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| 1 // Copyright 2014 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. |
| 4 |
| 5 #include "ui/gfx/render_text_harfbuzz.h" |
| 6 |
| 7 #include <map> |
| 8 |
| 9 #include "base/i18n/break_iterator.h" |
| 10 #include "base/i18n/char_iterator.h" |
| 11 #include "third_party/harfbuzz-ng/src/hb-icu.h" |
| 12 #include "third_party/harfbuzz-ng/src/hb.h" |
| 13 #include "third_party/icu/source/common/unicode/ubidi.h" |
| 14 #include "third_party/skia/include/core/SkColor.h" |
| 15 #include "third_party/skia/include/core/SkTypeface.h" |
| 16 #include "ui/gfx/canvas.h" |
| 17 #include "ui/gfx/utf16_indexing.h" |
| 18 |
| 19 #if defined(OS_WIN) |
| 20 #include "ui/gfx/font_smoothing_win.h" |
| 21 #endif |
| 22 |
| 23 namespace gfx { |
| 24 |
| 25 namespace { |
| 26 |
| 27 // The maximum number of scripts a Unicode character can belong to. This value |
| 28 // is arbitrarily chosen to be a good limit because it is unlikely for a single |
| 29 // character to belong to more scripts. |
| 30 const size_t kMaxScripts = 5; |
| 31 |
| 32 // Maps from code points to glyph indices in a font. |
| 33 typedef std::map<uint32_t, uint16_t> GlyphCache; |
| 34 |
| 35 // Font data provider for HarfBuzz using Skia. Copied from Blink. |
| 36 // TODO(ckocagil): Eliminate the duplication. http://crbug.com/368375 |
| 37 struct FontData { |
| 38 FontData(GlyphCache* glyph_cache) : glyph_cache_(glyph_cache) {} |
| 39 |
| 40 SkPaint paint_; |
| 41 GlyphCache* glyph_cache_; |
| 42 }; |
| 43 |
| 44 hb_position_t SkiaScalarToHarfBuzzPosition(SkScalar value) { |
| 45 return SkScalarToFixed(value); |
| 46 } |
| 47 |
| 48 // Deletes the object at the given pointer after casting it to the given type. |
| 49 template<typename Type> |
| 50 void DeleteByType(void* data) { |
| 51 Type* typed_data = reinterpret_cast<Type*>(data); |
| 52 delete typed_data; |
| 53 } |
| 54 |
| 55 template<typename Type> |
| 56 void DeleteArrayByType(void* data) { |
| 57 Type* typed_data = reinterpret_cast<Type*>(data); |
| 58 delete[] typed_data; |
| 59 } |
| 60 |
| 61 // Outputs the |width| and |extents| of the glyph with index |codepoint| in |
| 62 // |paint|'s font. |
| 63 void GetGlyphWidthAndExtents(SkPaint* paint, |
| 64 hb_codepoint_t codepoint, |
| 65 hb_position_t* width, |
| 66 hb_glyph_extents_t* extents) { |
| 67 DCHECK_LE(codepoint, 0xFFFFU); |
| 68 paint->setTextEncoding(SkPaint::kGlyphID_TextEncoding); |
| 69 |
| 70 SkScalar sk_width; |
| 71 SkRect sk_bounds; |
| 72 uint16_t glyph = codepoint; |
| 73 |
| 74 paint->getTextWidths(&glyph, sizeof(glyph), &sk_width, &sk_bounds); |
| 75 if (width) |
| 76 *width = SkiaScalarToHarfBuzzPosition(sk_width); |
| 77 if (extents) { |
| 78 // Invert y-axis because Skia is y-grows-down but we set up HarfBuzz to be |
| 79 // y-grows-up. |
| 80 extents->x_bearing = SkiaScalarToHarfBuzzPosition(sk_bounds.fLeft); |
| 81 extents->y_bearing = SkiaScalarToHarfBuzzPosition(-sk_bounds.fTop); |
| 82 extents->width = SkiaScalarToHarfBuzzPosition(sk_bounds.width()); |
| 83 extents->height = SkiaScalarToHarfBuzzPosition(-sk_bounds.height()); |
| 84 } |
| 85 } |
| 86 |
| 87 // Writes the |glyph| index for the given |unicode| code point. Returns whether |
| 88 // the glyph exists, i.e. it is not a missing glyph. |
| 89 hb_bool_t GetGlyph(hb_font_t* font, |
| 90 void* data, |
| 91 hb_codepoint_t unicode, |
| 92 hb_codepoint_t variation_selector, |
| 93 hb_codepoint_t* glyph, |
| 94 void* user_data) { |
| 95 FontData* font_data = reinterpret_cast<FontData*>(data); |
| 96 GlyphCache* cache = font_data->glyph_cache_; |
| 97 |
| 98 bool exists = cache->count(unicode) != 0; |
| 99 if (!exists) { |
| 100 SkPaint* paint = &font_data->paint_; |
| 101 paint->setTextEncoding(SkPaint::kUTF32_TextEncoding); |
| 102 paint->textToGlyphs(&unicode, sizeof(hb_codepoint_t), &(*cache)[unicode]); |
| 103 } |
| 104 *glyph = (*cache)[unicode]; |
| 105 return !!*glyph; |
| 106 } |
| 107 |
| 108 // Returns the horizontal advance value of the |glyph|. |
| 109 hb_position_t GetGlyphHorizontalAdvance(hb_font_t* font, |
| 110 void* data, |
| 111 hb_codepoint_t glyph, |
| 112 void* user_data) { |
| 113 FontData* font_data = reinterpret_cast<FontData*>(data); |
| 114 hb_position_t advance = 0; |
| 115 |
| 116 GetGlyphWidthAndExtents(&font_data->paint_, glyph, &advance, 0); |
| 117 return advance; |
| 118 } |
| 119 |
| 120 hb_bool_t GetGlyphHorizontalOrigin(hb_font_t* font, |
| 121 void* data, |
| 122 hb_codepoint_t glyph, |
| 123 hb_position_t* x, |
| 124 hb_position_t* y, |
| 125 void* user_data) { |
| 126 // Just return true, like the HarfBuzz-FreeType implementation. |
| 127 return true; |
| 128 } |
| 129 |
| 130 // Writes the |extents| of |glyph|. |
| 131 hb_bool_t GetGlyphExtents(hb_font_t* font, |
