modules/skunicode/include/SkUnicode.h - skia - Git at Google

 /*
  * Copyright 2020 Google LLC
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkUnicode_DEFINED
 #define SkUnicode_DEFINED
 #include "include/core/SkSpan.h"
 #include "include/core/SkString.h"
 #include "include/core/SkTypes.h"
 #include "include/private/SkBitmaskEnum.h" // IWYU pragma: keep
 #include "include/private/base/SkTArray.h"
 #include "src/base/SkUTF.h"

 #include <cstddef>
 #include <cstdint>
 #include <memory>
 #include <string>
 #include <vector>

 #if !defined(SKUNICODE_IMPLEMENTATION)
     #define SKUNICODE_IMPLEMENTATION 0
 #endif

 #if !defined(SKUNICODE_API)
     #if defined(SKUNICODE_DLL)
         #if defined(_MSC_VER)
             #if SKUNICODE_IMPLEMENTATION
                 #define SKUNICODE_API __declspec(dllexport)
             #else
                 #define SKUNICODE_API __declspec(dllimport)
             #endif
         #else
             #define SKUNICODE_API __attribute__((visibility("default")))
         #endif
     #else
         #define SKUNICODE_API
     #endif
 #endif

 class SKUNICODE_API SkBidiIterator {
 public:
     typedef int32_t Position;
     typedef uint8_t Level;
     struct Region {
         Region(Position start, Position end, Level level)
             : start(start), end(end), level(level) { }
         Position start;
         Position end;
         Level level;
     };
     enum Direction {
         kLTR,
         kRTL,
     };
     virtual ~SkBidiIterator() = default;
     virtual Position getLength() = 0;
     virtual Level getLevelAt(Position) = 0;
 };

 class SKUNICODE_API SkBreakIterator {
 public:
     typedef int32_t Position;
     typedef int32_t Status;
     virtual ~SkBreakIterator() = default;
     virtual Position first() = 0;
     virtual Position current() = 0;
     virtual Position next() = 0;
     virtual Status status() = 0;
     virtual bool isDone() = 0;
     virtual bool setText(const char utftext8[], int utf8Units) = 0;
     virtual bool setText(const char16_t utftext16[], int utf16Units) = 0;
 };

 class SKUNICODE_API SkUnicode {
     public:
         enum CodeUnitFlags {
             kNoCodeUnitFlag = 0x00,
             kPartOfWhiteSpaceBreak = 0x01,
             kGraphemeStart = 0x02,
             kSoftLineBreakBefore = 0x04,
             kHardLineBreakBefore = 0x08,
             kPartOfIntraWordBreak = 0x10,
             kControl = 0x20,
             kTabulation = 0x40,
         };
         enum class TextDirection {
             kLTR,
             kRTL,
         };
         typedef size_t Position;
         typedef uint8_t BidiLevel;
         struct BidiRegion {
             BidiRegion(Position start, Position end, BidiLevel level)
               : start(start), end(end), level(level) { }
             Position start;
             Position end;
             BidiLevel level;
         };
         enum class LineBreakType {
             kSoftLineBreak = 0,
             kHardLineBreak = 100,
         };

         enum class BreakType {
             kWords,
             kGraphemes,
             kLines
         };
         struct LineBreakBefore {
             LineBreakBefore(Position pos, LineBreakType breakType)
               : pos(pos), breakType(breakType) { }
             Position pos;
             LineBreakType breakType;
         };

         virtual ~SkUnicode() = default;

         virtual SkString toUpper(const SkString&) = 0;

         // Methods used in SkShaper and SkText
         virtual std::unique_ptr<SkBidiIterator> makeBidiIterator
             (const uint16_t text[], int count, SkBidiIterator::Direction) = 0;
         virtual std::unique_ptr<SkBidiIterator> makeBidiIterator
             (const char text[], int count, SkBidiIterator::Direction) = 0;
         virtual std::unique_ptr<SkBreakIterator> makeBreakIterator
             (const char locale[], BreakType breakType) = 0;
         virtual std::unique_ptr<SkBreakIterator> makeBreakIterator(BreakType type) = 0;

