This is a improved version of a73cd88f0c
The old commit was reverted in 552dd18696
The new version only paints an element into a new layer if background
blend modes other than normal are used. The rasterization performance
of most websites should therefore not suffer.
Co-Authored-By: Alexander Kalenik <kalenik.aliaksandr@gmail.com>
This reverts commit a73cd88f0c.
Emitting SaveLayer for each paintable made rasterization a lot slower
on every website because now Skia has to allocate enormous amounts of
temporary surfaces. Let's revert it for now and figure how to implement
it with less aggressive SaveLayer usage.
This makes them accessible outside of PropertyParsing.cpp (which will be
useful if/when descriptors can include them). I've also renamed them to
use the correct term: "arbitrary substitution function".
We now parse `<counter-name>` values as a `<custom-ident>`. This
disallows `default` and CSS-wide keywords as counter names. The
specification additionally disallows `none` as a counter name.
The `cursor` property accepts a list of possible cursors, which behave
as a fallback: We use whichever cursor is the first available one. This
is a little complicated because initially, any remote images have not
loaded, so we need to use the fallback standard cursor, and then switch
to another when it loads.
So, ComputedValues stores a Vector of cursors, and then in EventHandler
we scan down that list until we find a cursor that's ready for use.
The spec defines cursors as being `<url>`, but allows for `<image>`
instead. That includes functions like `linear-gradient()`.
This commit implements image cursors in the Qt UI, but not AppKit.
Before this change, we only parsed fit-content as a standalone keyword,
but CSS-SIZING-3 added it as a function as well. I don't know of
anything else in CSS that is overloaded like this, so it ends up looking
a little awkward in the implementation.
Note that a lot of code had already been prepped for fit-content values
to have an argument, we just weren't parsing it.
The spec wants these keywords to appear in a particular order when
serialized, so let's just put them in that order during parsing.
This also fixes a bug where we didn't reject `font-variant-east-asian`
that contains `normal` alongside another value.
Also, rather than always parsing them as a StyleValueList, parse single
values on their own, and then support that in the to_font_variant_foo()
methods.
Without this, we'd happily parse `font-variant-caps: small-caps potato`
as just `small-caps` and ignore the fact that unused tokens were left
over.
This fix gets us some WPT subtest passes, and removes the need for a
bespoke parsing function for font-variant-caps.
This is a weird behaviour specific to `font` - it can reset some
properties that it never actually sets. As such, it didn't seem worth
adding this concept to the code generator, but just manually stuffing
the ShorthandStyleValue with them during parsing.
This file has been a pain to edit for a while, even with the previous
splits. So, I've divided it up into 3 parts:
- Parser.cpp has the "base" code. It's the algorithms and entry-points
defined in the Syntax spec.
- ValueParsing.cpp contains code for parsing single values, such as a
length, or a color, or a calculation.
- PropertyParsing.cpp contains code for parsing an entire property's
value. A few of these sit in a grey area between being a property's
value and a value in their own right, but the rule I've used is "is
this useful outside of a single property and its shorthands?"
This only moves code, with as few modifications as possible to make that
work. I did add explicit instantiations for the template implementations
as part of this, which revealed a few that are actually only compatible
with a single type, so I'll clear those up in a subsequent commit.