| 132 void* data, |
| 133 hb_codepoint_t glyph, |
| 134 hb_glyph_extents_t* extents, |
| 135 void* user_data) { |
| 136 FontData* font_data = reinterpret_cast<FontData*>(data); |
| 137 |
| 138 GetGlyphWidthAndExtents(&font_data->paint_, glyph, 0, extents); |
| 139 return true; |
| 140 } |
| 141 |
| 142 // Returns a HarfBuzz font data provider that uses Skia. |
| 143 hb_font_funcs_t* GetFontFuncs() { |
| 144 static hb_font_funcs_t* font_funcs = 0; |
| 145 |
| 146 // We don't set callback functions which we can't support. |
| 147 // HarfBuzz will use the fallback implementation if they aren't set. |
| 148 // TODO(ckocagil): Merge Blink's kerning funcs. |
| 149 if (!font_funcs) { |
| 150 // The object created by |hb_font_funcs_create()| below lives indefinitely |
| 151 // and is intentionally leaked. |
| 152 font_funcs = hb_font_funcs_create(); |
| 153 hb_font_funcs_set_glyph_func(font_funcs, GetGlyph, 0, 0); |
| 154 hb_font_funcs_set_glyph_h_advance_func( |
| 155 font_funcs, GetGlyphHorizontalAdvance, 0, 0); |
| 156 hb_font_funcs_set_glyph_h_origin_func( |
| 157 font_funcs, GetGlyphHorizontalOrigin, 0, 0); |
| 158 hb_font_funcs_set_glyph_extents_func( |
| 159 font_funcs, GetGlyphExtents, 0, 0); |
| 160 hb_font_funcs_make_immutable(font_funcs); |
| 161 } |
| 162 return font_funcs; |
| 163 } |
| 164 |
| 165 // Returns the raw data of the font table |tag|. |
| 166 hb_blob_t* GetFontTable(hb_face_t* face, hb_tag_t tag, void* user_data) { |
| 167 SkTypeface* typeface = reinterpret_cast<SkTypeface*>(user_data); |
| 168 |
| 169 const size_t table_size = typeface->getTableSize(tag); |
| 170 if (!table_size) |
| 171 return 0; |
| 172 |
| 173 scoped_ptr<char[]> buffer(new char[table_size]); |
| 174 if (!buffer) |
| 175 return 0; |
| 176 size_t actual_size = typeface->getTableData(tag, 0, table_size, buffer.get()); |
| 177 if (table_size != actual_size) |
| 178 return 0; |
| 179 |
| 180 char* buffer_raw = buffer.release(); |
| 181 return hb_blob_create(buffer_raw, table_size, HB_MEMORY_MODE_WRITABLE, |
| 182 buffer_raw, DeleteArrayByType<char>); |
| 183 } |
| 184 |
| 185 void UnrefSkTypeface(void* data) { |
| 186 SkTypeface* skia_face = reinterpret_cast<SkTypeface*>(data); |
| 187 SkSafeUnref(skia_face); |
| 188 } |
| 189 |
| 190 // Creates a HarfBuzz face from the given Skia face. |
| 191 hb_face_t* CreateHarfBuzzFace(SkTypeface* skia_face) { |
| 192 SkSafeRef(skia_face); |
| 193 hb_face_t* face = hb_face_create_for_tables(GetFontTable, skia_face, |
| 194 UnrefSkTypeface); |
| 195 DCHECK(face); |
| 196 return face; |
| 197 } |
| 198 |
| 199 // Creates a HarfBuzz font from the given Skia face and text size. |
| 200 hb_font_t* CreateHarfBuzzFont(SkTypeface* skia_face, int text_size) { |
| 201 typedef std::pair<hb_face_t*, GlyphCache> FaceCache; |
| 202 |
| 203 // TODO(ckocagil): This shouldn't grow indefinitely. Maybe use base::MRUCache? |
| 204 static std::map<SkFontID, FaceCache> face_caches; |
| 205 |
| 206 FaceCache* face_cache = &face_caches[skia_face->uniqueID()]; |
| 207 if (face_cache->first == 0) { |
| 208 hb_face_t* harfbuzz_face = CreateHarfBuzzFace(skia_face); |
| 209 *face_cache = FaceCache(harfbuzz_face, GlyphCache()); |
| 210 } |
| 211 |
| 212 hb_font_t* harfbuzz_font = hb_font_create(face_cache->first); |
| 213 // TODO(ckocagil): Investigate whether disabling hinting here has any effect |
| 214 // on text quality. |
| 215 int upem = hb_face_get_upem(face_cache->first); |
| 216 hb_font_set_scale(harfbuzz_font, upem, upem); |
| 217 FontData* hb_font_data = new FontData(&face_cache->second); |
| 218 hb_font_data->paint_.setTypeface(skia_face); |
| 219 hb_font_data->paint_.setTextSize(text_size); |
| 220 hb_font_set_funcs(harfbuzz_font, GetFontFuncs(), hb_font_data, |
| 221 DeleteByType<FontData>); |
| 222 hb_font_make_immutable(harfbuzz_font); |
| 223 return harfbuzz_font; |
| 224 } |
| 225 |
| 226 // Returns true if characters of |block_code| may trigger font fallback. |
| 227 bool IsUnusualBlockCode(UBlockCode block_code) { |
| 228 return block_code == UBLOCK_GEOMETRIC_SHAPES || |
| 229 block_code == UBLOCK_MISCELLANEOUS_SYMBOLS; |
| 230 } |
| 231 |
| 232 // If the given scripts match, returns the one that isn't USCRIPT_COMMON or |
| 233 // USCRIPT_INHERITED, i.e. the more specific one. Otherwise returns |
| 234 // USCRIPT_INVALID_CODE. |
| 235 UScriptCode ScriptIntersect(UScriptCode first, UScriptCode second) { |
| 236 if (first == second || |
| 237 (second > USCRIPT_INVALID_CODE && second <= USCRIPT_INHERITED)) { |
| 238 return first; |
| 239 } |
| 240 if (first > USCRIPT_INVALID_CODE && first <= USCRIPT_INHERITED) |
| 241 return second; |
| 242 return USCRIPT_INVALID_CODE; |
| 243 } |
| 244 |
| 245 // Writes the script and the script extensions of the character with the |
