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.
We don't yet have generic parsing support for `<filter-value-list>` or
`<paint>`, so listing them here confuses the new StyleValue parsing code
I'm working on. For now, let's skip `<filter-value-list>` since it's
only used in one pkace which manually parses it, and list the parts of
`<paint>` instead which are taken from here:
https://www.w3.org/TR/SVG2/painting.html#SpecifyingPaint
This fixes a plethora of rounding problems on many websites.
In the future, we may want to replace this with fixed-point arithmetic
(bug #18566) for performance (and consistency with other engines),
but in the meantime this makes the web look a bit better. :^)
There's a lot more things that could be converted to doubles, which
would reduce the amount of casting necessary in this patch.
We can do that incrementally, however.
SVG presentation attributes are parsed as CSS values, so we also need to
handle CSS variable expansion when handling them.
This (roughly) matches the behavior of other engines. It's also used on
the web, for example on https://stripe.com/ :^)
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.
Previously, calling `.right()` on a `Gfx::Rect` would return the last
column's coordinate still inside the rectangle, or `left + width - 1`.
This is called 'endpoint inclusive' and does not make a lot of sense for
`Gfx::Rect<float>` where a rectangle of width 5 at position (0, 0) would
return 4 as its right side. This same problem exists for `.bottom()`.
This changes `Gfx::Rect` to be endpoint exclusive, which gives us the
nice property that `width = right - left` and `height = bottom - top`.
It enables us to treat `Gfx::Rect<int>` and `Gfx::Rect<float>` exactly
the same.
All users of `Gfx::Rect` have been updated accordingly.
It's not safe to allocate from the GC heap while in the constructor of a
GC heap cell. (Because if this ends up triggering a collection, we may
end up trying to call through an uninitialized vtable).
This was already done safely in the initialize() virtual in much of
LibJS and LibWeb. This patch moves the logic for prototypes, mixins,
and CSSStyleDeclaration as well.
Fixes a long-standing GC crash that was pretty easy to reproduce by
refreshing https://vercel.com/
This implements the stop-opacity, fill-opacity, and stroke-opacity
properties (in CSS). This replaces the existing more ad-hoc
fill-opacity attribute handling.
The resolved property sets are stored with the element in a
per-pseudo-element array (same as for pseudo element layout nodes).
Longer term, we should stop storing this with elements entirely and make
it temporary state in StyleComputer somehow, so we don't waste memory
keeping all the resolved properties around.
This makes various gradients show up on https://shopify.com/ :^)
1. Propagate calc() values from StyleProperties to ComputedValues.
2. Actually resolve calc() values when determining the used flex basis.
This makes the "support" section on https://shopify.com/ show up
correctly as a 2x2 grid (instead of 1x4). :^)
Note that this simple form of text-indent only affects the first line
of formatted content in each block.
Percentages are resolved against the width of the block.
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 makes hovering around on GitHub fast again, as it no longer
believes that the grid-template-areas property keeps changing
when it didn't :^)
Also made to_string() work for calc() values as well, since I stumbled
upon that while debugging this.
