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Issue 891013003: Delete RenderTextWin and RenderTextPango. (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: update switch comment Created 5 years, 10 months ago
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1 // Copyright (c) 2012 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_win.h"
6
7 #include <algorithm>
8
9 #include "base/i18n/break_iterator.h"
10 #include "base/i18n/char_iterator.h"
11 #include "base/i18n/rtl.h"
12 #include "base/logging.h"
13 #include "base/strings/string_util.h"
14 #include "base/strings/utf_string_conversions.h"
15 #include "base/win/windows_version.h"
16 #include "third_party/icu/source/common/unicode/uchar.h"
17 #include "ui/gfx/canvas.h"
18 #include "ui/gfx/font_fallback_win.h"
19 #include "ui/gfx/font_render_params.h"
20 #include "ui/gfx/geometry/size_conversions.h"
21 #include "ui/gfx/platform_font_win.h"
22 #include "ui/gfx/utf16_indexing.h"
23
24 namespace gfx {
25
26 namespace {
27
28 // The maximum length of text supported for Uniscribe layout and display.
29 // This empirically chosen value should prevent major performance degradations.
30 // TODO(msw): Support longer text, partial layout/painting, etc.
31 const size_t kMaxUniscribeTextLength = 10000;
32
33 // The initial guess and maximum supported number of runs; arbitrary values.
34 // TODO(msw): Support more runs, determine a better initial guess, etc.
35 const int kGuessRuns = 100;
36 const size_t kMaxRuns = 10000;
37
38 // The maximum number of glyphs per run; ScriptShape fails on larger values.
39 const size_t kMaxGlyphs = 65535;
40
41 // Changes |font| to have the specified |font_size| (or |font_height| on Windows
42 // XP) and |font_style| if it is not the case already. Only considers bold and
43 // italic styles, since the underlined style has no effect on glyph shaping.
44 void DeriveFontIfNecessary(int font_size,
45 int font_height,
46 int font_style,
47 Font* font) {
48 const int kStyleMask = (Font::BOLD | Font::ITALIC);
49 const int target_style = (font_style & kStyleMask);
50
51 // On Windows XP, the font must be resized using |font_height| instead of
52 // |font_size| to match GDI behavior.
53 if (base::win::GetVersion() < base::win::VERSION_VISTA) {
54 PlatformFontWin* platform_font =
55 static_cast<PlatformFontWin*>(font->platform_font());
56 *font = platform_font->DeriveFontWithHeight(font_height, target_style);
57 return;
58 }
59
60 const int current_style = (font->GetStyle() & kStyleMask);
61 const int current_size = font->GetFontSize();
62 if (current_style != target_style || current_size != font_size)
63 *font = font->Derive(font_size - current_size, target_style);
64 }
65
66 // Returns true if |c| is a Unicode BiDi control character.
67 bool IsUnicodeBidiControlCharacter(base::char16 c) {
68 return c == base::i18n::kRightToLeftMark ||
69 c == base::i18n::kLeftToRightMark ||
70 c == base::i18n::kLeftToRightEmbeddingMark ||
71 c == base::i18n::kRightToLeftEmbeddingMark ||
72 c == base::i18n::kPopDirectionalFormatting ||
73 c == base::i18n::kLeftToRightOverride ||
74 c == base::i18n::kRightToLeftOverride;
75 }
76
77 // Returns the corresponding glyph range of the given character range.
78 // |range| is in text-space (0 corresponds to |GetLayoutText()[0]|).
79 // Returned value is in run-space (0 corresponds to the first glyph in the run).
80 Range CharRangeToGlyphRange(const internal::TextRun& run,
81 const Range& range) {
82 DCHECK(run.range.Contains(range));
83 DCHECK(!range.is_reversed());
84 DCHECK(!range.is_empty());
85 const Range run_range(range.start() - run.range.start(),
86 range.end() - run.range.start());
87 Range result;
88 if (run.script_analysis.fRTL) {
89 result = Range(run.logical_clusters[run_range.end() - 1],
90 run_range.start() > 0 ? run.logical_clusters[run_range.start() - 1]
91 : run.glyph_count);
92 } else {
93 result = Range(run.logical_clusters[run_range.start()],
94 run_range.end() < run.range.length() ?
95 run.logical_clusters[run_range.end()] : run.glyph_count);
96 }
97 DCHECK(!result.is_reversed());
98 DCHECK(Range(0, run.glyph_count).Contains(result));
99 return result;
100 }
101
102 // Starting from |start_char|, finds a suitable line break position at or before
103 // |available_width| using word break info from |breaks|. If |empty_line| is
104 // true, this function will not roll back to |start_char| and |*next_char| will
105 // be greater than |start_char| (to avoid constructing empty lines). Returns
106 // whether to skip the line before |*next_char|.
107 // TODO(ckocagil): Do not break ligatures and diacritics.
108 // TextRun::logical_clusters might help.
109 // TODO(ckocagil): We might have to reshape after breaking at ligatures.
110 // See whether resolving the TODO above resolves this too.
111 // TODO(ckocagil): Do not reserve width for whitespace at the end of lines.
112 bool BreakRunAtWidth(const wchar_t* text,
113 const internal::TextRun& run,
114 const BreakList<size_t>& breaks,
115 size_t start_char,
116 int available_width,
117 bool empty_line,
118 int* width,
119 size_t* next_char) {
120 DCHECK(run.range.Contains(Range(start_char, start_char + 1)));
121 BreakList<size_t>::const_iterator word = breaks.GetBreak(start_char);
122 BreakList<size_t>::const_iterator next_word = word + 1;
123 // Width from |std::max(word->first, start_char)| to the current character.
124 int word_width = 0;
125 *width = 0;
126
127 for (size_t i = start_char; i < run.range.end(); ++i) {
128 if (U16_IS_SINGLE(text[i]) && text[i] == L'\n') {
129 *next_char = i + 1;
130 return true;
131 }
132
133 // |word| holds the word boundary at or before |i|, and |next_word| holds
134 // the word boundary right after |i|. Advance both |word| and |next_word|
135 // when |i| reaches |next_word|.
136 if (next_word != breaks.breaks().end() && i >= next_word->first) {
137 word = next_word++;
138 word_width = 0;
139 }
140
141 Range glyph_range = CharRangeToGlyphRange(run, Range(i, i + 1));
142 int char_width = 0;
143 for (size_t j = glyph_range.start(); j < glyph_range.end(); ++j)
144 char_width += run.advance_widths[j];
145
146 *width += char_width;
147 word_width += char_width;
148
149 if (*width > available_width) {
150 if (!empty_line || word_width < *width) {
151 // Roll back one word.
152 *width -= word_width;
153 *next_char = std::max(word->first, start_char);
154 } else if (char_width < *width) {
155 // Roll back one character.
