626
--tanrei-comp-navigation-drawer-selected-focused-item-supporting-text-color	—	#262626
--tanrei-comp-navigation-drawer-selected-focused-item-trailing-icon-color	—	#262626
--tanrei-comp-navigation-drawer-selected-focused-item-trailing-text-color	—	#262626
--tanrei-comp-navigation-drawer-selected-hovered-item-container-color	—	#262626 · 22.7%
--tanrei-comp-navigation-drawer-selected-hovered-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-selected-hovered-item-icon-color	—	#262626
--tanrei-comp-navigation-drawer-selected-hovered-item-label-color	—	#262626
--tanrei-comp-navigation-drawer-selected-hovered-item-state-layer-color	—	#262626
--tanrei-comp-navigation-drawer-selected-hovered-item-supporting-text-color	—	#262626
--tanrei-comp-navigation-drawer-selected-hovered-item-trailing-icon-color	—	#262626
--tanrei-comp-navigation-drawer-selected-hovered-item-trailing-text-color	—	#262626
--tanrei-comp-navigation-drawer-selected-item-container-color	sys.color.secondary-container	#262626 · 16%
--tanrei-comp-navigation-drawer-selected-item-icon-indicator-color	comp.navigation-drawer.unselected.item.icon-indicator.color	#000000 · 0%
--tanrei-comp-navigation-drawer-selected-item-icon-color	sys.color.on-secondary-container	#262626
--tanrei-comp-navigation-drawer-selected-item-label-color	sys.color.on-secondary-container	#262626
--tanrei-comp-navigation-drawer-selected-item-state-layer-color	comp.navigation-drawer.selected.item.label.color	#262626
--tanrei-comp-navigation-drawer-selected-item-supporting-text-color	sys.color.on-secondary-container	#262626
--tanrei-comp-navigation-drawer-selected-item-trailing-icon-color	sys.color.on-secondary-container	#262626
--tanrei-comp-navigation-drawer-selected-item-trailing-text-color	sys.color.on-secondary-container	#262626
--tanrei-comp-navigation-drawer-selected-pressed-item-container-color	—	#262626 · 24.4%
--tanrei-comp-navigation-drawer-selected-pressed-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-selected-pressed-item-icon-color	—	#262626
--tanrei-comp-navigation-drawer-selected-pressed-item-label-color	—	#262626
--tanrei-comp-navigation-drawer-selected-pressed-item-state-layer-color	—	#262626
--tanrei-comp-navigation-drawer-selected-pressed-item-supporting-text-color	—	#262626
--tanrei-comp-navigation-drawer-selected-pressed-item-trailing-icon-color	—	#262626
--tanrei-comp-navigation-drawer-selected-pressed-item-trailing-text-color	—	#262626
--tanrei-comp-navigation-drawer-sticky-container-color	comp.navigation-drawer.container.color.standard	#ffffff
--tanrei-comp-navigation-drawer-sticky-divider-color	sys.color.outline-variant	#000000 · 8%
--tanrei-comp-navigation-drawer-sticky-divider-width	sys.border.hairline	1px
--tanrei-comp-navigation-drawer-unselected-disabled-item-container-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-unselected-disabled-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-unselected-disabled-item-icon-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-unselected-disabled-item-label-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-unselected-disabled-item-state-layer-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-unselected-disabled-item-supporting-text-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-unselected-disabled-item-trailing-icon-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-unselected-disabled-item-trailing-text-color	—	#1b1b1b · 38%
--tanrei-comp-navigation-drawer-unselected-focused-item-container-color	—	#4b4b4b · 10%
--tanrei-comp-navigation-drawer-unselected-focused-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-unselected-focused-item-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-focused-item-label-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-focused-item-state-layer-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-focused-item-supporting-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-focused-item-trailing-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-focused-item-trailing-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-hovered-item-container-color	—	#4b4b4b · 8%
--tanrei-comp-navigation-drawer-unselected-hovered-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-unselected-hovered-item-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-hovered-item-label-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-hovered-item-state-layer-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-hovered-item-supporting-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-hovered-item-trailing-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-hovered-item-trailing-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-item-container-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-unselected-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-unselected-item-icon-color	sys.color.on-surface-variant	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-item-label-color	sys.color.on-surface-variant	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-item-state-layer-color	comp.navigation-drawer.unselected.item.label.color	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-item-supporting-text-color	sys.color.on-surface-variant	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-item-trailing-icon-color	sys.color.on-surface-variant	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-item-trailing-text-color	sys.color.on-surface-variant	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-pressed-item-container-color	—	#4b4b4b · 10%
--tanrei-comp-navigation-drawer-unselected-pressed-item-icon-indicator-color	—	#000000 · 0%
--tanrei-comp-navigation-drawer-unselected-pressed-item-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-pressed-item-label-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-pressed-item-state-layer-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-pressed-item-supporting-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-pressed-item-trailing-icon-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-unselected-pressed-item-trailing-text-color	—	#4b4b4b
--tanrei-comp-navigation-drawer-collapsed-item-label-typescale	sys.typescale.label-small	500 12px/1.3333
--tanrei-comp-navigation-drawer-filter-shortcut-typescale	sys.typescale.label-small	500 12px/1.3333
--tanrei-comp-navigation-drawer-filter-status-typescale	sys.typescale.body-small	400 13px/1.5385
--tanrei-comp-navigation-drawer-header-typescale	sys.typescale.heading-5	500 16px/1.5
--tanrei-comp-navigation-drawer-heading-typescale	sys.typescale.label-small	500 12px/1.3333
--tanrei-comp-navigation-drawer-item-label-typescale-compact	sys.typescale.label	500 14px/1.4286
--tanrei-comp-navigation-drawer-item-label-typescale-regular	sys.typescale.label	500 14px/1.4286
--tanrei-comp-navigation-drawer-item-supporting-text-typescale	sys.typescale.body-small	400 13px/1.5385
--tanrei-comp-navigation-drawer-item-trailing-text-typescale	sys.typescale.body-small	400 13px/1.5385

