Closed Bug 1501483 Opened 2 years ago Closed 2 years ago
Add -webkit-appearance:meter and make that the default for <meter> for compatibility with other UAs
We should add a new 'meter' value to '-webkit-appearance' in the style system, and make the existing 'meterbar' value an alias for 'meter'. We should also replace any existing 'meterbar' values in our UA sheets with 'meter'. In particular, the default value for <meter>. Chrome uses '-webkit-appearance:meter' on the <meter> element. Setting '-webkit-appearance:none' removes the theme and it renders its contents instead. Setting display:inline appears to work but it appears they use an inner anonymous block to render the contents, so it ends up as a block-in-inline. display:contents works as display:none. Edge, on the other hand, uses '-webkit-appearance:none' by default on <meter> and it never renders its contents. display:contents appears to have no effect. Setting the 'background' doesn't seem to work at all. https://html.spec.whatwg.org/multipage/form-elements.html#the-meter-element says: "Content model: Phrasing content, but there must be no meter element descendants." ... "Authors are encouraged to include a textual representation of the gauge's state in the element's contents, for users of user agents that do not support the meter element."
> Edge, ... display:contents appears to have no effect. Oh right, I forgot - they don't support it, LOL.
Safari also has '-webkit-appearance:meter' on <meter>. It renders the test somewhat like Firefox - not rendering its contents in particular. We should probably try to avoid emulating that part Chrome's behavior if we can (and file a bug on Chrome instead).
Note that chrome has something similar for <progress> and it's not fun: https://bugs.chromium.org/p/chromium/issues/detail?id=853558 I don't know if they have the same bug with <meter>, but it wouldn't surprise me.
Yeah, technically it's a violation of the HTML spec since they do support <meter>. I read the spec text as only applying to UAs that don't support the <meter> element at all, in which case the contents will render naturally.
Assignee: nobody → mats
Keep our old value 'meterbar' as an alias for now, but unship 'meterchunk' by restricting it to UA/chrome sheets only.
Attachment #9023257 - Flags: review?(jwatt)
Pushed by email@example.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/06421db62f78 Add -webkit-appearance:meter and make that the default for <meter> for compatibility with other UAs. r=jwatt
Note to MDN writers: I've added a note to the Fx65 rel notes to cover this: https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/65#CSS As for the docs, this should be a simple matter of adding the value to the appearance reference page and the compat data.
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