156 *width -= char_width;
157 *next_char = i;
158 } else {
159 // Continue from the next character.
160 *next_char = i + 1;
161 }
162
163 return true;
164 }
165 }
166
167 *next_char = run.range.end();
168 return false;
169 }
170
171 // For segments in the same run, checks the continuity and order of |x_range|
172 // and |char_range| fields.
173 void CheckLineIntegrity(const std::vector<internal::Line>& lines,
174 const ScopedVector<internal::TextRun>& runs) {
175 size_t previous_segment_line = 0;
176 const internal::LineSegment* previous_segment = NULL;
177
178 for (size_t i = 0; i < lines.size(); ++i) {
179 for (size_t j = 0; j < lines[i].segments.size(); ++j) {
180 const internal::LineSegment* segment = &lines[i].segments[j];
181 internal::TextRun* run = runs[segment->run];
182
183 if (!previous_segment) {
184 previous_segment = segment;
185 } else if (runs[previous_segment->run] != run) {
186 previous_segment = NULL;
187 } else {
188 DCHECK_EQ(previous_segment->char_range.end(),
189 segment->char_range.start());
190 if (!run->script_analysis.fRTL) {
191 DCHECK_EQ(previous_segment->x_range.end(), segment->x_range.start());
192 } else {
193 DCHECK_EQ(segment->x_range.end(), previous_segment->x_range.start());
194 }
195
196 previous_segment = segment;
197 previous_segment_line = i;
198 }
199 }
200 }
201 }
202
203 // Returns true if characters of |block_code| may trigger font fallback.
204 bool IsUnusualBlockCode(const UBlockCode block_code) {
205 return block_code == UBLOCK_GEOMETRIC_SHAPES ||
206 block_code == UBLOCK_MISCELLANEOUS_SYMBOLS;
207 }
208
209 // Returns the index of the first unusual character after a usual character or
210 // vice versa. Unusual characters are defined by |IsUnusualBlockCode|.
211 size_t FindUnusualCharacter(const base::string16& text,
212 size_t run_start,
213 size_t run_break) {
214 const int32 run_length = static_cast<int32>(run_break - run_start);
215 base::i18n::UTF16CharIterator iter(text.c_str() + run_start,
216 run_length);
217 const UBlockCode first_block_code = ublock_getCode(iter.get());
218 const bool first_block_unusual = IsUnusualBlockCode(first_block_code);
219 while (iter.Advance() && iter.array_pos() < run_length) {
220 const UBlockCode current_block_code = ublock_getCode(iter.get());
221 if (current_block_code != first_block_code &&
222 (first_block_unusual || IsUnusualBlockCode(current_block_code))) {
223 return run_start + iter.array_pos();
224 }
225 }
226 return run_break;
227 }
228
229 } // namespace
230
231 namespace internal {
232
233 TextRun::TextRun()
234 : font_style(0),
235 strike(false),
236 diagonal_strike(false),
237 underline(false),
238 width(0),
239 preceding_run_widths(0),
240 glyph_count(0),
241 script_cache(NULL) {
242 memset(&script_analysis, 0, sizeof(script_analysis));
243 memset(&abc_widths, 0, sizeof(abc_widths));
244 }
245
246 TextRun::~TextRun() {
247 ScriptFreeCache(&script_cache);
248 }
249
250 // Returns the X coordinate of the leading or |trailing| edge of the glyph
251 // starting at |index|, relative to the left of the text (not the view).
252 int GetGlyphXBoundary(const internal::TextRun* run,
253 size_t index,
254 bool trailing) {
255 DCHECK_GE(index, run->range.start());
256 DCHECK_LT(index, run->range.end() + (trailing ? 0 : 1));
257 int x = 0;
258 HRESULT hr = ScriptCPtoX(
259 index - run->range.start(),
260 trailing,
261 run->range.length(),
262 run->glyph_count,
263 run->logical_clusters.get(),
264 run->visible_attributes.get(),
265 run->advance_widths.get(),
266 &run->script_analysis,
267 &x);
268 DCHECK(SUCCEEDED(hr));
269 return run->preceding_run_widths + x;
270 }
271
272 // Internal class to generate Line structures. If |multiline| is true, the text
273 // is broken into lines at |words| boundaries such that each line is no longer
274 // than |max_width|. If |multiline| is false, only outputs a single Line from
275 // the given runs. |min_baseline| and |min_height| are the minimum baseline and
276 // height for each line.
277 // TODO(ckocagil): Expose the interface of this class in the header and test
278 // this class directly.
279 class LineBreaker {
280 public:
281 LineBreaker(int max_width,
282 int min_baseline,
283 int min_height,
284 bool multiline,
285 const wchar_t* text,
286 const BreakList<size_t>* words,
287 const ScopedVector<TextRun>& runs)
288 : max_width_(max_width),
289 min_baseline_(min_baseline),
290 min_height_(min_height),
291 multiline_(multiline),
292 text_(text),
293 words_(words),
294 runs_(runs),
295 text_x_(0),
296 line_x_(0),
297 line_ascent_(0),
298 line_descent_(0) {
299 AdvanceLine();
300 }
301
302 // Breaks the run at given |run_index| into Line structs.
303 void AddRun(int run_index) {
304 const TextRun* run = runs_[run_index];
305 bool run_fits = !multiline_;
306 if (multiline_ && line_x_ + run->width <= max_width_) {
307 DCHECK(!run->range.is_empty());
308 const wchar_t first_char = text_[run->range.start()];
309 // Uniscribe always puts newline characters in their own runs.
310 if (!U16_IS_SINGLE(first_char) || first_char != L'\n')
311 run_fits = true;
312 }
313
314 if (!run_fits)
315 BreakRun(run_index);
316 else
317 AddSegment(run_index, run->range, run->width);
318 }
319
320 // Finishes line breaking and outputs the results. Can be called at most once.
321 void Finalize(std::vector<Line>* lines, Size* size) {
322 DCHECK(!lines_.empty());
323 // Add an empty line to finish the line size calculation and remove it.
324 AdvanceLine();
325 lines_.pop_back();
326 *size = total_size_;
327 lines->swap(lines_);
328 }
329
330 private:
331 // A (line index, segment index) pair that specifies a segment in |lines_|.
332 typedef std::pair<size_t, size_t> SegmentHandle;
333
334 LineSegment* SegmentFromHandle(const SegmentHandle& handle) {
335 return &lines_[handle.first].segments[handle.second];
336 }
337
338 // Breaks a run into segments that fit in the last line in |lines_| and adds
339 // them. Adds a new Line to the back of |lines_| whenever a new segment can't
340 // be added without the Line's width exceeding |max_width_|.
341 void BreakRun(int run_index) {
342 DCHECK(words_);
343 const TextRun* const run = runs_[run_index];
344 int width = 0;
345 size_t next_char = run->range.start();
346
347 // Break the run until it fits the current line.
