This requires an implementation of the "text preparation algorithm" as
specified here:
html.spec.whatwg.org/multipage/canvas.html#text-preparation-algorithm
However, we're missing a lot of things such as the
CanvasTextDrawingStyles interface, so most of the algorithm was not
implemented. Additionally, we also are not able to use a LineBox like
the algorithm suggests, because our layouting infra is not up to the
task yet. The prepare_text function does nothing other than figuring out
the width of the given text and return glyphs with offsets at the
moment.
This function initially returned a ByteBuffer, so `return {}` was fine.
It was then changed to return Optional<ByteBuffer>, so we accidentally
started returning an empty Optional instead. Explicitly specify the
constructor name to fix this.
Thanks to DexesTTP for catching this!
Just some boilerplate code to get started :^)
This adds both the SubtleCrypto constructor to the window object, as
well as the crypto.subtle instance attribute.
Being really close to Object.prototype.valueOf() name wise makes this
unnecessarily confusing - while it sometimes serves as the
implementation of a valueOf() function, it's an abstraction which the
spec doesn't have.
Use the appropriate getters to retrieve specific internal slots instead,
most commonly [[FooData]] from the primitive wrapper objects.
For the Object class specifically, use the Value(Object*) ctor instead.
This changes Web::Bindings::throw_dom_exception_if_needed() to return a
JS::ThrowCompletionOr instead of an Optional. This allows callers to
wrap the invocation with a TRY() macro instead of making a follow-up
call to should_return_empty(). Further, this removes all invocations to
vm.exception() in the generated bindings.
Both at the same time because many of them call construct() in call()
and I'm not keen on adding a bunch of temporary plumbing to turn
exceptions into throw completions.
Also changes the return value of construct() to Object* instead of Value
as it always needs to return an object; allowing an arbitrary Value is a
massive foot gun.
The old versions were renamed to JS_DECLARE_OLD_NATIVE_FUNCTION and
JS_DEFINE_OLD_NATIVE_FUNCTION, and will be eventually removed once all
native functions were converted to the new format.
Note there are a couple of type differences between the spec and the IDL
file added in this commit. For example, we will need to support a type
of Variant to handle spec types such as "(double or sequence<double>)".
But for now, this allows web pages to construct an IntersectionObserver
with any valid type.
This paves the way for the rejectionhandled and unhandledrejection
events.
It's also used by core-js (in browsers, at least) to check whether
Promise needs to be polyfilled, so adding it should allow more websites
to leverage LibJS's native Promise implementation :^)
Websites being able to query whether we support a given CSS feature
should prevent them from loading unnecessary polyfills for things we
already support! Or at least, that's the nice theory. :^)
This is the `CSS` namespace defined in IDL here:
https://www.w3.org/TR/cssom-1/#namespacedef-css , not to be confused
with our `Web::CSS` namespace. Words are hard.
`CSS.escape()` lets you escape identifiers that can then be used to
create a CSS string.
I've also stubbed out the `CSS.supports()` function.
This was incorrectly calling DOM::Window::clear_timeout(). In practice,
these functions are interchangeable, but let's have things looking
correct regardless.
Instead of passing a function it is also possible to pass a string,
which is then evaluated as a classic script.
This means we now support the following example from the "timer
initialization steps", step 16 - except that it runs the timers in
reverse order, so the `log` result is `"TWO ONE "`.
https://html.spec.whatwg.org/multipage/timers-and-user-prompts.html#timer-initialisation-steps
var log = '';
function logger(s) { log += s + ' '; }
setTimeout({ toString: function () {
setTimeout("logger('ONE')", 100);
return "logger('TWO')";
} }, 100);
This introduces 3 classes: NodeList, StaticNodeList and LiveNodeList.
NodeList is the base of the static and live versions. Static is a
snapshot whereas live acts on the underlying data and thus inhibits
the same issues we have currently with HTMLCollection.
They were split into separate classes to not have them weirdly
mis-mashed together.
The create functions for static and live both return a NNRP to the base
class. This is to prevent having to do awkward casting at creation
and/or return, as the bindings expect to see the base NodeList only.
Since we don't support IDL typedefs or unions yet, the responsibility
of verifying the type of the argument is temporarily moved from the
generated Wrapper to the implementation.
