プログレスインジケーター
タスクがどこまで進んだかを、進み具合が分からないときは進行中であることを、バーまたはリングで示します。
- カテゴリ
- コミュニケーション
- トークン
comp.progress-indicator- レベル
- 基礎
- Web
tanrei-progress-indicatorschedule - SwiftUI
TanreiProgressIndicatorschedule - Jetpack Compose
TanreiProgressIndicatorschedule - Flutter
TanreiProgressIndicatorschedule - React Native
ProgressIndicatorschedule
生成元 docs/status/status.json, specs/progress-indicator.spec.json
リニアとサーキュラー
Web と React の例は現在の仕様に沿っています。SwiftUI、Compose、Flutter、React Native は追従待ちで、まだ separation がありません。これらの例は、いま提供しているものを示しています。
<tanrei-progress-indicator value="0.4" label="report.pdf をアップロード中"></tanrei-progress-indicator>
<tanrei-progress-indicator value="3" max="10" value-text="10 件中 3 件" label="アップロード中"></tanrei-progress-indicator>
<!-- value がなければ、value のない <progress> と同じく不確定です。 -->
<tanrei-progress-indicator variant="circular" size="small" label="同期中"></tanrei-progress-indicator>
<!-- デザインシステムの選択にかかわらず、インジケーターとトラックの残りの間に間隔を空けます。 -->
<tanrei-progress-indicator separation="gap" value="0.4" label="report.pdf をアップロード中"></tanrei-progress-indicator>
<script type="module">
import '@tanrei/web/components/progress-indicator';
const bar = document.querySelector('tanrei-progress-indicator');
bar.value = sent / total;
</script>import { ProgressIndicator } from '@tanrei/react';
<ProgressIndicator value={sent / total} label="report.pdf をアップロード中" />
<ProgressIndicator value={files} max={10} valueText={`10 件中 ${files} 件`} label="アップロード中" />
<ProgressIndicator variant="circular" size="small" value={null} label="同期中" />
<ProgressIndicator separation="gap" value={sent / total} label="report.pdf をアップロード中" />import Tanrei
TanreiProgressIndicator("report.pdf をアップロード中", value: sent / total)
TanreiProgressIndicator("アップロード中", value: Double(files), in: 0...10, currentValueLabel: "10 件中 \(files) 件")
// value を渡さなければ（既定値）不確定です。
TanreiProgressIndicator("同期中", variant: .circular, size: .small)import io.github.chnotchy.tanrei.components.TanreiProgressIndicator
import io.github.chnotchy.tanrei.components.TanreiProgressIndicatorVariant
import io.github.chnotchy.tanrei.tokens.TanreiProgressIndicatorSize
// progress はラムダなので、値が変わっても再コンポーズせずに描き直します。
TanreiProgressIndicator(progress = { sent / total }, contentDescription = "report.pdf をアップロード中")
TanreiProgressIndicator(
progress = { files.toFloat() },
contentDescription = "アップロード中",
valueRange = 0f..10f,
stateDescription = "10 件中 $files 件",
)
// progress を取らないオーバーロードが不確定です。
TanreiProgressIndicator(
contentDescription = "同期中",
variant = TanreiProgressIndicatorVariant.Circular,
size = TanreiProgressIndicatorSize.Small,
)import 'package:tanrei/tanrei.dart';
TanreiProgressIndicator(value: sent / total, semanticsLabel: 'report.pdf をアップロード中');
TanreiProgressIndicator(
value: files.toDouble(),
max: 10,
semanticsValue: '10 件中 $files 件',
semanticsLabel: 'アップロード中',
);
// value: null（既定値）は不確定です。
const TanreiProgressIndicator(
variant: TanreiProgressIndicatorVariant.circular,
size: TanreiProgressIndicatorSize.small,
semanticsLabel: '同期中',
);import { ProgressIndicator } from '@tanrei/react-native';
<ProgressIndicator accessibilityLabel="report.pdf をアップロード中" value={sent / total} />
<ProgressIndicator accessibilityLabel="アップロード中" value={files} max={10} valueText={`10 件中 ${files} 件`} />
<ProgressIndicator accessibilityLabel="同期中" variant="circular" size="small" />サイズ、範囲の両端、独自の範囲
区切り方：divider（既定のシステムの選択）と gap
構成要素
構成要素
linear-determinate の上に描いています。| パーツ | 説明 |
|---|---|
1 track | The full length of the bar, or the full circle of the ring: the whole of the task. |
2 indicator | The part of the track drawn in the indicator color: the fraction done (determinate), or a moving segment or arc (indeterminate). It meets the rest of the track, or stands a gap from it (separation). |
3 stop-indicator · 任意 | A dot at the end of a determinate bar's track that marks where the task ends. Drawn under either separation whenever its size is above 0; 0 draws none. |
