ladybird/Userland/Libraries/LibWeb/Layout/Box.cpp
Sam Atkins 1051624084 LibWeb: Obey CSS aspect-ratio property during layout
Calculate a "preferred aspect ratio" based on the value of
`aspect-ratio` and the presence of a natural aspect ratio, and use that
in layout.

This is by no means complete or perfect, but we do now apply the given
aspect-ratio to things.

The spec is a bit vague, just saying to calculate sizes for
aspect-ratio'ed boxes the same as you would for replaced elements. My
naive solution here is to find everywhere we were checking for a
ReplacedBox, and then also accept a regular Box with a preferred aspect
ratio. This gets us pretty far. :^)

https://www.w3.org/TR/css-sizing-4/#aspect-ratio-minimum is not at all
implemented.
2023-06-09 20:37:51 +02:00

102 lines
2.9 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 <LibGfx/Painter.h>
#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, 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_scrollable() const
{
// FIXME: Support horizontal scroll as well (overflow-x)
return computed_values().overflow_y() == CSS::Overflow::Scroll;
}
void Box::set_scroll_offset(CSSPixelPoint offset)
{
// FIXME: If there is horizontal and vertical scroll ignore only part of the new offset
if (offset.y() < 0 || m_scroll_offset == offset)
return;
m_scroll_offset = offset;
set_needs_display();
}
void Box::set_needs_display()
{
if (paintable_box())
browsing_context().set_needs_display(paintable_box()->absolute_rect());
}
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 const* Box::paintable_box() const
{
return static_cast<Painting::PaintableBox const*>(Node::paintable());
}
Optional<float> 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 ratio.value(); });
}
}