...in hover style invalidation. Instead, pass down a flag that indicates
all subsequent nodes in tree traversal have to be marked for inherited
style update.
By using ancestor filters some selectors could be early rejected
skipping selector engine invocation. According to my measurements it's
30-80% hover selectors depending on the website.
Instead of allocating 3 vectors with size equal to the number of
elements potentially affected by hover:
- for the elements themselves
- for selector match state of each element before hovered node change
- for selector match state of each element after hovered node change
now we allocate none of them, but mark element for style recalculation
as we traverse the tree.
This currently uses a non spec-compliant property on the Response
object, which represents the time that the Response was created.
Setting this value allows `Performance.timeOrigin` to return a
reasonable value.
Instead of traversing the entire DOM subtrees and marking nodes for
style update, this patch adds a new mechanism where we can mark a
subtree root as "entire subtree needs style update".
A new pass in Document::update_style() then takes care of coalescing
all these invalidations in a single traversal of the DOM.
This shaves *minutes* of loading time off of https://wpt.fyi/ subpages.
Instead, change the APIs from "has :foo" to "may have :foo" and return
true if we don't have a valid rule cache at the moment.
This allows us to defer the rebuilding of the rule cache until a later
time, for the cost of a wider invalidation at the moment.
Do note that if our rule cache is invalid, the whole document has
invalid style anyway! So this is actually always less work. :^)
Knocks ~1 second of loading time off of https://wpt.fyi/
Instead of ignoring any paintable immediately when they're invisible to
hit-testing, consider every candidate and while the most specific
candidate is invisible to hit-testing, traverse up to its parent
paintable.
This more closely reflects the behavior expected when wrapping block
elements inside inline elements, where although the block element might
have `pointer-events: none`, it still becomes part of the hit-test body
of the inline parent.
This makes the following link work as expected:
<a href="https://ladybird.org">
<div style="pointer-events: none">Ladybird</div>
</a>
DOM nodes now have two additional flags:
- Needs layout tree update
- Child needs layout tree update
These work similarly to the needs-style-update flags, but instead signal
the need to rebuild the corresponding part of the layout tree.
When a specific DOM node needs a layout tree update, we try to create
a new subtree starting at that node, and then replace the subtree in the
old layout tree with the newly created subtree.
This required some refactoring in TreeBuilder so that we can skip over
entire subtrees during a tree update.
Note that no partial updates happen yet (as of this commit) since we
always invalidate the full layout tree still. That will change in the
next commit.
The use of this HashMap looks very spooky, but let's at least use
finalize when cleaning them up on destruction to make things slightly
less dangerous looking.
This makes it more convenient to use the 'relvant agent' concept,
instead of the awkward dynamic casts we needed to do for every call
site.
mutation_observers is also changed to hold a GC::Root instead of raw
GC::Ptr. Somehow this was not causing problems before, but trips up CI
after these changes.
Previously, we optimized hover style invalidation to mark for style
updates only those elements that were matched by :hover selectors in the
last style calculation.
This change takes it a step further by invalidating only the elements
where the set of selectors that use :hover changes after hovered element
is modified. The implementation is as follows:
1. Collect all elements whose styles might be affected by a change in
the hovered element.
2. Retrieve a list of all selectors that use :hover.
3. Test each selector against each element and record which selectors
match.
4. Update m_hovered_node to the newly hovered element.
5. Repeat step 3.
6. For each element, compare the previous and current sets of matched
selectors. If they differ, mark the element for style recalculation.
Instead of recalculating styles for all nodes in the common ancestor of
the new and old hovered nodes' subtrees, this change introduces the
following approach:
- While calculating ComputedProperties, a flag is saved if any rule
applied to an element is affected by the hover state during the
execution of SelectorEngine::matches().
- When the hovered element changes, styles are marked for recalculation
only if the flag saved in ComputedProperties indicates that the
element could be affected by the hover state.
Instead of storing all storage objects in static memory, we now
follow the the spec by lazily creating a unique Storage object
on each document object.
