03ed37eb14
As noted, the ascent of the font is not the best heuristic for this, but it is one that's listed as OK to use by the spec: > In the cases where it is impossible or impractical to determine the cap-height, the font’s ascent must be used.
258 lines
7.7 KiB
C++
258 lines
7.7 KiB
C++
/*
|
|
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
|
|
* Copyright (c) 2021, Tobias Christiansen <tobyase@serenityos.org>
|
|
* Copyright (c) 2022-2023, Sam Atkins <atkinssj@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <AK/NonnullOwnPtr.h>
|
|
#include <AK/Variant.h>
|
|
#include <LibGfx/Font/Font.h>
|
|
#include <LibGfx/Rect.h>
|
|
#include <LibWeb/CSS/Length.h>
|
|
#include <LibWeb/CSS/Percentage.h>
|
|
#include <LibWeb/DOM/Document.h>
|
|
#include <LibWeb/HTML/BrowsingContext.h>
|
|
#include <LibWeb/HTML/HTMLHtmlElement.h>
|
|
|
|
namespace Web::CSS {
|
|
|
|
Length::FontMetrics::FontMetrics(CSSPixels font_size, Gfx::FontPixelMetrics const& pixel_metrics, CSSPixels line_height)
|
|
: font_size(font_size)
|
|
, x_height(pixel_metrics.x_height)
|
|
// FIXME: This is only approximately the cap height. The spec suggests measuring the "O" glyph:
|
|
// https://www.w3.org/TR/css-values-4/#cap
|
|
, cap_height(pixel_metrics.ascent)
|
|
, zero_advance(pixel_metrics.advance_of_ascii_zero + pixel_metrics.glyph_spacing)
|
|
, line_height(line_height)
|
|
{
|
|
}
|
|
|
|
Length::Length(int value, Type type)
|
|
: m_type(type)
|
|
, m_value(value)
|
|
{
|
|
}
|
|
Length::Length(float value, Type type)
|
|
: m_type(type)
|
|
, m_value(value)
|
|
{
|
|
}
|
|
Length::~Length() = default;
|
|
|
|
Length Length::make_auto()
|
|
{
|
|
return Length(0, Type::Auto);
|
|
}
|
|
|
|
Length Length::make_px(CSSPixels value)
|
|
{
|
|
return Length(value.value(), Type::Px);
|
|
}
|
|
|
|
Length Length::percentage_of(Percentage const& percentage) const
|
|
{
|
|
if (is_auto()) {
|
|
dbgln("Attempting to get percentage of an auto length, this seems wrong? But for now we just return the original length.");
|
|
return *this;
|
|
}
|
|
|
|
return Length { percentage.as_fraction() * raw_value(), m_type };
|
|
}
|
|
|
|
Length Length::resolved(Layout::Node const& layout_node) const
|
|
{
|
|
if (is_relative())
|
|
return make_px(to_px(layout_node));
|
|
if (!isfinite(m_value))
|
|
return make_auto();
|
|
return *this;
|
|
}
|
|
|
|
CSSPixels Length::relative_length_to_px(CSSPixelRect const& viewport_rect, FontMetrics const& font_metrics, FontMetrics const& root_font_metrics) const
|
|
{
|
|
switch (m_type) {
|
|
case Type::Em:
|
|
return m_value * font_metrics.font_size;
|
|
case Type::Rem:
|
|
return m_value * root_font_metrics.font_size;
|
|
case Type::Ex:
|
|
return m_value * font_metrics.x_height;
|
|
case Type::Rex:
|
|
return m_value * root_font_metrics.x_height;
|
|
case Type::Cap:
|
|
return m_value * font_metrics.cap_height;
|
|
case Type::Rcap:
|
|
return m_value * root_font_metrics.cap_height;
|
|
case Type::Ch:
|
|
return m_value * font_metrics.zero_advance;
|
|
case Type::Rch:
|
|
return m_value * root_font_metrics.zero_advance;
|
|
case Type::Lh:
|
|
return m_value * font_metrics.line_height;
|
|
case Type::Rlh:
|
|
return m_value * root_font_metrics.line_height;
|
|
case Type::Vw:
|
|
return viewport_rect.width() * (m_value / 100);
|
|
case Type::Vh:
|
|
return viewport_rect.height() * (m_value / 100);
|
|
case Type::Vmin:
|
|
return min(viewport_rect.width(), viewport_rect.height()) * (m_value / 100);
|
|
case Type::Vmax:
|
|
return max(viewport_rect.width(), viewport_rect.height()) * (m_value / 100);
|
|
default:
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
}
|
|
|
|
CSSPixels Length::to_px(Layout::Node const& layout_node) const
|
|
{
|
|
if (is_absolute())
|
|
return absolute_length_to_px();
|
|
|
|
if (!layout_node.document().browsing_context())
|
|
return 0;
|
|
auto const& viewport_rect = layout_node.document().browsing_context()->viewport_rect();
|
|
auto* root_element = layout_node.document().document_element();
|
|
if (!root_element || !root_element->layout_node())
|
|
return 0;
|
|
|
|
FontMetrics font_metrics {
|
