This change fixes GC-leak caused by following mutual dependency:
- SVGDecodedImageData owns JS::Handle for Page.
- SVGDecodedImageData is owned by visited objects.
by making everything inherited from HTML::DecodedImageData and
ListOfAvailableImages to be GC-allocated.
Generally, if visited object has a handle, very likely we leak
everything visited from object in a handle.
Before this change, we used Gfx::Bitmap to represent both decoded
images that are not going to be mutated and bitmaps corresponding
to canvases that could be mutated.
This change introduces a wrapper for bitmaps that are not going to be
mutated, so the painter could do caching: texture caching in the case
of GPU painter and potentially scaled bitmap caching in the case of CPU
painter.
With this change, we now have ~1200 CellAllocators across both LibJS and
LibWeb in a normal WebContent instance.
This gives us a minimum heap size of 4.7 MiB in the scenario where we
only have one cell allocated per type. Of course, in practice there will
be many more of each type, so the effective overhead is quite a bit
smaller than that in practice.
I left a few types unconverted to this mechanism because I got tired of
doing this. :^)
This commit removes DeprecatedString's "null" state, and replaces all
its users with one of the following:
- A normal, empty DeprecatedString
- Optional<DeprecatedString>
Note that null states of DeprecatedFlyString/StringView/etc are *not*
affected by this commit. However, DeprecatedString::empty() is now
considered equal to a null StringView.
This should allow us to add a Element::attribute which returns an
Optional<String>. Eventually all callers should be ported to switch from
the DeprecatedString version, but in the meantime, this should allow us
to port some more IDL interfaces away from DeprecatedString.
This allows us to retain perfect precision for aspect ratios derived
from either the intrinsic sizes of replaced elements, or the
`aspect-ratio` CSS property.
This allows to partially solve the problem of cyclic dependency between
HTMLImageElement and SharedImageRequest that prevents all image
elements from being deallocated.
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.
Like the piggybacking in CSS, this is also totally ad-hoc, since there's
no spec to follow.
The code here is weird and definitely sub-optimal as we do a second load
if it turns out the loaded resource is an image, but given that object
elements are rarely used nowadays, I doubt we'll even notice.
That said, we should of course improve this code as we move forward.
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).
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.
The "browsing context container" concept in the HTML spec has been
replaced with "navigable container". Renaming this is the first step of
many towards implementing the new world.
Co-authored-by: Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
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 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.
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 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.
We were using the literal string "unknown" as the unknown MIME type,
which caused us to treat the object as a nested browsing context (as
"unknown" does not start with "image/"). Use an Optional instead to
prevent this mishap.
We currently only supported loading image data from an HTMLObjectElement
node. This adds (some) support for non-image data. A big FIXME is to
actually paint that data. We will need to make FrameBox and
NestedBrowsingContextPaintable work with HTMLObjectElement for this
(they currently only work with HTMLIFrameElement).
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.
This is another event upon which the task to determine an object's
respresentation must be queued:
* one of the element's ancestor object elements changes to or from
showing its fallback content
For example, on Acid2, the image for the eyes is nested below an object
that is designed to fail to load. This ensures the eyes will render as
the fallback of the failed parent object.
There are a long list of conditions under which the HTMLObjectElement is
to queue an element task to load / determine an object's representation.
This handles the case where the data attribute has changed.
Much of the spec for determining the object's representation is not
implemented here. Namely, anything to do with XML documents or browser
plugins are left as FIXMEs.
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.
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 *
