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1 // Copyright 2014 The PDFium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6 
7 #include "core/fpdftext/cpdf_textpage.h"
8 
9 #include <math.h>
10 #include <stdint.h>
11 
12 #include <algorithm>
13 #include <utility>
14 #include <vector>
15 
16 #include "core/fpdfapi/font/cpdf_cidfont.h"
17 #include "core/fpdfapi/font/cpdf_font.h"
18 #include "core/fpdfapi/page/cpdf_form.h"
19 #include "core/fpdfapi/page/cpdf_formobject.h"
20 #include "core/fpdfapi/page/cpdf_page.h"
21 #include "core/fpdfapi/page/cpdf_pageobject.h"
22 #include "core/fpdfapi/page/cpdf_textobject.h"
23 #include "core/fpdfapi/parser/cpdf_dictionary.h"
24 #include "core/fpdfapi/parser/cpdf_string.h"
25 #include "core/fpdftext/unicodenormalizationdata.h"
26 #include "core/fxcrt/check.h"
27 #include "core/fxcrt/check_op.h"
28 #include "core/fxcrt/compiler_specific.h"
29 #include "core/fxcrt/data_vector.h"
30 #include "core/fxcrt/fx_bidi.h"
31 #include "core/fxcrt/fx_extension.h"
32 #include "core/fxcrt/fx_unicode.h"
33 #include "core/fxcrt/notreached.h"
34 #include "core/fxcrt/span.h"
35 #include "core/fxcrt/stl_util.h"
36 
37 namespace {
38 
39 constexpr float kDefaultFontSize = 1.0f;
40 constexpr float kSizeEpsilon = 0.01f;
41 constexpr std::array<pdfium::span<const uint16_t>, 3>
42     kUnicodeDataNormalizationMaps = {{kUnicodeDataNormalizationMap2,
43                                       kUnicodeDataNormalizationMap3,
44                                       kUnicodeDataNormalizationMap4}};
45 
NormalizeThreshold(float threshold,int t1,int t2,int t3)46 float NormalizeThreshold(float threshold, int t1, int t2, int t3) {
47   DCHECK(t1 < t2);
48   DCHECK(t2 < t3);
49   if (threshold < t1)
50     return threshold / 2.0f;
51   if (threshold < t2)
52     return threshold / 4.0f;
53   if (threshold < t3)
54     return threshold / 5.0f;
55   return threshold / 6.0f;
56 }
57 
CalculateBaseSpace(const CPDF_TextObject * pTextObj,const CFX_Matrix & matrix)58 float CalculateBaseSpace(const CPDF_TextObject* pTextObj,
59                          const CFX_Matrix& matrix) {
60   const size_t nItems = pTextObj->CountItems();
61   const float char_space = pTextObj->text_state().GetCharSpace();
62   if (char_space == 0.0f || nItems < 3) {
63     return 0.0f;
64   }
65 
66   bool bAllChar = true;
67   const float spacing = matrix.TransformDistance(char_space);
68   const float fontsize_h = pTextObj->text_state().GetFontSizeH();
69   float base_space = spacing;
70   for (size_t i = 0; i < nItems; ++i) {
71     CPDF_TextObject::Item item = pTextObj->GetItemInfo(i);
72     if (item.m_CharCode == 0xffffffff) {
73       float kerning = -fontsize_h * item.m_Origin.x / 1000;
74       base_space = std::min(base_space, kerning + spacing);
75       bAllChar = false;
76     }
77   }
78   if (base_space < 0.0 || (nItems == 3 && !bAllChar)) {
79     return 0.0f;
80   }
81 
82   return base_space;
83 }
84 
CalculateBaseSpaceAdjustment(const CPDF_TextObject * pTextObj,const CFX_Matrix & matrix)85 float CalculateBaseSpaceAdjustment(const CPDF_TextObject* pTextObj,
86                                    const CFX_Matrix& matrix) {
87   float char_space = pTextObj->text_state().GetCharSpace();
88   if (char_space > 0.001f) {
89     return -matrix.TransformDistance(char_space);
90   }
91   if (char_space < -0.001f) {
92     return matrix.TransformDistance(fabs(char_space));
93   }
94   return 0.0f;
95 }
96 
GetUnicodeNormalization(wchar_t wch)97 DataVector<wchar_t> GetUnicodeNormalization(wchar_t wch) {
98   wch = wch & 0xFFFF;
99   wchar_t wFind = kUnicodeDataNormalization[wch];
100   if (!wFind) {
101     return DataVector<wchar_t>(1, wch);
102   }
103   if (wFind >= 0x8000) {
104     return DataVector<wchar_t>(1,
105                                kUnicodeDataNormalizationMap1[wFind - 0x8000]);
106   }
