raze/libraries/ZWidget/include/zwidget/core/utf8reader.h
2024-01-04 20:54:04 +01:00

78 lines
2.3 KiB
C++

/*
** Copyright (c) 1997-2015 Mark Page
**
** This software is provided 'as-is', without any express or implied
** warranty. In no event will the authors be held liable for any damages
** arising from the use of this software.
**
** Permission is granted to anyone to use this software for any purpose,
** including commercial applications, and to alter it and redistribute it
** freely, subject to the following restrictions:
**
** 1. The origin of this software must not be misrepresented; you must not
** claim that you wrote the original software. If you use this software
** in a product, an acknowledgment in the product documentation would be
** appreciated but is not required.
** 2. Altered source versions must be plainly marked as such, and must not be
** misrepresented as being the original software.
** 3. This notice may not be removed or altered from any source distribution.
**
*/
#pragma once
#include <string>
/// \brief UTF8 reader helper functions.
class UTF8Reader
{
public:
/// Important: text is not copied by this class and must remain valid during its usage.
UTF8Reader(const std::string::value_type *text, std::string::size_type length);
/// \brief Returns true if the current position is at the end of the string
bool is_end();
/// \brief Get the character at the current position
unsigned int character();
/// \brief Returns the length of the current character
std::string::size_type char_length();
/// \brief Moves position to the previous character
void prev();
/// \brief Moves position to the next character
void next();
/// \brief Moves position to the lead byte of the character
void move_to_leadbyte();
/// \brief Get the current position of the reader
std::string::size_type position();
/// \brief Set the current position of the reader
void set_position(std::string::size_type position);
static size_t utf8_length(const std::string& text)
{
return utf8_length(text.data(), text.size());
}
static size_t utf8_length(const std::string::value_type* text, std::string::size_type length)
{
UTF8Reader reader(text, length);
size_t i = 0;
while (!reader.is_end())
{
reader.next();
i++;
}
return i;
}
private:
std::string::size_type current_position = 0;
std::string::size_type length = 0;
const unsigned char *data = nullptr;
};