By the time we're painting, we've already built the stacking context
tree. So instead of asking if a box establishes a stacking context, we
can ask if its paintable *has* a stacking context.
This was taking up ~6% of the profile when mousing around on the HTML
specification. With this change, it disappears completely. :^)
Instead of invalidating style for the entire document, we now locate the
nearest common ancestor between the old and new innermost hovered node,
and only invalidate that ancestor and its descendants.
This drastically reduces the amount of style update work when mousing
around on GitHub (and any other pages, really.) It's actually really
really snappy now. Very cool! :^)
Use the new CSS::property_affects_layout() helper to figure out if we
actually need to perform a full relayout after recomputing style.
There are three tiers of required invalidation after an element receives
new style: none, repaint only, or full relayout.
This avoids the need to rebuild the layout tree (and perform layout on
it) when trivial properties like "color" etc are changed.
This patch adds CSS::property_affects_layout(PropertyID) which tells us
whether a CSS property would affect layout if it were changed.
This will be used to avoid unnecessary relayout work when something
changes that really only requires us to repaint the page.
To mark a property as not affecting layout, set "affects-layout" to
false in the corresponding Properties.json entry. Note that all
properties affect layout by default.
Use the stub implementation of HTMLOptionsCollection to expose the
`option` children of `select` elements.
This fixes a JS error on openstreetmap.org, which occured when JQuery
code tried to access `options.length`:
https://github.com/jquery/jquery/blob/main/src/attributes/val.js#L121
This is a subtype of `DOM::HTMLCollection` that only holds
`HTMLOptionElement`s. In this stub implementation only `item`,
`namedItem` and `length`, inherited from HTMLCollection, are exposed.
This is good enough for applications that only read the collection.
Relative font-sizes like "2em" were previously resolved against the
fallback value (10px) which led to incorrect layouts in many places.
Fix this by resolving relative font-sizes against the absolutized
font-size of the parent or root element as appropriate.
This doesn't have any performance benefit yet as we still do string
comparisons everytime, but it should improve once type_state() has a
better implementation.
This commit is messy due to the Paintable and Layout classes being
tangled together.
The RadioButton, CheckBox and ButtonBox classes are now subclasses of
FormAssociatedLabelableNode. This subclass separates these layout nodes
from LabelableNode, which is also the superclass of non-form associated
labelable nodes (Progress).
ButtonPaintable, CheckBoxPaintable and RadioButtonPaintable no longer
call events on DOM nodes directly from their mouse event handlers;
instead, all the functionality is now directly in EventHandler, which
dispatches the related events. handle_mousedown and related methods
return a bool indicating whether the event handling should proceed.
Paintable classes can now return an alternative DOM::Node which should
be the target of the mouse event. Labels use this to indicate that the
labeled control should be the target of the mouse events.
HTMLInputElement put its activation behavior on run_activation_behavior,
which wasn't actually called anywhere and had to be manually called by
other places. We now use activation_behavior which is used by
EventDispatcher.
This commit also brings HTMLInputElement closer to spec by removing the
did_foo functions that did ad-hoc event dispatching and unifies the
behavior under run_input_activation_behavior.
TreeBuilder wasn't taking advantage of the fact that we already have
computed style cached on each DOM::Element by the time we're
constructing a layout tree.
So instead of using the cached style, we recomputed it from scratch for
every element. This was done because invalidation was broken in many
places, but now that it's more or less trustworthy, stop recomputing
style on the fly in TreeBuilder and use what the preceding style update
pass gave us instead.
This basically cuts style computation work in half. :^)
We were not actually walking past the first ancestor when setting
child-needs-update bit upwards.
Also, let's walk all the way to the root, even if there's a
child-needs-update bit already set. This ensures that we always leave
this function with the ancestor chain in a sane state.
- Access members directly instead of going through accessors,
avoiding a lot of redundant traversal done by accessors.
- Cross shadow boundaries and make sure that shadow trees get their
dirty bits updated as well.
- Do the minimum amount of traversal needed when setting the "child
needs style update" bit upwards through ancestors.
This adds the default behavior of search and highlighting of
abstractView to the inspectorWidget. Search results are based on
the titles in the first columns.
Let's make it very clear that these are *computed* values, and not at
all the specified values. The specified values are currently discarded
by the CSS cascade algorithm.
Get rid of the old, roundabout way of invalidating the rule cache by
incrementing the StyleSheetList "generation".
Instead, when something wants to invalidate the rule cache, just have it
directly invalidate the rule cache. This makes it much easier to see
what's happening anyway.
Previously, we were creating a user-agent shadow tree when constructing
a layout tree. This meant that we did DOM manipulation (and consequently
style invalidation) during layout tree construction, which made things
very hard to reason about in Layout::TreeBuilder.
Simply everything by simply creating the UA shadow tree when the input
element inserted into a parent node instead.
Style computation always happens *before* layout, so we can't rely on
things having (or not having) layout nodes, as that information will
always be one step behind.
Instead, we have to use the DOM to find all the information we need.
The style update mechanism was happily ignoring shadow subtrees.
Fix this by checking if an element has a shadow root, and recursing into
it if needed.
Before this change, style invalidation didn't propagate upwards across
shadow boundaries, so our shadow trees were sitting there with invalid
style, never actually getting updated.
Previously we were making a copy of the full set of custom properties
that applied to a DOM element. This was very costly and dominated the
profile when mousing around on GitHub.
Note that this may break custom properties on pseudo elements a little
bit, and that's something we'll have to look into.