测试样例

作为基准的渲染结果。所有平台都以相同的 ID 为每个样例截取快照，以便相互比较。

variant: standard (45)

standard

open: true value: inbox label: Mail items: 2 单独绘制在 256 × 560 的窗口中

standard-no-icons

open: true value: deployments label: Project items: 4 单独绘制在 256 × 560 的窗口中

standard-disabled

open: true value: inbox label: Mail items: 4 单独绘制在 256 × 560 的窗口中

collapsible-expanded

open: true collapsible: true expanded: true value: inbox label: Mail items: 6 slots: header 单独绘制在 256 × 560 的窗口中

collapsed

open: true collapsible: true expanded: false value: inbox label: Mail items: 6 slots: header 单独绘制在 88 × 560 的窗口中

collapsed-labels-always

open: true collapsible: true expanded: false collapsedLabels: always value: inbox label: Mail items: 5 单独绘制在 88 × 560 的窗口中

collapsed-labels-selected

open: true collapsible: true expanded: false collapsedLabels: selected value: starred label: Mail items: 5 单独绘制在 88 × 560 的窗口中

collapsed-badges

open: true collapsible: true expanded: false value: inbox label: Mail items: 5 单独绘制在 88 × 560 的窗口中

collapsed-disabled

open: true collapsible: true expanded: false value: inbox label: Mail items: 5 单独绘制在 88 × 560 的窗口中

collapsed-short-labels

open: true collapsible: true expanded: false collapsedLabels: always value: shared-with-me label: Files items: 5 单独绘制在 88 × 560 的窗口中

trailing

open: true value: inbox label: Mail items: 5 单独绘制在 256 × 560 的窗口中

groups

open: true value: website label: Workspace items: 4 单独绘制在 256 × 560 的窗口中

groups-nested

open: true value: tokens label: Docs items: 1 单独绘制在 256 × 560 的窗口中

nested-icons

open: true chevron: end value: website label: Workspace items: 3 单独绘制在 256 × 560 的窗口中

compact

open: true density: compact chevron: end value: tree-view label: Workspace items: 3 单独绘制在 256 × 560 的窗口中

compact-collapsed

open: true collapsible: true expanded: false density: compact value: inbox label: Mail items: 6 单独绘制在 72 × 560 的窗口中

chevron-end

open: true chevron: end value: posts label: Workspace items: 3 单独绘制在 256 × 560 的窗口中

chevron-none

open: true chevron: none value: posts label: Workspace items: 3 单独绘制在 256 × 560 的窗口中

guides

open: true guides: shown value: posts label: Workspace items: 3 单独绘制在 256 × 560 的窗口中

guides-chevron-none

open: true chevron: none guides: shown value: posts label: Workspace items: 3 单独绘制在 256 × 560 的窗口中

indent-zero

open: true chevron: end indent: 0 value: posts label: Workspace items: 3 单独绘制在 256 × 560 的窗口中

highlight-full

open: true chevron: end highlight: full value: posts label: Workspace items: 3 单独绘制在 256 × 560 的窗口中

icon-space

open: true chevron: end value: inbox label: Mail items: 4 单独绘制在 256 × 560 的窗口中

not-expandable

open: true expandable: false value: color label: Docs items: 2 单独绘制在 256 × 560 的窗口中

supporting

open: true chevron: end value: inbox label: Mail items: 3 单独绘制在 256 × 560 的窗口中

one-line

open: true chevron: end value: long label: Projects items: 2 单独绘制在 256 × 560 的窗口中

label-wrap

open: true chevron: end labelWrap: true supportingWrap: true value: long label: Projects items: 2 单独绘制在 256 × 560 的窗口中

group-loading

open: true chevron: end value: inbox loadingLabel: Loading… label: Mail items: 2 单独绘制在 256 × 560 的窗口中

sticky

open: true chevron: end value: a-3-4 scrollOffset: 220 stickyParents: true label: Archive items: 2 单独绘制在 256 × 560 的窗口中

group-closed-selected

open: true value: website label: Workspace items: 3 单独绘制在 256 × 560 的窗口中

selectable-groups

open: true value: components selectableGroups: true label: Documentation items: 4 单独绘制在 256 × 560 的窗口中

collapsed-groups

open: true collapsible: true expanded: false value: website label: Workspace items: 4 单独绘制在 88 × 560 的窗口中

responsive-wide

collapsible: true responsive: true value: inbox label: Mail items: 6 slots: header 单独绘制在 1280 × 640 的窗口中

responsive-medium

collapsible: true responsive: true value: inbox label: Mail items: 6 单独绘制在 800 × 640 的窗口中

responsive-narrow

open: true collapsible: true responsive: true value: inbox label: Mail items: 6 slots: header 单独绘制在 400 × 640 的窗口中

site-sidebar

open: true value: /components/navigation-drawer/ revealSelected: true label: Documentation items: 5 单独绘制在 256 × 560 的窗口中

site-sidebar-long

open: true value: /components/navigation-drawer/ label: Documentation items: 5 单独绘制在 256 × 800 的窗口中

site-sidebar-restored

open: true value: /components/navigation-drawer/ scrollOffset: 2900 label: Documentation items: 5 单独绘制在 256 × 800 的窗口中

filter-empty-field

open: true value: /components/navigation-drawer/ revealSelected: true filterable: true filterLabel: Filter navigation filterPlaceholder: Filter filterEmptyText: No matches filterCountText: Matches: {count} filterClearLabel: Clear label: Documentation items: 5 单独绘制在 256 × 560 的窗口中

filter

open: true value: /components/navigation-drawer/ revealSelected: true filterable: true filterValue: dr filterLabel: Filter navigation filterPlaceholder: Filter filterEmptyText: No matches filterCountText: Matches: {count} filterClearLabel: Clear label: Documentation items: 5 单独绘制在 256 × 560 的窗口中

filter-count-hidden

open: true value: /components/navigation-drawer/ revealSelected: true filterable: true filterValue: dr filterLabel: Filter navigation filterPlaceholder: Filter filterEmptyText: No matches filterCountText: Matches: {count} filterCountHidden: true filterClearLabel: Clear label: Documentation items: 5 单独绘制在 256 × 560 的窗口中

filter-group

open: true value: /components/navigation-drawer/ revealSelected: true filterable: true filterValue: found filterLabel: Filter navigation filterPlaceholder: Filter filterEmptyText: No matches filterCountText: Matches: {count} filterClearLabel: Clear label: Documentation items: 5 单独绘制在 256 × 560 的窗口中

filter-matches

open: true value: /components/navigation-drawer/ revealSelected: true filterable: true filterValue: nav filterLabel: Filter navigation filterPlaceholder: Filter filterEmptyText: No matches filterCountText: Matches: {count} filterClearLabel: Clear label: Documentation items: 5 单独绘制在 256 × 560 的窗口中

filter-none

open: true value: /components/navigation-drawer/ revealSelected: true filterable: true filterValue: zzz filterLabel: Filter navigation filterPlaceholder: Filter filterEmptyText: No matches filterCountText: Matches: {count} filterClearLabel: Clear label: Documentation items: 5 单独绘制在 256 × 560 的窗口中

filter-compact

open: true density: compact value: /components/navigation-drawer/ revealSelected: true filterable: true filterValue: o filterLabel: Filter navigation filterPlaceholder: Filter filterEmptyText: No matches filterCountText: Matches: {count} filterClearLabel: Clear label: Documentation items: 5 单独绘制在 256 × 560 的窗口中

variant: modal (3)

modal

variant: modal open: true value: inbox label: Mail items: 2 单独绘制在 480 × 640 的窗口中

modal-collapsible-closed

variant: modal open: false collapsible: true value: inbox label: Mail items: 5

modal-collapsible-open

variant: modal open: true collapsible: true value: inbox label: Mail items: 5 slots: header 单独绘制在 480 × 640 的窗口中