         // Methods used in SkParagraph
         static bool isTabulation(SkUnicode::CodeUnitFlags flags);
         static bool isHardLineBreak(SkUnicode::CodeUnitFlags flags);
         static bool isSoftLineBreak(SkUnicode::CodeUnitFlags flags);
         static bool isGraphemeStart(SkUnicode::CodeUnitFlags flags);
         static bool isControl(SkUnicode::CodeUnitFlags flags);
         static bool isPartOfWhiteSpaceBreak(SkUnicode::CodeUnitFlags flags);
         virtual bool getBidiRegions(const char utf8[],
                                     int utf8Units,
                                     TextDirection dir,
                                     std::vector<BidiRegion>* results) = 0;
         virtual bool getWords(const char utf8[], int utf8Units, const char* locale,
                               std::vector<Position>* results) = 0;
         virtual bool computeCodeUnitFlags(char utf8[], int utf8Units, bool replaceTabs,
                                       SkTArray<SkUnicode::CodeUnitFlags, true>* results) = 0;
         virtual bool computeCodeUnitFlags(char16_t utf16[], int utf16Units, bool replaceTabs,
                                       SkTArray<SkUnicode::CodeUnitFlags, true>* results) = 0;

         static SkString convertUtf16ToUtf8(const char16_t * utf16, int utf16Units);
         static SkString convertUtf16ToUtf8(const std::u16string& utf16);
         static std::u16string convertUtf8ToUtf16(const char* utf8, int utf8Units);
         static std::u16string convertUtf8ToUtf16(const SkString& utf8);

         template <typename Appender8, typename Appender16>
         static bool extractUtfConversionMapping(SkSpan<const char> utf8, Appender8&& appender8, Appender16&& appender16) {
             size_t size8 = 0;
             size_t size16 = 0;
             auto ptr = utf8.begin();
             auto end = utf8.end();
             while (ptr < end) {

                 size_t index = ptr - utf8.begin();
                 SkUnichar u = SkUTF::NextUTF8(&ptr, end);

                 // All UTF8 code units refer to the same codepoint
                 size_t next = ptr - utf8.begin();
                 for (auto i = index; i < next; ++i) {
                     //fUTF16IndexForUTF8Index.emplace_back(fUTF8IndexForUTF16Index.size());
                     appender16(size8);
                     ++size16;
                 }
                 //SkASSERT(fUTF16IndexForUTF8Index.size() == next);
                 SkASSERT(size16 == next);
                 if (size16 != next) {
                     return false;
                 }

                 // One or two UTF16 code units refer to the same codepoint
                 uint16_t buffer[2];
                 size_t count = SkUTF::ToUTF16(u, buffer);
                 //fUTF8IndexForUTF16Index.emplace_back(index);
                 appender8(index);
                 ++size8;
                 if (count > 1) {
                     //fUTF8IndexForUTF16Index.emplace_back(index);
                     appender8(index);
                     ++size8;
                 }
             }
             //fUTF16IndexForUTF8Index.emplace_back(fUTF8IndexForUTF16Index.size());
             appender16(size8);
             ++size16;
             //fUTF8IndexForUTF16Index.emplace_back(fText.size());
             appender8(utf8.size());
             ++size8;

             return true;
         }

         template <typename Callback>
         void forEachCodepoint(const char* utf8, int32_t utf8Units, Callback&& callback) {
             const char* current = utf8;
             const char* end = utf8 + utf8Units;
             while (current < end) {
                 auto before = current - utf8;
                 SkUnichar unichar = SkUTF::NextUTF8(&current, end);
                 if (unichar < 0) unichar = 0xFFFD;
                 auto after = current - utf8;
                 uint16_t buffer[2];
                 size_t count = SkUTF::ToUTF16(unichar, buffer);
                 callback(unichar, before, after, count);
             }
         }

         template <typename Callback>
         void forEachCodepoint(const char16_t* utf16, int32_t utf16Units, Callback&& callback) {
             const char16_t* current = utf16;
             const char16_t* end = utf16 + utf16Units;
             while (current < end) {
                 auto before = current - utf16;
                 SkUnichar unichar = SkUTF::NextUTF16((const uint16_t**)&current, (const uint16_t*)end);
                 auto after = current - utf16;
                 callback(unichar, before, after);
             }
         }

         template <typename Callback>
         void forEachBidiRegion(const uint16_t utf16[], int utf16Units, SkBidiIterator::Direction dir, Callback&& callback) {
             auto iter = makeBidiIterator(utf16, utf16Units, dir);
             const uint16_t* start16 = utf16;
             const uint16_t* end16 = utf16 + utf16Units;
             SkBidiIterator::Level currentLevel = 0;