Each Storage object now holds a 'proxy' to the underlying backing
storage. For now, this proxy is simply a reference to the backing
object. In the future, it will need to be some type of interface
object that stores on a SQLite database or similar.
Session storage is now correctly stored / tracked as part of the
TraversableNavigable object.
Local storage is still stored in a static map, but eventually this
should be factored into something that is stored at the user agent
level.
This event is fired while both the previous and the current phase are
active.
This prevents this test from timing out:
- css/css-animations/animationevent-types.txt
We can now mark an element as needing an "inherited style update" rather
than a full "style update". This effectively means that the next style
update will visit the element and pull all of its inherited properties
from the relevant ancestor element.
This is now used for descendants of elements with animated style.
We currently (sometimes) copy the observer map to a vector for iteration
to ensure we are not iterating over the map if the callback happens to
remove the observer. But that list was not protected from GC.
This patch ensures we protect that list, and makes all document observer
notifiers protected from removal during iteration.
There are essentially 3 URL parsing AOs defined by the spec:
1. Parse a URL
2. Encoding parse a URL
3. Encoding parse a URL and serialize the result
Further, these are replicated between the Document and the ESO.
This patch defines these methods in accordance with the spec and updates
existing users to invoke the correct method. In places where the correct
method is ambiguous, we use the encoding parser to preserve existing ad-
hoc behavior.
The DOM spec defines what it means for an element to be an "editing
host", and the Editing spec does the same for the "editable" concept.
Replace our `Node::is_editable()` implementation with these
spec-compliant algorithms.
An editing host is an element that has the properties to make its
contents effectively editable. Editable elements are descendants of an
editing host. Concepts like the inheritable contenteditable attribute
are propagated through the editable algorithm.
These variables are all captured in queued events or other event loop
tasks, but are all guarded by event loop spins later in the function.
The IGNORE_USE_IN_ESCAPING_LAMBDA will soon be required for all locals
that are captured by ref in GC::Function as well as AK::Function.
To facilitate the implementation of "delete" and all associated
algorithms, split off this piece of `Document` into a separate
directory.
This sets up the infrastructure for arbitrary commands to be supported.
This lets us move a few Host-related functions (like serialization and
checks for what the Host is) into Host instead of having them dotted
around the codebase.
For now, the interface is still very Variant-like, to avoid having to
change quite so much in one go.
An inopportune garbage collection may cause collected `ResizeObserver`s
to unregister themselves from `m_resize_observers` while we are
iterating over it, resulting in a use-after-free.
In line with the ShadowRealm proposal changes in the WebIDL spec:
webidl#1437 and supporting changes in HTML spec.
This is required for ShadowRealms as they have no relevant settings
object on the shadow realm, so fixes a crash in the QueueingStrategy
test in this commit.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
Now that the heap has no knowledge about a JavaScript realm and is
purely for managing the memory of the heap, it does not make sense
to name this function to say that it is a non-realm variant.
The main motivation behind this is to remove JS specifics of the Realm
from the implementation of the Heap.
As a side effect of this change, this is a bit nicer to read than the
previous approach, and in my opinion, also makes it a little more clear
that this method is specific to a JavaScript Realm.
Instead of doing a forced layout synchronously whenever an element's
style is changed, use a zero-timer to do the forced relayout on next
event loop iteration.
This effectively coalesces a lot of layouts and makes many pages such
as GitHub spend way less time doing redundant layout work.
The StyleResolver can find the specified CSS values for the parent
element via the DOM. Forcing everyone to locate specified values for
their parent was completely unnecessary.
Another step towards not having to carry the full specified style with
us everywhere. This isn't the ideal final layout, since we're mixing
computed and used values a bit randomly here, but one step at a time.
Now that documents are attached to their frame *before* parsing, we can
create the content frame of <iframe> elements right away, instead of
waiting for the host frame attachment.
Fixes#4408.
This patch adds a second style dirty bit that tracks whether a DOM node
has one or more children with dirty style. This allows the style update
to skip over entire subtrees where all nodes are clean.
I didn't generalize this into a helper since the HTML spec doesn't
seem to use this particular algorithm for anything else.
