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1 /*
2  * Copyright 2020 Google LLC
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 #ifndef SkUnicode_DEFINED
8 #define SkUnicode_DEFINED
9 #include "include/core/SkSpan.h"
10 #include "include/core/SkString.h"
11 #include "include/core/SkTypes.h"
12 #include "include/private/SkBitmaskEnum.h" // IWYU pragma: keep
13 #include "include/private/SkTArray.h"
14 #include "include/private/SkTo.h"
15 #include "src/utils/SkUTF.h"
16 
17 #include <cstddef>
18 #include <cstdint>
19 #include <memory>
20 #include <string>
21 #include <vector>
22 
23 #if !defined(SKUNICODE_IMPLEMENTATION)
24     #define SKUNICODE_IMPLEMENTATION 0
25 #endif
26 
27 #if !defined(SKUNICODE_API)
28     #if defined(SKUNICODE_DLL)
29         #if defined(_MSC_VER)
30             #if SKUNICODE_IMPLEMENTATION
31                 #define SKUNICODE_API __declspec(dllexport)
32             #else
33                 #define SKUNICODE_API __declspec(dllimport)
34             #endif
35         #else
36             #define SKUNICODE_API __attribute__((visibility("default")))
37         #endif
38     #else
39         #define SKUNICODE_API
40     #endif
41 #endif
42 
43 class SKUNICODE_API SkBidiIterator {
44 public:
45     typedef int32_t Position;
46     typedef uint8_t Level;
47     struct Region {
RegionRegion48         Region(Position start, Position end, Level level)
49             : start(start), end(end), level(level) { }
50         Position start;
51         Position end;
52         Level level;
53     };
54     enum Direction {
55         kLTR,
56         kRTL,
57     };
58     virtual ~SkBidiIterator() = default;
59     virtual Position getLength() = 0;
60     virtual Level getLevelAt(Position) = 0;
61 };
62 
63 class SKUNICODE_API SkBreakIterator {
64 public:
65     typedef int32_t Position;
66     typedef int32_t Status;
67     virtual ~SkBreakIterator() = default;
68     virtual Position first() = 0;
69     virtual Position current() = 0;
70     virtual Position next() = 0;
71     virtual Status status() = 0;
72     virtual bool isDone() = 0;
73     virtual bool setText(const char utftext8[], int utf8Units) = 0;
74     virtual bool setText(const char16_t utftext16[], int utf16Units) = 0;
75 };
76 
77 class SKUNICODE_API SkUnicode {
78     public:
79         enum CodeUnitFlags {
80             kNoCodeUnitFlag = 0x00,
81             kPartOfWhiteSpaceBreak = 0x01,
82             kGraphemeStart = 0x02,
83             kSoftLineBreakBefore = 0x04,
84             kHardLineBreakBefore = 0x08,
85             kPartOfIntraWordBreak = 0x10,
86             kControl = 0x20,
87             kTabulation = 0x40,
88             kGlyphClusterStart = 0x80,
89             kIdeographic = 0x100,
90 #ifdef OHOS_SUPPORT
91             kCombine = 0x200,
92 #endif
93         };
94         enum class TextDirection {
95             kLTR,
96             kRTL,
97         };
98         typedef size_t Position;
99         typedef uint8_t BidiLevel;
100         struct BidiRegion {
BidiRegionBidiRegion101             BidiRegion(Position start, Position end, BidiLevel level)
102               : start(start), end(end), level(level) { }
103             Position start;
104             Position end;
105             BidiLevel level;
106         };
107         enum class LineBreakType {
108             kSoftLineBreak = 0,
109             kHardLineBreak = 100,
110         };
111 
112         enum class BreakType {
113             kWords,
114             kGraphemes,
115             kLines
116         };
117         struct LineBreakBefore {
LineBreakBeforeLineBreakBefore118             LineBreakBefore(Position pos, LineBreakType breakType)
119               : pos(pos), breakType(breakType) { }
120             Position pos;
121             LineBreakType breakType;
122         };
123 
124         virtual ~SkUnicode() = default;
125 
126         virtual SkString toUpper(const SkString&) = 0;
127 
128         // Methods used in SkShaper and SkText
129         virtual std::unique_ptr<SkBidiIterator> makeBidiIterator
130             (const uint16_t text[], int count, SkBidiIterator::Direction) = 0;
131         virtual std::unique_ptr<SkBidiIterator> makeBidiIterator
