Intent to Ship: Show true window position on Android

[Chromestatus]

Contact emails

chomi...@google.com

Specification

https://www.w3.org/TR/cssom-view-1/#dom-window-screenx

Summary

Chrome on Android accurately reports the browser window's position and size using window.screenX, window.screenY, window.outerWidth, and window.outerHeight. Previously Chrome incorrectly assumed all browser windows on Android start at coordinates (0, 0). This is inaccurate for Android tablets using freeform windowing mode, causing websites to always receive 0 when querying the window's on-screen position using window.screenX and window.screenY (these fields store the coordinates of window's top-left corner in global work area coordinate space). Moreover, Chrome on Android incorrectly assumed that outer dimensions of the browser window are equal to the inner dimensions of the website viewport. Remark: window.screenX and window.screenY have aliases, window.screenLeft and window.screenTop.

Blink component

Blink>HTML

Web Feature ID

window

Motivation

Chrome on Android in desktop form factors should be in functional parity with Chrome for other desktop operating systems. This includes the ability to report valid window position to websites that query window.screenX or window.screenY fields (also aliases, window.screenLeft and window.screenTop).

Initial public proposal

No information provided

Search tags

window, position, screen, coordinates, android

TAG review

No information provided

TAG review status

Not applicable

Risks

Interoperability and Compatibility

No information provided

Gecko: No signal

WebKit: No signal

Web developers: No signals

Other signals:

WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

This should not change any observable behavior of WebView.

Debuggability

No information provided

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?

Yes

Is this feature fully tested by web-platform-tests?

No

Flag name on about://flags

android-use-correct-window-bounds

Finch feature name

AndroidUseCorrectWindowBounds

Rollout plan

Will ship enabled for all users

Requires code in //chrome?

False

Tracking bug

https://g-issues.chromium.org/issues/417632037

Launch bug

https://launch.corp.google.com/launch/4400019

Availability expectation

N/A – Chrome for Android catches up.

Adoption expectation

Already widely adopted – recently 16% of all page loads use window.screenX per https://chromestatus.com/metrics/feature/timeline/popularity/2712.

Adoption plan

N/A

Non-OSS dependencies

Does the feature depend on any code or APIs outside the Chromium open source repository and its open-source dependencies to function?

Depends on Android providing a public API for apps to learn whereabouts of the windows they are in.

Estimated milestones

Shipping on Android

145

Anticipated spec changes

Open questions about a feature may be a source of future web compat or interop issues. Please list open issues (e.g. links to known github issues in the project for the feature specification) whose resolution may introduce web compat/interop risk (e.g., changing to naming or structure of the API in a non-backward-compatible way).

No spec changes – Chrome for Android catches up.

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5164958878531584?gate=6272126285512704

Links to previous Intent discussions

Intent to Prototype: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAAz0gKehdm7rOzKSmQZ99L%3DJoYs6XTOip8fbxBhAqB7F6YE7EQ%40mail.gmail.com

This intent message was generated by Chrome Platform Status.