ladybird/Userland/Libraries/LibWeb/Layout/Box.cpp
Andreas Kling ad7e6878fe LibWeb: Allocate CSS::ComputedValues objects on the heap
This makes them cheap to move around, since we can store them in a
NonnullOwnPtr instead of memcopying 2584(!) bytes.

Drastically reduces the chance of stack overflow while building the
layout tree for deeply nested DOMs (since tree building was putting
these things on the stack).

This change also exposed a completely unnecessary ComputedValues deep
copy in block layout.
2024-01-27 12:27:44 +01:00

92 lines
2.7 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021-2022, Sam Atkins <atkinssj@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibWeb/DOM/Document.h>
#include <LibWeb/HTML/HTMLHtmlElement.h>
#include <LibWeb/Layout/BlockContainer.h>
#include <LibWeb/Layout/Box.h>
#include <LibWeb/Layout/FormattingContext.h>
#include <LibWeb/Painting/PaintableBox.h>
namespace Web::Layout {
Box::Box(DOM::Document& document, DOM::Node* node, NonnullRefPtr<CSS::StyleProperties> style)
: NodeWithStyleAndBoxModelMetrics(document, node, move(style))
{
}
Box::Box(DOM::Document& document, DOM::Node* node, NonnullOwnPtr<CSS::ComputedValues> computed_values)
: NodeWithStyleAndBoxModelMetrics(document, node, move(computed_values))
{
}
Box::~Box()
{
}
// https://www.w3.org/TR/css-overflow-3/#overflow-control
static bool overflow_value_makes_box_a_scroll_container(CSS::Overflow overflow)
{
switch (overflow) {
case CSS::Overflow::Clip:
case CSS::Overflow::Visible:
return false;
case CSS::Overflow::Auto:
case CSS::Overflow::Hidden:
case CSS::Overflow::Scroll:
return true;
}
VERIFY_NOT_REACHED();
}
// https://www.w3.org/TR/css-overflow-3/#scroll-container
bool Box::is_scroll_container() const
{
// NOTE: This isn't in the spec, but we want the viewport to behave like a scroll container.
if (is_viewport())
return true;
return overflow_value_makes_box_a_scroll_container(computed_values().overflow_x())
|| overflow_value_makes_box_a_scroll_container(computed_values().overflow_y());
}
bool Box::is_user_scrollable() const
{
// FIXME: Support horizontal scroll as well (overflow-x)
return computed_values().overflow_y() == CSS::Overflow::Scroll || computed_values().overflow_y() == CSS::Overflow::Auto;
}
bool Box::is_body() const
{
return dom_node() && dom_node() == document().body();
}
JS::GCPtr<Painting::Paintable> Box::create_paintable() const
{
return Painting::PaintableBox::create(*this);
}
Painting::PaintableBox* Box::paintable_box()
{
return static_cast<Painting::PaintableBox*>(Node::paintable());
}
Painting::PaintableBox const* Box::paintable_box() const
{
return static_cast<Painting::PaintableBox const*>(Node::paintable());
}
Optional<CSSPixelFraction> Box::preferred_aspect_ratio() const
{
auto computed_aspect_ratio = computed_values().aspect_ratio();
if (computed_aspect_ratio.use_natural_aspect_ratio_if_available && natural_aspect_ratio().has_value())
return natural_aspect_ratio();
return computed_aspect_ratio.preferred_ratio.map([](CSS::Ratio const& ratio) { return CSSPixelFraction(CSSPixels(ratio.numerator()), CSSPixels(ratio.denominator())); });
}
}