Add <meta name="supported-color-schemes"> to control what color schemes the page supports

• Component: CSS
• Status: RESOLVED FIXED

[Timothy Hatcher]

To know when to allow semantic colors to switch between dark and light mode, as well as form controls, we need a way for the page to tell us what color schemes they support.

Proposal is to add: <meta name="supported-color-schemes" content="light dark">

[Radar WebKit Bug Importer]

<rdar://problem/45230140>

[Simon Fraser (smfr)]

What's the standardization story here?

[Timothy Hatcher]

Created attachment 352193 [details]
Patch

[EWS Watchlist]

Comment on attachment 352193 [details]
Patch

Attachment 352193 [details] did not pass mac-ews (mac):
Output: https://webkit-queues.webkit.org/results/9555486

New failing tests:
css-dark-mode/supported-color-schemes.html

[EWS Watchlist]

Created attachment 352199 [details]
Archive of layout-test-results from ews100 for mac-sierra

The attached test failures were seen while running run-webkit-tests on the mac-ews.
Bot: ews100  Port: mac-sierra  Platform: Mac OS X 10.12.6

[EWS Watchlist]

Comment on attachment 352193 [details]
Patch

Attachment 352193 [details] did not pass mac-wk2-ews (mac-wk2):
Output: https://webkit-queues.webkit.org/results/9555605

New failing tests:
css-dark-mode/supported-color-schemes.html

[EWS Watchlist]

Created attachment 352202 [details]
Archive of layout-test-results from ews106 for mac-sierra-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews106  Port: mac-sierra-wk2  Platform: Mac OS X 10.12.6

[EWS Watchlist]

Comment on attachment 352193 [details]
Patch

Attachment 352193 [details] did not pass win-ews (win):
Output: https://webkit-queues.webkit.org/results/9556301

New failing tests:
css-dark-mode/supported-color-schemes.html

[EWS Watchlist]

Created attachment 352217 [details]
Archive of layout-test-results from ews200 for win-future

The attached test failures were seen while running run-webkit-tests on the win-ews.
Bot: ews200  Port: win-future  Platform: CYGWIN_NT-6.1-2.9.0-0.318-5-3-x86_64-64bit

[Timothy Hatcher]

Wont pass until bug 190499 lands.

[EWS Watchlist]

Comment on attachment 352193 [details]
Patch

Attachment 352193 [details] did not pass mac-debug-ews (mac):
Output: https://webkit-queues.webkit.org/results/9556743

New failing tests:
css-dark-mode/supported-color-schemes.html

[EWS Watchlist]

Created attachment 352223 [details]
Archive of layout-test-results from ews115 for mac-sierra

The attached test failures were seen while running run-webkit-tests on the mac-debug-ews.
Bot: ews115  Port: mac-sierra  Platform: Mac OS X 10.12.6

[Dean Jackson]

Comment on attachment 352193 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=352193&action=review

> Source/WebCore/dom/Document.cpp:3575
> +            i++;

Why i++ here and ++i above? :)

> Source/WebCore/dom/Document.cpp:3594
> +    processColorSchemes(colorSchemes, [&supportedColorSchemes](StringView key) {
> +        if (equalLettersIgnoringASCIICase(key, "light"))
> +            supportedColorSchemes.add(ColorSchemes::Light);
> +        else if (equalLettersIgnoringASCIICase(key, "dark"))
> +            supportedColorSchemes.add(ColorSchemes::Dark);
> +    });

I like this way of doing this parsing!

> Source/WebCore/dom/Document.h:898
> +    enum class ColorSchemes : uint8_t {

Shouldn't this be singular ColorScheme?

> LayoutTests/css-dark-mode/supported-color-schemes.html:68
> +    document.getElementById("meta").content = "dark";

More test suggestions
"     dark"
"dark    "
"light, dark" (light should fail)
"foo dark"

[EWS Watchlist]

Comment on attachment 352193 [details]
Patch

Attachment 352193 [details] did not pass ios-sim-ews (ios-simulator-wk2):
Output: https://webkit-queues.webkit.org/results/9565309

New failing tests:
css-dark-mode/supported-color-schemes.html

[EWS Watchlist]

Created attachment 352270 [details]
Archive of layout-test-results from ews121 for ios-simulator-wk2

The attached test failures were seen while running run-webkit-tests on the ios-sim-ews.
Bot: ews121  Port: ios-simulator-wk2  Platform: Mac OS X 10.13.6

[Timothy Hatcher]

Comment on attachment 352193 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=352193&action=review

>> Source/WebCore/dom/Document.cpp:3575
>> +            i++;
> 
> Why i++ here and ++i above? :)

No reason. Fixed.

>> Source/WebCore/dom/Document.h:898
>> +    enum class ColorSchemes : uint8_t {
> 
> Shouldn't this be singular ColorScheme?

I'm not so sure. There are other cases in the code where we use plural for the enum class name. It reads better when using it too: OptionSet<ColorSchemes>

>> LayoutTests/css-dark-mode/supported-color-schemes.html:68
>> +    document.getElementById("meta").content = "dark";
> 
> More test suggestions
> "     dark"
> "dark    "
> "light, dark" (light should fail)
> "foo dark"

I'll add more cases. "light, dark" is valid.

[Timothy Hatcher]

Created attachment 352483 [details]
Patch

[EWS Watchlist]

Comment on attachment 352483 [details]
Patch

Attachment 352483 [details] did not pass mac-wk2-ews (mac-wk2):
Output: https://webkit-queues.webkit.org/results/9625960

New failing tests:
css-dark-mode/supported-color-schemes.html

[EWS Watchlist]

Created attachment 352497 [details]
Archive of layout-test-results from ews107 for mac-sierra-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews107  Port: mac-sierra-wk2  Platform: Mac OS X 10.12.6

[Timothy Hatcher]

Created attachment 352498 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 352498 [details]
Patch

Clearing flags on attachment: 352498

Committed r237204: <https://trac.webkit.org/changeset/237204>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.