We have this code duplicated in multiple places, and we'll want to
handle registered custom properties too at some point, so wrap it in a
reusable `CalculationContext::for_property()` method.
Noticed while doing this that ValueParsingContext will eventually need
to take a PropertyNameAndID, not a PropertyID, so I've added a FIXME.
This struct will in the future hold information other than a length
resolution context (e.g. context for tree counting functions) and a
single struct is easier to work with than multiple parameters.
Previously we would clamp the percentage value to the allowed range for
canonical dimension values rather than the percentage value.
Also fixes an issue where we would clamp pure percentages (i.e.
percentages that don't have a hint) against the allowed values for the
first dimension we checked (i.e. angle)
When we have a `calc` which is a mix of a dimension and a percentage, we
should use the percentage alone for the computed value if the dimension
component is 0 e.g. `calc(50% + 0px)` should use `50%` as it's computed
value.
From the CSS token side, we already have these in FlyString form. From
the generated code side, we can easily return FlyStrings instead of
StringViews. So, let's do that, and save some work converting back and
forth.
This has always been a bit of a hack. Initially it made sense as a lot
of properties that accept a length also accept `auto`, but while
convenient, that leads to problems: It's easy to forget to check if a
length is `auto`, and places that don't accept it end up with an
invalid state lurking in the type system, which makes things unclear.
The CSSNumericType defined in the spec is a simple dictionary which is
only used for OM purposes. This NumericType class is used internally
and matches the more abstract definition of a "type".
We now clamp the values returned from calc into the allowed range (where
we know it) and censor any `NaN`s to `0` both when we resolve and when
we serialize.
Gains us 76 WPT passes.
Returning this struct will allow us to modify the underlying value of
the `CalculationResult` without requiring us to go through the process
of constructing a whole new `CalculationResult` to return.
This reverts 0e3487b9ab.
Back when I made that change, I thought we could make our StyleValue
classes match the typed-om definitions directly. However, they have
different requirements. Typed-om types need to be mutable and GCed,
whereas StyleValues are immutable and ideally wouldn't require a JS VM.
While I was already making such a cataclysmic change, I've moved it into
the StyleValues directory, because it *not* being there has bothered me
for a long time. 😅
Previously we were converting lengths to CSSPixels values when we didn't
need to, this had a couple of effects in that:
- We rounded to CSSPixel resolution prematurely (sometimes giving
incorrect results)
- We converted NaN to 0 when we shouldn't have.
We now avoid prematurely converting lengths to CSSPixels values in two
places:
- `CalculationResult::from_value`
- `CalculatedStyleValue::resolve_length_deprecated` (the new method
already avoided rounding).
Gains us 16 WPT tests.
These new methods are built on top of the spec's
`simplify_a_calculation_tree` algorithm where the old methods were
ad-hoc.
These methods are not used anywhere yet as callers will need to be
migrated over from the deprecated methods one-by-one to account for
differences in behaviour.
No functionality changes.
The existing resolve methods are not to spec and we are working to
replace them with new ones based on the `simplify_a_calculation_tree`
method.
These are marked as deprecated rather than replaced outright as work
will need to be done on the caller side to be made compatible with the
new methods, for instance the new methods can fail to resolve (e.g.
if we are missing required context), where the existing methods will
always resolve (albeit sometimes with an incorrect value).
No functionality changes.
Previously we would never get a valid `consistent_type` as we were
trying to make the node types consistent with the initial empty type
which isn't possible.
Gains us 7 WPT tests.
The main users were the `dump()` functions, which now dump their
children instead, which is more correct anyway.
The others are for serializing numeric values, so
NumericCalculationNode's to_string() is renamed to value_to_string
() and used for those for convenience.
This gets us 37 new subtest passes in css/css-values, and 13 passes in
our other in-tree tests (and probably some random other ones!)
As noted in comments, a few parts of this algorithm have ad-hoc
behaviour to handle some issues in the spec.
Having multiple kinds of node that hold numeric values made things more
complicated than they needed to be, and we were already converting
ConstantCalculationNodes to NumericCalculationNodes in the first
simplification pass that happens at parse-time, so they didn't exist
after that.
As noted, the spec allows for other contexts to introduce their own
numeric keywords, which might be resolved later than parse-time. We'll
need a different mechanism to support those, but
ConstantCalculationNode could not have done so anyway.
