With this change, elements that want to receive viewport rect updates
will need to register on document instead of the browsing context.
This change solves the problem where a browsing context for a document
is guaranteed to exist only while the document is active so browsing
context might not exit by the time DOM node that want to register is
constructed.
This is a part of preparation work before switching to navigables where
this issue becomes more visible.
This allows to partially solve the problem of cyclic dependency between
HTMLImageElement and SharedImageRequest that prevents all image
elements from being deallocated.
Stop worrying about tiny OOMs. Work towards #20449.
While going through these, I also changed the function signature in many
places where returning ThrowCompletionOr<T> is no longer necessary.
Reactive images that had an image source selected based on viewport
size would only update when the images were first fetched, meaning the
last valid image source would become stuck in an image element. By
implementing the last step for reacting to environment changes, we can
run the proper updates even when the image does not need to be fetched.
This patch implements "react to changes in the environment" from the
HTML spec and hooks HTMLImageElement up with viewport rect change
notifications (from the browsing context).
This fixes the issue where we'd load a low-resolution image and not
switch to a high-resolution image after resizing the window.
Note that we currently can't resolve calc() values without a layout
node, so when normalizing an image's source set, we'll flush any pending
layout updates and hope that gives us an up-to-date layout node.
I've left a FIXME about implementing this in a more elegant and less
layout-thrashy way, as that will require more architectural work.
Before this change, we would process each image as it finished
downloading. This often led to a situation where we'd decode 1 image,
schedule a layout, do the layout, then decode another image, schedule
a layout, do the layout, etc. Basically decoding and layouts would get
interleaved even though we had multiple images fetched and ready for
decoding.
This patch adds a simple BatchingDispatcher thingy that HTMLImageElement
uses to batch the handling of successful fetches.
With this, the number of layouts while loading https://shopify.com/ goes
from 48 to 6, and the page loads noticeably faster. :^)
Now that we use the HTML image loading algorithm from spec, we can
implement complete correctly.
This (finally) fixes an issue where images were not loading on
https://twinings.co.uk/ :^)
As it turns out, making everyone piggyback on HTML::ImageRequest had
some major flaws, as HTMLImageElement may decide to abort an ongoing
fetch or wipe out image data, even when someone else is using the same
image request.
To avoid this issue, this patch introduces SharedImageRequest, and then
implements ImageRequest on top of that.
Other clients of the ImageRequest API are moved to SharedImageRequest
as well, and ImageRequest is now only used by HTMLImageElement.
This fixes an issue with image data disappearing and leading to asserts
and/or visually absent images.
Although DistinctNumeric, which is supposed to abstract the underlying
type, was used to represent CSSPixels, we have a whole bunch of places
in the layout code that assume CSSPixels::value() returns a
floating-point type. This assumption makes it difficult to replace the
underlying type in CSSPixels with a non-floating type.
To make it easier to transition CSSPixels to fixed-point math, one step
we can take is to prevent access to the underlying type using value()
and instead use explicit conversions with the to_float(), to_double(),
and to_int() methods.
This forces us to diverge from the spec, but it's for a good cause:
by moving it into ImageRequest, we'll be able to reuse fetching and
decoding logic from CSS and other places.
This patch also makes ImageRequests shareable, currently keyed by
the URL (this part needs improvement!)
Now that the processResponseConsumeBody algorithm receives the internal
response body of the fetched object, we do not need to go out of our way
to read its body from outside of fetch.
However, several elements do still need to manually inspect the internal
response for other data, such as response headers and status. Note that
HTMLScriptElement already does the new workaround as a proper spec step.
In order to separate the SVG content from the rest of the engine, it
gets its very own Page, PageClient, top-level browsing context, etc.
Unfortunately, we do have to get the palette and CSS/device pixel ratios
from the host Page for now, maybe that's something we could refactor in
the future.
Note that this doesn't work visually yet, since we don't calculate the
intrinsic sizes & ratio for SVG images. That comes next. :^)
This allows the painting subsystem to request a bitmap with the exact
size needed for painting, instead of being limited to "just give me a
bitmap" (which was perfectly enough for raster images, but not for
vector graphics).