生成自 specs/navigation-drawer.spec.json, tokens/comp/navigation-drawer.tokens.json, design/tokens/

指南

link

何时使用

link

当产品的目的地多到导航栏放不下，或者这些目的地可以归成几组时，使用导航抽屉：邮件应用的文件夹和标签、项目的各个部分、管理后台。在大窗口上，标准抽屉作为侧边栏位于内容旁边。在 compact 窗口上，模态抽屉由菜单按钮唤出，从内容上方滑入，选定目的地之后随即消失。

在导航栏与导航抽屉之间选择

link

方面	导航栏	收起的导航抽屉	展开的导航抽屉
所在位置	沿底边	沿起始侧边缘的一列图标	起始侧边缘的一块面板里
窗口	Compact	Medium 及更宽	Expanded 及更宽（标准），或 compact（模态）
目的地	三到五个	它的顶级目的地和分组，各占一个单元格	产品有多少就放多少，按分区和分组组织
一个目的地	图标在上，单行标签在下，图标上可带徽标	在图标之后截断的行：只有图标，图标上可带徽标，名称放在工具提示里	一行：可选的图标、可换行的标签，以及末尾的后置文本或内容
它还容纳	没有别的	页眉：菜单按钮和主操作，后者收起为它的图标	页眉：菜单按钮、标题或账户切换器，以及主操作
在原生平台上，目的地是	标签栏的一个标签	带选中状态的按钮	带选中状态的按钮
它是什么	布局区域	布局区域，或布局中的一列，模态抽屉从这一列展宽	标准：布局区域。模态：模态浮层

• 收起的导航抽屉就是导航轨道。 可收起的抽屉在内容需要宽度时收窄为一列图标，它的菜单按钮再把它展宽；每个图标都留在原位。Tanrei 原先独立的导航轨道已并入这种形态。
• 导航栏和导航抽屉是同一组目的地的两种摆放位置。 它们接收相同的目的地和相同的选择，所以随窗口自适应的产品可以在某个断点把导航栏换成导航抽屉，而不必改动目的地。一次只显示其中一个，绝不同时显示。
• 导航抽屉容纳得更多。 当产品的目的地多到导航栏放不下，或者它们可以归成几组（例如邮件应用的文件夹和标签）时，使用展开的导航抽屉。在大窗口上，标准抽屉位于内容旁边。在 compact 窗口上，模态抽屉由菜单按钮唤出，从内容上方滑入。
• 可收起的模态抽屉把它那一列图标留在布局中；菜单按钮打开它时，它在遮罩之上、内容上方展宽。
• 在每个平台上，两者都按目的地的值选择（Compose 用每个项上的标志，Flutter 用索引），并触发 change 和 reselect。

导航轨道去了哪里

link

Tanrei 没有单独的导航轨道：导航轨道就是一个处于收起形态的可收起抽屉。

以前	现在
导航轨道	带 collapsible 且 expanded 设为 false 的导航抽屉
导航轨道的目的地，图标在上、标签在下	目的地，收起时画成在图标之后截断的行：只有图标，名称放在工具提示里
导航轨道的标签可见性	collapsedLabels：never（默认）、selected 或 always。后两者在图标下方绘制 shortLabel
导航轨道在图标上的徽标	目的地的 badge、badgeCount 和 badgeLabel，两种形态下都绘制
导航轨道的菜单按钮和 FAB	抽屉的第一个 header-button（即它的菜单按钮），以及收起为图标的 main-action
抽屉行末的 badge 文本	trailingText，或 trailing 插槽
导航轨道的令牌	comp.navigation-drawer.collapsed.* 和收起形态的条件

Web 已经实现了它；SwiftUI、Compose、Flutter 和 React Native 在跟上之前，提供的仍是各自独立的导航轨道，本文档已不再介绍它。

Material 3 的名称

link

Material 3	Tanrei
Navigation rail	处于收起形态的可收起导航抽屉
Expanded navigation rail	处于展开形态的可收起导航抽屉
Modal expanded navigation rail	可收起的模态导航抽屉
Navigation drawer	不可收起的导航抽屉

如何选择变体

link

变体	它是什么	适用于
标准（默认）	布局中的一块面板，末尾侧边缘有一条细线。它打开和关闭时，旁边的内容随之调整大小。它不绘制遮罩，用户在内容中工作时它保持打开。	宽窗口，抽屉可以作为侧边栏一直开着。
模态	一块抬升的面板，末尾侧的角是圆角，在遮罩之上从内容上方滑入。它在关闭之前一直持有焦点，并在选定目的地之后自行关闭。	compact 窗口，由应用栏里或收起的抽屉页眉里的菜单按钮打开。

设计系统可以增加变体。它增加的变体，行为与标准变体相同。

打开、焦点与关闭

link

• 打开标准抽屉。 它滑入的同时，旁边的内容为它让出位置。当你是为了响应用户（例如通过菜单按钮）而打开它时，焦点移到当前目的地，否则移到抽屉中第一个可聚焦的元素。一开始就打开着的抽屉不移动焦点。
• 在标准抽屉旁边工作。 Tab 从抽屉移入内容，抽屉保持打开。焦点在抽屉内时关闭它，会把焦点交还给它打开之前所在的位置。
• 打开模态抽屉。 它从起始侧边缘滑入，同时遮罩在窗口的其余部分上淡入。焦点移到当前目的地，否则移到第一个可聚焦的元素，并留在抽屉内。它背后的一切对指针、触摸、键盘和辅助技术都是惰性的（inert）。
• 关闭模态抽屉。 按下遮罩、Escape、平台的返回操作、朝起始侧边缘拖动超过其宽度的一半或朝那个方向快速滑动，以及选择目的地，每一种都会让它关闭一次。它滑出，遮罩淡出，焦点交还给原先持有它的元素。
• 不能从边缘滑动打开。 在 iOS 上，屏幕的起始侧边缘是返回手势，所以抽屉从不从那里打开。请通过一个可见的菜单按钮打开它。
• 在减弱动态效果时，抽屉的打开和关闭立即完成。