プロパティ
| プロパティ | 型 | 既定値 | 説明 |
|---|---|---|---|
variant | linear | circular | "linear" | Linear is a bar that fills the width its layout gives it, for content and pages; circular is a ring of a fixed size, for tight places and next to text. A structural choice drawn by code, not a token axis: a design system cannot add a form by values. |
size | small | medium | large | "medium" | The bar's thickness (2 / 4 / 8) or the ring's box (16 / 24 / 40). A design system may add values. |
separation | auto | divider | gap | "auto" | How a determinate indicator is told from the rest of its track. divider: it is drawn on the track with no space between them. gap: empty space is left between them. Whether a bar marks the track's end with a dot is comp.progress-indicator.stop-indicator.size, not the separation. Auto takes comp.progress-indicator.track.separation, the design system's answer (divider in the default system). |
value | number | null | How far the task has come, between min and max. Null makes the indicator indeterminate. |
min | number | 0 | The value at which nothing is done. |
max | number | 1 | The value at which the task is done. |
label | string | "" | The accessible name: what is in progress ("Uploading report.pdf"). Required: a bar alone is not a name. |
valueText | string | "" | How assistive technology reads the value when a percentage is not the natural reading ("3 of 10 files"). Empty reads the platform's percentage. |
状態
振る舞い
EARS 記法による要件です。各プラットフォームの実装は、この ID に対応するテストで検証されます。要件の原文は仕様ファイルのものをそのまま掲載しています。
| ID | 要件 |
|---|---|
PRG-1 | WHILE value is a number THE progress indicator SHALL be determinate and draw the indicator over the fraction (value − min) / (max − min) of the track, from the track's start: the inline-start of a bar, the top of a ring, turning clockwise. |
PRG-2 | WHILE value is null THE progress indicator SHALL be indeterminate: a bar SHALL move a segment of the indicator, two fifths of the track long, from beyond the track's start to beyond its end once per comp.progress-indicator.motion.cycle-duration with comp.progress-indicator.motion.cycle-easing; a ring SHALL turn an arc of the indicator a quarter of the circle long clockwise once per comp.progress-indicator.motion.cycle-duration at constant speed (sys.motion.easing.linear). |
PRG-3 | THE progress indicator SHALL draw a bar comp.progress-indicator.linear.thickness.medium high for medium (and so on for each size) across the full inline size its layout gives it, and a ring whose outer edge fills a comp.progress-indicator.circular.size.medium square with a stroke of comp.progress-indicator.circular.thickness.medium for medium (and so on for each size). |
PRG-4 | THE progress indicator SHALL draw the track in comp.progress-indicator.track.color and the indicator over it in comp.progress-indicator.indicator.color; the ends of a bar's track and indicator SHALL be rounded by comp.progress-indicator.track.shape, clamped to half the thickness, and a ring's arcs SHALL have round caps unless comp.progress-indicator.track.shape is sys.shape.corner.none. |
PRG-5 | WHILE determinate, its separation is gap (PRG-17) and value lies strictly between min and max THE progress indicator SHALL leave comp.progress-indicator.track.gap of empty space, measured along the track, between the indicator and the rest of the track — on a bar between the indicator's end and the track, on a ring at both ends of the indicator's arc. WHILE its separation is divider THE progress indicator SHALL draw the indicator on the track with no empty space between them: the edge where the indicator's color ends is what divides them. WHILE a bar is determinate THE progress indicator SHALL draw, under either separation, a dot of comp.progress-indicator.stop-indicator.size, and no larger than the bar is thick, in comp.progress-indicator.indicator.color centered in the thickness with its center half the thickness before the track's end (concentric with the track's rounded end); it SHALL NOT be drawn while value is at max, where the indicator covers it, and a size of 0 SHALL draw none. Whether the dot is drawn is independent of the separation. |