The existing implementation moves down into a new subclass called
AnimatedBitmapDecodedImageData.
The purpose of this change is to create an extension point where we can
plug in an SVG renderer. :^)
The spec seems to neglect the potential nullity of an image's pending
request in various cases.
Let's protect against crashing and mark these cases with a FIXME about
figuring out whether they are really spec bugs or not.
We achieve this by adding a new Layout::ImageProvider class and having
both HTMLImageElement and HTMLObjectElement inherit from it.
The HTML spec is vague on how object image loading should work, which
is why this first pass is focusing on image elements.
This ports MouseEvent, UIEvent, WheelEvent, and Event to new String.
They all had a dependency to T::create() in
WebDriverConnection::fire_an_event() and therefore had to be ported in
the same commit.
This is something we're supposed to do according to the HTML spec.
Note that image loading is currently completely ad-hoc, and this just
adds a simple DocumentLoadEventDelayer to the existing implementation.
This will allow us to use images in layout tests, which rely on the
document load event firing at a predictable time.
Because of interdependencies between DOM::Event and UIEvents::MouseEvent
to template function fire_an_event() in WebDriverConnection.cpp, the
commit: 'LibWeb: Make factory methods of UIEvents::MouseEvent fallible'
have been squashed into this commit.
ARIA has its own spec and is not part of the DOM spec, which is what the
Web::DOM namespace is for (https://www.w3.org/TR/wai-aria-1.2/).
This allows us to stay closer to the spec with function names and don't
have to add the word "ARIA" to identifiers constantly - the namespace
now provides that clarity.
Note that as of this commit, there aren't any such throwers, and the
call site in Heap::allocate will drop exceptions on the floor. This
commit only serves to change the declaration of the overrides, make sure
they return an empty value, and to propagate OOM errors frm their base
initialize invocations.
This replaces the FlyStrings for ARIA roles that were constructed in
a [[gnu::constructor]] with a single enum. I came across this as the
DOM inspector was crashing due to a null FlyString for an ARIA role.
After fixing that, I was confused as to why these roles were not an
enum. Looking at the spec there's a fixed list of roles and switching
from references to static strings to an enum was pretty much an
exercise in find and replace :).
No functional changes (outside of fixing the mentioned crash).
This needs to happen before prototype/constructor intitialization can be
made lazy. Otherwise, GC could run during the C++ constructor and try to
collect the object currently being created.
DeprecatedFlyString relies heavily on DeprecatedString's StringImpl, so
let's rename it to A) match the name of DeprecatedString, B) write a new
FlyString class that is tied to String.
This fixes a few sizing issues too. The page size is now correct in most
cases! \o/
We get to remove some of the `to_type<>()` shenanigans, though it
reappears in some other places.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
This removes a set of complex reference cycles between DOM, layout tree
and browsing context.
It also makes lifetimes much easier to reason about, as the DOM and
layout trees are now free to keep each other alive.
This was fairly straightforward, although a small part had to be ad-hoc
since we don't yet load images through Fetch.
With this, we can now see annotation labels on deskto.ps :^)
We were constantly measuring and re-measuring the "alt" attribute text
of ImageBox layout nodes, even when the alt text didn't change. By
caching this, we avoid a *lot* of repeated text measurement work.
Unlike ensure_web_prototype<T>(), the cached version doesn't require the
prototype type to be fully formed, so we can use it without including
the FooPrototype.h header. It's also a bit less verbose. :^)
This is a monster patch that turns all EventTargets into GC-allocated
PlatformObjects. Their C++ wrapper classes are removed, and the LibJS
garbage collector is now responsible for their lifetimes.
There's a fair amount of hacks and band-aids in this patch, and we'll
have a lot of cleanup to do after this.
HTMLObjectElement will need to be both a FormAssociatedElement and a
BrowsingContextContainer. Currently, both of these classes inherit from
HTMLElement. This can work in C++, but is generally frowned upon, and
doesn't play particularly well with the rest of LibWeb.
