Intent to Prototype: Visual order caret movement for Bidirectional text

[Chromestatus]

Contact emails

sambamurt...@microsoft.com

Explainer

https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/Editing/bidi-visual-order-caret-movement-explainer.md

Specification

https://w3c.github.io/selection-api/#dom-selection-modify

Summary

Changes caret movement in bidirectional text from logical order (forward/backward in DOM order based on paragraph direction) to visual order, where pressing Right always moves the caret rightward on screen and Left always moves it leftward, regardless of text or line direction. This applies to both keyboard-driven caret movement and the Selection.modify() API when called with 'left'/'right' directions.

Blink component

Blink

Web Feature ID

Missing feature

Motivation

Chromium currently maps Left/Right arrow keys to logical (forward/backward) movement based on the paragraph's base direction. In bidirectional text (e.g., Arabic or Hebrew mixed with Latin), this causes the caret to move in the opposite visual direction or jump unpredictably at script boundaries. For example, in <p dir="ltr">Hello שלום world</p>, pressing Right while inside the Hebrew run moves the caret visually leftward, opposite to user expectation. Firefox and Safari already default to visual caret movement. Chromium is the only major browser that still uses logical movement. A usability study with Arabic–English bilingual users confirmed the overwhelming expectation is visual movement. This feature aligns Chromium with the cross-browser and cross-platform consensus (Firefox, Safari, macOS TextKit, GTK) and makes Selection.modify() with 'left'/'right' behave as true visual directions. The spec already defines these as visual, but steps 7–8 of modify() incorrectly use "inline base direction"; an in-progress spec fix (https://github.com/w3c/selection-api/pull/357) corrects this to use "resolved text direction at the focus", matching Firefox/Safari behavior.

Initial public proposal

No information provided

Search tags

bidi, caret, movement, bidirectional

Goals for experimentation

None

Requires code in //chrome?

False

Tracking bug

https://issues.chromium.org/issues/499819853

Estimated milestones

No milestones specified

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5074816756482048?gate=5068203748360192

This intent message was generated by Chrome Platform Status.