PRG-6 | WHEN value changes while determinate THE progress indicator SHALL move the indicator's end to the new value over comp.progress-indicator.motion.value-duration with comp.progress-indicator.motion.value-easing; a switch between determinate and indeterminate SHALL take effect at once. |
PRG-7 | WHERE reduced motion is requested THE progress indicator SHALL show a value change at once, and WHILE indeterminate SHALL NOT move: it SHALL draw the indicator over the whole track (the whole circle of a ring) and ease its opacity from 1 to 0 and back to 1 once per comp.progress-indicator.motion.cycle-duration with comp.progress-indicator.motion.cycle-easing, over a track that stays still. |
PRG-8 | WHILE value is a number THE progress indicator SHALL expose the progressbar role to assistive technology with label as its name, min and max as its range, the clamped value as its current value, and valueText as the value's text when valueText is not empty. |
PRG-9 | WHILE value is null THE progress indicator SHALL expose the progressbar role with label as its name, no current value, and the platform's busy or indeterminate state. |
PRG-10 | THE progress indicator SHALL NOT be focusable and SHALL NOT announce value changes by itself; assistive technology SHALL read the current value when it reaches the indicator, and a platform that marks frequently updating elements SHALL mark it so. |
PRG-11 | IF value is below min or above max THE progress indicator SHALL draw and expose it clamped to that range; IF max is not greater than min THE progress indicator SHALL draw the track with no indicator and expose a current value of 0 in a range of 0 to 1; in each case debug builds SHALL report the values. |
PRG-12 | WHEN size names a value that the active design system does not have, or variant or separation a value the component does not define, THE progress indicator SHALL render with the default value's tokens (medium, linear, auto), and in debug builds report the unknown value. |
PRG-13 | WHERE the layout direction is right-to-left THE progress indicator SHALL fill a bar and move its indeterminate segment from right to left; a ring SHALL NOT be mirrored: it starts at the top and turns clockwise in every direction, as a clock does. |
PRG-14 | WHILE the progress indicator is not visible (scrolled out of view, in a hidden view, or in an app in the background) THE progress indicator SHALL NOT run its indeterminate animation, and SHALL resume it when it becomes visible. |
PRG-15 | WHILE label is empty THE progress indicator SHALL still render, and in debug builds report that it has no accessible name. |
PRG-16 | THE progress indicator 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 progress indicator is shown THE progress indicator SHALL draw itself for the new direction at once, without a motion of its own, keeping its value, and the place of an indeterminate segment in its cycle. |
PRG-17 | THE progress indicator SHALL tell a determinate indicator from the rest of its track as its separation names: WHILE separation is auto, as comp.progress-indicator.track.separation names, which follows sys.behavior.separation unless a design system sets it apart; WHILE separation is divider or gap, as that value names, whatever the tokens say; each as PRG-5 draws it. WHEN separation, or the token it follows, changes THE progress indicator SHALL draw the other form at once, without animation, keeping its value. WHILE indeterminate THE progress indicator SHALL be drawn the same under either (PRG-2, PRG-7). A platform that cannot draw a choice SHALL fall back to the first value, divider, and state that in its README. |