348 while (next_char < run->range.end()) {
349 const size_t current_char = next_char;
350 const bool skip_line = BreakRunAtWidth(text_, *run, *words_, current_char,
351 max_width_ - line_x_, line_x_ == 0, &width, &next_char);
352 AddSegment(run_index, Range(current_char, next_char), width);
353 if (skip_line)
354 AdvanceLine();
355 }
356 }
357
358 // RTL runs are broken in logical order but displayed in visual order. To find
359 // the text-space coordinate (where it would fall in a single-line text)
360 // |x_range| of RTL segments, segment widths are applied in reverse order.
361 // e.g. {[5, 10], [10, 40]} will become {[35, 40], [5, 35]}.
362 void UpdateRTLSegmentRanges() {
363 if (rtl_segments_.empty())
364 return;
365 int x = SegmentFromHandle(rtl_segments_[0])->x_range.start();
366 for (size_t i = rtl_segments_.size(); i > 0; --i) {
367 LineSegment* segment = SegmentFromHandle(rtl_segments_[i - 1]);
368 const size_t segment_width = segment->x_range.length();
369 segment->x_range = Range(x, x + segment_width);
370 x += segment_width;
371 }
372 rtl_segments_.clear();
373 }
374
375 // Finishes the size calculations of the last Line in |lines_|. Adds a new
376 // Line to the back of |lines_|.
377 void AdvanceLine() {
378 if (!lines_.empty()) {
379 Line* line = &lines_.back();
380 // TODO(ckocagil): Determine optimal multiline height behavior.
381 if (line_ascent_ + line_descent_ == 0) {
382 line_ascent_ = min_baseline_;
383 line_descent_ = min_height_ - min_baseline_;
384 }
385 // Set the single-line mode Line's metrics to be at least
386 // |RenderText::font_list()| to not break the current single-line code.
387 line_ascent_ = std::max(line_ascent_, min_baseline_);
388 line_descent_ = std::max(line_descent_, min_height_ - min_baseline_);
389
390 line->baseline = line_ascent_;
391 line->size.set_height(line_ascent_ + line_descent_);
392 line->preceding_heights = total_size_.height();
393 const Size line_size(ToCeiledSize(line->size));
394 total_size_.set_height(total_size_.height() + line_size.height());
395 total_size_.set_width(std::max(total_size_.width(), line_size.width()));
396 }
397 line_x_ = 0;
398 line_ascent_ = 0;
399 line_descent_ = 0;
400 lines_.push_back(Line());
401 }
402
403 // Adds a new segment with the given properties to |lines_.back()|.
404 void AddSegment(int run_index, Range char_range, int width) {
405 if (char_range.is_empty()) {
406 DCHECK_EQ(width, 0);
407 return;
408 }
409 const TextRun* run = runs_[run_index];
410 line_ascent_ = std::max(line_ascent_, run->font.GetBaseline());
411 line_descent_ = std::max(line_descent_,
412 run->font.GetHeight() - run->font.GetBaseline());
413
414 LineSegment segment;
415 segment.run = run_index;
416 segment.char_range = char_range;
417 segment.x_range = Range(text_x_, text_x_ + width);
418
419 Line* line = &lines_.back();
420 line->segments.push_back(segment);
421 line->size.set_width(line->size.width() + segment.x_range.length());
422 if (run->script_analysis.fRTL) {
423 rtl_segments_.push_back(SegmentHandle(lines_.size() - 1,
424 line->segments.size() - 1));
425 // If this is the last segment of an RTL run, reprocess the text-space x
426 // ranges of all segments from the run.
427 if (char_range.end() == run->range.end())
428 UpdateRTLSegmentRanges();
429 }
430 text_x_ += width;
431 line_x_ += width;
432 }
433
434 const int max_width_;
435 const int min_baseline_;
436 const int min_height_;
437 const bool multiline_;
438 const wchar_t* text_;
439 const BreakList<size_t>* const words_;
440 const ScopedVector<TextRun>& runs_;
441
442 // Stores the resulting lines.
443 std::vector<Line> lines_;
444
445 // Text space and line space x coordinates of the next segment to be added.
446 int text_x_;
447 int line_x_;
448
449 // Size of the multiline text, not including the currently processed line.
450 Size total_size_;
451
452 // Ascent and descent values of the current line, |lines_.back()|.
453 int line_ascent_;
454 int line_descent_;
455
456 // The current RTL run segments, to be applied by |UpdateRTLSegmentRanges()|.
457 std::vector<SegmentHandle> rtl_segments_;
458
459 DISALLOW_COPY_AND_ASSIGN(LineBreaker);
460 };
461
462 } // namespace internal
463
464 // static
465 HDC RenderTextWin::cached_hdc_ = NULL;
466
467 // static
468 std::map<std::string, Font> RenderTextWin::successful_substitute_fonts_;
469
470 RenderTextWin::RenderTextWin() : RenderText(), needs_layout_(false) {
471 set_truncate_length(kMaxUniscribeTextLength);
472 memset(&script_control_, 0, sizeof(script_control_));
473 memset(&script_state_, 0, sizeof(script_state_));
474 MoveCursorTo(EdgeSelectionModel(CURSOR_LEFT));
475 }
476
477 RenderTextWin::~RenderTextWin() {}
478
479 scoped_ptr<RenderText> RenderTextWin::CreateInstanceOfSameType() const {
480 return scoped_ptr<RenderTextWin>(new RenderTextWin);
481 }
482
483 Size RenderTextWin::GetStringSize() {
484 EnsureLayout();
485 return multiline_string_size_;
486 }
487
488 SelectionModel RenderTextWin::FindCursorPosition(const Point& point) {
489 if (text().empty())
490 return SelectionModel();
491
492 EnsureLayout();
493 // Find the run that contains the point and adjust the argument location.