| 246 // Unicode |codepoint|. Returns the number of written scripts. |
| 247 int GetScriptExtensions(UChar32 codepoint, UScriptCode* scripts) { |
| 248 UErrorCode icu_error = U_ZERO_ERROR; |
| 249 // ICU documentation incorrectly states that the result of |
| 250 // |uscript_getScriptExtensions| will contain the regular script property. |
| 251 // Write the character's script property to the first element. |
| 252 scripts[0] = uscript_getScript(codepoint, &icu_error); |
| 253 if (U_FAILURE(icu_error)) |
| 254 return 0; |
| 255 // Fill the rest of |scripts| with the extensions. |
| 256 int count = uscript_getScriptExtensions(codepoint, scripts + 1, |
| 257 kMaxScripts - 1, &icu_error); |
| 258 if (U_FAILURE(icu_error)) |
| 259 count = 0; |
| 260 return count + 1; |
| 261 } |
| 262 |
| 263 // Intersects the script extensions set of |codepoint| with |result| and writes |
| 264 // to |result|, reading and updating |result_size|. |
| 265 void ScriptSetIntersect(UChar32 codepoint, |
| 266 UScriptCode* result, |
| 267 size_t* result_size) { |
| 268 UScriptCode scripts[kMaxScripts] = { USCRIPT_INVALID_CODE }; |
| 269 int count = GetScriptExtensions(codepoint, scripts); |
| 270 |
| 271 size_t out_size = 0; |
| 272 |
| 273 for (size_t i = 0; i < *result_size; ++i) { |
| 274 for (int j = 0; j < count; ++j) { |
| 275 UScriptCode intersection = ScriptIntersect(result[i], scripts[j]); |
| 276 if (intersection != USCRIPT_INVALID_CODE) { |
| 277 result[out_size++] = intersection; |
| 278 break; |
| 279 } |
| 280 } |
| 281 } |
| 282 |
| 283 *result_size = out_size; |
| 284 } |
| 285 |
| 286 // Find the longest sequence of characters from 0 and up to |length| that |
| 287 // have at least one common UScriptCode value. Writes the common script value to |
| 288 // |script| and returns the length of the sequence. Takes the characters' script |
| 289 // extensions into account. http://www.unicode.org/reports/tr24/#ScriptX |
| 290 // |
| 291 // Consider 3 characters with the script values {Kana}, {Hira, Kana}, {Kana}. |
| 292 // Without script extensions only the first script in each set would be taken |
| 293 // into account, resulting in 3 runs where 1 would be enough. |
| 294 // TODO(ckocagil): Write a unit test for the case above. |
| 295 int ScriptInterval(const base::string16& text, |
| 296 size_t start, |
| 297 size_t length, |
| 298 UScriptCode* script) { |
| 299 DCHECK_GT(length, 0U); |
| 300 |
| 301 UScriptCode scripts[kMaxScripts] = { USCRIPT_INVALID_CODE }; |
| 302 |
| 303 base::i18n::UTF16CharIterator char_iterator(text.c_str() + start, length); |
| 304 size_t scripts_size = GetScriptExtensions(char_iterator.get(), scripts); |
| 305 *script = scripts[0]; |
| 306 |
| 307 while (char_iterator.Advance()) { |
| 308 ScriptSetIntersect(char_iterator.get(), scripts, &scripts_size); |
| 309 if (scripts_size == 0U) |
| 310 return char_iterator.array_pos(); |
| 311 *script = scripts[0]; |
| 312 } |
| 313 |
| 314 return length; |
| 315 } |
| 316 |
| 317 } // namespace |
| 318 |
| 319 namespace internal { |
| 320 |
| 321 TextRunHarfBuzz::TextRunHarfBuzz() |
| 322 : width(0), |
| 323 preceding_run_widths(0), |
| 324 direction(UBIDI_LTR), |
| 325 level(0), |
| 326 script(USCRIPT_INVALID_CODE), |
| 327 glyph_count(-1), |
| 328 font_size(0), |
| 329 font_style(0), |
| 330 strike(false), |
| 331 diagonal_strike(false), |
| 332 underline(false) {} |
| 333 |
| 334 TextRunHarfBuzz::~TextRunHarfBuzz() {} |
| 335 |
| 336 size_t TextRunHarfBuzz::CharToGlyph(size_t pos) const { |
| 337 DCHECK(range.start() <= pos && pos < range.end()); |
| 338 |
| 339 if (direction == UBIDI_LTR) { |
| 340 for (size_t i = 0; i < glyph_count - 1; ++i) { |
| 341 if (pos < glyph_to_char[i + 1]) |
| 342 return i; |
| 343 } |
| 344 return glyph_count - 1; |
| 345 } |
| 346 |
| 347 for (size_t i = 0; i < glyph_count; ++i) { |
| 348 if (pos >= glyph_to_char[i]) |
| 349 return i; |
| 350 } |
| 351 NOTREACHED(); |
| 352 return 0; |
| 353 } |
| 354 |
| 355 Range TextRunHarfBuzz::CharRangeToGlyphRange(const Range& range) const { |
| 356 DCHECK(range.Contains(range)); |
| 357 DCHECK(!range.is_reversed()); |
| 358 DCHECK(!range.is_empty()); |
| 359 |
| 360 const size_t first = CharToGlyph(range.start()); |
| 361 const size_t last = CharToGlyph(range.end() - 1); |
| 362 // TODO(ckocagil): What happens when the character has zero or multiple |
| 363 // glyphs? Is the "+ 1" below correct then? |
| 364 return Range(std::min(first, last), std::max(first, last) + 1); |
| 365 } |
| 366 |
| 367 // Returns whether the given shaped run contains any missing glyphs. |
| 368 bool TextRunHarfBuzz::HasMissingGlyphs() const { |
| 369 static const int kMissingGlyphId = 0; |
| 370 for (size_t i = 0; i < glyph_count; ++i) { |
| 371 if (glyphs[i] == kMissingGlyphId) |
| 372 return true; |
| 373 } |
| 374 return false; |
