ladybird/Userland/Libraries/LibGfx/Color.cpp
Sam Atkins 094dc04695 LibGfx: Make Color::from_string() case-insensitive
This function implements CSS color syntax, which is case-insensitive in
HTML contexts. Making it insensitive here means not having to remember
to do it in every user, (many of the HTML elements do not do this,) and
means they don't have to produce a lowercase copy of the input string
before passing it.
2021-10-24 22:12:35 +02:00

334 lines
10 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Assertions.h>
#include <AK/Optional.h>
#include <AK/String.h>
#include <AK/Vector.h>
#include <LibGfx/Color.h>
#include <LibGfx/SystemTheme.h>
#include <LibIPC/Decoder.h>
#include <LibIPC/Encoder.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
namespace Gfx {
String Color::to_string() const
{
return String::formatted("#{:02x}{:02x}{:02x}{:02x}", red(), green(), blue(), alpha());
}
String Color::to_string_without_alpha() const
{
return String::formatted("#{:02x}{:02x}{:02x}", red(), green(), blue());
}
static Optional<Color> parse_rgb_color(StringView const& string)
{
VERIFY(string.starts_with("rgb(", CaseSensitivity::CaseInsensitive));
VERIFY(string.ends_with(")"));
auto substring = string.substring_view(4, string.length() - 5);
auto parts = substring.split_view(',');
if (parts.size() != 3)
return {};
auto r = parts[0].to_uint().value_or(256);
auto g = parts[1].to_uint().value_or(256);
auto b = parts[2].to_uint().value_or(256);
if (r > 255 || g > 255 || b > 255)
return {};
return Color(r, g, b);
}
static Optional<Color> parse_rgba_color(StringView const& string)
{
VERIFY(string.starts_with("rgba(", CaseSensitivity::CaseInsensitive));
VERIFY(string.ends_with(")"));
auto substring = string.substring_view(5, string.length() - 6);
auto parts = substring.split_view(',');
if (parts.size() != 4)
return {};
auto r = parts[0].to_int().value_or(256);
auto g = parts[1].to_int().value_or(256);
auto b = parts[2].to_int().value_or(256);
double alpha = strtod(parts[3].to_string().characters(), nullptr);
unsigned a = alpha * 255;
if (r > 255 || g > 255 || b > 255 || a > 255)
return {};
return Color(r, g, b, a);
}
Optional<Color> Color::from_string(StringView const& string)
{
if (string.is_empty())
return {};
struct ColorAndWebName {
constexpr ColorAndWebName(RGBA32 c, char const* n)
: color(c)
, name(n)
{
}
RGBA32 color;
StringView name;
};
constexpr ColorAndWebName web_colors[] = {
// CSS Level 1
{ 0x000000, "black" },
{ 0xc0c0c0, "silver" },
{ 0x808080, "gray" },
{ 0xffffff, "white" },
{ 0x800000, "maroon" },
{ 0xff0000, "red" },
{ 0x800080, "purple" },
{ 0xff00ff, "fuchsia" },
{ 0x008000, "green" },
{ 0x00ff00, "lime" },
{ 0x808000, "olive" },
{ 0xffff00, "yellow" },
{ 0x000080, "navy" },
{ 0x0000ff, "blue" },
{ 0x008080, "teal" },
{ 0x00ffff, "aqua" },
// CSS Level 2 (Revision 1)
{ 0xffa500, "orange" },
// CSS Color Module Level 3
{ 0xf0f8ff, "aliceblue" },
{ 0xfaebd7, "antiquewhite" },
{ 0x7fffd4, "aquamarine" },
{ 0xf0ffff, "azure" },