This makes the ACID1 test title show up correctly. :^)
The BFC "context box" is now the outer box of the block formatting
context. Previously the context box was always the current target box,
which made it hard to reason about who was really the containing block
of whom in various places.
Note that IFC still has the containing block as its context box, this
change only affects BFC. However, to clarify the situation in IFC,
I've added a containing_block() getter than returns the context_box().
Note that we're taking a shortcut here and returning the elements as an
Array instead of HTMLCollection. One day we'll have to bite the bullet
and deal with HTMLCollection, but not today.
Instead of hiding JS exceptions raised on the web, we now print them to
the debug log. This will make it a bit easier to work out why some web
pages aren't working right. :^)
Specification: https://dom.spec.whatwg.org/#concept-event-dispatch
This also introduces shadow roots due to it being a requirement of
the event dispatcher.
However, it does not introduce the full shadow DOM, that can be
left for future work.
This changes some event dispatches which require certain attributes
to be initialised to a value.
Bring the names of various boxes closer to spec language. This should
hopefully make things easier to understand and hack on. :^)
Some notable changes:
- LayoutNode -> Layout::Node
- LayoutBox -> Layout::Box
- LayoutBlock -> Layout::BlockBox
- LayoutReplaced -> Layout::ReplacedBox
- LayoutDocument -> Layout::InitialContainingBlockBox
- LayoutText -> Layout::TextNode
- LayoutInline -> Layout::InlineNode
Note that this is not strictly a "box tree" as we also hang inline/text
nodes in the same tree, and they don't generate boxes. (Instead, they
contribute line box fragments to their containing block!)
This is a first (huge) step towards modernizing the layout architecture
and bringing it closer to spec language.
Layout is now performed by a stack of formatting contexts, operating on
the box tree (or layout tree, if you will.)
There are currently three types of formatting context:
- BlockFormattingContext (BFC)
- InlineFormattingContext (IFC)
- TableFormattingContext (TFC)
Document::layout() creates the initial BlockFormattingContext (BFC)
which lays out the initial containing block (ICB), and then we recurse
through the tree, creating BFC, IFC or TFC as appropriate and handing
over control at the context boundaries.
The majority of this patch is just refactoring the old logic spread out
in LayoutBlock and LayoutTableRowGroup, and turning into these context
classes instead. A lot more cleanup will be needed.
There are many architectural wins here, the main one being that layout
is no longer performed by boxes themselves, which gives us much greater
flexibility in the outer/inner layout of a given box.
This patch makes Page weakable and allows page-less frames to exist.
Page is single-owner, and Frame is multiple-owner, so it's not sound
for Frame to assume its containing Page will stick around for its own
entire lifetime.
Fixes#3976.
This makes most operations thread safe, especially so that they
can safely be used in the Kernel. This includes obtaining a strong
reference from a weak reference, which now requires an explicit
call to WeakPtr::strong_ref(). Another major change is that
Weakable::make_weak_ref() may require the explicit target type.
Previously we used reinterpret_cast in WeakPtr, assuming that it
can be properly converted. But WeakPtr does not necessarily have
the knowledge to be able to do this. Instead, we now ask the class
itself to deliver a WeakPtr to the type that we want.
Also, WeakLink is no longer specific to a target type. The reason
for this is that we want to be able to safely convert e.g. WeakPtr<T>
to WeakPtr<U>, and before this we just reinterpret_cast the internal
WeakLink<T> to WeakLink<U>, which is a bold assumption that it would
actually produce the correct code. Instead, WeakLink now operates
on just a raw pointer and we only make those constructors/operators
available if we can verify that it can be safely cast.
In order to guarantee thread safety, we now use the least significant
bit in the pointer for locking purposes. This also means that only
properly aligned pointers can be used.
When a document reaches ref_count==0, we will now remove all of the
descendant nodes from the document, and also break all the explicit
links (such as the currently hovered element.)
Basically, DOM nodes will keep the document alive even after the
document reaches ref_count==0. This allows JS wrappers to stay alive
and keep the document alive as well. This matches the behavior of
at least some other browsers.
