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/*
* Copyright (C) 2005-2021 Team Kodi
* This file is part of Kodi - https://kodi.tv
*
* SPDX-License-Identifier: GPL-2.0-or-later
* See LICENSES/README.md for more information.
*/
#include "CSSUtils.h"
#include <cstdint>
#include <string>
namespace
{
// https://www.w3.org/TR/css-syntax-3/#hex-digit
bool isHexDigit(char c)
{
return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f');
}
// https://www.w3.org/TR/css-syntax-3/#hex-digit
uint32_t convertHexDigit(char c)
{
if (c >= '0' && c <= '9')
{
return c - '0';
}
else if (c >= 'A' && c <= 'F')
{
return 10 + c - 'A';
}
else
{
return 10 + c - 'a';
}
}
// https://infra.spec.whatwg.org/#surrogate
bool isSurrogateCodePoint(uint32_t c)
{
return c >= 0xD800 && c <= 0xDFFF;
}
// https://www.w3.org/TR/css-syntax-3/#maximum-allowed-code-point
bool isGreaterThanMaximumAllowedCodePoint(uint32_t c)
{
return c > 0x10FFFF;
}
// https://www.w3.org/TR/css-syntax-3/#consume-escaped-code-point
std::string escapeStringChunk(std::string& str, size_t& pos)
{
if (str.size() < pos + 1)
return "";
uint32_t codePoint = convertHexDigit(str[pos + 1]);
if (str.size() >= pos + 2)
pos += 2;
else
return "";
int numDigits = 1;
while (numDigits < 6 && isHexDigit(str[pos]))
{
codePoint = 16 * codePoint + convertHexDigit(str[pos]);
if (str.size() >= pos + 1)
{
pos += 1;
numDigits += 1;
}
else
break;
}
std::string result;
// Convert code point to UTF-8 bytes
if (codePoint == 0 || isSurrogateCodePoint(codePoint) ||
isGreaterThanMaximumAllowedCodePoint(codePoint))
{
result += u8"\uFFFD";
}
else if (codePoint < 0x80)
{
// 1-byte UTF-8: 0xxxxxxx
result += static_cast<char>(codePoint);
}
else if (codePoint < 0x800)
{
// 2-byte UTF-8: 110xxxxx 10xxxxxx
uint32_t x1 = codePoint >> 6; // 6 = num of x's in 2nd byte
uint32_t x2 = codePoint - (x1 << 6); // 6 = num of x's in 2nd byte
uint32_t b1 = (6 << 5) + x1; // 6 = 0b110 ; 5 = num of x's in 1st byte
uint32_t b2 = (2 << 6) + x2; // 2 = 0b10 ; 6 = num of x's in 2nd byte
result += static_cast<char>(b1);
result += static_cast<char>(b2);
}
else if (codePoint < 0x10000)
{
// 3-byte UTF-8: 1110xxxx 10xxxxxx 10xxxxxx
uint32_t y1 = codePoint >> 6;
uint32_t x3 = codePoint - (y1 << 6);
uint32_t x1 = y1 >> 6;
uint32_t x2 = y1 - (x1 << 6);
uint32_t b1 = (14 << 4) + x1;
uint32_t b2 = (2 << 6) + x2;
uint32_t b3 = (2 << 6) + x3;
result += static_cast<char>(b1);
result += static_cast<char>(b2);
result += static_cast<char>(b3);
}
else
{
// 4-byte UTF-8: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
uint32_t y2 = codePoint >> 6;
uint32_t x4 = codePoint - (y2 << 6);
uint32_t y1 = y2 >> 6;
uint32_t x3 = y2 - (y1 << 6);
uint32_t x1 = y1 >> 6;
uint32_t x2 = y1 - (x1 << 6);
uint32_t b1 = (30 << 3) + x1;
uint32_t b2 = (2 << 6) + x2;
uint32_t b3 = (2 << 6) + x3;
uint32_t b4 = (2 << 6) + x4;
result += static_cast<char>(b1);
result += static_cast<char>(b2);
result += static_cast<char>(b3);
result += static_cast<char>(b4);
}
return result;
}
} // unnamed namespace
void UTILS::CSS::Escape(std::string& str)
{
std::string result;
for (size_t pos = 0; pos < str.size(); pos++)
{
if (str[pos] == '\\')
result += escapeStringChunk(str, pos);
else
result += str[pos];
}
str = result;
}
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