{ 0xf5f5dc, "beige" },
{ 0xffe4c4, "bisque" },
{ 0xffebcd, "blanchedalmond" },
{ 0x8a2be2, "blueviolet" },
{ 0xa52a2a, "brown" },
{ 0xdeb887, "burlywood" },
{ 0x5f9ea0, "cadetblue" },
{ 0x7fff00, "chartreuse" },
{ 0xd2691e, "chocolate" },
{ 0xff7f50, "coral" },
{ 0x6495ed, "cornflowerblue" },
{ 0xfff8dc, "cornsilk" },
{ 0xdc143c, "crimson" },
{ 0x00ffff, "cyan" },
{ 0x00008b, "darkblue" },
{ 0x008b8b, "darkcyan" },
{ 0xb8860b, "darkgoldenrod" },
{ 0xa9a9a9, "darkgray" },
{ 0x006400, "darkgreen" },
{ 0xa9a9a9, "darkgrey" },
{ 0xbdb76b, "darkkhaki" },
{ 0x8b008b, "darkmagenta" },
{ 0x556b2f, "darkolivegreen" },
{ 0xff8c00, "darkorange" },
{ 0x9932cc, "darkorchid" },
{ 0x8b0000, "darkred" },
{ 0xe9967a, "darksalmon" },
{ 0x8fbc8f, "darkseagreen" },
{ 0x483d8b, "darkslateblue" },
{ 0x2f4f4f, "darkslategray" },
{ 0x2f4f4f, "darkslategrey" },
{ 0x00ced1, "darkturquoise" },
{ 0x9400d3, "darkviolet" },
{ 0xff1493, "deeppink" },
{ 0x00bfff, "deepskyblue" },
{ 0x696969, "dimgray" },
{ 0x696969, "dimgrey" },
{ 0x1e90ff, "dodgerblue" },
{ 0xb22222, "firebrick" },
{ 0xfffaf0, "floralwhite" },
{ 0x228b22, "forestgreen" },
{ 0xdcdcdc, "gainsboro" },
{ 0xf8f8ff, "ghostwhite" },
{ 0xffd700, "gold" },
{ 0xdaa520, "goldenrod" },
{ 0xadff2f, "greenyellow" },
{ 0x808080, "grey" },
{ 0xf0fff0, "honeydew" },
{ 0xff69b4, "hotpink" },
{ 0xcd5c5c, "indianred" },
{ 0x4b0082, "indigo" },
{ 0xfffff0, "ivory" },
{ 0xf0e68c, "khaki" },
{ 0xe6e6fa, "lavender" },
{ 0xfff0f5, "lavenderblush" },
{ 0x7cfc00, "lawngreen" },
{ 0xfffacd, "lemonchiffon" },
{ 0xadd8e6, "lightblue" },
{ 0xf08080, "lightcoral" },
{ 0xe0ffff, "lightcyan" },
{ 0xfafad2, "lightgoldenrodyellow" },
{ 0xd3d3d3, "lightgray" },
{ 0x90ee90, "lightgreen" },
{ 0xd3d3d3, "lightgrey" },
{ 0xffb6c1, "lightpink" },
{ 0xffa07a, "lightsalmon" },
{ 0x20b2aa, "lightseagreen" },
{ 0x87cefa, "lightskyblue" },
{ 0x778899, "lightslategray" },
{ 0x778899, "lightslategrey" },
{ 0xb0c4de, "lightsteelblue" },
{ 0xffffe0, "lightyellow" },
{ 0x32cd32, "limegreen" },
{ 0xfaf0e6, "linen" },
{ 0xff00ff, "magenta" },
{ 0x66cdaa, "mediumaquamarine" },
{ 0x0000cd, "mediumblue" },
{ 0xba55d3, "mediumorchid" },
{ 0x9370db, "mediumpurple" },
{ 0x3cb371, "mediumseagreen" },
{ 0x7b68ee, "mediumslateblue" },
{ 0x00fa9a, "mediumspringgreen" },
{ 0x48d1cc, "mediumturquoise" },
{ 0xc71585, "mediumvioletred" },
{ 0x191970, "midnightblue" },
{ 0xf5fffa, "mintcream" },
{ 0xffe4e1, "mistyrose" },
{ 0xffe4b5, "moccasin" },
{ 0xffdead, "navajowhite" },
{ 0xfdf5e6, "oldlace" },
{ 0x6b8e23, "olivedrab" },
{ 0xff4500, "orangered" },
{ 0xda70d6, "orchid" },
{ 0xeee8aa, "palegoldenrod" },
{ 0x98fb98, "palegreen" },
{ 0xafeeee, "paleturquoise" },
{ 0xdb7093, "palevioletred" },
{ 0xffefd5, "papayawhip" },
{ 0xffdab9, "peachpuff" },
{ 0xcd853f, "peru" },
{ 0xffc0cb, "pink" },
{ 0xdda0dd, "plum" },
{ 0xb0e0e6, "powderblue" },
{ 0xbc8f8f, "rosybrown" },
{ 0x4169e1, "royalblue" },
{ 0x8b4513, "saddlebrown" },
{ 0xfa8072, "salmon" },
{ 0xf4a460, "sandybrown" },
{ 0x2e8b57, "seagreen" },