| 375 } |
| 376 |
| 377 int TextRunHarfBuzz::GetGlyphXBoundary(size_t text_index, bool trailing) const { |
| 378 int x = preceding_run_widths; |
| 379 Range glyph_range; |
| 380 if (text_index == range.end()) { |
| 381 trailing = true; |
| 382 glyph_range = direction == UBIDI_LTR ? |
| 383 Range(glyph_count - 1, glyph_count) : Range(0, 1); |
| 384 } else { |
| 385 glyph_range = CharRangeToGlyphRange(Range(text_index, text_index + 1)); |
| 386 } |
| 387 const int trailing_step = trailing ? 1 : 0; |
| 388 const size_t glyph_pos = glyph_range.start() + |
| 389 (direction == UBIDI_LTR ? trailing_step : (1 - trailing_step)); |
| 390 x += glyph_pos < glyph_count ? |
| 391 SkScalarRoundToInt(positions[glyph_pos].x()) : width; |
| 392 return x; |
| 393 } |
| 394 |
| 395 } // namespace internal |
| 396 |
| 397 RenderTextHarfBuzz::RenderTextHarfBuzz() |
| 398 : RenderText(), |
| 399 needs_layout_(false) {} |
| 400 |
| 401 RenderTextHarfBuzz::~RenderTextHarfBuzz() {} |
| 402 |
| 403 Size RenderTextHarfBuzz::GetStringSize() { |
| 404 EnsureLayout(); |
| 405 return Size(lines()[0].size.width(), font_list().GetHeight()); |
| 406 } |
| 407 |
| 408 SelectionModel RenderTextHarfBuzz::FindCursorPosition(const Point& point) { |
| 409 EnsureLayout(); |
| 410 |
| 411 int x = ToTextPoint(point).x(); |
| 412 int offset = 0; |
| 413 size_t run_index = GetRunContainingXCoord(x, &offset); |
| 414 if (run_index >= runs_.size()) |
| 415 return EdgeSelectionModel((x < 0) ? CURSOR_LEFT : CURSOR_RIGHT); |
| 416 const internal::TextRunHarfBuzz& run = *runs_[run_index]; |
| 417 |
| 418 for (size_t i = 0; i < run.glyph_count; ++i) { |
| 419 const SkScalar end = |
| 420 i + 1 == run.glyph_count ? run.width : run.positions[i + 1].x(); |
| 421 const SkScalar middle = (end + run.positions[i].x()) / 2; |
| 422 const bool is_rtl = run.direction == UBIDI_RTL; |
| 423 if (offset < middle) { |
| 424 return SelectionModel(LayoutIndexToTextIndex( |
| 425 run.glyph_to_char[i] + (is_rtl ? 1 : 0)), |
| 426 (is_rtl ? CURSOR_BACKWARD : CURSOR_FORWARD)); |
| 427 } |
| 428 if (offset < end) { |
| 429 return SelectionModel(LayoutIndexToTextIndex( |
| 430 run.glyph_to_char[i] + (is_rtl ? 0 : 1)), |
| 431 (is_rtl ? CURSOR_FORWARD : CURSOR_BACKWARD)); |
| 432 } |
| 433 } |
| 434 return EdgeSelectionModel(CURSOR_RIGHT); |
| 435 } |
| 436 |
| 437 std::vector<RenderText::FontSpan> RenderTextHarfBuzz::GetFontSpansForTesting() { |
| 438 NOTIMPLEMENTED(); |
| 439 return std::vector<RenderText::FontSpan>(); |
| 440 } |
| 441 |
| 442 int RenderTextHarfBuzz::GetLayoutTextBaseline() { |
| 443 EnsureLayout(); |
| 444 return lines()[0].baseline; |
| 445 } |
| 446 |
| 447 SelectionModel RenderTextHarfBuzz::AdjacentCharSelectionModel( |
| 448 const SelectionModel& selection, |
| 449 VisualCursorDirection direction) { |
| 450 DCHECK(!needs_layout_); |
| 451 internal::TextRunHarfBuzz* run; |
| 452 size_t run_index = GetRunContainingCaret(selection); |
| 453 if (run_index >= runs_.size()) { |
| 454 // The cursor is not in any run: we're at the visual and logical edge. |
| 455 SelectionModel edge = EdgeSelectionModel(direction); |
| 456 if (edge.caret_pos() == selection.caret_pos()) |
| 457 return edge; |
| 458 int visual_index = (direction == CURSOR_RIGHT) ? 0 : runs_.size() - 1; |
| 459 run = runs_[visual_to_logical_[visual_index]]; |
| 460 } else { |
| 461 // If the cursor is moving within the current run, just move it by one |
| 462 // grapheme in the appropriate direction. |
| 463 run = runs_[run_index]; |
| 464 size_t caret = selection.caret_pos(); |
| 465 bool forward_motion = |
| 466 (run->direction == UBIDI_RTL) == (direction == CURSOR_LEFT); |
| 467 if (forward_motion) { |
| 468 if (caret < LayoutIndexToTextIndex(run->range.end())) { |
| 469 caret = IndexOfAdjacentGrapheme(caret, CURSOR_FORWARD); |
| 470 return SelectionModel(caret, CURSOR_BACKWARD); |
| 471 } |
| 472 } else { |
| 473 if (caret > LayoutIndexToTextIndex(run->range.start())) { |
| 474 caret = IndexOfAdjacentGrapheme(caret, CURSOR_BACKWARD); |
| 475 return SelectionModel(caret, CURSOR_FORWARD); |
| 476 } |
| 477 } |
| 478 // The cursor is at the edge of a run; move to the visually adjacent run. |
| 479 int visual_index = logical_to_visual_[run_index]; |
| 480 visual_index += (direction == CURSOR_LEFT) ? -1 : 1; |
| 481 if (visual_index < 0 || visual_index >= static_cast<int>(runs_.size())) |
| 482 return EdgeSelectionModel(direction); |
| 483 run = runs_[visual_to_logical_[visual_index]]; |
| 484 } |
| 485 bool forward_motion = |
| 486 (run->direction == UBIDI_RTL) == (direction == CURSOR_LEFT); |
| 487 return forward_motion ? FirstSelectionModelInsideRun(run) : |
| 488 LastSelectionModelInsideRun(run); |
| 489 } |
| 490 |
| 491 SelectionModel RenderTextHarfBuzz::AdjacentWordSelectionModel( |