This patch also adds a bunch of sanity checking assertions around
DOM teardown, to help catch mistakes in the future.
Fixes#3771.
Instead of just ripping out the root of the layout tree from its RefPtr
in Document, actually go through the DOM and gather up all the layout
nodes. Then destroy them all in one swoop.
Also, make sure to do this when detaching Document from Frame,
to enforce the invariant that layout only occurs in framed documents.
In addition to being reference-counted, all nodes that are part of a
document must also keep the document alive.
This is achieved by adding a second ref-count to the Document object
and incrementing/decrementing it whenever a node is created/destroyed
in that document.
This brings us much closer to a proper DOM lifetime model, although
the JS bindings still need more work.
Taking a big step towards a world of multiple global object, this patch
adds a new JS::VM object that houses the JS::Heap.
This means that the Heap moves out of Interpreter, and the same Heap
can now be used by multiple Interpreters, and can also outlive them.
The VM keeps a stack of Interpreter pointers. We push/pop on this
stack when entering/exiting execution with a given Interpreter.
This allows us to make this change without disturbing too much of
the existing code.
There is still a 1-to-1 relationship between Interpreter and the
global object. This will change in the future.
Ultimately, the goal here is to make Interpreter a transient object
that only needs to exist while you execute some code. Getting there
will take a lot more work though. :^)
Note that in LibWeb, the global JS::VM is called main_thread_vm(),
to distinguish it from future worker VM's.
...{All} to ParentNode. Exposes createDocumentFragment and
createComment on Document. Stubs out the document.body setter.
Also adds ParentNode back :^).
You can now cycle through focusable elements (currently only hyperlinks
are focusable) with the Tab key.
The focus outline is rendered in a new FocusOutline paint phase.
We don't want to carry over exceptions across multiple
Document::run_javascript() calls as Interpreter::run() and every of its
exception checks will get confused - in this case there would be an
exception, but not because a certain action failed.
Real-life example:
<script>var a = {}; a.test()</script>
<script>alert("It worked!")</script>
The above HTML will invoke Document::run_javascript() twice, the first
call will result in a TypeError, which is still stored during the second
call. The interpreter will eventually call the following functions (in
order) for the alert() invocation:
- Identifier::execute()
- Interpreter::get_variable()
- Object::get() (on the global object)
That last Object::get() call has an exception check which is triggered
as we still carry around the exception from earlier - and eventually
returns an empty value.
Long story short, the second script will wrongly fail with
"ReferenceError, 'alert' is not defined".
Fixes#3091.
Now that document element returns a generic DOM element, we need to
make sure head and body get a html element.
The spec just says to check if the document element is a html element,
so let's do that.
Also change DOM::Document::document_element() to return an Element*
and not an HTML::HTMLHtmlElement since that's not the only kind of
documentElement we might encounter.
LibWeb keeps growing and the Web namespace is filling up fast.
Let's put DOM stuff into Web::DOM, just like we already started doing
with SVG stuff in Web::SVG.
To prepare for fully qualified tag names, let's call this local_name.
Note that we still keep an Element::tag_name() around since that's what
the JS bindings end up calling into for the Element.tagName property.
This allows us to determine which mode to render the page in.
Exposes "doctype" and "compatMode" on Document.
Exposes "name", "publicId" and "systemId" on DocumentType.
Fixes https://github.com/SerenityOS/serenity/issues/2649
Loading a page with iframes could lead to a scenario, where the iframe
document finished layout prior to the main frame beeing laid out
initially. This caused a crash/assertion of the browser.
"width: 500" is not a valid CSS property in standards mode and should
be ignored.
To plumb the quirks-mode flag into CSS parsing, this patch adds a new
CSS::ParsingContext object that must be passed to the CSS parser.
Currently it only allows you to check the quirks-mode flag. In the
future it will be a good place to put additional information needed
for things like relative URL resolution, etc.
This narrows <div class=parser> on ACID2 to the correct width. :^)
This patch implements most of the HTML fragment parsing algorithm and
ports Element::set_inner_html() to it. This was the last remaining user
of the old HTML parser. :^)
To make this possible, I also had to give each LayoutNode a Document&
so it can resolve document-specific colors correctly. There's probably
ways to avoid having this extra member by resolving colors later, but
this works for now.