107   wch = wFind & 0x0FFF;
108   wFind >>= 12;
109   auto pMap = kUnicodeDataNormalizationMaps[wFind - 2].subspan(wch);
110   if (wFind == 4) {
111     wFind = pMap.front();
112     pMap = pMap.subspan(1);
113   }
114   const auto range = pMap.first(wFind);
115   return DataVector<wchar_t>(range.begin(), range.end());
116 }
117 
MaskPercentFilled(const std::vector<bool> & mask,int32_t start,int32_t end)118 float MaskPercentFilled(const std::vector<bool>& mask,
119                         int32_t start,
120                         int32_t end) {
121   if (start >= end)
122     return 0;
123   float count = std::count_if(mask.begin() + start, mask.begin() + end,
124                               [](bool r) { return r; });
125   return count / (end - start);
126 }
127 
IsControlChar(const CPDF_TextPage::CharInfo & char_info)128 bool IsControlChar(const CPDF_TextPage::CharInfo& char_info) {
129   switch (char_info.unicode()) {
130     case 0x2:
131     case 0x3:
132     case 0x93:
133     case 0x94:
134     case 0x96:
135     case 0x97:
136     case 0x98:
137     case 0xfffe:
138       return char_info.char_type() != CPDF_TextPage::CharType::kHyphen;
139     default:
140       return false;
141   }
142 }
143 
IsHyphenCode(wchar_t c)144 bool IsHyphenCode(wchar_t c) {
145   return c == 0x2D || c == 0xAD;
146 }
147 
IsRectIntersect(const CFX_FloatRect & rect1,const CFX_FloatRect & rect2)148 bool IsRectIntersect(const CFX_FloatRect& rect1, const CFX_FloatRect& rect2) {
149   CFX_FloatRect rect = rect1;
150   rect.Intersect(rect2);
151   return !rect.IsEmpty();
152 }
153 
IsRightToLeft(const CPDF_TextObject & text_obj)154 bool IsRightToLeft(const CPDF_TextObject& text_obj) {
155   RetainPtr<const CPDF_Font> font = text_obj.GetFont();
156   const size_t nItems = text_obj.CountItems();
157   WideString str;
158   str.Reserve(nItems);
159   for (size_t i = 0; i < nItems; ++i) {
160     CPDF_TextObject::Item item = text_obj.GetItemInfo(i);
161     if (item.m_CharCode == 0xffffffff)
162       continue;
163     WideString unicode = font->UnicodeFromCharCode(item.m_CharCode);
164     wchar_t wChar = !unicode.IsEmpty() ? unicode[0] : 0;
165     if (wChar == 0)
166       wChar = item.m_CharCode;
167     if (wChar)
168       str += wChar;
169   }
170   return CFX_BidiString(str).OverallDirection() ==
171          CFX_BidiChar::Direction::kRight;
172 }
173 
GetCharWidth(uint32_t charCode,CPDF_Font * pFont)174 int GetCharWidth(uint32_t charCode, CPDF_Font* pFont) {
175   if (charCode == CPDF_Font::kInvalidCharCode)
176     return 0;
177 
178   int w = pFont->GetCharWidthF(charCode);
179   if (w > 0)
180     return w;
181 
182   ByteString str;
183   pFont->AppendChar(&str, charCode);
184   w = pFont->GetStringWidth(str.AsStringView());
185   if (w > 0)
186     return w;
187 
188   FX_RECT rect = pFont->GetCharBBox(charCode);
189   if (!rect.Valid())
190     return 0;
191 
192   return std::max(rect.Width(), 0);
193 }
194 
CalculateSpaceThreshold(CPDF_Font * font,float fontsize_h,uint32_t char_code)195 float CalculateSpaceThreshold(CPDF_Font* font,
196                               float fontsize_h,
197                               uint32_t char_code) {
198   const uint32_t space_charcode = font->CharCodeFromUnicode(' ');
199   float threshold = 0;
200   if (space_charcode != CPDF_Font::kInvalidCharCode) {
201     threshold = fontsize_h * font->GetCharWidthF(space_charcode) / 1000;
202   }
203   if (threshold > fontsize_h / 3) {
204     threshold = 0;
205   } else {
206     threshold /= 2;
207   }
208   if (threshold == 0) {
209     threshold = GetCharWidth(char_code, font);
210     threshold = NormalizeThreshold(threshold, 300, 500, 700);
211     threshold = fontsize_h * threshold / 1000;
212   }
213   return threshold;
214 }
215 
GenerateSpace(const CFX_PointF & pos,float last_pos,float this_width,float last_width,float threshold)216 bool GenerateSpace(const CFX_PointF& pos,
