CSS Syntax 3 (https://drafts.csswg.org/css-syntax) has changed
significantly since we implemented it a couple of years ago. Just about
every parsing algorithm has been rewritten in terms of the new token
stream concept, and to support nested styles. As all of those
algorithms call into each other, this is an unfortunately chonky diff.
As part of this, the transitory types (Declaration, Function, AtRule...)
have been rewritten. That's both because we have new requirements of
what they should be and contain, and also because the spec asks us to
create and then gradually modify them in place, which is easier if they
are plain structs.
There was no need to use FlyString for error messages, and it just
caused a bunch of churn since these strings typically only existed
during the lifetime of the error.
DedicatedWorkerGlobalScope is an object with a Global extended
attribute, but does not define any named property getters. This needs to
be handled by setting the prototype chain to:
DedicatedWorkerGlobalScope
^ DedicatedWorkerGlobalScopePrototype
^ WorkerGlobalScopePrototype
(This is different from something like Window, where there is an
intermediate WindowProperties object for named properties.)
Previously, we treated the GlobalMixin object as if it was a simple
prototype object, accidentally setting DedicatedWorkerGlobalScope's
prototype to WorkerGlobalScopePrototype. This caused the expression
self instanceof DedicatedWorkerGlobalScope
to return false inside workers.
This makes us pass many more of the "/xhr/idlharness.any.worker" WPT
tests than before, rather than failing early.
When the TokenStream code was originally written, there was no such
concept in the CSS Syntax spec. But since then, it's been officially
added, (https://drafts.csswg.org/css-syntax/#css-token-stream) and the
parsing algorithms are described in terms of it. This patch brings our
implementation in line with the spec. A few deprecated TokenStream
methods are left around until their users are also updated to match the
newer spec.
There are a few differences:
- They name things differently. The main confusing one is we had
`next_token()` which consumed a token and returned it, but the spec
has a `next_token()` which peeks the next token. The spec names are
honestly better than what I'd come up with. (`discard_a_token()` is a
nice addition too!)
- We used to store the index of the token that was just consumed, and
they instead store the index of the token that will be consumed next.
This is a perfect breeding ground for off-by-one errors, so I've
finally added a test suite for TokenStream itself.
- We use a transaction system for rewinding, and the spec uses a stack
of "marks", which can be manually rewound to. These should be able to
coexist as long as we stick with marks in the parser spec algorithms,
and stick with transactions elsewhere.
https://www.w3.org/TR/event-timing/#sec-performance-event-timing
Add idl, header and stubs for PerformanceEventTiming interface.
Two missing `PerformanceEntry` types that have come up in issues
are the `first-input` and the `event` entryTypes. Those are both
this.
Also, because both of those are this same interface, the static
methods from the parent class are difficult to implement because
of instance-specific details. Might either need subclasses or to
edit the parent and also everything that inherits from it :/
While Origin is defined in the HTML spec - this leaves us with quite an
awkward relationship as the URL spec makes use of AO's from what is
defined in the HTML spec.
To simplify this factoring, relocate Origin into LibURL.
This is a special form of `<string>` so doesn't need its own style value
type. It's used in a couple of font-related properties. For completeness
it's included in ValueType.
We had numerous NiH-based implementations of audio formats and metadata
that we now no longer need because we either don't make use of the code,
or we replaced its implementation by FFmpeg.
When a property is a "legacy name alias", any time it is used in CSS or
via the CSSOM its aliased name is used instead.
(See https://drafts.csswg.org/css-cascade-5/#legacy-name-alias)
This means we only care about the alias when parsing a string as a
PropertyID - and we can just return the PropertyID it is an alias for.
No need for a distinct PropertyID for it, and no need for LibWeb to
care about it at all.
Previously, we had a bunch of these properties, which misused our code
for "logical aliases", some of which I've discovered were not even
fully implemented. But with this change, all that code can go away, and
making a legacy alias is just a case of putting it in the JSON. This
also shrinks `StyleProperties` as it doesn't need to contain data for
these aliases, and removes a whole load of `-webkit-*` spam from the
style inspector.
The IPCs to request a page's text, layout tree, etc. are currently all
synchronous. This can result in a deadlock when WebContent also makes
a synchronous IPC call, as both ends will be waiting on each other.
This replaces the page info IPCs with a single, asynchronous IPC. This
new IPC is promise-based, much like our screenshot IPC.
UI event handlers currently return a boolean where false means the event
was cancelled by a script on the page, or otherwise dropped. It has been
a point of confusion for some time now, as it's not particularly clear
what should be returned in some special cases, or how the UI process
should handle the response.
This adds an enumeration with a few states that indicate exactly how the
WebContent process handled the event. This should remove all ambiguity,
and let us properly handle these states going forward.
There should be no behavior change with this patch. It's meant to only
introduce the enum, not change any of our decisions based on the result.
Instead of switching on the PropertyID and doing a boatload of
comparisons, we reorder the PropertyID enum so that all inherited
properties are in two contiguous ranges (one for shorthands,
one for longhands).
This replaces the switch statement with two simple range checks.
Note that the property order change is observable via
window.getComputedStyle(), but the order of those properties is
implementation defined anyway.
Removes a 1.5% item from the profile when loading https://hemnet.se/
This header held a bunch of utility functions shared across several code
generators. The only user of any of these utilities now is the public
suffix generator. Move the one used function to that generator, and
remove the common header.
This change should move us forward toward emoji support, as we are no
longer limited by our own OpenType implementation, which was failing
to parse the TrueType Collection format used to store emoji fonts
(at least on macOS).
We don't actually generate any such events ourselves. But Google Lens
will create one with the DataTransfer attribute set to that of any drop
event we send it.
The identifier "Protocol" is claimed by Objective-C and Swift for use
by the language's built-in protocol conformance feature, which is
similar to Rust traits or Java interfaces.
Rename LibProtocol -> LibRequests, and its namespace from Protocol to
Requests to accomodate this.
USVString attributes Now replace any surrogates with the replacement
character U+FFFD and resolve any relative URLs to an absolute URL. This
brings our implementation in line with the specification.
For a long time, we've used two terms, inconsistently:
- "Identifier" is a spec term, but refers to a sequence of alphanumeric
characters, which may or may not be a keyword. (Keywords are a
subset of all identifiers.)
- "ValueID" is entirely non-spec, and is directly called a "keyword" in
the CSS specs.
So to avoid confusion as much as possible, let's align with the spec
terminology. I've attempted to change variable names as well, but
obviously we use Keywords in a lot of places in LibWeb and so I may
have missed some.
One exception is that I've not renamed "valid-identifiers" in
Properties.json... I'd like to combine that and the "valid-types" array
together eventually, so there's no benefit to doing an extra rename
now.
Implements the corresponding encoders, selects the appropriate one when
encoding URL search params. If an encoder for the given encoding could
not be found, fallback to utf-8.
USVString is defined in the IDL spec as:
> The USVString type corresponds to scalar value strings. Depending on
> the context, these can be treated as sequences of either 16-bit
> unsigned integer code units or scalar values.
This means we need to account for surrogate code points by using the
replacement character.
This fixes the last test in https://wpt.live/url/url-constructor.any.html
Previously we were assuming that the attribute return value was never
nullable and going to be returned in an Optional<IntegralType>, causing
complile errors for something such as: `attribute unsigned long?`.