             SkBidiIterator::Position pos16 = 0;
             while (pos16 <= iter->getLength()) {
                 auto level = iter->getLevelAt(pos16);
                 if (pos16 == 0) {
                     currentLevel = level;
                 } else if (level != currentLevel) {
                     callback(pos16, start16 - utf16, currentLevel);
                     currentLevel = level;
                 }
                 if (start16 == end16) {
                     break;
                 }
                 SkUnichar u = SkUTF::NextUTF16(&start16, end16);
                 pos16 += SkUTF::ToUTF16(u);
             }
         }

         template <typename Callback>
         void forEachBreak(const char16_t utf16[], int utf16Units, SkUnicode::BreakType type, Callback&& callback) {
             auto iter = makeBreakIterator(type);
             iter->setText(utf16, utf16Units);
             auto pos = iter->first();
             do {
                 callback(pos, iter->status());
                 pos = iter->next();
             } while (!iter->isDone());
         }

         virtual void reorderVisual(const BidiLevel runLevels[], int levelsCount, int32_t logicalFromVisual[]) = 0;

         virtual std::unique_ptr<SkUnicode> copy() = 0;

         static std::unique_ptr<SkUnicode> Make();

         static std::unique_ptr<SkUnicode> MakeIcuBasedUnicode();

         static std::unique_ptr<SkUnicode> MakeClientBasedUnicode(
                 SkSpan<char> text,
                 std::vector<SkUnicode::BidiRegion> bidiRegions,
                 std::vector<SkUnicode::Position> words,
                 std::vector<SkUnicode::Position> graphemeBreaks,
                 std::vector<SkUnicode::LineBreakBefore> lineBreaks);
 };

 namespace sknonstd {
     template <> struct is_bitmask_enum<SkUnicode::CodeUnitFlags> : std::true_type {};
 }  // namespace sknonstd
 #endif // SkUnicode_DEFINED
	/*
	* Copyright 2020 Google LLC
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/
	#ifndef SkUnicode_DEFINED
	#define SkUnicode_DEFINED
	#include "include/core/SkSpan.h"
	#include "include/core/SkString.h"
	#include "include/core/SkTypes.h"
	#include "include/private/SkBitmaskEnum.h" // IWYU pragma: keep
	#include "include/private/base/SkTArray.h"
	#include "src/base/SkUTF.h"

	#include <cstddef>
	#include <cstdint>
	#include <memory>
	#include <string>
	#include <vector>

	#if !defined(SKUNICODE_IMPLEMENTATION)
	#define SKUNICODE_IMPLEMENTATION 0
	#endif

	#if !defined(SKUNICODE_API)
	#if defined(SKUNICODE_DLL)
	#if defined(_MSC_VER)
	#if SKUNICODE_IMPLEMENTATION
	#define SKUNICODE_API __declspec(dllexport)
	#else
	#define SKUNICODE_API __declspec(dllimport)
	#endif
	#else
	#define SKUNICODE_API __attribute__((visibility("default")))
	#endif
	#else
	#define SKUNICODE_API
	#endif
	#endif

	class SKUNICODE_API SkBidiIterator {
	public:
	typedef int32_t Position;
	typedef uint8_t Level;
	struct Region {
	Region(Position start, Position end, Level level)
	: start(start), end(end), level(level) { }
	Position start;
	Position end;
	Level level;
	};
	enum Direction {
	kLTR,
	kRTL,
	};
	virtual ~SkBidiIterator() = default;
	virtual Position getLength() = 0;
	virtual Level getLevelAt(Position) = 0;
	};

	class SKUNICODE_API SkBreakIterator {
	public:
	typedef int32_t Position;
	typedef int32_t Status;
	virtual ~SkBreakIterator() = default;
	virtual Position first() = 0;
	virtual Position current() = 0;
	virtual Position next() = 0;
	virtual Status status() = 0;
	virtual bool isDone() = 0;
	virtual bool setText(const char utftext8[], int utf8Units) = 0;
	virtual bool setText(const char16_t utftext16[], int utf16Units) = 0;
	};

