jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
3 * Copyright (c) 2021, Tobias Christiansen <tobyase@serenityos.org>
4 * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
5 *
6 * SPDX-License-Identifier: BSD-2-Clause
7 */
8
9#include <AK/NonnullOwnPtr.h>
10#include <AK/Variant.h>
11#include <LibGfx/Font/Font.h>
12#include <LibGfx/Rect.h>
13#include <LibWeb/CSS/Length.h>
14#include <LibWeb/CSS/Percentage.h>
15#include <LibWeb/DOM/Document.h>
16#include <LibWeb/HTML/BrowsingContext.h>
17#include <LibWeb/HTML/HTMLHtmlElement.h>
18
19namespace Web::CSS {
20
21Length::Length(int value, Type type)
22 : m_type(type)
23 , m_value(value)
24{
25}
26Length::Length(float value, Type type)
27 : m_type(type)
28 , m_value(value)
29{
30}
31Length::~Length() = default;
32
33Length Length::make_auto()
34{
35 return Length(0, Type::Auto);
36}
37
38Length Length::make_px(CSSPixels value)
39{
40 return Length(value.value(), Type::Px);
41}
42
43Length Length::make_calculated(NonnullRefPtr<CalculatedStyleValue> calculated_style_value)
44{
45 Length length { 0, Type::Calculated };
46 length.m_calculated_style = move(calculated_style_value);
47 return length;
48}
49
50Length Length::percentage_of(Percentage const& percentage) const
51{
52 VERIFY(!is_calculated());
53
54 if (is_auto()) {
55 dbgln("Attempting to get percentage of an auto length, this seems wrong? But for now we just return the original length.");
56 return *this;
57 }
58
59 return Length { percentage.as_fraction() * raw_value(), m_type };
60}
61
62Length Length::resolved(Layout::Node const& layout_node) const
63{
64 if (is_calculated())
65 return m_calculated_style->resolve_length(layout_node).release_value();
66 if (is_relative())
67 return make_px(to_px(layout_node));
68 if (!isfinite(m_value))
69 return make_auto();
70 return *this;
71}
72
73CSSPixels Length::relative_length_to_px(CSSPixelRect const& viewport_rect, Gfx::FontPixelMetrics const& font_metrics, CSSPixels font_size, CSSPixels root_font_size) const
74{
75 switch (m_type) {
76 case Type::Ex:
77 return m_value * font_metrics.x_height;
78 case Type::Em:
79 return m_value * font_size;
80 case Type::Ch:
81 // FIXME: Use layout_node.font().pixel_size() when writing-mode is not horizontal-tb (it has to be implemented first)
82 return m_value * (font_metrics.advance_of_ascii_zero + font_metrics.glyph_spacing);
83 case Type::Rem:
84 return m_value * root_font_size;
85 case Type::Vw:
86 return viewport_rect.width() * (m_value / 100);
87 case Type::Vh:
88 return viewport_rect.height() * (m_value / 100);
89 case Type::Vmin:
90 return min(viewport_rect.width(), viewport_rect.height()) * (m_value / 100);
91 case Type::Vmax:
92 return max(viewport_rect.width(), viewport_rect.height()) * (m_value / 100);
93 default:
94 VERIFY_NOT_REACHED();
95 }
96}
97
98CSSPixels Length::to_px(Layout::Node const& layout_node) const
99{
100 if (is_calculated())
101 return m_calculated_style->resolve_length(layout_node)->to_px(layout_node);
102
103 if (is_absolute())
104 return absolute_length_to_px();
105
106 if (!layout_node.document().browsing_context())
107 return 0;
108 auto const& viewport_rect = layout_node.document().browsing_context()->viewport_rect();
109 auto* root_element = layout_node.document().document_element();
110 if (!root_element || !root_element->layout_node())
111 return 0;
112 return to_px(viewport_rect, layout_node.font().pixel_metrics(), layout_node.computed_values().font_size(), root_element->layout_node()->computed_values().font_size());
113}
114
115ErrorOr<String> Length::to_string() const
116{
117 if (is_calculated())
118 return m_calculated_style->to_string();
119 if (is_auto())
120 return "auto"_string;
121 return String::formatted("{}{}", m_value, unit_name());
122}
123
124char const* Length::unit_name() const
125{
126 switch (m_type) {
127 case Type::Cm:
128 return "cm";
129 case Type::In:
130 return "in";
131 case Type::Px:
132 return "px";
133 case Type::Pt:
134 return "pt";
135 case Type::Mm:
136 return "mm";
137 case Type::Q:
138 return "Q";
139 case Type::Pc:
140 return "pc";
141 case Type::Ex:
142 return "ex";
143 case Type::Em:
144 return "em";
145 case Type::Ch:
146 return "ch";
147 case Type::Rem:
148 return "rem";
149 case Type::Auto:
150 return "auto";
151 case Type::Vh:
152 return "vh";
153 case Type::Vw:
154 return "vw";
155 case Type::Vmax:
156 return "vmax";
157 case Type::Vmin:
158 return "vmin";
159 case Type::Calculated:
160 return "calculated";
161 }
162 VERIFY_NOT_REACHED();
163}
164
165Optional<Length::Type> Length::unit_from_name(StringView name)
166{
167 if (name.equals_ignoring_ascii_case("px"sv)) {
168 return Length::Type::Px;
169 } else if (name.equals_ignoring_ascii_case("pt"sv)) {
170 return Length::Type::Pt;
171 } else if (name.equals_ignoring_ascii_case("pc"sv)) {
172 return Length::Type::Pc;
173 } else if (name.equals_ignoring_ascii_case("mm"sv)) {
174 return Length::Type::Mm;
175 } else if (name.equals_ignoring_ascii_case("rem"sv)) {
176 return Length::Type::Rem;
177 } else if (name.equals_ignoring_ascii_case("em"sv)) {
178 return Length::Type::Em;
179 } else if (name.equals_ignoring_ascii_case("ex"sv)) {
180 return Length::Type::Ex;
181 } else if (name.equals_ignoring_ascii_case("ch"sv)) {
182 return Length::Type::Ch;
183 } else if (name.equals_ignoring_ascii_case("vw"sv)) {
184 return Length::Type::Vw;
185 } else if (name.equals_ignoring_ascii_case("vh"sv)) {
186 return Length::Type::Vh;
187 } else if (name.equals_ignoring_ascii_case("vmax"sv)) {
188 return Length::Type::Vmax;
189 } else if (name.equals_ignoring_ascii_case("vmin"sv)) {
190 return Length::Type::Vmin;
191 } else if (name.equals_ignoring_ascii_case("cm"sv)) {
192 return Length::Type::Cm;
193 } else if (name.equals_ignoring_ascii_case("in"sv)) {
194 return Length::Type::In;
195 } else if (name.equals_ignoring_ascii_case("Q"sv)) {
196 return Length::Type::Q;
197 }
198
199 return {};
200}
201
202NonnullRefPtr<CalculatedStyleValue> Length::calculated_style_value() const
203{
204 VERIFY(!m_calculated_style.is_null());
205 return *m_calculated_style;
206}
207
208bool Length::operator==(Length const& other) const
209{
210 if (is_calculated())
211 return m_calculated_style == other.m_calculated_style;
212 return m_type == other.m_type && m_value == other.m_value;
213}
214
215}