| 492 const SelectionModel& selection, |
| 493 VisualCursorDirection direction) { |
| 494 // TODO(ckocagil): This implementation currently matches RenderTextWin, but it |
| 495 // should match the native behavior on other platforms. |
| 496 if (obscured()) |
| 497 return EdgeSelectionModel(direction); |
| 498 |
| 499 base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD); |
| 500 bool success = iter.Init(); |
| 501 DCHECK(success); |
| 502 if (!success) |
| 503 return selection; |
| 504 |
| 505 size_t pos; |
| 506 if (direction == CURSOR_RIGHT) { |
| 507 pos = std::min(selection.caret_pos() + 1, text().length()); |
| 508 while (iter.Advance()) { |
| 509 pos = iter.pos(); |
| 510 if (iter.IsWord() && pos > selection.caret_pos()) |
| 511 break; |
| 512 } |
| 513 } else { // direction == CURSOR_LEFT |
| 514 // Notes: We always iterate words from the beginning. |
| 515 // This is probably fast enough for our usage, but we may |
| 516 // want to modify WordIterator so that it can start from the |
| 517 // middle of string and advance backwards. |
| 518 pos = std::max<int>(selection.caret_pos() - 1, 0); |
| 519 while (iter.Advance()) { |
| 520 if (iter.IsWord()) { |
| 521 size_t begin = iter.pos() - iter.GetString().length(); |
| 522 if (begin == selection.caret_pos()) { |
| 523 // The cursor is at the beginning of a word. |
| 524 // Move to previous word. |
| 525 break; |
| 526 } else if (iter.pos() >= selection.caret_pos()) { |
| 527 // The cursor is in the middle or at the end of a word. |
| 528 // Move to the top of current word. |
| 529 pos = begin; |
| 530 break; |
| 531 } |
| 532 pos = iter.pos() - iter.GetString().length(); |
| 533 } |
| 534 } |
| 535 } |
| 536 return SelectionModel(pos, CURSOR_FORWARD); |
| 537 } |
| 538 |
| 539 Range RenderTextHarfBuzz::GetGlyphBounds(size_t index) { |
| 540 const size_t run_index = |
| 541 GetRunContainingCaret(SelectionModel(index, CURSOR_FORWARD)); |
| 542 // Return edge bounds if the index is invalid or beyond the layout text size. |
| 543 if (run_index >= runs_.size()) |
| 544 return Range(GetStringSize().width()); |
| 545 const size_t layout_index = TextIndexToLayoutIndex(index); |
| 546 return Range(runs_[run_index]->GetGlyphXBoundary(layout_index, false), |
| 547 runs_[run_index]->GetGlyphXBoundary(layout_index, true)); |
| 548 } |
| 549 |
| 550 std::vector<Rect> RenderTextHarfBuzz::GetSubstringBounds(const Range& range) { |
| 551 DCHECK(!needs_layout_); |
| 552 DCHECK(Range(0, text().length()).Contains(range)); |
| 553 Range layout_range(TextIndexToLayoutIndex(range.start()), |
| 554 TextIndexToLayoutIndex(range.end())); |
| 555 DCHECK(Range(0, GetLayoutText().length()).Contains(layout_range)); |
| 556 |
| 557 std::vector<Rect> rects; |
| 558 if (layout_range.is_empty()) |
| 559 return rects; |
| 560 std::vector<Range> bounds; |
| 561 |
| 562 // Add a Range for each run/selection intersection. |
| 563 // TODO(msw): The bounds should probably not always be leading the range ends. |
| 564 for (size_t i = 0; i < runs_.size(); ++i) { |
| 565 const internal::TextRunHarfBuzz* run = runs_[visual_to_logical_[i]]; |
| 566 Range intersection = run->range.Intersect(layout_range); |
| 567 if (intersection.IsValid()) { |
| 568 DCHECK(!intersection.is_reversed()); |
| 569 Range range_x(run->GetGlyphXBoundary(intersection.start(), false), |
| 570 run->GetGlyphXBoundary(intersection.end(), false)); |
| 571 if (range_x.is_empty()) |
| 572 continue; |
| 573 range_x = Range(range_x.GetMin(), range_x.GetMax()); |
| 574 // Union this with the last range if they're adjacent. |
| 575 DCHECK(bounds.empty() || bounds.back().GetMax() <= range_x.GetMin()); |
| 576 if (!bounds.empty() && bounds.back().GetMax() == range_x.GetMin()) { |
| 577 range_x = Range(bounds.back().GetMin(), range_x.GetMax()); |
| 578 bounds.pop_back(); |
| 579 } |
| 580 bounds.push_back(range_x); |
| 581 } |
| 582 } |
| 583 for (size_t i = 0; i < bounds.size(); ++i) { |
| 584 std::vector<Rect> current_rects = TextBoundsToViewBounds(bounds[i]); |
| 585 rects.insert(rects.end(), current_rects.begin(), current_rects.end()); |
| 586 } |
| 587 return rects; |
| 588 } |
| 589 |
| 590 size_t RenderTextHarfBuzz::TextIndexToLayoutIndex(size_t index) const { |
| 591 DCHECK_LE(index, text().length()); |
| 592 ptrdiff_t i = obscured() ? UTF16IndexToOffset(text(), 0, index) : index; |
| 593 CHECK_GE(i, 0); |
| 594 // Clamp layout indices to the length of the text actually used for layout. |
| 595 return std::min<size_t>(GetLayoutText().length(), i); |
| 596 } |
| 597 |
| 598 size_t RenderTextHarfBuzz::LayoutIndexToTextIndex(size_t index) const { |
| 599 if (!obscured()) |
| 600 return index; |
| 601 |
| 602 DCHECK_LE(index, GetLayoutText().length()); |
| 603 const size_t text_index = UTF16OffsetToIndex(text(), 0, index); |