	class SKUNICODE_API SkUnicode {
	public:
	enum CodeUnitFlags {
	kNoCodeUnitFlag = 0x00,
	kPartOfWhiteSpaceBreak = 0x01,
	kGraphemeStart = 0x02,
	kSoftLineBreakBefore = 0x04,
	kHardLineBreakBefore = 0x08,
	kPartOfIntraWordBreak = 0x10,
	kControl = 0x20,
	kTabulation = 0x40,
	};
	enum class TextDirection {
	kLTR,
	kRTL,
	};
	typedef size_t Position;
	typedef uint8_t BidiLevel;
	struct BidiRegion {
	BidiRegion(Position start, Position end, BidiLevel level)
	: start(start), end(end), level(level) { }
	Position start;
	Position end;
	BidiLevel level;
	};
	enum class LineBreakType {
	kSoftLineBreak = 0,
	kHardLineBreak = 100,
	};

	enum class BreakType {
	kWords,
	kGraphemes,
	kLines
	};
	struct LineBreakBefore {
	LineBreakBefore(Position pos, LineBreakType breakType)
	: pos(pos), breakType(breakType) { }
	Position pos;
	LineBreakType breakType;
	};

	virtual ~SkUnicode() = default;

	virtual SkString toUpper(const SkString&) = 0;

	// Methods used in SkShaper and SkText
	virtual std::unique_ptr<SkBidiIterator> makeBidiIterator
	(const uint16_t text[], int count, SkBidiIterator::Direction) = 0;
	virtual std::unique_ptr<SkBidiIterator> makeBidiIterator
	(const char text[], int count, SkBidiIterator::Direction) = 0;
	virtual std::unique_ptr<SkBreakIterator> makeBreakIterator
	(const char locale[], BreakType breakType) = 0;
	virtual std::unique_ptr<SkBreakIterator> makeBreakIterator(BreakType type) = 0;

	// Methods used in SkParagraph
	static bool isTabulation(SkUnicode::CodeUnitFlags flags);
	static bool isHardLineBreak(SkUnicode::CodeUnitFlags flags);
	static bool isSoftLineBreak(SkUnicode::CodeUnitFlags flags);
	static bool isGraphemeStart(SkUnicode::CodeUnitFlags flags);
	static bool isControl(SkUnicode::CodeUnitFlags flags);
	static bool isPartOfWhiteSpaceBreak(SkUnicode::CodeUnitFlags flags);
	virtual bool getBidiRegions(const char utf8[],
	int utf8Units,
	TextDirection dir,
	std::vector<BidiRegion>* results) = 0;
	virtual bool getWords(const char utf8[], int utf8Units, const char* locale,
	std::vector<Position>* results) = 0;
	virtual bool computeCodeUnitFlags(char utf8[], int utf8Units, bool replaceTabs,
	SkTArray<SkUnicode::CodeUnitFlags, true>* results) = 0;
	virtual bool computeCodeUnitFlags(char16_t utf16[], int utf16Units, bool replaceTabs,
	SkTArray<SkUnicode::CodeUnitFlags, true>* results) = 0;

	static SkString convertUtf16ToUtf8(const char16_t * utf16, int utf16Units);
	static SkString convertUtf16ToUtf8(const std::u16string& utf16);
	static std::u16string convertUtf8ToUtf16(const char* utf8, int utf8Units);
	static std::u16string convertUtf8ToUtf16(const SkString& utf8);

	template <typename Appender8, typename Appender16>
	static bool extractUtfConversionMapping(SkSpan<const char> utf8, Appender8&& appender8, Appender16&& appender16) {
	size_t size8 = 0;
	size_t size16 = 0;
	auto ptr = utf8.begin();
	auto end = utf8.end();
	while (ptr < end) {

	size_t index = ptr - utf8.begin();
	SkUnichar u = SkUTF::NextUTF8(&ptr, end);