PRG-18 | WHERE the platform has ARIA attributes (the web), the host carries its progressbar role (PRG-8) itself, so what the product writes on it is not moved, but for a name: WHILE label is not empty THE progress indicator SHALL hold the product's aria-label and aria-labelledby on that host as their data-aria- twins, so that label is its whole name although the platform gives aria-labelledby the precedence, and WHEN label is emptied SHALL give them back as they were written; WHILE label is empty a name the product gives so — aria-label, or aria-labelledby naming an element — SHALL be its name and SHALL NOT be reported as having none in debug builds (PRG-15). WHEN the product removes one, or its data-aria- twin, or sets the ARIA property that reflects it (ariaLabel, ariaLabelledByElements) to null, THE progress indicator SHALL take it away. |
プラットフォーム別の名前対応
パリティは API が同一であることを意味しません。同じ契約を、各プラットフォームの流儀で表現します。
| 仕様 | Web | SwiftUI | Jetpack Compose | Flutter | React Native |
|---|---|---|---|---|---|
| コンポーネント | tanrei-progress-indicator | TanreiProgressIndicator | TanreiProgressIndicator | TanreiProgressIndicator | ProgressIndicator |
variant · プロパティ | variant | variant | variant | variant | variant |
size · プロパティ | size | size | size | size | size |
separation · プロパティ | separation | separation | separation | separation | separation |
value · プロパティ | value | value | progress | value | value |
min · プロパティ | min | bounds | valueRange | min | min |
max · プロパティ | max | bounds | valueRange | max | max |
label · プロパティ | label | label | contentDescription | semanticsLabel | accessibilityLabel |
valueText · プロパティ | valueText | currentValueLabel | stateDescription | semanticsValue | valueText |
| 備考 | As a native <progress>: no value attribute (or removing it) is indeterminate. valueText is the value-text attribute. The host carries role="progressbar" and the aria-value attributes. separation is an attribute (auto, divider, gap); auto reads the name in --tanrei-comp-progress-indicator-track-separation. | Initialisers follow ProgressView: TanreiProgressIndicator(_ label:, value: Double?, in bounds: ClosedRange<Double> = 0...1, currentValueLabel:). value: nil is indeterminate; bounds carries min and max as Slider's in: does. Not built on this platform yet: separation (auto, divider, gap), PRG-17 and the seven gap and divider fixtures; reading comp.progress-indicator.track.separation as a typed choice needs the token emitters to write a choice of kind as a typed enumeration, which they do not yet. Not built on this platform yet: the stage color a fixture's surface names, which the linear-on-container-highest fixture draws on. | Two overloads, as Material's indicators have: with progress: () -> Float it is determinate (a lambda, so a changing value redraws without recomposing), read within valueRange: ClosedFloatingPointRange<Float> = 0f..1f (as Slider names it); without progress it is indeterminate. stateDescription is the semantics property of the same name. Not built on this platform yet: separation (auto, divider, gap), PRG-17 and the seven gap and divider fixtures; reading comp.progress-indicator.track.separation as a typed choice needs the token emitters to write a choice of kind as a typed enumeration, which they do not yet. Not built on this platform yet: the stage color a fixture's surface names, which the linear-on-container-highest fixture draws on. | As Flutter's ProgressIndicator: value: null is indeterminate, and semanticsLabel / semanticsValue are its names. Unlike Flutter's (a fraction from 0 to 1), value is read between min and max, as Slider does. Not built on this platform yet: separation (auto, divider, gap), PRG-17 and the seven gap and divider fixtures; reading comp.progress-indicator.track.separation