494 int x = ToTextPoint(point).x();
495 size_t run_index = GetRunContainingXCoord(x);
496 if (run_index >= runs_.size())
497 return EdgeSelectionModel((x < 0) ? CURSOR_LEFT : CURSOR_RIGHT);
498 internal::TextRun* run = runs_[run_index];
499
500 int position = 0, trailing = 0;
501 HRESULT hr = ScriptXtoCP(x - run->preceding_run_widths,
502 run->range.length(),
503 run->glyph_count,
504 run->logical_clusters.get(),
505 run->visible_attributes.get(),
506 run->advance_widths.get(),
507 &(run->script_analysis),
508 &position,
509 &trailing);
510 DCHECK(SUCCEEDED(hr));
511 DCHECK_GE(trailing, 0);
512 position += run->range.start();
513 const size_t cursor = LayoutIndexToTextIndex(position + trailing);
514 DCHECK_LE(cursor, text().length());
515 return SelectionModel(cursor, trailing ? CURSOR_BACKWARD : CURSOR_FORWARD);
516 }
517
518 std::vector<RenderText::FontSpan> RenderTextWin::GetFontSpansForTesting() {
519 EnsureLayout();
520
521 std::vector<RenderText::FontSpan> spans;
522 for (size_t i = 0; i < runs_.size(); ++i) {
523 spans.push_back(RenderText::FontSpan(runs_[i]->font,
524 Range(LayoutIndexToTextIndex(runs_[i]->range.start()),
525 LayoutIndexToTextIndex(runs_[i]->range.end()))));
526 }
527
528 return spans;
529 }
530
531 int RenderTextWin::GetLayoutTextBaseline() {
532 EnsureLayout();
533 return lines()[0].baseline;
534 }
535
536 SelectionModel RenderTextWin::AdjacentCharSelectionModel(
537 const SelectionModel& selection,
538 VisualCursorDirection direction) {
539 DCHECK(!needs_layout_);
540 internal::TextRun* run;
541 size_t run_index = GetRunContainingCaret(selection);
542 if (run_index >= runs_.size()) {
543 // The cursor is not in any run: we're at the visual and logical edge.
544 SelectionModel edge = EdgeSelectionModel(direction);
545 if (edge.caret_pos() == selection.caret_pos())
546 return edge;
547 int visual_index = (direction == CURSOR_RIGHT) ? 0 : runs_.size() - 1;
548 run = runs_[visual_to_logical_[visual_index]];
549 } else {
550 // If the cursor is moving within the current run, just move it by one
551 // grapheme in the appropriate direction.
552 run = runs_[run_index];
553 size_t caret = selection.caret_pos();
554 bool forward_motion =
555 run->script_analysis.fRTL == (direction == CURSOR_LEFT);
556 if (forward_motion) {
557 if (caret < LayoutIndexToTextIndex(run->range.end())) {
558 caret = IndexOfAdjacentGrapheme(caret, CURSOR_FORWARD);
559 return SelectionModel(caret, CURSOR_BACKWARD);
560 }
561 } else {
562 if (caret > LayoutIndexToTextIndex(run->range.start())) {
563 caret = IndexOfAdjacentGrapheme(caret, CURSOR_BACKWARD);
564 return SelectionModel(caret, CURSOR_FORWARD);
565 }
566 }
567 // The cursor is at the edge of a run; move to the visually adjacent run.
568 int visual_index = logical_to_visual_[run_index];
569 visual_index += (direction == CURSOR_LEFT) ? -1 : 1;
570 if (visual_index < 0 || visual_index >= static_cast<int>(runs_.size()))
571 return EdgeSelectionModel(direction);
572 run = runs_[visual_to_logical_[visual_index]];
573 }
574 bool forward_motion = run->script_analysis.fRTL == (direction == CURSOR_LEFT);
575 return forward_motion ? FirstSelectionModelInsideRun(run) :
576 LastSelectionModelInsideRun(run);
577 }
578
579 // TODO(msw): Implement word breaking for Windows.
580 SelectionModel RenderTextWin::AdjacentWordSelectionModel(
581 const SelectionModel& selection,
582 VisualCursorDirection direction) {
583 if (obscured())
584 return EdgeSelectionModel(direction);
585
586 base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD);
587 bool success = iter.Init();
588 DCHECK(success);
589 if (!success)
590 return selection;
591
592 size_t pos;
593 if (direction == CURSOR_RIGHT) {
594 pos = std::min(selection.caret_pos() + 1, text().length());
595 while (iter.Advance()) {
596 pos = iter.pos();
597 if (iter.IsWord() && pos > selection.caret_pos())
598 break;
599 }
600 } else { // direction == CURSOR_LEFT
601 // Notes: We always iterate words from the beginning.
602 // This is probably fast enough for our usage, but we may
603 // want to modify WordIterator so that it can start from the
604 // middle of string and advance backwards.
605 pos = std::max<int>(selection.caret_pos() - 1, 0);
606 while (iter.Advance()) {
607 if (iter.IsWord()) {
608 size_t begin = iter.pos() - iter.GetString().length();
609 if (begin == selection.caret_pos()) {
610 // The cursor is at the beginning of a word.
611 // Move to previous word.
612 break;
613 } else if (iter.pos() >= selection.caret_pos()) {
614 // The cursor is in the middle or at the end of a word.
615 // Move to the top of current word.
616 pos = begin;
617 break;
618 } else {
619 pos = iter.pos() - iter.GetString().length();
620 }
621 }
622 }
623 }
624 return SelectionModel(pos, CURSOR_FORWARD);
625 }
626
627 Range RenderTextWin::GetGlyphBounds(size_t index) {
628 EnsureLayout();
629 const size_t run_index =
630 GetRunContainingCaret(SelectionModel(index, CURSOR_FORWARD));
631 // Return edge bounds if the index is invalid or beyond the layout text size.
632 if (run_index >= runs_.size())
633 return Range(string_width_);
634 internal::TextRun* run = runs_[run_index];
635 const size_t layout_index = TextIndexToLayoutIndex(index);
636 return Range(GetGlyphXBoundary(run, layout_index, false),
637 GetGlyphXBoundary(run, layout_index, true));
638 }
639
640 std::vector<Rect> RenderTextWin::GetSubstringBounds(const Range& range) {
641 DCHECK(!needs_layout_);
642 DCHECK(Range(0, text().length()).Contains(range));
643 Range layout_range(TextIndexToLayoutIndex(range.start()),
644 TextIndexToLayoutIndex(range.end()));
645 DCHECK(Range(0, GetLayoutText().length()).Contains(layout_range));
646
647 std::vector<Rect> rects;
648 if (layout_range.is_empty())
649 return rects;
650 std::vector<Range> bounds;
651
652 // Add a Range for each run/selection intersection.
653 // TODO(msw): The bounds should probably not always be leading the range ends.
654 for (size_t i = 0; i < runs_.size(); ++i) {
655 const internal::TextRun* run = runs_[visual_to_logical_[i]];
656 Range intersection = run->range.Intersect(layout_range);
657 if (intersection.IsValid()) {
658 DCHECK(!intersection.is_reversed());
659 Range range_x(GetGlyphXBoundary(run, intersection.start(), false),
660 GetGlyphXBoundary(run, intersection.end(), false));
661 if (range_x.is_empty())
662 continue;
663 range_x = Range(range_x.GetMin(), range_x.GetMax());
664 // Union this with the last range if they're adjacent.