Instead, we can essentially revert commit 3bb5c62 to remove HTMLElement
from FormAssociatedElement's hierarchy. This means that objects such as
HTMLObjectElement individually inherit from FormAssociatedElement and
HTMLElement now.
Some caveats are:
* FormAssociatedElement still needs to know when the HTMLElement is
inserted into and removed from the DOM. This hook is automatically
injected via a macro now, while still allowing classes like
HTMLInputElement to also know when the element is inserted.
* Casting from a DOM::Element to a FormAssociatedElement is now a
sideways cast, rather than directly following an inheritance chain.
This means static_cast cannot be used here; but we can safely use
dynamic_cast since the only 2 instances of this already use RTTI to
verify the cast.
The "paintable" state in Layout::Box was actually not safe to access
until after layout had been performed.
As a first step towards making this harder to mess up accidentally,
this patch moves painting information from Layout::Box to a new class:
Painting::Box. Every layout can have a corresponding paint box, and
it holds the final used metrics determined by layout.
The paint box is created and populated by FormattingState::commit().
I've also added DOM::Node::paint_box() as a convenient way to access
the paint box (if available) of a given DOM node.
Going forward, I believe this will allow us to better separate data
that belongs to layout vs painting, and also open up opportunities
for naturally invalidating caches in the paint box (since it's
reconstituted by every layout.)
The new event target implementation requires us to downcast an
EventTarget to a FormAssociatedElement to check if the current Element
EventTarget has a form owner to setup a with scope for the form owner.
This also makes all form associated elements inherit from
FormAssociatedElement where it was previously missing.
https://html.spec.whatwg.org/#form-associated-element
Instead of making each Layout::Node compute style for itself, we now
compute it in TreeBuilder before even calling create_layout_node().
For non-element DOM nodes, we create the style and layout tree node
in TreeBuilder. This allows us to move create_layout_node() from
DOM::Node to DOM::Element.
Until now, we've internally thought of the CSS "display" property as a
single-value property. In practice, "display" is a much more complex
property that comes in a number of configurations.
The most interesting one is the two-part format that describes the
outside and inside behavior of a box. Switching our own internal
representation towards this model will allow for much cleaner
abstractions around layout and the various formatting contexts.
Note that we don't *parse* two-part "display" yet, this is only about
changing the internal representation of the property.
Spec: https://drafts.csswg.org/css-display
Instead of doing layout synchronously whenever something changes,
we now use a basic event loop timer to defer and coalesce relayouts.
If you did something that requires a relayout of the page, make sure
to call Document::set_needs_layout() and it will get coalesced with all
the other layout updates.
There's lots of room for improvement here, but this already makes many
web pages significantly snappier. :^)
Also, note that this exposes a number of layout bugs where we have been
relying on multiple relayouts to calculate the correct dimensions for
things. Now that we only do a single layout in many cases, these kind of
problems are much more noticeable. That should also make them easier to
figure out and fix. :^)
Resolved style is a spec concept that refers to the weird mix of
computed style and used style reflected by getComputedStyle().
The purpose of this class is to produce the *computed* style for a given
element, so let's call it StyleComputer.
Change all the places that were including the deprecated parser, to
include the new one instead, and then delete the old parser code.
`ParentNode::query_selector[_all]()` now treat their input as a
comma-separated list of selectors, instead of just one, and return
elements that match any of the selectors in that list. This is according
to these specs:
- querySelector/querySelectorAll:
https://dom.spec.whatwg.org/#ref-for-dom-parentnode-queryselector%E2%91%A0
- selector matching algorithm:
https://www.w3.org/TR/selectors-4/#match-against-tree
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
The ImageDecoder service now returns a list of image frames, each with
a duration value.
The code for in-process image decoding is removed from LibWeb, an all
image decode requests are sent out-of-process to ImageDecoder. :^)
This won't scale super well to very long and/or large animations, but
we can work on improving that separately. The main goal here is simply
to stop doing any image decoding inside LibWeb.
Fixes#5165.
