The main differences between our current implementation and the spec
are:
* The title element need not be a child of the head element.
* If the title element does not exist, the default value should be
the empty string - we currently return a null string.
* We've since added AOs for several of the spec steps here, so we
do not need to implement those steps inline.
The implementations are correct as-is. The spec comments are mostly to
help point out that an upcoming getter (the title element) is currently
accessed incorrectly. It is currently implemented like the head element
and searches the "expected" parent head element for its first title
element; instead it should search the document itself. This incorrect
behavior becomes clearer if all of these elements have spec comments.
The spec for the `<use>` element requires a shadow tree for the
rendered content, so we need to be able to escape shadow trees when
rendering svg content.
This makes it possible to set a pseudo-element as the inspected node
using Document::set_inspected_node(), Document then provides
inspected_layout_node() for the painting related functions.
Solves conflict in layout tree "type system" when elements <label> (or
<button>) can't have `display: table` because Box can't be
Layout::Label (or Layout::ButtonBox) and Layout::TableBox at the same
time.
This allows us to figure out where a specific CSS property comes from,
which is going to be used in a future commit to uniquely identify
running animations.
We now create a flex container inside the input element's UA shadow tree
and add the placeholder and non-placeholder text as flex items (wrapped
in elements whose style we can manipulate).
This fixes the visual glitch where the placeholder would appear below
the bounding box of the input element. It also allows us to align the
text vertically inside the input element (like we're supposed to).
In order to achieve this, I had to make two small architectural changes
to layout tree building:
- Elements can now report that they represent a given pseudo element.
This allows us to instantiate the ::placeholder pseudo element as an
actual DOM element inside the input element's UA shadow tree.
- We no longer create a separate layout node for the shadow root itself.
Instead, children of the shadow root are treated as if they were
children of the DOM element itself for the purpose of layout tree
building.
This is a clear sign that they want to use a UnixDateTime instead.
This also adds support for placing durations and date times into SQL
databases via their millisecond offset to UTC.
That's what this class really is; in fact that's what the first line of
the comment says it is.
This commit does not rename the main files, since those will contain
other time-related classes in a little bit.
This fixes a plethora of rounding problems on many websites.
In the future, we may want to replace this with fixed-point arithmetic
(bug #18566) for performance (and consistency with other engines),
but in the meantime this makes the web look a bit better. :^)
There's a lot more things that could be converted to doubles, which
would reduce the amount of casting necessary in this patch.
We can do that incrementally, however.
Introduce optimization that determines if one node is preceding,
following, ancestor or descdendant of another node by comparing
ancestors chains of both nodes which is much cheaper than using
Node::is_before() that can walk whole subtree in the worst case.
Some of the live HTMLCollection only ever contain children of their root
node. When we know that's the case, we can avoid doing a full subtree
traversal of all descendants and only visit children.
This cuts the ECMA262 spec loading time by over 10 seconds. :^)
Before this change, LayoutState essentially had a Vector<UsedValues*>
resized to the exact number of layout nodes in the current document.
When a nested layout is performed (to calculate the intrinsic size of
something), we make a new LayoutState with its own Vector. If an entry
is missing in a nested LayoutState, we check the parent chain all the
way up to the root.
Because each nested LayoutState had to allocate a new Vector with space
for all layout nodes, this could get really nasty on very large pages
(such as the ECMA262 specification).
This patch replaces the Vector with a HashMap. There's now a small cost
to lookups, but what we get in return is the ability to handle huge
layout trees without spending eternity in page faults.
By deferring allocation of StaticNodeList objects until we know somebody
actually wants the MutationRecord, we avoid a *lot* of allocation work.
This shaves several seconds off of loading https://tc39.es/ecma262/
At least one other engine (WebKit) skips creating mutation records if
nobody is interested, so even if this is observable somehow, we would
at least match the behavior of a major engine.
Before this, any style change that mutated a property we consider
"layout-affecting" would trigger a complete teardown and rebuild of the
layout tree.
This isn't actually necessary for the vast majority of CSS properties,
so this patch makes the invalidation a bit finer, and we now only
rebuild the layout tree when the CSS display property changes.
For other layout-affecting properties, we keep the old layout tree (if
we have one) and run the layout algorithms over that once again.
This is significantly faster, since we don't have to run all the CSS
selectors all over again.
The resolved property sets are stored with the element in a
per-pseudo-element array (same as for pseudo element layout nodes).
Longer term, we should stop storing this with elements entirely and make
it temporary state in StyleComputer somehow, so we don't waste memory
keeping all the resolved properties around.
This makes various gradients show up on https://shopify.com/ :^)
There's no need for this to require a DeprecatedString - the method it
wraps around already only expects a StringView. This allows passing a
String instance without any conversion.
This lets elements figure out if they're visible within the viewport or
not, so they take appropriate action.
Fixes the issues with animations not starting until the viewport was
resized or scrolled.
Layout will be identical for both of those values, so only a repaint is
necessary. If it changes to/from "collapse" however, we do need to
relayout. This means we can't simply use the "affects-layout" mechanism.
We have to write a little bit of custom code.
This makes Google Groups (and surely many other sites) significantly
more responsive by avoiding large amounts of layout work.
If something else has already caused a layout, there's no need to force
a new relayout when the layout timer fires.
This avoids a lot of redundant work on many pages. :^)