217                    float last_pos,
218                    float this_width,
219                    float last_width,
220                    float threshold) {
221   if (fabs(last_pos + last_width - pos.x) <= threshold)
222     return false;
223 
224   float threshold_pos = threshold + last_width;
225   float pos_difference = pos.x - last_pos;
226   if (fabs(pos_difference) > threshold_pos)
227     return true;
228   if (pos.x < 0 && -threshold_pos > pos_difference)
229     return true;
230   return pos_difference > this_width + last_width;
231 }
232 
EndHorizontalLine(const CFX_FloatRect & this_rect,const CFX_FloatRect & prev_rect)233 bool EndHorizontalLine(const CFX_FloatRect& this_rect,
234                        const CFX_FloatRect& prev_rect) {
235   if (this_rect.Height() <= 4.5 || prev_rect.Height() <= 4.5)
236     return false;
237 
238   float top = std::min(this_rect.top, prev_rect.top);
239   float bottom = std::max(this_rect.bottom, prev_rect.bottom);
240   return bottom >= top;
241 }
242 
EndVerticalLine(const CFX_FloatRect & this_rect,const CFX_FloatRect & prev_rect,const CFX_FloatRect & curline_rect,float this_fontsize,float prev_fontsize)243 bool EndVerticalLine(const CFX_FloatRect& this_rect,
244                      const CFX_FloatRect& prev_rect,
245                      const CFX_FloatRect& curline_rect,
246                      float this_fontsize,
247                      float prev_fontsize) {
248   if (this_rect.Width() <= this_fontsize * 0.1f ||
249       prev_rect.Width() <= prev_fontsize * 0.1f) {
250     return false;
251   }
252 
253   float left = std::max(this_rect.left, curline_rect.left);
254   float right = std::min(this_rect.right, curline_rect.right);
255   return right <= left;
256 }
257 
GetPageMatrix(const CPDF_Page * pPage)258 CFX_Matrix GetPageMatrix(const CPDF_Page* pPage) {
259   const FX_RECT rect(0, 0, static_cast<int>(pPage->GetPageWidth()),
260                      static_cast<int>(pPage->GetPageHeight()));
261   return pPage->GetDisplayMatrix(rect, 0);
262 }
263 
GetFontSize(const CPDF_TextObject * text_object)264 float GetFontSize(const CPDF_TextObject* text_object) {
265   bool has_font = text_object && text_object->GetFont();
266   return has_font ? text_object->GetFontSize() : kDefaultFontSize;
267 }
268 
GetLooseBounds(const CPDF_TextPage::CharInfo & charinfo)269 CFX_FloatRect GetLooseBounds(const CPDF_TextPage::CharInfo& charinfo) {
270   float font_size = GetFontSize(charinfo.text_object());
271   if (charinfo.text_object() && !FXSYS_IsFloatZero(font_size)) {
272     bool is_vert_writing = charinfo.text_object()->GetFont()->IsVertWriting();
273     if (is_vert_writing && charinfo.text_object()->GetFont()->IsCIDFont()) {
274       CPDF_CIDFont* pCIDFont = charinfo.text_object()->GetFont()->AsCIDFont();
275       uint16_t cid = pCIDFont->CIDFromCharCode(charinfo.char_code());
276 
277       CFX_Point16 vertical_origin = pCIDFont->GetVertOrigin(cid);
278       double offsetx = (vertical_origin.x - 500) * font_size / 1000.0;
279       double offsety = vertical_origin.y * font_size / 1000.0;
280       int16_t vert_width = pCIDFont->GetVertWidth(cid);
281       double height = vert_width * font_size / 1000.0;
282 
283       float left = charinfo.origin().x + offsetx;
284       float right = left + font_size;
285       float bottom = charinfo.origin().y + offsety;
286       float top = bottom + height;
287       return CFX_FloatRect(left, bottom, right, top);
288     }
289 
290     int ascent = charinfo.text_object()->GetFont()->GetTypeAscent();
291     int descent = charinfo.text_object()->GetFont()->GetTypeDescent();
292     if (ascent != descent) {
293       float width = charinfo.matrix().a *
294                     charinfo.text_object()->GetCharWidth(charinfo.char_code());