132             (const char text[], int count, SkBidiIterator::Direction) = 0;
133         virtual std::unique_ptr<SkBreakIterator> makeBreakIterator
134             (const char locale[], BreakType breakType) = 0;
135         virtual std::unique_ptr<SkBreakIterator> makeBreakIterator(BreakType type) = 0;
136 
137         // Methods used in SkParagraph
138         static bool isTabulation(SkUnicode::CodeUnitFlags flags);
139         static bool isHardLineBreak(SkUnicode::CodeUnitFlags flags);
140         static bool isSoftLineBreak(SkUnicode::CodeUnitFlags flags);
141         static bool isGraphemeStart(SkUnicode::CodeUnitFlags flags);
142         static bool isControl(SkUnicode::CodeUnitFlags flags);
143         static bool isPartOfWhiteSpaceBreak(SkUnicode::CodeUnitFlags flags);
144         static bool isIdeographic(SkUnichar utf8);
145         static bool extractBidi(const char utf8[],
146                                 int utf8Units,
147                                 TextDirection dir,
148                                 std::vector<BidiRegion>* bidiRegions);
149         virtual bool getBidiRegions(const char utf8[],
150                                     int utf8Units,
151                                     TextDirection dir,
152                                     std::vector<BidiRegion>* results) = 0;
153         virtual bool getWords(const char utf8[], int utf8Units, const char* locale,
154                               std::vector<Position>* results) = 0;
155         virtual bool computeCodeUnitFlags(
156                 char utf8[], int utf8Units, bool replaceTabs,
157                 SkTArray<SkUnicode::CodeUnitFlags, true>* results) = 0;
158         virtual bool computeCodeUnitFlags(
159                 char16_t utf16[], int utf16Units, bool replaceTabs,
160                 SkTArray<SkUnicode::CodeUnitFlags, true>* results) = 0;
161 
162         static SkString convertUtf16ToUtf8(const char16_t * utf16, int utf16Units);
163         static SkString convertUtf16ToUtf8(const std::u16string& utf16);
164         static std::u16string convertUtf8ToUtf16(const char* utf8, int utf8Units);
165         static std::u16string convertUtf8ToUtf16(const SkString& utf8);
166 
167         template <typename Appender8, typename Appender16>
extractUtfConversionMapping(SkSpan<const char> utf8,Appender8 && appender8,Appender16 && appender16)168         static bool extractUtfConversionMapping(SkSpan<const char> utf8, Appender8&& appender8, Appender16&& appender16) {
169             size_t size8 = 0;
170             size_t size16 = 0;
171             auto ptr = utf8.begin();
172             auto end = utf8.end();
173             while (ptr < end) {
174 
175                 size_t index = SkToSizeT(ptr - utf8.begin());
176                 SkUnichar u = SkUTF::NextUTF8(&ptr, end);
177 
178                 // All UTF8 code units refer to the same codepoint
179                 size_t next = SkToSizeT(ptr - utf8.begin());
180                 for (auto i = index; i < next; ++i) {
181                     //fUTF16IndexForUTF8Index.emplace_back(fUTF8IndexForUTF16Index.size());
182                     appender16(size8);
183                     ++size16;
184                 }
185                 //SkASSERT(fUTF16IndexForUTF8Index.size() == next);
186                 SkASSERT(size16 == next);
187                 if (size16 != next) {
188                     return false;
189                 }
190 
191                 // One or two UTF16 code units refer to the same codepoint
192                 uint16_t buffer[2];
193                 size_t count = SkUTF::ToUTF16(u, buffer);
194                 //fUTF8IndexForUTF16Index.emplace_back(index);
195                 appender8(index);
196                 ++size8;
197                 if (count > 1) {
198                     //fUTF8IndexForUTF16Index.emplace_back(index);
199                     appender8(index);
200                     ++size8;
201                 }
202             }
203             //fUTF16IndexForUTF8Index.emplace_back(fUTF8IndexForUTF16Index.size());
204             appender16(size8);
205             ++size16;
206             //fUTF8IndexForUTF16Index.emplace_back(fText.size());