665 DCHECK(bounds.empty() || bounds.back().GetMax() <= range_x.GetMin());
666 if (!bounds.empty() && bounds.back().GetMax() == range_x.GetMin()) {
667 range_x = Range(bounds.back().GetMin(), range_x.GetMax());
668 bounds.pop_back();
669 }
670 bounds.push_back(range_x);
671 }
672 }
673 for (size_t i = 0; i < bounds.size(); ++i) {
674 std::vector<Rect> current_rects = TextBoundsToViewBounds(bounds[i]);
675 rects.insert(rects.end(), current_rects.begin(), current_rects.end());
676 }
677 return rects;
678 }
679
680 size_t RenderTextWin::TextIndexToLayoutIndex(size_t index) const {
681 DCHECK_LE(index, text().length());
682 ptrdiff_t i = obscured() ? UTF16IndexToOffset(text(), 0, index) : index;
683 CHECK_GE(i, 0);
684 // Clamp layout indices to the length of the text actually used for layout.
685 return std::min<size_t>(GetLayoutText().length(), i);
686 }
687
688 size_t RenderTextWin::LayoutIndexToTextIndex(size_t index) const {
689 if (!obscured())
690 return index;
691
692 DCHECK_LE(index, GetLayoutText().length());
693 const size_t text_index = UTF16OffsetToIndex(text(), 0, index);
694 DCHECK_LE(text_index, text().length());
695 return text_index;
696 }
697
698 bool RenderTextWin::IsValidCursorIndex(size_t index) {
699 if (index == 0 || index == text().length())
700 return true;
701 if (!IsValidLogicalIndex(index))
702 return false;
703 EnsureLayout();
704 // Disallow indices amid multi-character graphemes by checking glyph bounds.
705 // These characters are not surrogate-pairs, but may yield a single glyph:
706 // \x0915\x093f - (ki) - one of many Devanagari biconsonantal conjuncts.
707 // \x0e08\x0e33 - (cho chan + sara am) - a Thai consonant and vowel pair.
708 return GetGlyphBounds(index) != GetGlyphBounds(index - 1);
709 }
710
711 void RenderTextWin::ResetLayout() {
712 // Layout is performed lazily as needed for drawing/metrics.
713 needs_layout_ = true;
714 }
715
716 void RenderTextWin::EnsureLayout() {
717 if (needs_layout_) {
718 // TODO(msw): Skip complex processing if ScriptIsComplex returns false.
719 ItemizeLogicalText();
720 if (!runs_.empty())
721 LayoutVisualText();
722 needs_layout_ = false;
723 std::vector<internal::Line> lines;
724 set_lines(&lines);
725 }
726
727 // Compute lines if they're not valid. This is separate from the layout steps
728 // above to avoid text layout and shaping when we resize |display_rect_|.
729 if (lines().empty()) {
730 DCHECK(!needs_layout_);
731 std::vector<internal::Line> lines;
732 internal::LineBreaker line_breaker(display_rect().width() - 1,
733 font_list().GetBaseline(),
734 font_list().GetHeight(), multiline(),
735 GetLayoutText().c_str(),
736 multiline() ? &GetLineBreaks() : NULL,
737 runs_);
738 for (size_t i = 0; i < runs_.size(); ++i)
739 line_breaker.AddRun(visual_to_logical_[i]);
740 line_breaker.Finalize(&lines, &multiline_string_size_);
741 DCHECK(!lines.empty());
742 #ifndef NDEBUG
743 CheckLineIntegrity(lines, runs_);
744 #endif
745 set_lines(&lines);
746 }
747 }
748
749 void RenderTextWin::DrawVisualText(Canvas* canvas) {
750 DCHECK(!needs_layout_);
751 DCHECK(!lines().empty());
752
753 std::vector<SkPoint> pos;
754
755 internal::SkiaTextRenderer renderer(canvas);
756 ApplyFadeEffects(&renderer);
757 ApplyTextShadows(&renderer);
758
759 renderer.SetFontRenderParams(
760 font_list().GetPrimaryFont().GetFontRenderParams(),
761 background_is_transparent());
762
763 ApplyCompositionAndSelectionStyles();
764
765 for (size_t i = 0; i < lines().size(); ++i) {
766 const internal::Line& line = lines()[i];
767 const Vector2d line_offset = GetLineOffset(i);
768
769 // Skip painting empty lines or lines outside the display rect area.
770 if (!display_rect().Intersects(Rect(PointAtOffsetFromOrigin(line_offset),
771 ToCeiledSize(line.size))))
772 continue;
773
774 const Vector2d text_offset = line_offset + Vector2d(0, line.baseline);
775 int preceding_segment_widths = 0;
776
777 for (size_t j = 0; j < line.segments.size(); ++j) {
778 const internal::LineSegment* segment = &line.segments[j];
779 const int segment_width = segment->x_range.length();
780 const internal::TextRun* run = runs_[segment->run];
781 DCHECK(!segment->char_range.is_empty());
782 DCHECK(run->range.Contains(segment->char_range));
783 Range glyph_range = CharRangeToGlyphRange(*run, segment->char_range);
784 DCHECK(!glyph_range.is_empty());
785 // Skip painting segments outside the display rect area.
786 if (!multiline()) {
787 const Rect segment_bounds(PointAtOffsetFromOrigin(line_offset) +
788 Vector2d(preceding_segment_widths, 0),
789 Size(segment_width, line.size.height()));
790 if (!display_rect().Intersects(segment_bounds)) {
791 preceding_segment_widths += segment_width;
792 continue;
793 }
794 }
795
796 // |pos| contains the positions of glyphs. An extra terminal |pos| entry
797 // is added to simplify width calculations.
798 int segment_x = preceding_segment_widths;
799 pos.resize(glyph_range.length() + 1);
800 for (size_t k = glyph_range.start(); k < glyph_range.end(); ++k) {
801 pos[k - glyph_range.start()].set(
802 SkIntToScalar(text_offset.x() + run->offsets[k].du + segment_x),
803 SkIntToScalar(text_offset.y() - run->offsets[k].dv));
804 segment_x += run->advance_widths[k];
805 }
806 pos.back().set(SkIntToScalar(text_offset.x() + segment_x),
807 SkIntToScalar(text_offset.y()));
808
809 renderer.SetTextSize(SkIntToScalar(run->font.GetFontSize()));
810 renderer.SetFontFamilyWithStyle(run->font.GetFontName(), run->font_style);
811
812 for (BreakList<SkColor>::const_iterator it =
813 colors().GetBreak(segment->char_range.start());
814 it != colors().breaks().end() &&
815 it->first < segment->char_range.end();
816 ++it) {
817 const Range intersection =
818 colors().GetRange(it).Intersect(segment->char_range);
819 const Range colored_glyphs = CharRangeToGlyphRange(*run, intersection);
820 // The range may be empty if a portion of a multi-character grapheme is
821 // selected, yielding two colors for a single glyph. For now, this just
822 // paints the glyph with a single style, but it should paint it twice,
823 // clipped according to selection bounds. See http://crbug.com/366786
824 if (colored_glyphs.is_empty())
825 continue;
826 DCHECK(glyph_range.Contains(colored_glyphs));
827 const SkPoint& start_pos =
828 pos[colored_glyphs.start() - glyph_range.start()];
829 const SkPoint& end_pos =
830 pos[colored_glyphs.end() - glyph_range.start()];
831
832 renderer.SetForegroundColor(it->second);
833 renderer.DrawPosText(&start_pos, &run->glyphs[colored_glyphs.start()],
834 colored_glyphs.length());
835 int start_x = SkScalarRoundToInt(start_pos.x());
836 renderer.DrawDecorations(
837 start_x, text_offset.y(), SkScalarRoundToInt(end_pos.x()) - start_x,
838 run->underline, run->strike, run->diagonal_strike);
839 }
840
841 preceding_segment_widths += segment_width;
842 }
843
844 renderer.EndDiagonalStrike();
845 }
846
847 UndoCompositionAndSelectionStyles();
848 }
849
850 void RenderTextWin::ItemizeLogicalText() {
851 runs_.clear();
852 string_width_ = 0;
853 multiline_string_size_ = Size();
854
855 // Set Uniscribe's base text direction.