295       float font_scale = charinfo.matrix().a * font_size / (ascent - descent);
296 
297       float left = charinfo.origin().x;
298       float right = charinfo.origin().x + (is_vert_writing ? -width : width);
299       float bottom = charinfo.origin().y + descent * font_scale;
300       float top = charinfo.origin().y + ascent * font_scale;
301       return CFX_FloatRect(left, bottom, right, top);
302     }
303   }
304 
305   // Fallback to the tight bounds in empty text scenarios, or bad font metrics
306   return charinfo.char_box();
307 }
308 
309 }  // namespace
310 
311 CPDF_TextPage::TransformedTextObject::TransformedTextObject() = default;
312 
313 CPDF_TextPage::TransformedTextObject::TransformedTextObject(
314     const TransformedTextObject& that) = default;
315 
316 CPDF_TextPage::TransformedTextObject::~TransformedTextObject() = default;
317 
318 CPDF_TextPage::CharInfo::CharInfo() = default;
319 
CharInfo(CharType char_type,uint32_t char_code,wchar_t unicode,CFX_PointF origin,CFX_FloatRect char_box,CFX_Matrix matrix,CPDF_TextObject * text_object)320 CPDF_TextPage::CharInfo::CharInfo(CharType char_type,
321                                   uint32_t char_code,
322                                   wchar_t unicode,
323                                   CFX_PointF origin,
324                                   CFX_FloatRect char_box,
325                                   CFX_Matrix matrix,
326                                   CPDF_TextObject* text_object)
327     : char_type_(char_type),
328       unicode_(unicode),
329       char_code_(char_code),
330       origin_(origin),
331       char_box_(char_box),
332       matrix_(matrix),
333       text_object_(text_object) {}
334 
335 CPDF_TextPage::CharInfo::CharInfo(const CharInfo&) = default;
336 
337 CPDF_TextPage::CharInfo::~CharInfo() = default;
338 
CPDF_TextPage(const CPDF_Page * pPage,bool rtl)339 CPDF_TextPage::CPDF_TextPage(const CPDF_Page* pPage, bool rtl)
340     : m_pPage(pPage), m_rtl(rtl), m_DisplayMatrix(GetPageMatrix(pPage)) {
341   Init();
342 }
343 
344 CPDF_TextPage::~CPDF_TextPage() = default;
345 
Init()346 void CPDF_TextPage::Init() {
347   m_TextBuf.SetAllocStep(10240);
348   ProcessObject();
349 
350   const int nCount = CountChars();
351   if (nCount)
352     m_CharIndices.push_back({0, 0});
353 
354   bool skipped = false;
355   for (int i = 0; i < nCount; ++i) {
356     const CharInfo& charinfo = m_CharList[i];
357     if (charinfo.char_type() == CharType::kGenerated ||
358         (charinfo.unicode() != 0 && !IsControlChar(charinfo)) ||
359         (charinfo.unicode() == 0 && charinfo.char_code() != 0)) {
360       m_CharIndices.back().count++;
361       skipped = true;
362     } else {
363       if (skipped) {
364         m_CharIndices.push_back({i + 1, 0});
365         skipped = false;
366       } else {
367         m_CharIndices.back().index = i + 1;
368       }
369     }
370   }
371 }
372 
CountChars() const373 int CPDF_TextPage::CountChars() const {
374   return fxcrt::CollectionSize<int>(m_CharList);
375 }
376 
CharIndexFromTextIndex(int text_index) const377 int CPDF_TextPage::CharIndexFromTextIndex(int text_index) const {
378   int count = 0;
379   for (const auto& info : m_CharIndices) {
380     count += info.count;
381     if (count > text_index)
382       return text_index - count + info.count + info.index;
383   }
384   return -1;
385 }
386 
TextIndexFromCharIndex(int char_index) const387 int CPDF_TextPage::TextIndexFromCharIndex(int char_index) const {
388   int count = 0;
389   for (const auto& info : m_CharIndices) {
390     int text_index = char_index - info.index;
391     if (text_index < info.count)
392       return text_index >= 0 ? text_index + count : -1;
393 
394     count += info.count;
395   }
396   return -1;
397 }
398 
