w3c/csswg-drafts

[cssom-view] window.innerScreenX windows.innerScreenY

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#809 opened on Dec 15, 2016

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Help Wantedcssom-view-1

Description

For the browser as such it is possible to obtain both the dimensions and the positon on the (operating system) screen area:

https://drafts.csswg.org/cssom-view/#dom-window-outerwidth https://drafts.csswg.org/cssom-view/#dom-window-outerheight https://drafts.csswg.org/cssom-view/#dom-window-screenx https://drafts.csswg.org/cssom-view/#dom-window-screenx

However, for the viewport it is only possible to obtain the dimensions, not the position:

https://drafts.csswg.org/cssom-view/#dom-window-innerwidth https://drafts.csswg.org/cssom-view/#dom-window-innerheight

The fact that the position is not available makes it impossible to translate coordinates on the screen to coordinates in the viewport.

I therefore propose the addition of corresponding innerScreenX and innerScreenY properties.

Since this translation is already performed by e.g. window.onMouseMove(), implementing the properties should not present any new technical or conceptual challenges.

The need arises when you get (OS) screen coordinates from some non-mouse source (in our particular case an gaze-tracking device), and want to relate them to the corresponding position in the displayed document.

There are non-standard implementations, e.g. mozInnerScreenX https://developer.mozilla.org/en-US/docs/Web/API/Window/mozInnerScreenX.

A previous request for another vendor-specific implementation was declined awaiting standardization https://bugs.chromium.org/p/chromium/issues/detail?id=151983 .

Contributor guide

Tech stack
javascriptcss
Domain
frontendapi
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
CSSOM View specificationbrowser coordinate systemsJavaScript window object
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50
Research direction
The issue proposes adding innerScreenX and innerScreenY properties to the Window interface in the CSSOM View spec. Refer to the linked spec sections for outerWidth/outerHeight and screenX/screenY. Also review the non standard mozInnerScreenX implementation and the Chrome bug referenced. The discussion in the comments may provide additional context on prior vendor specific implementations and standardization concerns.
[cssom-view] window.innerScreenX windows.innerScreenY · w3c/csswg-drafts#809 | Good First Issue