856 script_state_.uBidiLevel =
857 (GetTextDirection() == base::i18n::RIGHT_TO_LEFT) ? 1 : 0;
858
859 const base::string16& layout_text = GetLayoutText();
860 if (layout_text.empty())
861 return;
862
863 HRESULT hr = E_OUTOFMEMORY;
864 int script_items_count = 0;
865 std::vector<SCRIPT_ITEM> script_items;
866 const size_t layout_text_length = layout_text.length();
867 // Ensure that |kMaxRuns| is attempted and the loop terminates afterward.
868 for (size_t runs = kGuessRuns; hr == E_OUTOFMEMORY && runs <= kMaxRuns;
869 runs = std::max(runs + 1, std::min(runs * 2, kMaxRuns))) {
870 // Derive the array of Uniscribe script items from the logical text.
871 // ScriptItemize always adds a terminal array item so that the length of
872 // the last item can be derived from the terminal SCRIPT_ITEM::iCharPos.
873 script_items.resize(runs);
874 hr = ScriptItemize(layout_text.c_str(), layout_text_length, runs - 1,
875 &script_control_, &script_state_, &script_items[0],
876 &script_items_count);
877 }
878 DCHECK(SUCCEEDED(hr));
879 if (!SUCCEEDED(hr) || script_items_count <= 0)
880 return;
881
882 // Temporarily apply composition underlines and selection colors.
883 ApplyCompositionAndSelectionStyles();
884
885 // Build the list of runs from the script items and ranged styles. Use an
886 // empty color BreakList to avoid breaking runs at color boundaries.
887 BreakList<SkColor> empty_colors;
888 empty_colors.SetMax(layout_text_length);
889 internal::StyleIterator style(empty_colors, styles());
890 SCRIPT_ITEM* script_item = &script_items[0];
891 const size_t max_run_length = kMaxGlyphs / 2;
892 for (size_t run_break = 0; run_break < layout_text_length;) {
893 internal::TextRun* run = new internal::TextRun();
894 run->range.set_start(run_break);
895 run->font = font_list().GetPrimaryFont();
896 run->font_style = (style.style(BOLD) ? Font::BOLD : 0) |
897 (style.style(ITALIC) ? Font::ITALIC : 0);
898 DeriveFontIfNecessary(run->font.GetFontSize(), run->font.GetHeight(),
899 run->font_style, &run->font);
900 run->strike = style.style(STRIKE);
901 run->diagonal_strike = style.style(DIAGONAL_STRIKE);
902 run->underline = style.style(UNDERLINE);
903 run->script_analysis = script_item->a;
904
905 // Find the next break and advance the iterators as needed.
906 const size_t script_item_break = (script_item + 1)->iCharPos;
907 run_break = std::min(script_item_break,
908 TextIndexToLayoutIndex(style.GetRange().end()));
909
910 // Clamp run lengths to avoid exceeding the maximum supported glyph count.
911 if ((run_break - run->range.start()) > max_run_length) {
912 run_break = run->range.start() + max_run_length;
913 if (!IsValidCodePointIndex(layout_text, run_break))
914 --run_break;
915 }
916
917 // Break runs adjacent to character substrings in certain code blocks.
918 // This avoids using their fallback fonts for more characters than needed,
919 // in cases like "\x25B6 Media Title", etc. http://crbug.com/278913
920 if (run_break > run->range.start()) {
921 run_break =
922 FindUnusualCharacter(layout_text, run->range.start(), run_break);
923 }
924
925 DCHECK(IsValidCodePointIndex(layout_text, run_break));
926
927 style.UpdatePosition(LayoutIndexToTextIndex(run_break));
928 if (script_item_break == run_break)
929 script_item++;
930 run->range.set_end(run_break);
931 runs_.push_back(run);
932 }
933
934 // Undo the temporarily applied composition underlines and selection colors.
935 UndoCompositionAndSelectionStyles();
936 }
937
938 void RenderTextWin::LayoutVisualText() {
939 DCHECK(!runs_.empty());
940
941 if (!cached_hdc_)
942 cached_hdc_ = CreateCompatibleDC(NULL);
943
944 HRESULT hr = E_FAIL;
945 // Ensure ascent and descent are not smaller than ones of the font list.
946 // Keep them tall enough to draw often-used characters.
947 // For example, if a text field contains a Japanese character, which is
948 // smaller than Latin ones, and then later a Latin one is inserted, this
949 // ensures that the text baseline does not shift.
950 int ascent = font_list().GetBaseline();
951 int descent = font_list().GetHeight() - font_list().GetBaseline();
952 for (size_t i = 0; i < runs_.size(); ++i) {
953 internal::TextRun* run = runs_[i];
954 LayoutTextRun(run);
955
956 ascent = std::max(ascent, run->font.GetBaseline());
957 descent = std::max(descent,
958 run->font.GetHeight() - run->font.GetBaseline());
959
960 if (run->glyph_count > 0) {
961 run->advance_widths.reset(new int[run->glyph_count]);
962 run->offsets.reset(new GOFFSET[run->glyph_count]);
963 hr = ScriptPlace(cached_hdc_,
964 &run->script_cache,
965 run->glyphs.get(),
966 run->glyph_count,
967 run->visible_attributes.get(),
968 &(run->script_analysis),
969 run->advance_widths.get(),
970 run->offsets.get(),
971 &(run->abc_widths));
972 DCHECK(SUCCEEDED(hr));
973 }
974 }
975
976 // Build the array of bidirectional embedding levels.
977 scoped_ptr<BYTE[]> levels(new BYTE[runs_.size()]);
978 for (size_t i = 0; i < runs_.size(); ++i)
979 levels[i] = runs_[i]->script_analysis.s.uBidiLevel;
980
981 // Get the maps between visual and logical run indices.
