This reintroduces bounds-checking for the CSS `<angle>`, `<frequency>`,
`<integer>`, `<length>`, `<number>`, `<percentage>`, `<resolution>`,
and `<time>` types.
I regressed this around 6b8f484114 when
changing how we parsed StyleValues.
This is an improvement from before though, since we now allow the bounds
of a dimension type to have units.
Added a test to make sure we don't regress this again. :^)
Having one StyleValue for `<number>` and `<integer>` is making user code
more complicated than it needs to be. We know based on the property
being parsed, whether it wants a `<number>` or an `<integer>`, so we
can use separate StyleValue types for these.
This partially implements CSS-Animations-1 (though there are references
to CSS-Animations-2).
Current limitations:
- Multi-selector keyframes are not supported.
- Most animation properties are ignored.
- Timing functions are not applied.
- Non-absolute values are not interpolated unless the target is also of
the same non-absolute type (e.g. 10% -> 25%, but not 10% -> 20px).
- The JavaScript interface is left as an exercise for the next poor soul
looking at this code.
With those said, this commit implements:
- Interpolation for most common types
- Proper keyframe resolution (including the synthetic from-keyframe
containing the initial state)
- Properly driven animations, and proper style invalidation
Co-Authored-By: Andreas Kling <kling@serenityos.org>
The comment mentions that zero is let through, but then immediately
errors out if it sees any number outside quirks mode.
This commit makes that check let zeros through.
Specifically, stop letting NumericStyleValues holding `0` from
pretending to hold a Length. The parser is now smart enough that we
don't have to do this. :^)
We're about to stop letting 0 NumericStyleValues pretend to be Lengths,
so this will break. As noted, the flex-basis property accepts
`<length>` not `<number>` so this is actually correct.
Introduces incomplete parsing of grid shorthand property. Only
<grid-template> part of syntax is supported for now but it is enough
to significantly improve rendering of websites that use this shorthand
to define grid :)
We know what types and identifiers a property can accept, so we can use
that information to only parse things that can be accepted. This solves
some awkward ambiguity problems that we have now or will face in the
future, including:
- Is `0` a number or a length with no unit?
- Is `3.5` a number or a ratio?
- Is `bottom` an identifier, or a custom-ident?
Two CSS Parser methods are introduced here:
`parse_css_value_for_property()` attempts to parse a StyleValue that the
property can accept, skipping any types that it doesn't want.
`parse_css_value_for_properties()` does the same, but takes multiple
PropertyIDs and additionally returns which one the parsed StyleValue is
for. This is intended for parsing shorthands, so you can give it a list
of longhands you haven't yet parsed.
Subsequent commits will actually use these new methods.
If we finish parsing a calculation tree and it still contains
UnparsedCalculationNodes, then it's not valid, and we shouldn't create
a StyleValue from it.
The spec says: "The first value gives the width of the corresponding
image, the second value its height. If only one value is given the
second is assumed to be auto."
Fixes#18782
This necessitated returning `nullptr` instead of just `{}` in a lot of
places. Also, some temporary hackiness in `parse_css_value()`: That
returns a special `ParseError` type already, so we now have a
`FIXME_TRY()` macro which logs the error and then returns a generic
`ParseError::InternalError` value. Eventually this macro will go away,
once I figure out how to deal with this more nicely.
