1561440 - Add support for non-integer values in HTML dimension attributes

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect, P3)

Description

[Boris Zbarsky [:bzbarsky]]

Something like this:

  <img src="whatever" width="50.5%">

should make the image 101px wide in a 200px container. Similarly,

  <img src="whatever" width="50.5">

should end up 50.5 CSS px wide (so 101 device pixels on 2dppx screen).

We don't do that right now, because we parse those as "50%" and "50" respectively. The issue is that nsAttrValue doesn't have generic (non-percentage) float storage. And even for percentages, we only use the mPercent of the misc container from SetIntValueAndType, if the value doesn't fit in the bits we have available to store it.

We should just add a SetFloatValueAndType that would explicitly store floats in the misc container as needed.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug is a enhancement, but please change it back in case of error.

Comment 2

[Boris Zbarsky [:bzbarsky]]

Well, it's technically a spec violation, and may have web compat impact, though none has been reported yet.

Comment 3

[Boris Zbarsky [:bzbarsky]]

Attachment: Bug 1561440 part 1. Move MapSizeAttributeInto to earlier in the file, where we will need it, and rename to be clearer about what sort of things it maps. r=mccr8

Comment 4

[Boris Zbarsky [:bzbarsky]]

Attachment: Bug 1561440 part 2. Add mapping and reflection support for dimension attributes stored as doubles. r=mccr8

Comment 5

[Boris Zbarsky [:bzbarsky]]

Attachment: Bug 1561440 part 3. Add a way to store a non-integer percent value in nsAttrValue. r=mccr8

In the new setup, if the value is an integer and fits in our restricted integer
range we store it directly; otherwise we just go ahead and store it as a double
in the misc container, since we have a double available there anyway.

Comment 6

[Boris Zbarsky [:bzbarsky]]

Attachment: Bug 1561440 part 4. Parse non-integer HTML dimension values. r=mccr8

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/56b4d2258093
part 1.  Move MapSizeAttributeInto to earlier in the file, where we will need it, and rename to be clearer about what sort of things it maps.  r=mccr8
https://hg.mozilla.org/integration/autoland/rev/3065c80f6ca8
part 2.  Add mapping and reflection support for dimension attributes stored as doubles.  r=mccr8,emilio
https://hg.mozilla.org/integration/autoland/rev/6e8779559140
part 3.  Add a way to store a non-integer percent value in nsAttrValue.  r=mccr8
https://hg.mozilla.org/integration/autoland/rev/5277a23512a6
part 4.  Parse non-integer HTML dimension values.  r=mccr8

Comment 8

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/56b4d2258093
https://hg.mozilla.org/mozilla-central/rev/3065c80f6ca8
https://hg.mozilla.org/mozilla-central/rev/6e8779559140
https://hg.mozilla.org/mozilla-central/rev/5277a23512a6

Comment 9

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/17757 for changes under testing/web-platform/tests

Comment 10

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged