A proposal for controlling screen brightness

[anssiko]

Hi CSS WG,

The Devices and Sensors WG has produced an explainer for a proposed new feature for controlling screen brightness:

https://github.com/w3c/screen-wake-lock/blob/gh-pages/brightness-mode-explainer.md

We know many CSS WG participants have expertise in this space, so we’re reaching out to you to gather your feedback and comments before advancing (or not). In particular, the open design issues and the proposed CSS property are looking for your feedback.

You can provide your feedback on this issue or via w3c/screen-wake-lock#129

Thanks everyone who already reviewed an earlier iteration of this proposal.

[tabatkins]

Looking over this, I think your JS API looks reasonable. This is something that should be permissioned, so I don't think we want this to be controllable via a CSS property. (In any case, this is more document-global rather than element-specific.)

I don't think we need to say anything about MQs; anything that's true of "screen locked to bright" should apply identically to "screen manually adjusted to bright" already.

[css-meeting-bot]

The CSS Working Group just discussed A proposal for controlling screen brightness.

The full IRC log of that discussion

<TabAtkins> fantasai: I flagged to ask people to review it. No opinion on it personally.
<chris> q+
<astearns> ack chris
<TabAtkins> chris: This idea of "maximum screen brightness", everyone thinks they know what it means until we get to hdr; then websites hsouldn't be able to request max brightness. it's not paper white, it's blinding
<TabAtkins> chris: So HDR might be available and we should have wording tha tmakes it clear what we're actually asking for
<TabAtkins> astearns: Looks like they don't actually have a proposal, just a placeholder, so we should raise a seaprate issue
<TabAtkins> chris: I'll raise an issue in their repo
<TabAtkins> florian: Do we want to wait to know more, or should we discuss this now?
<schenney> The explainer does mention HDR with respect to brightness values.
<TabAtkins> astearns: If you have opinions abou tit
<TabAtkins> florian: I'm not locked in, but I'm suspicious it might not be a great idea. This is useful for users, but having authors turn brightness up or down is somewhat questionable.
<TabAtkins> florian: Probably there's a button somewhere to force it abck down if that's not what you wanted, but that can be obnoxious.
<TabAtkins> astearns: The explainer does go into use-cases about the modes like this.
<TabAtkins> astearns: Any other comments?
<TabAtkins> astearns: We'll take this as an FYI, chris will raise an issue in their repo, and we'll likely come back to it at some point.

[svgeesus]

HDR is already being discussed in two issues:

• Control screen brightness 🔆 review feedback screen-wake-lock#335
• Need maximum screen brightness mode screen-wake-lock#129

[svgeesus]

@anssiko have you had enough review from CSSWG? If so we can close this issue.