| 604 DCHECK_LE(text_index, text().length()); |
| 605 return text_index; |
| 606 } |
| 607 |
| 608 bool RenderTextHarfBuzz::IsValidCursorIndex(size_t index) { |
| 609 if (index == 0 || index == text().length()) |
| 610 return true; |
| 611 if (!IsValidLogicalIndex(index)) |
| 612 return false; |
| 613 EnsureLayout(); |
| 614 // Disallow indices amid multi-character graphemes by checking glyph bounds. |
| 615 // These characters are not surrogate-pairs, but may yield a single glyph: |
| 616 // \x0915\x093f - (ki) - one of many Devanagari biconsonantal conjuncts. |
| 617 // \x0e08\x0e33 - (cho chan + sara am) - a Thai consonant and vowel pair. |
| 618 return GetGlyphBounds(index) != GetGlyphBounds(index - 1); |
| 619 } |
| 620 |
| 621 void RenderTextHarfBuzz::ResetLayout() { |
| 622 needs_layout_ = true; |
| 623 } |
| 624 |
| 625 void RenderTextHarfBuzz::EnsureLayout() { |
| 626 if (needs_layout_) { |
| 627 runs_.clear(); |
| 628 |
| 629 if (!GetLayoutText().empty()) { |
| 630 ItemizeText(); |
| 631 |
| 632 for (size_t i = 0; i < runs_.size(); ++i) |
| 633 ShapeRun(runs_[i]); |
| 634 |
| 635 // Precalculate run width information. |
| 636 size_t preceding_run_widths = 0; |
| 637 for (size_t i = 0; i < runs_.size(); ++i) { |
| 638 internal::TextRunHarfBuzz* run = runs_[visual_to_logical_[i]]; |
| 639 run->preceding_run_widths = preceding_run_widths; |
| 640 preceding_run_widths += run->width; |
| 641 } |
| 642 } |
| 643 |
| 644 needs_layout_ = false; |
| 645 std::vector<internal::Line> empty_lines; |
| 646 set_lines(&empty_lines); |
| 647 } |
| 648 |
| 649 if (lines().empty()) { |
| 650 std::vector<internal::Line> lines; |
| 651 lines.push_back(internal::Line()); |
| 652 |
| 653 int current_x = 0; |
| 654 SkPaint paint; |
| 655 |
| 656 for (size_t i = 0; i < runs_.size(); ++i) { |
| 657 const internal::TextRunHarfBuzz& run = *runs_[visual_to_logical_[i]]; |
| 658 internal::LineSegment segment; |
| 659 segment.x_range = Range(current_x, current_x + run.width); |
| 660 segment.char_range = run.range; |
| 661 segment.run = i; |
| 662 lines[0].segments.push_back(segment); |
| 663 |
| 664 paint.setTypeface(run.skia_face.get()); |
| 665 paint.setTextSize(run.font_size); |
| 666 SkPaint::FontMetrics metrics; |
| 667 paint.getFontMetrics(&metrics); |
| 668 |
| 669 lines[0].size.set_width(lines[0].size.width() + run.width); |
| 670 lines[0].size.set_height(std::max(lines[0].size.height(), |
| 671 SkScalarRoundToInt(metrics.fDescent - metrics.fAscent))); |
| 672 lines[0].baseline = std::max(lines[0].baseline, |
| 673 SkScalarRoundToInt(-metrics.fAscent)); |
| 674 } |
| 675 |
| 676 set_lines(&lines); |
| 677 } |
| 678 } |
| 679 |
| 680 void RenderTextHarfBuzz::DrawVisualText(Canvas* canvas) { |
| 681 DCHECK(!needs_layout_); |
| 682 |
| 683 int current_x = 0; |
| 684 |
| 685 internal::SkiaTextRenderer renderer(canvas); |
| 686 ApplyFadeEffects(&renderer); |
| 687 ApplyTextShadows(&renderer); |
| 688 |
| 689 #if defined(OS_WIN) |
| 690 bool smoothing_enabled; |
| 691 bool cleartype_enabled; |
| 692 GetCachedFontSmoothingSettings(&smoothing_enabled, &cleartype_enabled); |
| 693 // Note that |cleartype_enabled| corresponds to Skia's |enable_lcd_text|. |
| 694 renderer.SetFontSmoothingSettings( |
| 695 smoothing_enabled, cleartype_enabled && !background_is_transparent(), |
| 696 smoothing_enabled /* subpixel_positioning */); |
| 697 #endif |
| 698 |
| 699 ApplyCompositionAndSelectionStyles(); |
| 700 |
| 701 const Vector2d line_offset = GetLineOffset(0); |
| 702 |
| 703 for (size_t i = 0; i < runs_.size(); ++i) { |
| 704 const internal::TextRunHarfBuzz& run = *runs_[visual_to_logical_[i]]; |
| 705 renderer.SetTypeface(run.skia_face.get()); |
| 706 renderer.SetTextSize(run.font_size); |
| 707 |
| 708 canvas->Save(); |
| 709 Vector2d origin = line_offset + Vector2d(current_x, lines()[0].baseline); |
| 710 canvas->Translate(origin); |
| 711 |
| 712 for (BreakList<SkColor>::const_iterator it = |
| 713 colors().GetBreak(run.range.start()); |
| 714 it != colors().breaks().end() && it->first < run.range.end(); |
| 715 ++it) { |
| 716 const Range intersection = colors().GetRange(it).Intersect(run.range); |
| 717 const Range colored_glyphs = run.CharRangeToGlyphRange(intersection); |
| 718 // The range may be empty if a portion of a multi-character grapheme is |
| 719 // selected, yielding two colors for a single glyph. For now, this just |
| 720 // paints the glyph with a single style, but it should paint it twice, |
| 721 // clipped according to selection bounds. See http://crbug.com/366786 |
| 722 if (colored_glyphs.is_empty()) |
| 723 continue; |
| 724 |
| 725 renderer.SetForegroundColor(it->second); |
| 726 renderer.DrawPosText(&run.positions[colored_glyphs.start()], |
| 727 &run.glyphs[colored_glyphs.start()], |
| 728 colored_glyphs.length()); |
