beenull/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-09-30 00:31:14 +00:00
Code Issues Actions 5 Packages Projects Releases Wiki Activity

LibWeb: Implement CSS color parsing from Tokens

Browse source 
This was broken when we switched away from using StringStyleValues.
While I was at it, I have implemented hsl/a() and the percentage
syntax for rgb/a().

As a bonus, added `colors.html` as a test page for the various CSS
color syntaxes, since nothing was testing rgb() or rgba() before.

Much of the parsing code in LibGFX/Color.h seems to be centered
around CSS color values, but this is not used by the new Parser.
(And can't be used, because it requires a String value and we have
a list of Tokens of some kind instead.) Maybe that should be removed
from there when the new CSS parser is operational.
This commit is contained in:
Sam Atkins 2021-07-18 21:20:40 +01:00 committed by Andreas Kling
parent fabbd06de4
commit 7abfb18656
Notes: sideshowbarker 2024-07-18 08:31:19 +09:00 
Author: https://github.com/AtkinsSJ
Commit: https://github.com/SerenityOS/serenity/commit/7abfb18656d
Pull-request: https://github.com/SerenityOS/serenity/pull/8932
4 changed files with 195 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

29
Base/res/html/misc/colors.html Normal file
View file

@ -0,0 +1,29 @@
<html>
<head>
<title>CSS test</title>
<style type="text/css">
#a { background-color: lime; }
#b { background-color: #0F0; }
#c { background-color: #00ff00; }
#d { background-color: rgb(0, 255, 0); }
#e { background-color: rgb(0%, 100%, 0%); }
#e2 { background-color: rgb(-5%, 120%, -42%); }
#f { background-color: rgba(0, 255, 0, 1); }
#g { background-color: rgba(0%, 100%, 0%, 1); }
#h { background-color: hsl(120, 100%, 50%); }
#i { background-color: hsla(120, 100%, 50%, 1); }
</style>
</head>
<body>
<div id="a">This is green, using a named color.</div>
<div id="b">This is green, using #0F0.</div>
<div id="c">This is green, using #00ff00.</div>
<div id="d">This is green, using rgb(0, 255, 0).</div>
<div id="e">This is green, using rgb(0%, 100%, 0%).</div>
<div id="e2">This is green, using rgb(-5%, 120%, -42%).</div>
<div id="f">This is green, using rgba(0, 255, 0, 1).</div>
<div id="g">This is green, using rgba(0%, 100%, 0%, 1).</div>
<div id="h">This is green, using hsl(120, 100%, 50%).</div>
<div id="i">This is green, using hsla(120, 100%, 50%, 1).</div>
</body>
</html>

1
Base/res/html/misc/welcome.html
View file

@ -114,6 +114,7 @@
<li><a href="form.html">form</a></li>
<li><a href="borders.html">borders</a></li>
<li><a href="css.html">css</a></li>
<li><a href="colors.html">css colors</a></li>
<li><a href="acid1.html">acid1</a></li>
<li><a href="acid2.html">acid2</a></li>
<li><a href="attrselectors.html">attribute selectors</a></li>