{ 0xfff5ee, "seashell" },
{ 0xa0522d, "sienna" },
{ 0x87ceeb, "skyblue" },
{ 0x6a5acd, "slateblue" },
{ 0x708090, "slategray" },
{ 0x708090, "slategrey" },
{ 0xfffafa, "snow" },
{ 0x00ff7f, "springgreen" },
{ 0x4682b4, "steelblue" },
{ 0xd2b48c, "tan" },
{ 0xd8bfd8, "thistle" },
{ 0xff6347, "tomato" },
{ 0x40e0d0, "turquoise" },
{ 0xee82ee, "violet" },
{ 0xf5deb3, "wheat" },
{ 0xf5f5f5, "whitesmoke" },
{ 0x9acd32, "yellowgreen" },
// CSS Color Module Level 4
{ 0x663399, "rebeccapurple" },
// (Fallback)
{ 0x000000, nullptr }
};
if (string.equals_ignoring_case("transparent"))
return Color::from_rgba(0x00000000);
for (size_t i = 0; !web_colors[i].name.is_null(); ++i) {
if (string.equals_ignoring_case(web_colors[i].name))
return Color::from_rgb(web_colors[i].color);
}
if (string.starts_with("rgb(", CaseSensitivity::CaseInsensitive) && string.ends_with(")"))
return parse_rgb_color(string);
if (string.starts_with("rgba(", CaseSensitivity::CaseInsensitive) && string.ends_with(")"))
return parse_rgba_color(string);
if (string[0] != '#')
return {};
auto hex_nibble_to_u8 = [](char nibble) -> Optional<u8> {
if (!isxdigit(nibble))
return {};
if (nibble >= '0' && nibble <= '9')
return nibble - '0';
return 10 + (tolower(nibble) - 'a');
};
if (string.length() == 4) {
Optional<u8> r = hex_nibble_to_u8(string[1]);
Optional<u8> g = hex_nibble_to_u8(string[2]);
Optional<u8> b = hex_nibble_to_u8(string[3]);
if (!r.has_value() || !g.has_value() || !b.has_value())
return {};
return Color(r.value() * 17, g.value() * 17, b.value() * 17);
}
if (string.length() == 5) {
Optional<u8> r = hex_nibble_to_u8(string[1]);
Optional<u8> g = hex_nibble_to_u8(string[2]);
Optional<u8> b = hex_nibble_to_u8(string[3]);
Optional<u8> a = hex_nibble_to_u8(string[4]);
if (!r.has_value() || !g.has_value() || !b.has_value() || !a.has_value())
return {};
return Color(r.value() * 17, g.value() * 17, b.value() * 17, a.value() * 17);
}
if (string.length() != 7 && string.length() != 9)
return {};
auto to_hex = [&](char c1, char c2) -> Optional<u8> {
auto nib1 = hex_nibble_to_u8(c1);
auto nib2 = hex_nibble_to_u8(c2);
if (!nib1.has_value() || !nib2.has_value())
return {};
return nib1.value() << 4 | nib2.value();
};
Optional<u8> r = to_hex(string[1], string[2]);
Optional<u8> g = to_hex(string[3], string[4]);
Optional<u8> b = to_hex(string[5], string[6]);
Optional<u8> a = string.length() == 9 ? to_hex(string[7], string[8]) : Optional<u8>(255);
if (!r.has_value() || !g.has_value() || !b.has_value() || !a.has_value())
return {};
return Color(r.value(), g.value(), b.value(), a.value());
}
}
bool IPC::encode(IPC::Encoder& encoder, Color const& color)
{
encoder << color.value();
return true;
}
bool IPC::decode(IPC::Decoder& decoder, Color& color)
{
u32 rgba = 0;
if (!decoder.decode(rgba))
return false;
color = Color::from_rgba(rgba);
return true;
}
void AK::Formatter<Gfx::Color>::format(FormatBuilder& builder, Gfx::Color const& value)
{
Formatter<StringView>::format(builder, value.to_string());
}