as a typed choice needs the token emitters to write a choice of kind as a typed enumeration, which they do not yet. Not built on this platform yet: the stage color a fixture's surface names, which the linear-on-container-highest fixture draws on. | value undefined or null is indeterminate. min, max, value and valueText are passed together as accessibilityValue ({ min, max, now, text }); indeterminate sets accessibilityState={{ busy: true }} and no now. Not built on this platform yet: separation (auto, divider, gap), PRG-17 and the seven gap and divider fixtures; reading comp.progress-indicator.track.separation as a typed choice needs the token emitters to write a choice of kind as a typed enumeration, which they do not yet. Not built on this platform yet: the stage color a fixture's surface names, which the linear-on-container-highest fixture draws on. |
トークン
| トークン | 参照先 | 解決値（ライト） |
|---|---|---|
--tanrei-comp-progress-indicator-circular-size-large | — | 40px |
--tanrei-comp-progress-indicator-circular-size-medium | — | 24px |
--tanrei-comp-progress-indicator-circular-size-small | — | 16px |
--tanrei-comp-progress-indicator-circular-thickness-large | sys.border.thick | 2px |
--tanrei-comp-progress-indicator-circular-thickness-medium | sys.border.thick | 2px |
--tanrei-comp-progress-indicator-circular-thickness-small | sys.border.thick | 2px |
--tanrei-comp-progress-indicator-indicator-color | sys.color.primary | |
--tanrei-comp-progress-indicator-linear-thickness-large | — | 8px |
--tanrei-comp-progress-indicator-linear-thickness-medium | — | 4px |
--tanrei-comp-progress-indicator-linear-thickness-small | — | 2px |
--tanrei-comp-progress-indicator-motion-cycle-duration | sys.motion.duration.extra-long4 | 1000ms |
--tanrei-comp-progress-indicator-motion-cycle-easing | sys.motion.easing.standard | cubic-bezier(0.2, 0, 0, 1) |
--tanrei-comp-progress-indicator-motion-value-duration | sys.motion.duration.medium2 | 300ms |
--tanrei-comp-progress-indicator-motion-value-easing | sys.motion.easing.standard | cubic-bezier(0.2, 0, 0, 1) |
--tanrei-comp-progress-indicator-stop-indicator-size | sys.space.space0 | 0px |
--tanrei-comp-progress-indicator-track-color | sys.color.surface-variant | |
--tanrei-comp-progress-indicator-track-gap | sys.space.space50 | 4px |
--tanrei-comp-progress-indicator-track-separation | sys.behavior.separation | 0 |
--tanrei-comp-progress-indicator-track-shape | sys.shape.corner.full | 9999px |
フィクスチャ
基準となる描画パターンです。全プラットフォームが同じ ID でスナップショットを撮り、結果を比較できるようにしています。
size: small (3)
linear-small
variant: linear size: small value: 0.4 label: Uploading linear-gap-small
variant: linear size: small separation: gap value: 0.4 label: Uploading circular-small
variant: circular size: small value: 0.4 label: Uploading size: medium (12)
linear-determinate
variant: linear value: 0.4 label: Uploading linear-on-container-highest
variant: linear value: 0.4 label: Uploading linear-indeterminate
variant: linear label: Uploading linear-empty
variant: linear value: 0 label: Uploading linear-full
variant: linear value: 1 label: Uploading linear-range
variant: linear value: 3 min: 0 max: 10 label: Uploading valueText: 3 of 10 files linear-gap
variant: linear separation: gap value: 0.4 label: Uploading linear-gap-full
variant: linear separation: gap value: 1 label: Uploading linear-divider
variant: linear separation: divider value: 0.4 label: Uploading circular-determinate
variant: circular value: 0.4 label: Uploading circular-indeterminate
variant: circular label: Uploading circular-gap
variant: circular separation: gap value: 0.4 label: Uploading size: large (4)
linear-large
variant: linear size: large value: 0.4 label: Uploading linear-gap-large
variant: linear size: large separation: gap value: 0.4 label: Uploading circular-large
variant: circular size: large value: 0.4 label: Uploading circular-gap-large