|
layout_node.computed_values().font_size(),
|
|
layout_node.font().pixel_metrics(),
|
|
layout_node.line_height()
|
|
};
|
|
FontMetrics root_font_metrics {
|
|
root_element->layout_node()->computed_values().font_size(),
|
|
root_element->layout_node()->font().pixel_metrics(),
|
|
root_element->layout_node()->line_height()
|
|
};
|
|
|
|
return to_px(viewport_rect, font_metrics, root_font_metrics);
|
|
}
|
|
|
|
ErrorOr<String> Length::to_string() const
|
|
{
|
|
if (is_auto())
|
|
return "auto"_string;
|
|
return String::formatted("{}{}", m_value, unit_name());
|
|
}
|
|
|
|
char const* Length::unit_name() const
|
|
{
|
|
switch (m_type) {
|
|
case Type::Em:
|
|
return "em";
|
|
case Type::Rem:
|
|
return "rem";
|
|
case Type::Ex:
|
|
return "ex";
|
|
case Type::Rex:
|
|
return "rex";
|
|
case Type::Cap:
|
|
return "cap";
|
|
case Type::Rcap:
|
|
return "rcap";
|
|
case Type::Ch:
|
|
return "ch";
|
|
case Type::Rch:
|
|
return "rch";
|
|
case Type::Lh:
|
|
return "lh";
|
|
case Type::Rlh:
|
|
return "rlh";
|
|
case Type::Vw:
|
|
return "vw";
|
|
case Type::Vh:
|
|
return "vh";
|
|
case Type::Vmin:
|
|
return "vmin";
|
|
case Type::Vmax:
|
|
return "vmax";
|
|
case Type::Cm:
|
|
return "cm";
|
|
case Type::Mm:
|
|
return "mm";
|
|
case Type::Q:
|
|
return "Q";
|
|
case Type::In:
|
|
return "in";
|
|
case Type::Pt:
|
|
return "pt";
|
|
case Type::Pc:
|
|
return "pc";
|
|
case Type::Px:
|
|
return "px";
|
|
case Type::Auto:
|
|
return "auto";
|
|
}
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
|
|
Optional<Length::Type> Length::unit_from_name(StringView name)
|
|
{
|
|
if (name.equals_ignoring_ascii_case("em"sv)) {
|
|
return Length::Type::Em;
|
|
} else if (name.equals_ignoring_ascii_case("rem"sv)) {
|
|
return Length::Type::Rem;
|
|
} else if (name.equals_ignoring_ascii_case("ex"sv)) {
|
|
return Length::Type::Ex;
|
|
} else if (name.equals_ignoring_ascii_case("rex"sv)) {
|
|
return Length::Type::Rex;
|
|
} else if (name.equals_ignoring_ascii_case("cap"sv)) {
|
|
return Length::Type::Cap;
|
|
} else if (name.equals_ignoring_ascii_case("rcap"sv)) {
|
|
return Length::Type::Rcap;
|
|
} else if (name.equals_ignoring_ascii_case("ch"sv)) {
|
|
return Length::Type::Ch;
|
|
} else if (name.equals_ignoring_ascii_case("rch"sv)) {
|
|
return Length::Type::Rch;
|
|
} else if (name.equals_ignoring_ascii_case("lh"sv)) {
|
|
return Length::Type::Lh;
|
|
} else if (name.equals_ignoring_ascii_case("rlh"sv)) {
|
|
return Length::Type::Rlh;
|
|
} else if (name.equals_ignoring_ascii_case("vw"sv)) {
|
|
return Length::Type::Vw;
|
|
} else if (name.equals_ignoring_ascii_case("vh"sv)) {
|
|
return Length::Type::Vh;
|
|
} else if (name.equals_ignoring_ascii_case("vmin"sv)) {
|
|
return Length::Type::Vmin;
|
|
} else if (name.equals_ignoring_ascii_case("vmax"sv)) {
|
|
return Length::Type::Vmax;
|
|
} else if (name.equals_ignoring_ascii_case("cm"sv)) {
|
|
return Length::Type::Cm;
|
|
} else if (name.equals_ignoring_ascii_case("mm"sv)) {
|
|
return Length::Type::Mm;
|
|
} else if (name.equals_ignoring_ascii_case("Q"sv)) {
|
|
return Length::Type::Q;
|
|
} else if (name.equals_ignoring_ascii_case("in"sv)) {
|
|
return Length::Type::In;
|
|
} else if (name.equals_ignoring_ascii_case("pt"sv)) {
|
|
return Length::Type::Pt;
|
|
} else if (name.equals_ignoring_ascii_case("pc"sv)) {
|
|
return Length::Type::Pc;
|
|
} else if (name.equals_ignoring_ascii_case("px"sv)) {
|
|
return Length::Type::Px;
|
|
}
|
|
|
|
return {};
|
|
}
|
|
|
|
Optional<Length> Length::absolutize(CSSPixelRect const& viewport_rect, FontMetrics const& font_metrics, FontMetrics const& root_font_metrics) const
|
|
{
|
|
if (is_px())
|
|
return {};
|
|
if (is_absolute() || is_relative()) {
|
|
auto px = to_px(viewport_rect, font_metrics, root_font_metrics);
|
|
return CSS::Length::make_px(px);
|
|
}
|
|
return {};
|
|
}
|
|
|
|
Length Length::absolutized(CSSPixelRect const& viewport_rect, FontMetrics const& font_metrics, FontMetrics const& root_font_metrics) const
|
|
{
|
|
return absolutize(viewport_rect, font_metrics, root_font_metrics).value_or(*this);
|
|
}
|
|
|
|
}
|