Scenario

Scrolling cancels or disrupts IME composition

User scrolling the page or scrollable editor while the IME candidate window is open may cancel composition or move the caret out of sync—reported on iOS Safari with Japanese IME and Android Chrome with Chinese IME when scroll containers move the editing context.

ime

Scenario ID

scenario-ime-composition-scroll

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Details

User scrolling the page or scrollable editor while the IME candidate window is open may cancel composition or move the caret out of sync—reported on iOS Safari with Japanese IME and Android Chrome with Chinese IME when scroll containers move the editing context.

Problem Overview

IME UI is anchored to the caret; scroll changes the viewport without necessarily firing the same events as keyboard-driven caret moves.

Observed Behavior

Japanese + iOS Safari: scroll during composition cancels (see cases).
Chinese + Android Chrome: scroll cancels or loses candidate alignment.

Impact

Composition cancelled mid-syllable; frustrating on long pages or nested scrollers.

Solutions

Avoid programmatic scroll that fights the user during isComposing when possible.
Stabilize scroll containers around the active editor.

References

UI Events

Scenario flow

Visual view of how this scenario connects to its concrete cases and environments. Nodes can be dragged and clicked.

Variants

Each row is a concrete case for this scenario, with a dedicated document and playground.

Case	OS	Device	Browser	Keyboard	Status
ce-0194-japanese-ime-scroll-cancels-ios-safari	iOS 17.0	iPhone or iPad Any	Safari 17.0	Japanese (IME)	draft
ce-0205-chinese-ime-scroll-cancels-android-chrome	Android 14.0	Phone or Tablet Any	Chrome 120.0	Chinese (IME - Pinyin)	draft

Browser compatibility

This matrix shows which browser and OS combinations have documented cases for this scenario. Click on a cell to view the specific case.

Browser	Android	iOS
Chrome	ce-0205-chinese-ime-scroll-cancels-android-chrome 120.0	—
Safari	—	ce-0194-japanese-ime-scroll-cancels-ios-safari 17.0

Confirmed

Draft

— No case documented

Cases

This scenario affects multiple languages. Cases are grouped by language/input method below.

Chinese

1 case

Chinese IME composition cancelled by scrolling on Android Chrome

OS: Android 14.0 · Device: Phone or Tablet Any · Browser: Chrome 120.0

Open case →

Japanese

1 case

Japanese IME composition cancelled by scrolling on iOS Safari

OS: iOS 17.0 · Device: iPhone or iPad Any · Browser: Safari 17.0

Open case →

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Comments & Discussion

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