* A PageView is a view onto a Page object.
* A Page always has a main Frame (root of Frame tree.)
* Page has a PageClient. PageView is a PageClient.
The goal here is to allow building another kind of view onto
a Page while keeping the rest of LibWeb intact.
Until now we would simply apply stylesheets in the order they finished
loading. This patch adds a StyleSheetList object that hangs off of each
Document and contains all the style sheets in document order.
There's still a lot of work to do for a proper cascade, but at least
this makes us consistently wrong every time. :^)
This patch adds two script lists to Document:
- Scripts to execute when parsing has finished
- Scripts to execute as soon as possible
Since we don't actually load scripts asynchronously yet (we just do a
synchronous load when parsing the <script> element for simplicity),
these are already loaded by the time we get to "The end" of parsing.
Instead of creating extremely common FlyStrings like "id" and "class"
on demand every time they are needed, we now have AttributeNames.h,
which provides Web::HTML::AttributeNames::{id,class_}
This avoids a bunch of string allocations during selector matching.
And move canonicalized_path() to a static method on LexicalPath.
This is to make it clear that FileSystemPath/canonicalized_path() only
perform *lexical* canonicalization.
Rather than printing them to stderr directly the parser now keeps a
Vector<Error>, which allows the "owner" of the parser to consume them
individually after parsing.
The Error struct has a message, line number, column number and a
to_string() helper function to format this information into a meaningful
error message.
The Function() constructor will now include an error message when
throwing a SyntaxError.
Every Document now has an Origin, found via Document::origin().
It's based on the URL of the document.
This will be used to implement things like the same-origin policy.
We were allowing this dangerous kind of thing:
RefPtr<Base> base;
RefPtr<Derived> derived = base;
This patch changes the {Nonnull,}RefPtr constructors so this is no
longer possible.
To downcast one of these pointers, there is now static_ptr_cast<T>:
RefPtr<Derived> derived = static_ptr_cast<Derived>(base);
Fixing this exposed a ton of cowboy-downcasts in various places,
which we're now forced to fix. :^)
LibWeb now creates a WindowObject which inherits from GlobalObject.
Allocation of the global object is moved out of the Interpreter ctor
to allow for specialized construction.
The existing Window interfaces are moved to WindowObject with their
implementation code in the new Window class.
I made some mistakes in the selector parsing code. It's now able to
parse selectors composed of multiple complex selectors, instead of just
one complex selector.
This currently returns a JS::Array of elements matching a selector.
The more correct behavior would be to return a static NodeList, but as
we don't have NodeLists right now, that'll be a task for the future.
Native functions now only get the Interpreter& as an argument. They can
then extract |this| along with any indexed arguments it wants from it.
This forces functions that want |this| to actually deal with calling
interpreter.this_value().to_object(), and dealing with the possibility
of a non-object |this|.
This is still not great but let's keep massaging it forward.
This function allows you to throw away the entire layout tree if that's
something you want to do.
It's certainly not super cheap to reconstruct, but hey, who am I to
tell you what to do? :^)
We now support rAF, driven by GUI::DisplayLink callbacks. It's a bit
strange how we keep registering new callbacks over and over.
That's something we can definitely optimize.
This allows you to update animations/whatever without doing it more
often than the browser can display.
Instead of every NativeFunction callback having to ask the Interpreter
for the current "this" value and then converting it to an Object etc,
just pass "this" as an Object* directly.
This patch introduces the Wrapper and Wrappable classes.
Node now inherits from Wrappable, and can be wrapped in a GC-allocated
Bindings::NodeWrapper object. The only property we expose right now is
the very simple nodeName property.
When a Document's JS::Interpreter is first instantiated, we add a
"document" property with a DocumentWrapper object to the global object.
This is pretty cool! :^)
This patch begins integrating LibJS into LibWeb. Document holds the
JS::Interpreter for now, and it is created on demand when you first
call Document::interpreter().
We also add a simple "alert()" function to the global object.