收起

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• collapsible 让抽屉拥有宽 72 的收起形态：也就是去掉标签的展开抽屉。每个顶级目的地和分组都是在图标之后截断的那一行，尺寸为 48 × 48，带有行的圆角；选中的那个与它的行一样被填充。页眉的按钮在这一列中上下堆叠，主操作收起为它的图标。分区标题保留各自的行，但没有文字；页眉插槽和后置内容不绘制。
• 收起的单元格用工具提示显示名称，工具提示朝向内容一侧：指针停在单元格上时，经过工具提示的延迟后出现；键盘聚焦时立即出现；触摸时从不出现。标签本来就是单元格的无障碍名称，所以工具提示不会给朗读的内容增加任何东西。
• expanded 选择可收起的标准抽屉处于哪种形态。可收起的模态抽屉在关闭时把它那一列留在布局中，open 让它在遮罩之上、内容上方展宽。
• 菜单按钮是第一个 header-button。抽屉可收起时，它暴露为已展开或已收起，并控制着抽屉；激活它会触发 expandedChange，带着所要求的形态。Web 会自己应用这个形态；在其他平台上，由你据此设置 expanded 或 open。它的图标和名称由你决定。
• collapsedLabels 选择哪些单元格在图标下方绘制短标签：never（默认）、只有 selected 的那个，或 always。带标签的图标列是为想要它的产品或设计系统准备的。这时单元格绘制它的 shortLabel（没有提供时绘制它的标签），并且不显示工具提示。无论哪种情况，标签都仍是无障碍名称。
• 每个图标都留在原位。 两种形态下，图标都排在同一列、同一条线上，每个单元格也保持自己的高度，所以形态变化时移动的只有末尾侧边缘：边缘经过标签时标签淡出，在带标签的图标列中短标签淡入。展开的分组是唯一的例外：收起的抽屉不绘制它的项，所以下方的单元格会上移。 主操作的字形在两种形态下、按钮的任何尺寸、任一密度中，都与目的地的图标位于同一条线上：抽屉依据按钮自己的令牌来放置它。收起时比图标列更宽的正方形（默认系统中的大号主操作）会超出列的边缘，调试构建会报告这一点；请使用小号或中号，在紧凑的抽屉中使用小号，因为中号的正方形会占满整列。
• 选择在原位变色。 新的选择让各行在原地改变颜色，展开和收起时都是如此。不会有任何东西通过放大、缩小或滑动来表示选择。

密度

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• regular（默认）的行高 48，字形 24，与菜单的项一样高，适合既用触摸也用指针的产品。
• compact 采用树视图的紧凑行：高 32，字形 16，行内边距 8，行间距 2，标题高 28，收起时图标列宽 56。用于目的地很多、用指针操作的工具，例如文件浏览器或编辑器的侧边栏。
• 两种密度下，嵌套图标都对齐。 每深一层，内容向内缩进一档，缩进量等于该密度的图标加间距，因此嵌套目的地的图标正好位于其分组标签开始的位置，同一层的图标排成一列。
• 触摸保持其目标尺寸。 用触摸时，紧凑的行至少按触摸目标的高度绘制。用指针时，点击区域是这一行加上上下各半个间距：小于指针目标，但仍大于 WCAG 2.5.8 的 24。
• 设计系统可以通过抽屉的 .compact 令牌（例如 comp.navigation-drawer.item.container.height.compact）改变紧凑的含义，或增加新的密度。

与树视图共享的行

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• 与树视图相同的参数，名称和含义都相同：chevron、guides、indent、highlight、iconSpace、expandable、labelWrap 和 supportingWrap，行的 supportingText 和 supportingPosition，以及 stickyParents 和 stickyMax。
• chevron：默认的 start 把分组的展开箭头画在图标之前，并在每一行都留出它的位置，让同一层的图标对齐；end 把它画在行的最末端、尾部内容之后；none 不画，按下分组的图标即可展开和折叠，展开时显示它的 openIcon。可收起的抽屉把 start 画成 end，这样两种形态下每个图标都留在原位；没有分组的抽屉不留这个位置。
• indent：auto 让行的第一个部分对齐到其分组标签开始的位置，分组在标签前什么都不画时按该层的缩进；数值按相应的像素缩进，0 不缩进。行的标签绝不会从超过抽屉一半宽度的位置开始。
• highlight：默认的 indented 让嵌套行的填充和状态层从行开始的位置画起；full 在每一层都画满整个宽度。
• iconSpace 为没有图标的行保留图标的位置，让同一层的标签对齐：auto（同一层有别的行带图标时）、always、never。
• expandable 为 false 时，所有分组都以展开状态显示，没有展开箭头；分组的行只是为其内容命名，不是控件。
• guides：shown 在展开的分组内容旁画一条线，位于其展开箭头之下，没有则在图标之下，再没有则在标签开始处；hover 只在指针位于抽屉上方或焦点在其中时画。
• 一行：标签和辅助文本都是一行，放不下时以省略号截断；被截断的行在悬停和键盘聚焦时用工具提示显示全文；labelWrap 和 supportingWrap 允许换行。无障碍名称始终是完整的标签。
• 辅助文本放在标签下方（below）或之后（inline），并作为行的描述被朗读。
• 分组可以在末端展开箭头之前带尾部文本或内容，还可以有 openIcon 和 loading；loading 会在内容下方画一个加载行，以抽屉的 loadingLabel 命名。
• stickyParents（抽屉中默认关闭，树视图中默认开启）像编辑器的粘性滚动那样，把顶部可见行所属的展开分组的行固定在顶端，最多 stickyMax（2）个，内层优先。抽屉收起时不起作用。

跟随窗口的宽度

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responsive 让窗口的宽度决定抽屉的呈现方式，依据是其设计系统的两个断点（默认系统中为 1024 和 600）。这时 variant 被忽略。

窗口	呈现方式	抽屉是什么
不小于较宽的断点	standard	内容旁边的标准抽屉，无论 open 是什么都显示，并且可以收起，形态由 expanded 选择
不小于较窄的断点，且为 collapsible	column	可收起的模态抽屉：它那一列图标留在布局中，open 时在内容上方展宽
比这更窄	modal	不可收起的模态抽屉