207             appender8(utf8.size());
208             ++size8;
209 
210             return true;
211         }
212 
213         template <typename Callback>
forEachCodepoint(const char * utf8,int32_t utf8Units,Callback && callback)214         void forEachCodepoint(const char* utf8, int32_t utf8Units, Callback&& callback) {
215             const char* current = utf8;
216             const char* end = utf8 + utf8Units;
217             while (current < end) {
218                 auto before = current - utf8;
219                 SkUnichar unichar = SkUTF::NextUTF8(&current, end);
220                 if (unichar < 0) unichar = 0xFFFD;
221                 auto after = current - utf8;
222                 uint16_t buffer[2];
223                 size_t count = SkUTF::ToUTF16(unichar, buffer);
224                 callback(unichar, before, after, count);
225             }
226         }
227 
228         template <typename Callback>
forEachCodepoint(const char16_t * utf16,int32_t utf16Units,Callback && callback)229         void forEachCodepoint(const char16_t* utf16, int32_t utf16Units, Callback&& callback) {
230             const char16_t* current = utf16;
231             const char16_t* end = utf16 + utf16Units;
232             while (current < end) {
233                 auto before = current - utf16;
234                 SkUnichar unichar = SkUTF::NextUTF16((const uint16_t**)&current, (const uint16_t*)end);
235                 auto after = current - utf16;
236                 callback(unichar, before, after);
237             }
238         }
239 
240         template <typename Callback>
forEachBidiRegion(const uint16_t utf16[],int utf16Units,SkBidiIterator::Direction dir,Callback && callback)241         void forEachBidiRegion(const uint16_t utf16[], int utf16Units, SkBidiIterator::Direction dir, Callback&& callback) {
242             auto iter = makeBidiIterator(utf16, utf16Units, dir);
243             const uint16_t* start16 = utf16;
244             const uint16_t* end16 = utf16 + utf16Units;
245             SkBidiIterator::Level currentLevel = 0;
246 
247             SkBidiIterator::Position pos16 = 0;
248             while (pos16 <= iter->getLength()) {
249                 auto level = iter->getLevelAt(pos16);
250                 if (pos16 == 0) {
251                     currentLevel = level;
252                 } else if (level != currentLevel) {
253                     callback(pos16, start16 - utf16, currentLevel);
254                     currentLevel = level;
255                 }
256                 if (start16 == end16) {
257                     break;
258                 }
259                 SkUnichar u = SkUTF::NextUTF16(&start16, end16);
260                 pos16 += SkUTF::ToUTF16(u);
261             }
262         }
263 
264         template <typename Callback>
forEachBreak(const char16_t utf16[],int utf16Units,SkUnicode::BreakType type,Callback && callback)265         void forEachBreak(const char16_t utf16[], int utf16Units, SkUnicode::BreakType type, Callback&& callback) {
266             auto iter = makeBreakIterator(type);
267             iter->setText(utf16, utf16Units);
268             auto pos = iter->first();
269             do {
270                 callback(pos, iter->status());
271                 pos = iter->next();
272             } while (!iter->isDone());
273         }
274 
275         virtual void reorderVisual(const BidiLevel runLevels[], int levelsCount, int32_t logicalFromVisual[]) = 0;
276 
277         virtual std::unique_ptr<SkUnicode> copy() = 0;
278 
279         static std::unique_ptr<SkUnicode> Make();
280 
281         static std::unique_ptr<SkUnicode> MakeIcuBasedUnicode();
282 
283         static std::unique_ptr<SkUnicode> MakeClientBasedUnicode(
284                 SkSpan<char> text,
285                 std::vector<SkUnicode::Position> words,
286                 std::vector<SkUnicode::Position> graphemeBreaks,
287                 std::vector<SkUnicode::LineBreakBefore> lineBreaks);
288 };
289 
290 namespace sknonstd {
291     template <> struct is_bitmask_enum<SkUnicode::CodeUnitFlags> : std::true_type {};
292 }  // namespace sknonstd
293 #endif // SkUnicode_DEFINED
294