| 729 int width = (colored_glyphs.end() == run.glyph_count ? run.width : |
| 730 run.positions[colored_glyphs.end()].x()) - |
| 731 run.positions[colored_glyphs.start()].x(); |
| 732 renderer.DrawDecorations(0, 0, width, run.underline, run.strike, |
| 733 run.diagonal_strike); |
| 734 } |
| 735 |
| 736 canvas->Restore(); |
| 737 current_x += run.width; |
| 738 } |
| 739 |
| 740 renderer.EndDiagonalStrike(); |
| 741 |
| 742 UndoCompositionAndSelectionStyles(); |
| 743 } |
| 744 |
| 745 size_t RenderTextHarfBuzz::GetRunContainingCaret( |
| 746 const SelectionModel& caret) const { |
| 747 DCHECK(!needs_layout_); |
| 748 size_t layout_position = TextIndexToLayoutIndex(caret.caret_pos()); |
| 749 LogicalCursorDirection affinity = caret.caret_affinity(); |
| 750 for (size_t run = 0; run < runs_.size(); ++run) { |
| 751 if (RangeContainsCaret(runs_[run]->range, layout_position, affinity)) |
| 752 return run; |
| 753 } |
| 754 return runs_.size(); |
| 755 } |
| 756 |
| 757 size_t RenderTextHarfBuzz::GetRunContainingXCoord(int x, int* offset) const { |
| 758 DCHECK(!needs_layout_); |
| 759 if (x < 0) |
| 760 return runs_.size(); |
| 761 // Find the text run containing the argument point (assumed already offset). |
| 762 int current_x = 0; |
| 763 for (size_t i = 0; i < runs_.size(); ++i) { |
| 764 size_t run = visual_to_logical_[i]; |
| 765 current_x += runs_[run]->width; |
| 766 if (x < current_x) { |
| 767 *offset = x - (current_x - runs_[run]->width); |
| 768 return run; |
| 769 } |
| 770 } |
| 771 return runs_.size(); |
| 772 } |
| 773 |
| 774 SelectionModel RenderTextHarfBuzz::FirstSelectionModelInsideRun( |
| 775 const internal::TextRunHarfBuzz* run) { |
| 776 size_t position = LayoutIndexToTextIndex(run->range.start()); |
| 777 position = IndexOfAdjacentGrapheme(position, CURSOR_FORWARD); |
| 778 return SelectionModel(position, CURSOR_BACKWARD); |
| 779 } |
| 780 |
| 781 SelectionModel RenderTextHarfBuzz::LastSelectionModelInsideRun( |
| 782 const internal::TextRunHarfBuzz* run) { |
| 783 size_t position = LayoutIndexToTextIndex(run->range.end()); |
| 784 position = IndexOfAdjacentGrapheme(position, CURSOR_BACKWARD); |
| 785 return SelectionModel(position, CURSOR_FORWARD); |
| 786 } |
| 787 |
| 788 void RenderTextHarfBuzz::ItemizeText() { |
| 789 const base::string16& text = GetLayoutText(); |
| 790 const bool is_rtl = GetTextDirection() == base::i18n::RIGHT_TO_LEFT; |
| 791 DCHECK_NE(0U, text.length()); |
| 792 |
| 793 // If ICU fails to itemize the text, we set |fake_runs| and create a run that |
| 794 // spans the entire text. This is needed because early returning and leaving |
| 795 // the runs set empty causes some clients to crash/misbehave since they expect |
| 796 // non-zero text metrics from a non-empty text. |
| 797 bool fake_runs = false; |
| 798 UErrorCode result = U_ZERO_ERROR; |
| 799 |
| 800 UBiDi* line = ubidi_openSized(text.length(), 0, &result); |
| 801 if (U_FAILURE(result)) { |
| 802 NOTREACHED(); |
| 803 fake_runs = true; |
| 804 } else { |
| 805 ubidi_setPara(line, text.c_str(), text.length(), |
| 806 is_rtl ? UBIDI_DEFAULT_RTL : UBIDI_DEFAULT_LTR, NULL, |
| 807 &result); |
| 808 if (U_FAILURE(result)) { |
| 809 NOTREACHED(); |
| 810 fake_runs = true; |
| 811 } |
| 812 } |
| 813 |
| 814 // Temporarily apply composition underlines and selection colors. |
| 815 ApplyCompositionAndSelectionStyles(); |
| 816 |
| 817 // Build the list of runs from the script items and ranged styles. Use an |
| 818 // empty color BreakList to avoid breaking runs at color boundaries. |
| 819 BreakList<SkColor> empty_colors; |
| 820 empty_colors.SetMax(text.length()); |
| 821 internal::StyleIterator style(empty_colors, styles()); |
| 822 |
| 823 for (size_t run_break = 0; run_break < text.length();) { |
| 824 internal::TextRunHarfBuzz* run = new internal::TextRunHarfBuzz; |
| 825 run->range.set_start(run_break); |
| 826 run->font_style = (style.style(BOLD) ? Font::BOLD : 0) | |
| 827 (style.style(ITALIC) ? Font::ITALIC : 0); |
| 828 run->strike = style.style(STRIKE); |
| 829 run->diagonal_strike = style.style(DIAGONAL_STRIKE); |
| 830 run->underline = style.style(UNDERLINE); |
| 831 |
| 832 if (fake_runs) { |
| 833 run_break = text.length(); |
| 834 } else { |
| 835 int32 script_item_break = 0; |
| 836 ubidi_getLogicalRun(line, run_break, &script_item_break, &run->level); |
| 837 // Find the length and script of this script run. |
| 838 script_item_break = ScriptInterval(text, run_break, |
| 839 script_item_break - run_break, &run->script) + run_break; |
| 840 |
| 841 // Find the next break and advance the iterators as needed. |
| 842 run_break = std::min(static_cast<size_t>(script_item_break), |
| 843 TextIndexToLayoutIndex(style.GetRange().end())); |
| 844 |