• 呈现方式是推导出的，从不存储。 它只取决于宽度：抽屉不会把它写入 variant、open 或 expanded。presentationChange 会说明它是什么，第一次以及每当宽度改变它时都会触发。
• 进入新的呈现方式时，抽屉是关闭的。 它立即绘制，不带动效。原先打开着的浮层会被收回，close 触发一次。expanded、value 和每个分组的 open 都会保留，所以回到标准呈现方式时，它仍是离开时的形态。
• 在 modal 呈现方式下，菜单按钮由你提供。 呈现方式为 modal 时，请显示一个你自己的菜单按钮（例如放在应用栏里），并通过它设置 open。在这种呈现方式下，抽屉自己的菜单按钮只用来关闭它。
• 抽屉不会在两次访问之间记住任何东西。 要保留用户选择的形态，请把 expandedChange 带来的值存起来，并据此设置 expanded。

作为网站的侧边栏

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给每个目的地一个 href，再把页面自己的地址作为抽屉的 value，抽屉就成了一个文档型网站的侧边栏。

• 由页面说明自己在哪里。 按下从不选中链接。每个页面把 value 设为它自己对应的目的地：设为那个目的地的 value；目的地没有值时，设为它原样书写的 href。
• revealSelected 在抽屉初次出现时展开包含选中目的地的各个分组，在第一帧完成且不带动效；此后每当 value 变化时再次展开。用户之后折叠的分组会一直保持折叠，直到 value 变化。
• 到达时选中项就在可见范围内。 抽屉出现时，以及每当 value 变化时，如果显示选择的那一行没有完全可见，它会被带到可滚动行区域的中间；如果已经完全可见，则完全不动。所以，当前页面已在可见范围内的侧边栏，在页面之间切换时会留在原处。焦点不会移动。
• scrollOffset 读取并设置各行已滚动的距离。抽屉自己不存储任何东西。如果网站希望一棵很长的树停留在读者离开时的位置，就要自己保存这个偏移量和每个分组的 open（例如存在会话存储里），并在第一帧之前把它们交还给抽屉。包含当前页面的分组照样会展开，而且当某个偏移量会让选中项落在可见范围之外时，以选中项为准。
• 离开本站的链接把 target 设为 new。它在新标签页中打开；除非你在那里放了后置内容，否则它展开的行以图标集的 open_in_new 结尾；targetLabel 在它的名称之后朗读。这句话由你来写（“在新标签页中打开”）：Tanrei 不提供任何文案。
• 路由监听 change。 它在浏览器跟随链接之前触发，而且只针对普通激活：不带修饰键的主按键、触摸或 Enter，并且链接的 target 是 same。取消它，然后前往它带来的 href。在另一个标签页中打开的链接不会触发任何事件，模态抽屉也会保持打开。

筛选

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筛选是在原地缩小抽屉，而不是搜索。搜索会查找每个页面的内容，并在它自己的视图中显示找到的结果。筛选只看抽屉已经列出的那些地方的标签，并把它们留在原处，这样知道页面名称的读者只要按两次键——“/”和名称开头的几个字母——就能到达那里，并在周围的项中看到它。请为两者各分配一个键：像在侧边栏中提供筛选的文档网站那样，用“/”来筛选，用 ⌘K 或 Ctrl+K 来搜索。

• 什么算匹配。 标签中含有键入的每一个词的行算作匹配，每个词可以出现在标签中的任何位置，顺序不限，不区分大小写、字符的宽度（全角与半角）和字母上的附加符号：“nav dr”能找到“Navigation drawer”，“resume”能找到“Résumé”。只比较标签，不比较辅助文本、后置文本和地址。不获取、不排序，也不重新排列任何东西：在服务器上匹配、按排名匹配或比较标签以外内容的产品，请不要设置 filterable，而是像以前一样把匹配的行交给抽屉。
• 留下的内容。 不匹配的行被隐藏。包含匹配项的分组保留，因自身名称而匹配的分组连同内容整体保留；没有留下任何行的分区连同分区标题一起隐藏。
• 分组临时展开。 包含匹配项的折叠分组会为了筛选而画成展开的样子。它的 open 不变，也不会触发 toggle，所以清空输入框后它会重新折叠。筛选期间用户自己展开或折叠的分组归用户所有：它保持用户留下的状态。
• 第一个匹配项随时可取。 焦点在输入框中时，第一个匹配的行会画成获得焦点的样子。按 Enter 会像在那一行上按 Enter 一样取用它，按下方向键会把焦点移到它上面；键入的内容仍留在输入框中。Escape 清空输入框，再按一次会把焦点送回按“/”之前所在的地方。
• 在页面的任何地方按“/”都能来到输入框，只有焦点在文本输入框里时例外，那时它会输入一个斜杠。收起的抽屉会先展开。filterShortcut 可以换成别的键，空列表则不绑定任何键，供已经在使用“/”的产品选择。在窄窗口中，应用外壳会因这个键打开关闭着的抽屉，并把焦点放进它的输入框。
• 数量。 筛选期间，结果顶部会用低调的一行说明有多少行匹配（filterCountText），一行都不匹配时则显示 filterEmptyText。设置 filterCountHidden 后不画数量，但仍会告诉辅助技术。
• 不标记匹配项。 筛选后留下的行就是结果，所以每一行看起来都和不筛选时一样，就像代码评审中的文件树或文档网站侧边栏的筛选那样。
• 不保存任何东西。 抽屉消失后，文本也随之忘掉。如果希望筛选跟着读者走，请从 filterChange 保存 filterValue，并在下一个页面把它还原。