	// All UTF8 code units refer to the same codepoint
	size_t next = ptr - utf8.begin();
	for (auto i = index; i < next; ++i) {
	//fUTF16IndexForUTF8Index.emplace_back(fUTF8IndexForUTF16Index.size());
	appender16(size8);
	++size16;
	}
	//SkASSERT(fUTF16IndexForUTF8Index.size() == next);
	SkASSERT(size16 == next);
	if (size16 != next) {
	return false;
	}

	// One or two UTF16 code units refer to the same codepoint
	uint16_t buffer[2];
	size_t count = SkUTF::ToUTF16(u, buffer);
	//fUTF8IndexForUTF16Index.emplace_back(index);
	appender8(index);
	++size8;
	if (count > 1) {
	//fUTF8IndexForUTF16Index.emplace_back(index);
	appender8(index);
	++size8;
	}
	}
	//fUTF16IndexForUTF8Index.emplace_back(fUTF8IndexForUTF16Index.size());
	appender16(size8);
	++size16;
	//fUTF8IndexForUTF16Index.emplace_back(fText.size());
	appender8(utf8.size());
	++size8;

	return true;
	}

	template <typename Callback>
	void forEachCodepoint(const char* utf8, int32_t utf8Units, Callback&& callback) {
	const char* current = utf8;
	const char* end = utf8 + utf8Units;
	while (current < end) {
	auto before = current - utf8;
	SkUnichar unichar = SkUTF::NextUTF8(&current, end);
	if (unichar < 0) unichar = 0xFFFD;
	auto after = current - utf8;
	uint16_t buffer[2];
	size_t count = SkUTF::ToUTF16(unichar, buffer);
	callback(unichar, before, after, count);
	}
	}

	template <typename Callback>
	void forEachCodepoint(const char16_t* utf16, int32_t utf16Units, Callback&& callback) {
	const char16_t* current = utf16;
	const char16_t* end = utf16 + utf16Units;
	while (current < end) {
	auto before = current - utf16;
	SkUnichar unichar = SkUTF::NextUTF16((const uint16_t*)&current, (const uint16_t)end);
	auto after = current - utf16;
	callback(unichar, before, after);
	}
	}

	template <typename Callback>
	void forEachBidiRegion(const uint16_t utf16[], int utf16Units, SkBidiIterator::Direction dir, Callback&& callback) {
	auto iter = makeBidiIterator(utf16, utf16Units, dir);
	const uint16_t* start16 = utf16;
	const uint16_t* end16 = utf16 + utf16Units;
	SkBidiIterator::Level currentLevel = 0;

	SkBidiIterator::Position pos16 = 0;
	while (pos16 <= iter->getLength()) {
	auto level = iter->getLevelAt(pos16);
	if (pos16 == 0) {
	currentLevel = level;
	} else if (level != currentLevel) {
	callback(pos16, start16 - utf16, currentLevel);
	currentLevel = level;
	}
	if (start16 == end16) {
	break;
	}
	SkUnichar u = SkUTF::NextUTF16(&start16, end16);
	pos16 += SkUTF::ToUTF16(u);
	}
	}

	template <typename Callback>
	void forEachBreak(const char16_t utf16[], int utf16Units, SkUnicode::BreakType type, Callback&& callback) {
	auto iter = makeBreakIterator(type);
	iter->setText(utf16, utf16Units);
	auto pos = iter->first();
	do {
	callback(pos, iter->status());
	pos = iter->next();
	} while (!iter->isDone());
	}

	virtual void reorderVisual(const BidiLevel runLevels[], int levelsCount, int32_t logicalFromVisual[]) = 0;

	virtual std::unique_ptr<SkUnicode> copy() = 0;

	static std::unique_ptr<SkUnicode> Make();

	static std::unique_ptr<SkUnicode> MakeIcuBasedUnicode();

	static std::unique_ptr<SkUnicode> MakeClientBasedUnicode(
	SkSpan<char> text,
	std::vector<SkUnicode::BidiRegion> bidiRegions,
	std::vector<SkUnicode::Position> words,
	std::vector<SkUnicode::Position> graphemeBreaks,
	std::vector<SkUnicode::LineBreakBefore> lineBreaks);
	};

	namespace sknonstd {
	template <> struct is_bitmask_enum<SkUnicode::CodeUnitFlags> : std::true_type {};
	} // namespace sknonstd
	#endif // SkUnicode_DEFINED