variant: circular size: large separation: gap value: 0.4 label: Uploading 生成元 specs/progress-indicator.spec.json, tokens/comp/progress-indicator.tokens.json, design/tokens/
待っていることに気付く程度の時間がかかるタスクに使います。アップロード、インポート、デプロイ、時間のかかる保存などです。おおよそでも測れるなら、どこまで進んだかを示します。バーが進んでいると、人は落ち着いて待てます。まだ測れないときは不確定で表示し、値が分かった時点で切り替えます。
次のページを読み込んでいるリストのように、長さを測れない短い待ち時間には、代わりにローディングインジケーターを使います。値を約束しないので、トラックを持ちません。
| バリアント | 用途 |
|---|---|
| Linear | ページやセクションに属するタスク。ページの上端、カードの中、アップロード一覧のファイルの下など。バーはレイアウトが与える幅いっぱいに伸びます。 |
| Circular | 狭い場所や、テキストの横での進捗。ボタンの中、リストの行、小さなパネルなど。リングの大きさは固定です。 |
| サイズ | 既定のシステムでのバーの太さ / リングの大きさ | 用途 |
|---|---|---|
| Small | 2 / 16 | 密度の高い行、コントロールの中、小さなテキストの横。 |
| Medium | 4 / 24 | ほとんどの場所。既定値です。 |
| Large | 8 / 40 | その画面の主役であるタスクや、内容を待っている空のセクション。 |
確定のインジケーターをトラックの残りと見分ける方法は 2 つあります。divider では、インジケーターをトラックの上に、間を空けずに描きます。gap では、インジケーターのあとに少しだけ間隔を空けます。リングでは弧の両端に空けます。不確定のインジケーターは、どちらでも同じ見た目です。バーがトラックの終わりを点で示すかどうかは別の選択で、ストップインジケーターの大きさで決まります。大きさを与えたデザインシステムでは、どちらの区切り方でも点を描きます。既定のシステムでは描きません。
この選択は、デザインシステムが、同じ選択を持つすべてのコンポーネントについて一度だけ行います。既定のシステムは divider です。separation を auto のままにしておけば、その選択に従うので、周りのボタングループやメニューとそろいます。1 つのインジケーターだけを変える理由があるときに限り、divider か gap を指定します。
- 何が進行中なのかを表すラベルを付けます。「進捗」ではなく「report.pdf をアップロード中」です。横にキャプションを表示するなら、同じ言葉を使います。
- パーセントが自然な読み方でないときは、値のテキストを使います。「10 件中 3 件」「ステップ 2/4」などです。
- タスクが終わったら、言葉で伝えます。完了したというメッセージか、何がうまくいかず次に何をすればよいかです。
- 失敗を色で伝えない。赤いバーは、その色が見えない人には何も伝えません。インジケーターを止めて、横にメッセージを表示します。
- ストレージの使用量やパスワードの強度のような、量の目盛りとして使わない。それはメーターという別のコンポーネントです。
- タスクが終わる前に値を戻したり、最後まで飛ばしたりしない。バーは残りの待ち時間についての約束です。
- 1 つのタスクに複数のインジケーターを出さない。全体に 1 つ、または利用者が気にかける項目ごとに 1 つにします。
- ロール
progressbar- ラベル付け
- label is the accessible name. valueText, when given, replaces the platform's percentage as the spoken value. A visible caption next to the indicator is the product's composition; when it exists, use the same words as label.
- 最小ターゲット
- 見た目のサイズが小さくても、ヒット領域は最小ターゲットサイズを満たします。 minimum 32px · pointer 44px · spacing 8px · touch 48px
キーボード操作
| キー | 動作 |
|---|
備考
- Not interactive: the indicator takes no input and is never focusable (PRG-10), so the minimum target holds without extending anything.
- The value is read from the boundary between indicator and track: comp.progress-indicator.indicator.color must stay at least 3:1 against comp.progress-indicator.track.color and against the surface behind it, under divider and under gap alike. A faint track may leave the track's end hard to see; the stop indicator, in a system that gives it a size, marks it.
- Indeterminate is announced as busy with no value: on the web a progressbar without aria-valuenow (and aria-busy), on Apple platforms a progress element with no value, on Android the indeterminate range info, in Flutter a progress indicator with a null value.
- Reduced motion replaces movement with an opacity pulse of at most one per second (PRG-7), below the three-per-second flash threshold.
生成元 specs/progress-indicator.spec.json, tokens/sys/measure.tokens.json
- プログレスバーのロールと、名前としてのラベルを伝えます。確定のときは範囲、範囲内に収めた現在の値、値のテキスト（あれば）を、不確定のときは値を伝えずにプラットフォームのビジー状態を伝えます。Flutter にはまだプログレスバーのロールもビジー状態もないため、ラベルと値を伝えます。
- フォーカスを受けず、変化を自分から読み上げません。支援技術は、利用者がたどり着いたときに現在の値を読み上げます。
- 動きを減らす設定のときは、値の変化をすぐに反映し、不確定の表示は動きを止めて、代わりに不透明度をゆるやかに変化させます（1 秒に 1 回まで）。
- 繰り返すアニメーションは、見えていない間は止まり、見えるようになると再開します。アプリがバックグラウンドにあるときはすべてのプラットフォームで、スクロールして画面外に出たときや隠れた画面にあるときは、プラットフォームがそれを判別できる範囲で止まります。
- 空のラベル、範囲外の値、未知の
separationは、デバッグビルドで報告します。
- タスクの終わりは、プロダクト側で知らせます。ライブリージョンでメッセージを伝えるか、結果へフォーカスを移します。インジケーターは、完了や失敗を伝えません。
- インジケーターの色、トラックの色、背後のサーフェスの色を変えるときは、divider でも gap でも、インジケーターの色がトラックと背後のサーフェスの両方に対して 3:1 以上になるようにします。値は、インジケーターとトラックの境目から読み取られるからです。
- 塗りつぶしのカードのような、最も高いコンテナのトーンの面の上では、トラックはほぼ同じトーンなので見えにくくなります。そうした面の上に置くときは、レイヤーで
comp.progress-indicator.track.colorをより強いロールに付け替えます。インジケーターが示すものは、それでもトラックとの境目から読み取れます。 - タスクがページの一部を止めている間は、その領域をビジー状態にします（Web では
aria-busy）。