行、分组与分区

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• 行高至少为 48，与菜单的项一样高，圆角也相同。标签只有一行并会被截断，除非设置 labelWrap 让它换行、行随之增高。
• 要么给每个目的地都配上图标，要么都不配，这样标签才能对齐。可收起的抽屉在收起时靠图标来绘制每个顶级目的地和分组，所以请给它们每一个都配上图标。
• trailingText 是行末的简短文本，比标签更低调：一个计数（“24”）或一个词（“新”）。计数以文本写在这里，而不是放进 Badge：Badge 用来标记一个锚点，而行末没有可标记的锚点；要标记图标，请用 badge。trailing 插槽用来放其他任何东西，例如一个图标；它优先于 trailingText，并且永远不可交互。target 为 new 的链接会自动以 open_in_new 作为行的结尾，所以你不必自己放这个图标。后置内容在标签之后朗读，收起时不绘制。
• badge 在图标上绘制一个 Badge，两种形态下都有：一个圆点，或 badgeCount，由 badgeLabel 命名。
• 分组的行通过 chevron 所放位置的展开箭头（见上文）展开和折叠其中的目的地和分组。包含选中目的地的分组在折叠时画成选中的样子，抽屉收起时的顶级分组也是如此；在抽屉收起时激活某个分组，会展开抽屉并展开这个分组。嵌套不要超过三级。
• 同时作为目的地的分组（设置了 selectableGroups，且分组有 value 或 href）会像树视图那样把行分成两部分：展开箭头负责展开和折叠，行的其余部分选中它，一次按下绝不会同时做两件事。展开箭头是单独的控件，在焦点顺序中位于行之后，点击区域至少有指针目标那么宽。抽屉收起时，与其他分组不同，按下它的单元格会选中它，抽屉保持收起；它里面的目的地需要展开抽屉后才能到达。当这样的分组就是当前页面时，revealSelected 也会展开它，因此网站的侧边栏会显示当前分区的各个页面。
• 分区的标题为它下面的目的地命名。它是标题元素（heading），不是控件。分区可以没有标题，这时它是一个没有名称、只以分隔线隔开的组。
• 分区的 divider 在它前面绘制一条分隔线，把它与上面的内容分开。你永远不需要自己放分隔线。
• 页眉容纳各个页眉按钮（它们在图标列中上下堆叠），以及它们下方的主操作。页眉插槽在展开时位于菜单按钮旁边，用来放标题或账户切换器，收起时不绘制。放在这里的纯文本以抽屉的标题样式绘制（comp.navigation-drawer.header.typescale 和 comp.navigation-drawer.header.color）；自己设置了样式的元素保留它自己的样式。
• 当各行的总高度超过页眉下方的空间时，行可以滚动，页眉留在原处。滚动到任一端之后，不会接着去滚动抽屉背后的页面。

推荐

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• 把最常用的目的地放在最前面：放在分区之外，或放在第一个分区里。
• 目的地有自己的地址时，给它一个 href，让它成为真正的链接：它可以在新标签页中打开，可以复制，也能被爬虫跟随。
• 按分区中各目的地的共同点给分区命名：“标签”“管理”。
• 在模态和标准两种形态中使用相同的目的地和值，这样产品只凭窗口宽度就能在两者之间切换。

避免

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• 不要用抽屉放“退出登录”或“写邮件”这样的操作。它的行代表的是去处。
• 不要在分区里嵌套分区，也不要把分区放进分组。调试构建会报告这种情况，并在原处直接绘制内层分区的目的地。
• 不要在没有设置 selectableGroups 时给分组 value 或 href，指望它的行能选中它。它只会展开和折叠，调试构建会报告这一点。
• 不要在宽度足以容纳标准抽屉的窗口上使用模态抽屉。
• 不要让筛选代替网站的搜索。筛选靠名称找到地方；要在内容中找某个词的读者，需要的是搜索。

无障碍

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角色

navigation

标注

Each destination is named by its label in both forms, drawn or not, as a button or as a link; its icon is decorative; its badge's description and then its trailing content are part of its description. A group's row and the list of its items are named by the group's label. A section's heading is a heading. The drawer's label names the navigation landmark and, while the drawer is modal and open, the dialog. The menu button is named by its own label and carries the drawer's expanded state; the main action is named by its label in both forms. A collapsed drawer that draws no labels shows each cell's name where the platform shows a name for an icon alone (a tooltip on the web). The filter field is a search field named by filterLabel, the product's words, controlling the drawer's list; its clear button is named by filterClearLabel; its key hint is hidden and its chord is the field's keyboard shortcut. How many rows match is drawn at the top of the results, hidden from assistive technology, and said by a status of the drawer's own, in the product's filterCountText or filterEmptyText.

最小目标

即使外观尺寸更小，点击区域也满足最小目标尺寸。 minimum 32px · pointer 44px · spacing 8px · touch 48px

键盘操作

按键	动作
Tab / Shift+Tab	Moves focus through the header's content, then the destinations and group rows that are shown and not disabled, and after the row of a group that is a destination its chevron; inside an open modal drawer it wraps around and never leaves the drawer; from an open standard drawer, expanded or collapsed, it moves on to the content, and the drawer stays as it is.
Enter / Space	Activates the focused destination (Enter only for a destination that is a link: it follows the link, and Space is left to the platform), and a modal drawer then closes; on a group's row, opens or closes the group, or, for a group that is a destination (NVD-66), activates it as a destination and leaves it as it is; on that group's chevron, opens or closes the group; on a group's cell in the collapsed drawer, expands the drawer with the group open; on the menu button, changes the drawer's form.
Enter with a modifier key, on a link (the web)	What the browser does with a link: another tab or window, a download. The drawer emits nothing, selects nothing and stays as it is (NVD-60).
Right arrow / Left arrow (mirrored in right-to-left layouts)	On a closed group's row, the arrow toward the end of the line opens it; on an open group's row, the arrow toward the start closes it; on an item inside an open group, the arrow toward the start moves focus to the group's row. Elsewhere the keys do nothing.
Escape	Closes an open modal drawer (a collapsible one narrows back to its column) and returns focus to where it was.
/ (the filterShortcut chord, anywhere in the window)	WHILE filterable is true and the drawer is shown: moves focus to the filter field, expanding a collapsed drawer first. It types "/" while focus is in a text field.
Enter (in the filter field)	Takes the first row that matches — the active match, drawn as a focused row while focus stays in the field — as Enter on that row would: a destination is activated, a group's row opens or closes.
Down Arrow (in the filter field)	Moves focus to the active match.
Escape (in the filter field)	With text: empties the field and keeps focus there. Empty: returns focus to where it was before "/", or passes on (a modal drawer closes).
Escape (on a row, while a filter is applied)	A standard drawer: empties the filter and keeps focus on the row, which stays in view among its neighbours. A modal drawer: closes, as without a filter.