172
Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
View file

@ -1405,17 +1405,171 @@ RefPtr<StyleValue> Parser::parse_identifier_value(ParsingContext const&, StyleCo
RefPtr<StyleValue> Parser::parse_color_value(ParsingContext const&, StyleComponentValueRule const& component_value)
{
// https://www.w3.org/TR/css-color-3/
auto parse_css_color = [&]() -> Optional<Color> {
if (component_value.is(Token::Type::Ident) && component_value.token().ident().equals_ignoring_case("transparent"))
return Color::from_rgba(0x00000000);
if (component_value.is(Token::Type::Ident)) {
auto ident = component_value.token().ident();
if (ident.equals_ignoring_case("transparent"))
return Color::from_rgba(0x00000000);
// FIXME: Handle all the different color notations.
// https://www.w3.org/TR/css-color-3/
// Right now, this uses non-CSS-specific parsing, and assumes the whole color value is one token,
// which is isn't if it's a function-style syntax.
auto color = Color::from_string(component_value.token().m_value.to_string().to_lowercase());
if (color.has_value())
return color;
auto color = Color::from_string(ident.to_string().to_lowercase());
if (color.has_value())
return color;
} else if (component_value.is(Token::Type::Hash)) {
// FIXME: Read it directly
auto color = Color::from_string(String::formatted("#{}", component_value.token().m_value.to_string().to_lowercase()));
if (color.has_value())
return color;
} else if (component_value.is_function()) {
auto& function = component_value.function();
auto& values = function.values();
Vector<Token> params;
for (size_t i = 0; i < values.size(); ++i) {
auto& value = values.at(i);
if (value.is(Token::Type::Whitespace))
continue;
if (value.is(Token::Type::Percentage) || value.is(Token::Type::Number)) {
params.append(value.token());
// Eat following comma and whitespace
while ((i + 1) < values.size()) {
auto& next = values.at(i + 1);
if (next.is(Token::Type::Whitespace))
i++;
else if (next.is(Token::Type::Comma))
break;
return {};
}
}
}
if (function.name().equals_ignoring_case("rgb")) {
if (params.size() != 3)
return {};
auto r_val = params[0];
auto g_val = params[1];
auto b_val = params[2];
if (r_val.is(Token::NumberType::Integer)
&& g_val.is(Token::NumberType::Integer)
&& b_val.is(Token::NumberType::Integer)) {
auto maybe_r = r_val.m_value.string_view().to_uint<u8>();
auto maybe_g = g_val.m_value.string_view().to_uint<u8>();
auto maybe_b = b_val.m_value.string_view().to_uint<u8>();
if (maybe_r.has_value() && maybe_g.has_value() && maybe_b.has_value())
return Color(maybe_r.value(), maybe_g.value(), maybe_b.value());
} else if (r_val.is(Token::Type::Percentage)
&& g_val.is(Token::Type::Percentage)
&& b_val.is(Token::Type::Percentage)) {
auto maybe_r = try_parse_float(r_val.m_value.string_view());
auto maybe_g = try_parse_float(g_val.m_value.string_view());
auto maybe_b = try_parse_float(b_val.m_value.string_view());
if (maybe_r.has_value() && maybe_g.has_value() && maybe_b.has_value()) {
u8 r = clamp(lroundf(maybe_r.value() * 2.55f), 0, 255);
u8 g = clamp(lroundf(maybe_g.value() * 2.55f), 0, 255);
u8 b = clamp(lroundf(maybe_b.value() * 2.55f), 0, 255);
return Color(r, g, b);
}
}
} else if (function.name().equals_ignoring_case("rgba")) {
if (params.size() != 4)
return {};
auto r_val = params[0];
auto g_val = params[1];
auto b_val = params[2];
auto a_val = params[3];
if (r_val.is(Token::NumberType::Integer)
&& g_val.is(Token::NumberType::Integer)
&& b_val.is(Token::NumberType::Integer)
&& a_val.is(Token::Type::Number)) {
auto maybe_r = r_val.m_value.string_view().to_uint<u8>();
auto maybe_g = g_val.m_value.string_view().to_uint<u8>();
auto maybe_b = b_val.m_value.string_view().to_uint<u8>();
auto maybe_a = try_parse_float(a_val.m_value.string_view());
if (maybe_r.has_value() && maybe_g.has_value() && maybe_b.has_value() && maybe_a.has_value()) {
u8 a = clamp(lroundf(maybe_a.value() * 255.0f), 0, 255);
return Color(maybe_r.value(), maybe_g.value(), maybe_b.value(), a);
}
} else if (r_val.is(Token::Type::Percentage)
&& g_val.is(Token::Type::Percentage)
&& b_val.is(Token::Type::Percentage)
&& a_val.is(Token::Type::Number)) {
auto maybe_r = try_parse_float(r_val.m_value.string_view());
auto maybe_g = try_parse_float(g_val.m_value.string_view());
auto maybe_b = try_parse_float(b_val.m_value.string_view());
auto maybe_a = try_parse_float(a_val.m_value.string_view());
if (maybe_r.has_value() && maybe_g.has_value() && maybe_b.has_value() && maybe_a.has_value()) {
u8 r = clamp(lroundf(maybe_r.value() * 2.55f), 0, 255);
u8 g = clamp(lroundf(maybe_g.value() * 2.55f), 0, 255);
u8 b = clamp(lroundf(maybe_b.value() * 2.55f), 0, 255);
u8 a = clamp(lroundf(maybe_a.value() * 255.0f), 0, 255);
return Color(r, g, b, a);
}
}
} else if (function.name().equals_ignoring_case("hsl")) {
if (params.size() != 3)
return {};
auto h_val = params[0];
auto s_val = params[1];
auto l_val = params[2];
if (h_val.is(Token::Type::Number)
&& s_val.is(Token::Type::Percentage)
&& l_val.is(Token::Type::Percentage)) {
auto maybe_h = try_parse_float(h_val.m_value.string_view());
auto maybe_s = try_parse_float(s_val.m_value.string_view());
auto maybe_l = try_parse_float(l_val.m_value.string_view());
if (maybe_h.has_value() && maybe_s.has_value() && maybe_l.has_value()) {
float h = maybe_h.value();
float s = maybe_s.value() / 100.0f;
float l = maybe_l.value() / 100.0f;
return Color::from_hsl(h, s, l);
}
}
} else if (function.name().equals_ignoring_case("hsla")) {
if (params.size() != 4)
return {};
auto h_val = params[0];
auto s_val = params[1];
auto l_val = params[2];
auto a_val = params[3];
if (h_val.is(Token::Type::Number)
&& s_val.is(Token::Type::Percentage)
&& l_val.is(Token::Type::Percentage)
&& a_val.is(Token::Type::Number)) {
auto maybe_h = try_parse_float(h_val.m_value.string_view());
auto maybe_s = try_parse_float(s_val.m_value.string_view());
auto maybe_l = try_parse_float(l_val.m_value.string_view());
auto maybe_a = try_parse_float(a_val.m_value.string_view());
if (maybe_h.has_value() && maybe_s.has_value() && maybe_l.has_value() && maybe_a.has_value()) {
float h = maybe_h.value();
float s = maybe_s.value() / 100.0f;
float l = maybe_l.value() / 100.0f;
float a = maybe_a.value();
return Color::from_hsla(h, s, l, a);
}
}
}
return {};
}
return {};
};

2
Userland/Libraries/LibWeb/CSS/Parser/Token.h
View file

@ -76,6 +76,8 @@ public:
return m_value.string_view();
}
bool is(NumberType number_type) const { return is(Token::Type::Number) && m_number_type == number_type; }
int integer() const
{
VERIFY(m_type == Type::Number && m_number_type == NumberType::Integer);