| 845 // Break runs adjacent to character substrings in certain code blocks. |
| 846 // This avoids using their fallback fonts for more characters than needed, |
| 847 // in cases like "\x25B6 Media Title", etc. http://crbug.com/278913 |
| 848 if (run_break > run->range.start()) { |
| 849 const size_t run_start = run->range.start(); |
| 850 const int32 run_length = static_cast<int32>(run_break - run_start); |
| 851 base::i18n::UTF16CharIterator iter(text.c_str() + run_start, |
| 852 run_length); |
| 853 const UBlockCode first_block_code = ublock_getCode(iter.get()); |
| 854 const bool first_block_unusual = IsUnusualBlockCode(first_block_code); |
| 855 while (iter.Advance() && iter.array_pos() < run_length) { |
| 856 const UBlockCode current_block_code = ublock_getCode(iter.get()); |
| 857 if (current_block_code != first_block_code && |
| 858 (first_block_unusual || IsUnusualBlockCode(current_block_code))) { |
| 859 run_break = run_start + iter.array_pos(); |
| 860 break; |
| 861 } |
| 862 } |
| 863 } |
| 864 } |
| 865 |
| 866 DCHECK(IsValidCodePointIndex(text, run_break)); |
| 867 style.UpdatePosition(LayoutIndexToTextIndex(run_break)); |
| 868 run->range.set_end(run_break); |
| 869 const UChar* uchar_start = ubidi_getText(line); |
| 870 // TODO(ckocagil): Add |ubidi_getBaseDirection| to i18n::BiDiLineIterator |
| 871 // and remove the bare ICU use here. |
| 872 run->direction = ubidi_getBaseDirection(uchar_start + run->range.start(), |
| 873 run->range.length()); |
| 874 if (run->direction == UBIDI_NEUTRAL) |
| 875 run->direction = is_rtl ? UBIDI_RTL : UBIDI_LTR; |
| 876 runs_.push_back(run); |
| 877 } |
| 878 |
| 879 ubidi_close(line); |
| 880 |
| 881 // Undo the temporarily applied composition underlines and selection colors. |
| 882 UndoCompositionAndSelectionStyles(); |
| 883 |
| 884 const size_t num_runs = runs_.size(); |
| 885 std::vector<UBiDiLevel> levels(num_runs); |
| 886 for (size_t i = 0; i < num_runs; ++i) |
| 887 levels[i] = runs_[i]->level; |
| 888 visual_to_logical_.resize(num_runs); |
| 889 ubidi_reorderVisual(&levels[0], num_runs, &visual_to_logical_[0]); |
| 890 logical_to_visual_.resize(num_runs); |
| 891 ubidi_reorderLogical(&levels[0], num_runs, &logical_to_visual_[0]); |
| 892 } |
| 893 |
| 894 void RenderTextHarfBuzz::ShapeRun(internal::TextRunHarfBuzz* run) { |
| 895 const base::string16& text = GetLayoutText(); |
| 896 // TODO(ckocagil|yukishiino): Implement font fallback. |
| 897 const Font& primary_font = font_list().GetPrimaryFont(); |
| 898 run->skia_face = internal::CreateSkiaTypeface(primary_font.GetFontName(), |
| 899 run->font_style); |
| 900 run->font_size = primary_font.GetFontSize(); |
| 901 |
| 902 hb_font_t* harfbuzz_font = CreateHarfBuzzFont(run->skia_face.get(), |
| 903 run->font_size); |
| 904 |
| 905 // Create a HarfBuzz buffer and add the string to be shaped. The HarfBuzz |
| 906 // buffer holds our text, run information to be used by the shaping engine, |
| 907 // and the resulting glyph data. |
| 908 hb_buffer_t* buffer = hb_buffer_create(); |
| 909 hb_buffer_add_utf16(buffer, reinterpret_cast<const uint16*>(text.c_str()), |
| 910 text.length(), run->range.start(), run->range.length()); |
| 911 hb_buffer_set_script(buffer, hb_icu_script_to_script(run->script)); |
| 912 hb_buffer_set_direction(buffer, |
| 913 run->direction == UBIDI_LTR ? HB_DIRECTION_LTR : HB_DIRECTION_RTL); |
| 914 // TODO(ckocagil): Should we determine the actual language? |
| 915 hb_buffer_set_language(buffer, hb_language_get_default()); |
| 916 |
| 917 // Shape the text. |
| 918 hb_shape(harfbuzz_font, buffer, NULL, 0); |
| 919 |
| 920 // Populate the run fields with the resulting glyph data in the buffer. |
| 921 unsigned int glyph_count = 0; |
| 922 hb_glyph_info_t* infos = hb_buffer_get_glyph_infos(buffer, &glyph_count); |
| 923 hb_glyph_position_t* hb_positions = hb_buffer_get_glyph_positions(buffer, |
| 924 NULL); |
| 925 run->glyph_count = glyph_count; |
| 926 run->glyphs.reset(new uint16[run->glyph_count]); |
| 927 run->glyph_to_char.reset(new uint32[run->glyph_count]); |
| 928 run->positions.reset(new SkPoint[run->glyph_count]); |
| 929 for (size_t i = 0; i < run->glyph_count; ++i) { |
| 930 run->glyphs[i] = infos[i].codepoint; |
| 931 run->glyph_to_char[i] = infos[i].cluster; |
| 932 const int x_offset = |
| 933 SkScalarRoundToInt(SkFixedToScalar(hb_positions[i].x_offset)); |
| 934 const int y_offset = |
| 935 SkScalarRoundToInt(SkFixedToScalar(hb_positions[i].y_offset)); |
| 936 run->positions[i].set(run->width + x_offset, y_offset); |
| 937 run->width += |
| 938 SkScalarRoundToInt(SkFixedToScalar(hb_positions[i].x_advance)); |
| 939 } |
| 940 |
| 941 hb_buffer_destroy(buffer); |
| 942 hb_font_destroy(harfbuzz_font); |
| 943 } |
| 944 |
| 945 } // namespace gfx |
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