备注

• The drawer is a list of places, not a tab bar, in both forms: on native platforms its destinations are buttons (or links) with the selected state (as iPadOS sidebars and Android's drawer items are read), and on the web links or buttons with aria-current in a navigation landmark. The collapsed form keeps these semantics; it does not become a tab bar.
• Selected and the current page are one thing. The drawer lists the product's places and the selected one is the place being shown, which the web exposes as aria-current="page" on a button and on a link alike. A site of separate pages changes who says which it is — the page, through value, not a press — and nothing else: no destination is ever selected and another current, so a second state would have no case to draw.
• A drawer of links is a navigation landmark holding lists of links and disclosure buttons, the pattern assistive technology users know from site navigation: every link and every group's row is its own Tab stop, and the arrow keys only open, close and leave a group. It is deliberately not a choice per use. One Tab stop with roving arrow keys is a tree's or a menu's model, would hide links from the browser's own ways of listing and following them, and would make the same component answer the keyboard in two ways. A long tree is passed by the landmark, by the headings of its sections, by closing its groups, and by the page's skip link.
• Showing the selection (NVD-57, NVD-58) scrolls the drawer and opens groups without moving focus and without an announcement: the page's own title and heading say where the user is, and the current destination carries its state for whoever reaches it.
• Groups are disclosures, not a tree: a group's row is a button with an expanded state that shows or hides a named list, and every shown destination stays its own tab stop, as the links of a navigation region are. A tree's single tab stop and arrow-key roving would make the drawer's keyboard model depend on whether it has groups; the arrow keys here only open, close and leave a group.
• A group that is a destination (selectableGroups, NVD-66) is the WAI-ARIA Authoring Practices' disclosure navigation menu with top-level links: its row is the link or button of its own page, with the current-page state, and its chevron a separate disclosure button for its items, each a Tab stop. The two are never one control: a row that both navigates and toggles would announce one action and do two, and a keyboard user could not open the group without leaving the page. The chevron is named by the group's label, as Tanrei ships no words of its own; its role and its expanded state tell it from the row.
• Collapsing hides the header slot, the headings' text, trailing content and the items inside groups from assistive technology and focus; it changes no destination's role, name or state, and the menu button announces the change as its expanded state.
• A responsive drawer (NVD-53 to NVD-55) changes what it is with the window's width — a layout region where the window is wide, a modal overlay where it is narrow — and each presentation has the semantics of the drawer it stands for. A change of presentation closes an open overlay, releases focus that was kept inside it and announces nothing by itself; the presentation is never the only way to reach a destination, because the product's menu button opens the modal presentation.
• The standard form is a layout region, not an overlay, expanded or collapsed: opening it moves focus in, to the selected destination or else the first, closing it returns focus to where it was, and focus leaving it never closes it. The modal form is a modal overlay: it keeps focus in and draws a scrim; a collapsible modal drawer's column is a layout region while the drawer is closed. The web presents the open modal drawer with a modal <dialog> element (showModal gives inertness and Escape); Compose draws it in a window of its own (a Dialog, as TanreiDialog is) and Flutter as a controlled overlay in a Stack over the page, each with a scrim, trapping focus and answering back; SwiftUI, which has no side presentation, overlays it with the modal trait and the escape gesture; React Native presents it in a transparent Modal.
• Opening a modal drawer by a swipe from the screen edge is left out: on iOS the same edge is the back gesture. The product opens it from a menu button.
• How a state looks is a value decision of the active design system; components read the state's tokens and never compute the effect themselves.
• A filter narrows the drawer in place; it is not a search. The site's search (the Search component, opened with ⌘K or Ctrl+K) looks through the content of every page and offers results in a view of its own; the filter looks only at the labels of the places the drawer already lists and leaves them where they are, so that a person who knows a page's name reaches it in two keys ("/" and its first letters) and sees it among its neighbours. The two keep separate keys: "/" for the filter, as documentation sites with a sidebar filter do, and the search's own chord.
• Hidden rows are removed from what assistive technology is told, not only from view, so that every list position and size a person hears is the filter's (WCAG 1.3.1). The count is a status message (WCAG 4.1.3): said politely through a status of the drawer's own once typing pauses, never by moving focus, and drawn quietly at the top of the results unless the product hides it. The rows that match are not marked: what the filter leaves is the answer, as in a file tree's filter and a documentation site's sidebar, and the row Enter takes is drawn as a focused row (NVD-85, NVD-86), so that nothing is told by color alone (WCAG 1.4.1).
• The field is a separate stop before the items, as a search field above a list is. As in a search, the first row that matches is active as soon as there is one while focus stays in the field: Enter takes it, as Enter on its row would, and Down Arrow moves focus to it, so that a keyboard user neither Tabs through every row the filter left nor leaves the field to reach the place they typed for. The active match is drawn as a focused row; it is not the field's active descendant, because a destination is a link or a button, which an input's active descendant is not (a search's results are not either), and a screen reader user meets it by Down Arrow, the count telling how many rows are left.

生成自 specs/navigation-drawer.spec.json, tokens/sys/measure.tokens.json

组件负责的部分

link

• 在 Web 上，抽屉是一个由 label 命名的导航地标。每个目的地是链接（带 href）或按钮，当前目的地带有 aria-current="page"。模态抽屉同时还是一个由 label 命名的模态 <dialog>。
• 在 iOS、Android、Flutter 和 React Native 上，每个目的地是一个按钮，带有选中状态以及它在各目的地中的位置，这与这些平台上侧边栏和抽屉项的朗读方式一致。模态抽屉是一个由 label 命名的模态容器：使用模态特征，或窗格标题。
• 在两种形态下，目的地都是一个以其标签命名的元素。它的图标被隐藏；图标上徽标的描述以及随后的后置内容，在名称和状态之后朗读。
• 链接目的地在每一种状态下都与按钮目的地画得完全一样，没有“已访问”的外观。它保留浏览器赋予链接的一切：上下文菜单、在新标签页中打开、拖动，以及悬停时显示地址。在新标签页中打开的链接，会在其描述的末尾朗读它的 targetLabel。
• 收起单元格的工具提示是给使用指针或键盘、视力正常的用户看的。它对辅助技术隐藏，因为辅助技术本来就把标签作为单元格的名称来朗读。
• 分组的行是一个带展开状态的按钮，控制着它的嵌套列表。右方向键（在从左到右的布局中）展开折叠的分组，左方向键折叠展开的分组，在分组内部按左方向键则移到分组的行上。Tab 依次经过每一个显示出来的行。
• 同时作为目的地的分组就是 WAI-ARIA Authoring Practices 中“带顶层链接的展开式导航菜单”：它的行是链接或按钮，是当前页面时带有 aria-current="page"；它的展开箭头是另一个按钮，以分组的标签命名，带有展开状态，并控制嵌套列表。两者各是一个 Tab 停靠点，在行上仍可用右方向键和左方向键展开和折叠分组。
• 抽屉可收起时，它的菜单按钮暴露为已展开或已收起，并控制着抽屉。形态变化时，焦点留在原来所在的单元格上。
• 分区的标题暴露为标题元素，并且不可聚焦。
• Tab 依次经过页眉的内容和每一个未禁用的目的地。Enter 和 Space 激活获得焦点的目的地（对 Web 上的链接只有 Enter）。禁用的目的地不接受焦点，并朗读为已禁用。
• 在标准抽屉中，打开时焦点移入，关闭时焦点交还；Tab 会继续移到内容上，而不会关闭抽屉。在模态抽屉中，Tab 和 Shift+Tab 在抽屉内循环，Escape 和平台的返回操作关闭抽屉并交还焦点。
• 焦点环绘制在行的周围，只在键盘聚焦时显示。键盘焦点落在没有完全可见的行上时，会以最短的距离把它滚入可见范围。
• 两种形态下，点击区域都是整个单元格，并且绝不小于最小目标。
• 文本变大时，两种形态的宽度都保持不变，行和分区标题则变高。标签会换行；短标签会被截断。图标不会缩放。
• 筛选输入框是一个以 filterLabel 为名称的搜索字段，位于各行之前，并表明自己控制着抽屉的列表。它的清除按钮以 filterClearLabel 为名称；它的“/”作为它的键盘快捷键公开（在 Web 上是 aria-keyshortcuts），按键提示则对辅助技术隐藏。
• 被筛选隐藏的行对辅助技术来说也不存在了，所以用户听到的每一个位置和数量都是筛选之后的。键入停顿一秒后，抽屉自己的一个状态会以礼貌（polite）的方式说明有多少行匹配，或者一行都不匹配，焦点不会移动。结果顶部画出的数量对辅助技术隐藏，辅助技术听到的是这个状态。
• 匹配的行不加标记，因此没有只靠颜色传达的信息；按 Enter 选取的行绘制为获得焦点的行，行的名称仍是完整的标签。
• 调试构建会报告：目的地没有标签、模态抽屉没有 label、值不对应任何目的地、同一个值被使用了两次、嵌套的分区、分组里的分区、超过三级的嵌套、设计系统中没有的变体、可收起的抽屉没有菜单按钮、trailing 插槽里有可聚焦的元素、href 是 javascript: 地址或无法解析、未知的 target，以及 target 为 new 却没有 targetLabel 的链接。 设计系统中没有的密度，以及在未设置 selectableGroups 时带有 value 或 href 的分组，也会被报告。使用筛选时，还会报告没有 filterLabel 的输入框、没有名称的清除按钮、包含不止一个组合键的 filterShortcut，以及已被另一个抽屉或搜索占用的组合键。

