This simplifies the ownership model between DOM/layout/paint nodes
immensely by deferring to the garbage collector for figuring out what's
live and what's not.
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.)
We were painting this in the Foreground phase by mistake. Also, the
`inspected_node() == dom_node()` check returns true for pseudo-elements
(both values are nullptr) so I've added an extra check there. As noted,
once pseudo-elements are inspectable we will need to revisit this.
This means we can instantiate them for pseudo-elements, which don't have
an associated Element. They all pass it to their parent as a
`Layout::Node*` and handle a lack of `layout_node()` already so this
won't affect any functionality.
Nobody makes undefined Lengths now, (although actually removing
Undefined will come in a later commit) so we can remove this parameter,
and `resolved_or_auto()`/`resolved_or_zero()`.
Here's roughly how this works:
- InlineLevelIterator keeps a nesting stack of inline-level nodes with
box model metrics.
- When entering a node with box model metrics, we add them to the
current "leading metrics".
- When exiting a node with box model metrics, we add them to the
current "trailing metrics".
- Pending leading metrics are consumed by the first fragment added
to the line.
- Pending trailing metrics are consumed by the last fragment added
to the line.
Like before, the position of a line box fragment is the top left of its
content box. However, fragments are placed horizontally along the line
with space inserted for padding and border.
InlineNode::paint() now expands the content rect as appropriate when
painting background and borders.
Note that margins and margin collapsing is not yet implemented.
This makes the eyes on ACID2 horizontally centered. :^)
We also pass whether the shadow goes inside or outside the element. Only
outer shadows are rendered currently, and inner ones may want to be
handled separately from them, as they will never interfere with each
other.
Now that we build lines incrementally, we no longer need the atomic line
splitting API.
The new InlineLevelIterator and LineBuilder setup does have some
regressions from the old behavior, but we can deal with them as we go.
Despite looking like it was still needed, it was only used for passing
to other calls to Length::resolved() recursively. This makes the
various `foo.resolved().resolved()` calls a lot less awkward.
(Though, still quite awkward.)
I think we'd need to separate calculated lengths out to properly tidy
these calls up, but one yak at a time. :^)
A lot of this is quite ugly, but it should only be so until I remove
Length::Type::Percentage entirely. (Which should happen later in this
PR, otherwise, yell at me!) For now, a lot of things have to be
resolved twice, first from a LengthPercentage to a Length, and then
from a Length to a pixel one.
While right now this doesn't save much complexity, it will do once we
care about multiple background layers per node. Then, having a single
repeat value per layer will simplify things.
It also means we can remove the pseudo-property concept entirely! :^)
Per the spec, only a BlockContainer" can have line boxes, so let's not
clutter up every Layout::Box with line boxes.
This also allows us to establish an invariant that BFC and IFC always
operate on a Layout::BlockContainer.
Note that if BlockContainer has all block-level children, its line boxes
are not used for anything. They are only used in the all inline-level
children scenario.
There's a subtle difference here. A "block box" in the spec is a
block-level box, while a "block container" is a box whose children are
either all inline-level boxes in an IFC, or all block-level boxes
participating in a BFC.
Notably, an "inline-block" box is a "block container" but not a "block
box" since it is itself inline-level.
This iterates the fragments of the containing block, and paints their
outlines if they are descendants of the InlineNode.
If multiple fragments are adjacent, eg:
```html
<span><b>Well</b> hello <i>friends!</i></span>
```
...then we get a double-thick outline between "Well", " hello " and
"friends!", but we can come back to this after we implement
non-rectangular outlines for the `outline` CSS property.
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 *