982 visual_to_logical_.reset(new int[runs_.size()]);
983 logical_to_visual_.reset(new int[runs_.size()]);
984 hr = ScriptLayout(runs_.size(),
985 levels.get(),
986 visual_to_logical_.get(),
987 logical_to_visual_.get());
988 DCHECK(SUCCEEDED(hr));
989
990 // Precalculate run width information.
991 size_t preceding_run_widths = 0;
992 for (size_t i = 0; i < runs_.size(); ++i) {
993 internal::TextRun* run = runs_[visual_to_logical_[i]];
994 run->preceding_run_widths = preceding_run_widths;
995 const ABC& abc = run->abc_widths;
996 run->width = abc.abcA + abc.abcB + abc.abcC;
997 preceding_run_widths += run->width;
998 }
999 string_width_ = preceding_run_widths;
1000 }
1001
1002 void RenderTextWin::LayoutTextRun(internal::TextRun* run) {
1003 const size_t run_length = run->range.length();
1004 const wchar_t* run_text = &(GetLayoutText()[run->range.start()]);
1005 Font original_font = run->font;
1006
1007 run->logical_clusters.reset(new WORD[run_length]);
1008
1009 // Try shaping with |original_font|.
1010 Font current_font = original_font;
1011 int missing_count = CountCharsWithMissingGlyphs(run,
1012 ShapeTextRunWithFont(run, current_font));
1013 if (missing_count == 0)
1014 return;
1015
1016 // Keep track of the font that is able to display the greatest number of
1017 // characters for which ScriptShape() returned S_OK. This font will be used
1018 // in the case where no font is able to display the entire run.
1019 int best_partial_font_missing_char_count = missing_count;
1020 Font best_partial_font = current_font;
1021
1022 // Try to shape with the cached font from previous runs, if any.
1023 std::map<std::string, Font>::const_iterator it =
1024 successful_substitute_fonts_.find(original_font.GetFontName());
1025 if (it != successful_substitute_fonts_.end()) {
1026 current_font = it->second;
1027 missing_count = CountCharsWithMissingGlyphs(run,
1028 ShapeTextRunWithFont(run, current_font));
1029 if (missing_count == 0)
1030 return;
1031 if (missing_count < best_partial_font_missing_char_count) {
1032 best_partial_font_missing_char_count = missing_count;
1033 best_partial_font = current_font;
1034 }
1035 }
1036
1037 // Try finding a fallback font using a meta file.
1038 // TODO(msw|asvitkine): Support RenderText's font_list()?
1039 Font uniscribe_font;
1040 bool got_uniscribe_font = false;
1041 if (GetUniscribeFallbackFont(original_font, run_text, run_length,
1042 &uniscribe_font)) {
1043 got_uniscribe_font = true;
1044 current_font = uniscribe_font;
1045 missing_count = CountCharsWithMissingGlyphs(run,
1046 ShapeTextRunWithFont(run, current_font));
1047 if (missing_count == 0) {
1048 successful_substitute_fonts_[original_font.GetFontName()] = current_font;
1049 return;
1050 }
1051 if (missing_count < best_partial_font_missing_char_count) {
1052 best_partial_font_missing_char_count = missing_count;
1053 best_partial_font = current_font;
1054 }
1055 }
1056
1057 // Try fonts in the fallback list except the first, which is |original_font|.
1058 std::vector<std::string> fonts =
1059 GetFallbackFontFamilies(original_font.GetFontName());
1060 for (size_t i = 1; i < fonts.size(); ++i) {
1061 current_font = Font(fonts[i], original_font.GetFontSize());
1062 missing_count = CountCharsWithMissingGlyphs(run,
1063 ShapeTextRunWithFont(run, current_font));
1064 if (missing_count == 0) {
1065 successful_substitute_fonts_[original_font.GetFontName()] = current_font;
1066 return;
1067 }
1068 if (missing_count < best_partial_font_missing_char_count) {
1069 best_partial_font_missing_char_count = missing_count;
1070 best_partial_font = current_font;
1071 }
1072 }
1073
1074 // Try fonts in the fallback list of the Uniscribe font.
1075 if (got_uniscribe_font) {
1076 fonts = GetFallbackFontFamilies(uniscribe_font.GetFontName());
1077 for (size_t i = 1; i < fonts.size(); ++i) {
1078 current_font = Font(fonts[i], original_font.GetFontSize());
1079 missing_count = CountCharsWithMissingGlyphs(run,
1080 ShapeTextRunWithFont(run, current_font));
1081 if (missing_count == 0) {
1082 successful_substitute_fonts_[original_font.GetFontName()] =
1083 current_font;
1084 return;
1085 }
1086 if (missing_count < best_partial_font_missing_char_count) {
1087 best_partial_font_missing_char_count = missing_count;
1088 best_partial_font = current_font;
1089 }
1090 }
1091 }
1092
1093 // If a font was able to partially display the run, use that now.
1094 if (best_partial_font_missing_char_count < static_cast<int>(run_length)) {
1095 // Re-shape the run only if |best_partial_font| differs from the last font.
1096 if (best_partial_font.GetNativeFont() != run->font.GetNativeFont())
1097 ShapeTextRunWithFont(run, best_partial_font);
1098 return;
1099 }
1100
1101 // If no font was able to partially display the run, replace all glyphs
1102 // with |wgDefault| from the original font to ensure to they don't hold
1103 // garbage values.
1104 // First, clear the cache and select the original font on the HDC.
1105 ScriptFreeCache(&run->script_cache);
1106 run->font = original_font;
1107 SelectObject(cached_hdc_, run->font.GetNativeFont());
1108
1109 // Now, get the font's properties.
1110 SCRIPT_FONTPROPERTIES properties;
1111 memset(&properties, 0, sizeof(properties));
1112 properties.cBytes = sizeof(properties);
1113 HRESULT hr = ScriptGetFontProperties(cached_hdc_, &run->script_cache,
1114 &properties);
1115
1116 // The initial values for the "missing" glyph and the space glyph are taken
1117 // from the recommendations section of the OpenType spec:
1118 // https://www.microsoft.com/typography/otspec/recom.htm
1119 WORD missing_glyph = 0;
1120 WORD space_glyph = 3;
1121 if (hr == S_OK) {
1122 missing_glyph = properties.wgDefault;
1123 space_glyph = properties.wgBlank;
1124 }
1125
1126 // Finally, initialize |glyph_count|, |glyphs|, |visible_attributes| and
1127 // |logical_clusters| on the run (since they may not have been set yet).