已知的平台差距：

• Web：Firefox 无法为离开顶层（top layer）的元素播放动画，所以在那里模态抽屉会立即消失，而不是滑出。
• Web：所有尺寸都跟随 rem，因此调大浏览器的文本大小时，图标也会变大，但抽屉的宽度绝不会变。只放大 Tanrei 的文字则不会。
• Web：Tab 能离开打开着的标准抽屉这一点已有测试，但它落在内容中的哪个位置还没有测试，因为这在高负载下不稳定。
• SwiftUI 无法得知此前是哪个视图持有焦点，所以关闭抽屉时键盘焦点不会交还给任何元素：平台按默认行为放置它。打开抽屉时，焦点落在当前目的地上，否则落在第一个可用的目的地上，绝不落在页眉里的控件上。在 Mac 上，模态抽屉只覆盖并禁用它所附着的那个视图，所以请把它附着到窗口的根视图上。
• SwiftUI：Escape、无障碍的退出手势以及打开时焦点移入，都还没有做过端到端测试。目的地把它的位置作为值文本（“2 of 6”）携带，而且只有英文。
• Compose 在一个独立的 Dialog 窗口中呈现模态抽屉，与 TanreiDialog 一样，而不是像 Material 的抽屉那样放在应用的窗口之内。它看起来是一样的，这个窗口会把焦点限制在内、响应返回操作，并隐藏它背后的内容。
• Compose 没有抽屉级别的值，所以“值不对应任何目的地”这种情况无从报告。
• Flutter 的模态抽屉不是 Scaffold.drawer。由你把它作为填满窗口的 Stack 的最后一个子项放置，并用 open 控制它。它的目的地不带“在集合中的位置”。
• Flutter：当行加上行间隙比触摸目标还矮时（例如行较矮的设计系统），各行会相互拉开距离，而不是只扩大点击区域。
• React Native 无法得知此前是哪个元素持有焦点，所以关闭抽屉时不会把焦点交还给打开它的元素。模态抽屉把焦点留在平台放置的位置，标准抽屉则什么都不做。
• React Native 的抽屉还没有自己的 insets 属性：它只读取 TanreiProvider 的边衬区（insets）。目的地把它的位置作为值文本携带，除非你传入 positionText，否则是英文。
• React Native：模态抽屉的拖动和快速滑动、它的焦点移动以及退出手势，尚未在真机上验证。
• SwiftUI、Compose、Flutter 和 React Native（它们提供的是上一版）：第一行位于抽屉内边距下方半个间隙处，而且标签换行的行在各平台上变高的方式并不一致（SwiftUI 和 Compose 会保持行的最小高度，直到文本再也放不下）。各平台在跟上时，都会把内边距量到第一个单元格，并把行高当作最小值。
• Web：输入框中随时可取的第一个匹配项画成获得焦点的行，但它不是输入框的活动后代：目的地是链接或按钮，不能成为输入框的活动后代。屏幕阅读器用户可以用下方向键到达它。
• SwiftUI、Compose、Flutter 和 React Native 还没有筛选。
• Web：可收起的模态抽屉要等收窄回它那一列之后才交还焦点；拖动时移动的是整块面板；它的对话框按打开时测得的那一列的盒子来定位。

需要你做的事

link

• 给每个目的地一个标签。在收起的图标列绘制标签（collapsedLabels）的情况下，标签太长放不下时，请提供 shortLabel。
• 给 target 为 new 的链接一个用你的产品语言写的 targetLabel。
• 在网站上，把每个页面的 value 设为该页面自己对应的目的地。
• 响应式抽屉的呈现方式为 modal 时，请显示一个你自己的菜单按钮来打开它。
• 给菜单按钮一个名称，例如“菜单”；在 Web 以外的平台上，请根据 expandedChange 设置 expanded 或 open。
• 给抽屉一个 label，例如“邮件”。模态抽屉是一个对话框，这个标签就是它的名称。
• 通过一个带有自己标签（例如“菜单”）的可见菜单按钮来打开模态抽屉。
• 让 open 保持同步：模态抽屉关闭时把它设为 false（视平台而定，通过 onClose、绑定或抽屉状态）。
• 在 SwiftUI 上，抽屉关闭之后，请自己把键盘焦点交还给菜单按钮。
• 在 React Native 上，抽屉关闭之后，请自己把焦点移回菜单按钮，传入用你的产品语言写的 positionText，并把窗口的边衬区交给 TanreiProvider。
• 让每个目的地的值在标准和模态两种形态之间保持唯一且稳定。
• 设置 filterable 时，给输入框一个说明它筛选什么的 filterLabel（“筛选导航”），并为 filterCountText、filterEmptyText、filterClearLabel 和 filterPlaceholder 提供你的文字，可以写在抽屉上，也可以作为产品文字一次性给出。