notepad-plus-plus/scintilla/boostregex/UTF8DocumentIterator.cxx

136 lines
3.0 KiB
C++

#include "UTF8DocumentIterator.h"
#include "ILoader.h"
#include "ILexer.h"
#include "Scintilla.h"
#include "CharacterCategory.h"
#include "Position.h"
#include "SplitVector.h"
#include "Partitioning.h"
#include "RunStyles.h"
#include "CellBuffer.h"
#include "CharClassify.h"
#include "Decoration.h"
#include "CaseFolder.h"
#include "Document.h"
using namespace Scintilla;
UTF8DocumentIterator::UTF8DocumentIterator(Document* doc, Sci::Position pos, Sci::Position end) :
m_doc(doc),
m_pos(pos),
m_end(end),
m_characterIndex(0)
{
// Check for debug builds
PLATFORM_ASSERT(m_pos <= m_end);
// Ensure for release.
if (m_pos > m_end)
{
m_pos = m_end;
}
readCharacter();
}
UTF8DocumentIterator::UTF8DocumentIterator(const UTF8DocumentIterator& copy) :
m_doc(copy.m_doc),
m_pos(copy.m_pos),
m_end(copy.m_end),
m_characterIndex(copy.m_characterIndex),
m_utf8Length(copy.m_utf8Length),
m_utf16Length(copy.m_utf16Length)
{
// Check for debug builds
PLATFORM_ASSERT(m_pos <= m_end);
m_character[0] = copy.m_character[0];
m_character[1] = copy.m_character[1];
// Ensure for release.
if (m_pos > m_end)
{
m_pos = m_end;
}
}
UTF8DocumentIterator& UTF8DocumentIterator::operator -- ()
{
if (m_utf16Length == 2 && m_characterIndex == 1)
{
m_characterIndex = 0;
}
else
{
--m_pos;
// Skip past the UTF-8 extension bytes
while (0x80 == (m_doc->CharAt(m_pos) & 0xC0) && m_pos > 0)
--m_pos;
readCharacter();
if (m_utf16Length == 2)
{
m_characterIndex = 1;
}
}
return *this;
}
void UTF8DocumentIterator::readCharacter()
{
unsigned char currentChar = m_doc->CharAt(m_pos);
if (currentChar & 0x80)
{
int mask = 0x40;
int nBytes = 1;
do
{
mask >>= 1;
++nBytes;
} while (currentChar & mask);
int result = currentChar & m_firstByteMask[nBytes];
Sci::Position pos = m_pos;
m_utf8Length = 1;
// work out the unicode point, and count the actual bytes.
// If a byte does not start with 10xxxxxx then it's not part of the
// the code. Therefore invalid UTF-8 encodings are dealt with, simply by stopping when
// the UTF8 extension bytes are no longer valid.
while ((--nBytes) && (pos < m_end) && (0x80 == ((currentChar = m_doc->CharAt(++pos)) & 0xC0)))
{
result = (result << 6) | (currentChar & 0x3F);
++m_utf8Length;
}
if (result >= 0x10000)
{
result -= 0x10000;
m_utf16Length = 2;
// UTF-16 Pair
m_character[0] = static_cast<wchar_t>(0xD800 + (result >> 10));
m_character[1] = static_cast<wchar_t>(0xDC00 + (result & 0x3FF));
}
else
{
m_utf16Length = 1;
m_character[0] = static_cast<wchar_t>(result);
}
}
else
{
m_utf8Length = 1;
m_utf16Length = 1;
m_characterIndex = 0;
m_character[0] = static_cast<wchar_t>(currentChar);
}
}
const unsigned char UTF8DocumentIterator::m_firstByteMask[7] = { 0x7F, 0x3F, 0x1F, 0x0F, 0x07, 0x03, 0x01 };