1128 run->glyph_count = run_length;
1129 memset(run->visible_attributes.get(), 0,
1130 run->glyph_count * sizeof(SCRIPT_VISATTR));
1131 for (int i = 0; i < run->glyph_count; ++i)
1132 run->glyphs[i] = IsWhitespace(run_text[i]) ? space_glyph : missing_glyph;
1133 for (size_t i = 0; i < run_length; ++i) {
1134 run->logical_clusters[i] =
1135 static_cast<WORD>(run->script_analysis.fRTL ? run_length - 1 - i : i);
1136 }
1137
1138 // TODO(msw): Don't use SCRIPT_UNDEFINED. Apparently Uniscribe can
1139 // crash on certain surrogate pairs with SCRIPT_UNDEFINED.
1140 // See https://bugzilla.mozilla.org/show_bug.cgi?id=341500
1141 // And http://maxradi.us/documents/uniscribe/
1142 run->script_analysis.eScript = SCRIPT_UNDEFINED;
1143 }
1144
1145 HRESULT RenderTextWin::ShapeTextRunWithFont(internal::TextRun* run,
1146 const Font& font) {
1147 // Update the run's font only if necessary. If the two fonts wrap the same
1148 // PlatformFontWin object, their native fonts will have the same value.
1149 if (run->font.GetNativeFont() != font.GetNativeFont()) {
1150 const int font_size = run->font.GetFontSize();
1151 const int font_height = run->font.GetHeight();
1152 run->font = font;
1153 DeriveFontIfNecessary(font_size, font_height, run->font_style, &run->font);
1154 ScriptFreeCache(&run->script_cache);
1155 }
1156
1157 // Select the font desired for glyph generation.
1158 SelectObject(cached_hdc_, run->font.GetNativeFont());
1159
1160 HRESULT hr = E_OUTOFMEMORY;
1161 const size_t run_length = run->range.length();
1162 const wchar_t* run_text = &(GetLayoutText()[run->range.start()]);
1163 // Guess the expected number of glyphs from the length of the run.
1164 // MSDN suggests this at http://msdn.microsoft.com/en-us/library/dd368564.aspx
1165 size_t max_glyphs = static_cast<size_t>(1.5 * run_length + 16);
1166 while (hr == E_OUTOFMEMORY && max_glyphs <= kMaxGlyphs) {
1167 run->glyph_count = 0;
1168 run->glyphs.reset(new WORD[max_glyphs]);
1169 run->visible_attributes.reset(new SCRIPT_VISATTR[max_glyphs]);
1170 hr = ScriptShape(cached_hdc_, &run->script_cache, run_text, run_length,
1171 max_glyphs, &run->script_analysis, run->glyphs.get(),
1172 run->logical_clusters.get(), run->visible_attributes.get(),
1173 &run->glyph_count);
1174 // Ensure that |kMaxGlyphs| is attempted and the loop terminates afterward.
1175 max_glyphs = std::max(max_glyphs + 1, std::min(max_glyphs * 2, kMaxGlyphs));
1176 }
1177 return hr;
1178 }
1179
1180 int RenderTextWin::CountCharsWithMissingGlyphs(internal::TextRun* run,
1181 HRESULT shaping_result) const {
1182 if (shaping_result != S_OK) {
1183 DCHECK_EQ(shaping_result, USP_E_SCRIPT_NOT_IN_FONT);
1184 return INT_MAX;
1185 }
1186
1187 // If |hr| is S_OK, there could still be missing glyphs in the output.
1188 // http://msdn.microsoft.com/en-us/library/windows/desktop/dd368564.aspx
1189 int chars_not_missing_glyphs = 0;
1190 SCRIPT_FONTPROPERTIES properties;
1191 memset(&properties, 0, sizeof(properties));
1192 properties.cBytes = sizeof(properties);
1193 ScriptGetFontProperties(cached_hdc_, &run->script_cache, &properties);
1194
1195 const wchar_t* run_text = &(GetLayoutText()[run->range.start()]);
1196 for (size_t char_index = 0; char_index < run->range.length(); ++char_index) {
1197 const int glyph_index = run->logical_clusters[char_index];
1198 DCHECK_GE(glyph_index, 0);
1199 DCHECK_LT(glyph_index, run->glyph_count);
1200
1201 if (run->glyphs[glyph_index] == properties.wgDefault)
1202 continue;
1203
1204 // Windows Vista sometimes returns glyphs equal to wgBlank (instead of
1205 // wgDefault), with fZeroWidth set. Treat such cases as having missing
1206 // glyphs if the corresponding character is not whitespace.
1207 // See: http://crbug.com/125629
1208 if (run->glyphs[glyph_index] == properties.wgBlank &&
1209 run->visible_attributes[glyph_index].fZeroWidth &&
1210 !IsWhitespace(run_text[char_index]) &&
1211 !IsUnicodeBidiControlCharacter(run_text[char_index])) {
1212 continue;
1213 }
1214
1215 ++chars_not_missing_glyphs;
1216 }
1217
1218 DCHECK_LE(chars_not_missing_glyphs, static_cast<int>(run->range.length()));
1219 return run->range.length() - chars_not_missing_glyphs;
1220 }
1221
1222 size_t RenderTextWin::GetRunContainingCaret(const SelectionModel& caret) const {
1223 DCHECK(!needs_layout_);
1224 size_t layout_position = TextIndexToLayoutIndex(caret.caret_pos());
1225 LogicalCursorDirection affinity = caret.caret_affinity();
1226 for (size_t run = 0; run < runs_.size(); ++run)
1227 if (RangeContainsCaret(runs_[run]->range, layout_position, affinity))
1228 return run;
1229 return runs_.size();
1230 }
1231
1232 size_t RenderTextWin::GetRunContainingXCoord(int x) const {
1233 DCHECK(!needs_layout_);
1234 // Find the text run containing the argument point (assumed already offset).
1235 for (size_t run = 0; run < runs_.size(); ++run) {
1236 if ((runs_[run]->preceding_run_widths <= x) &&
1237 ((runs_[run]->preceding_run_widths + runs_[run]->width) > x))
1238 return run;
1239 }
1240 return runs_.size();
1241 }
1242
1243 SelectionModel RenderTextWin::FirstSelectionModelInsideRun(
1244 const internal::TextRun* run) {
1245 size_t position = LayoutIndexToTextIndex(run->range.start());
1246 position = IndexOfAdjacentGrapheme(position, CURSOR_FORWARD);
1247 return SelectionModel(position, CURSOR_BACKWARD);
1248 }
1249
1250 SelectionModel RenderTextWin::LastSelectionModelInsideRun(
1251 const internal::TextRun* run) {
1252 size_t position = LayoutIndexToTextIndex(run->range.end());
1253 position = IndexOfAdjacentGrapheme(position, CURSOR_BACKWARD);
1254 return SelectionModel(position, CURSOR_FORWARD);
1255 }
1256
1257 RenderText* RenderText::CreateNativeInstance() {
1258 return new RenderTextWin;
1259 }
1260
1261 } // namespace gfx
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