The absolute rect of a paintable is somewhat expensive to compute. This
is because all coordinates are relative to the nearest containing block,
so we have to traverse the containing block chain and apply each offset
to get the final rect.
Paintables will never move between containing blocks, nor will their
absolute rect change. If anything changes, we'll simpl make a new
paintable and replace the old one.
Take advantage of this by caching the containing block and absolute rect
after first access.
Previously this queried the root layout-node's font, which was both
wrong and could crash if the layout wasn't ready yet. Now, it's just
wrong. But at least all the font-related wrongness is grouped together
in StyleComputer. :^)
Everything related to hit testing is better off using the painting tree.
The thing being mousemoved over is a paintable, so let's hand that out
directly instead of the corresponding layout node.
Input events have nothing to do with layout, so let's not send them to
layout nodes.
The job of Paintable starts to become clear. It represents a paintable
item that can be rendered into the viewport, which means it can also
be targeted by the mouse cursor.
This patch adds a bunch of Paintable subclasses, each corresponding to
the Layout::Node subclasses that had a paint() override. All painting
logic is moved from layout nodes into their corresponding paintables.
Paintables are now created by asking a Layout::Box to produce one:
static NonnullOwnPtr<Paintable> Layout::Box::create_paintable()
Note that inline nodes still have their painting logic. Since they
are not boxes, and all paintables have a corresponding box, we'll need
to come up with some other solution for them.
BlockContainer paint boxes are the only ones that have line boxes
associated, so let's not waste memory on line boxes in all the other
types of boxes.
This also adds Layout::Box::paint_box() and the more tightly typed
Layout::BlockContainer::paint_box() to get at the paint box from the
corresponding layout box.
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.)
This expands the InspectorWidget::Selection to include an optional
PseudoElement, which is then passed over IPC to request style
information for it.
As noted, this has some pretty big limitations because pseudo-elements
don't have DOM nodes:
- Declared style has to be recalculated when it's requested.
- We don't display the computed style.
- We don't display custom properties.
This resolves the ambiguity between whether a single number is a number
or a ratio. :^)
Also removed the "no more tokens" checks from
deea129b8c - that logic was completely
wrong, since there are always tokens after a value in the `(123 < foo <
456)` syntax.
This works largely the same as the PropertyID and ValueID generators,
but using LibMain, Core::Stream, and TRY().
Rather than have a MediaFeatureID::Invalid, I decided to return an
Optional. We'll see if that turns out better or not. :^)
This data will be used to generate code for parsing media-queries. So
far, it includes all MEDIAQUERIES-4 features, and
`prefers-color-scheme` from MEDIAQUERIES-5 since we support that.
When rules are inserted or removed via the CSSOM API, we now invalidate
document style to ensure that any changes made are reflected.
1% progression on ACID3. :^)
Let's get this right before trying to make it fast. This patch removes
the code that tried to do less work when an element's style changes,
and instead simply invalidates the entire document.
Note that invalidations are still coalesced, and will not be
synchronized until update_style() and/or update_layout() is used.
If the style is dirty, update_style() may cause layout to become dirty.
Therefore we must always update style when updating layout, to ensure
up-to-date results.
This forces us to recompute style everywhere, since all kinds of
selectors may produce different results now.
In the future, we should look at narrowing down the invalidation that
occurs here, but for now let's just invalidate everything and make the
results correct before worrying about performance.
We were handing out stale values from window.getComputedStyle() objects
after the first layout.
Fix this by always updating layout on property access. This is not
necessary for all properties, but for now let's go with the simplest
approach to make it work correctly.
These steps run when a node is about to be removed from its parent,
and adjust the position of any live NodeIterators so that they don't
point at a now-removed node.
Note that while this commit implements what's in the DOM specification,
the specification doesn't fully match what other browsers do.
Spec bug: https://github.com/whatwg/dom/issues/907
This patch adds NodeIterator (created via Document.createNodeIterator())
which allows you to iterate through all the nodes in a subtree while
filtering with a provided NodeFilter callback along the way.
This first cut implements the full API, but does not yet handle nodes
being removed from the document while referenced by the iterator. That
will be done in a subsequent patch.