GetRectArray(int start,int count) const399 std::vector<CFX_FloatRect> CPDF_TextPage::GetRectArray(int start,
400                                                        int count) const {
401   std::vector<CFX_FloatRect> rects;
402   if (start < 0 || count == 0)
403     return rects;
404 
405   const int number_of_chars = CountChars();
406   if (start >= number_of_chars)
407     return rects;
408 
409   if (count < 0 || start + count > number_of_chars)
410     count = number_of_chars - start;
411   DCHECK(count > 0);
412 
413   const CPDF_TextObject* text_object = nullptr;
414   CFX_FloatRect rect;
415   int pos = start;
416   bool is_new_rect = true;
417   while (count--) {
418     const CharInfo& charinfo = m_CharList[pos++];
419     if (charinfo.char_type() == CharType::kGenerated) {
420       continue;
421     }
422     if (charinfo.char_box().Width() < kSizeEpsilon ||
423         charinfo.char_box().Height() < kSizeEpsilon) {
424       continue;
425     }
426     if (!text_object)
427       text_object = charinfo.text_object();
428     if (text_object != charinfo.text_object()) {
429       rects.push_back(rect);
430       text_object = charinfo.text_object();
431       is_new_rect = true;
432     }
433     if (is_new_rect) {
434       is_new_rect = false;
435       rect = charinfo.char_box();
436       rect.Normalize();
437       continue;
438     }
439     rect.Union(charinfo.char_box());
440   }
441   rects.push_back(rect);
442   return rects;
443 }
444 
GetIndexAtPos(const CFX_PointF & point,const CFX_SizeF & tolerance) const445 int CPDF_TextPage::GetIndexAtPos(const CFX_PointF& point,
446                                  const CFX_SizeF& tolerance) const {
447   int pos;
448   int NearPos = -1;
449   double xdif = 5000;
450   double ydif = 5000;
451   const int nCount = CountChars();
452   for (pos = 0; pos < nCount; ++pos) {
453     const CFX_FloatRect& orig_charrect = m_CharList[pos].char_box();
454     if (orig_charrect.Contains(point))
455       break;
456 
457     if (tolerance.width <= 0 && tolerance.height <= 0)
458       continue;
459 
460     CFX_FloatRect charrect = orig_charrect;
461     charrect.Normalize();
462     CFX_FloatRect char_rect_ext(charrect.left - tolerance.width / 2,
463                                 charrect.bottom - tolerance.height / 2,
464                                 charrect.right + tolerance.width / 2,
465                                 charrect.top + tolerance.height / 2);
466     if (!char_rect_ext.Contains(point))
467       continue;
468 
469     double curXdif =
470         std::min(fabs(point.x - charrect.left), fabs(point.x - charrect.right));
471     double curYdif =
472         std::min(fabs(point.y - charrect.bottom), fabs(point.y - charrect.top));
473     if (curYdif + curXdif < xdif + ydif) {
474       ydif = curYdif;
475       xdif = curXdif;
476       NearPos = pos;
477     }
478   }
479   return pos < nCount ? pos : NearPos;
480 }
481 
GetTextByPredicate(const std::function<bool (const CharInfo &)> & predicate) const482 WideString CPDF_TextPage::GetTextByPredicate(
483     const std::function<bool(const CharInfo&)>& predicate) const {
484   float posy = 0;
485   bool IsContainPreChar = false;
486   bool IsAddLineFeed = false;
487   WideString strText;
488   for (const auto& charinfo : m_CharList) {
489     if (predicate(charinfo)) {
490       if (fabs(posy - charinfo.origin().y) > 0 && !IsContainPreChar &&
491           IsAddLineFeed) {
492         posy = charinfo.origin().y;
493         if (!strText.IsEmpty())
494           strText += L"\r\n";
495       }
496       IsContainPreChar = true;
497       IsAddLineFeed = false;
498       if (charinfo.unicode()) {
499         strText += charinfo.unicode();
500       }
501     } else if (charinfo.unicode() == L' ') {
502       if (IsContainPreChar) {
503         strText += L' ';
504         IsContainPreChar = false;
505         IsAddLineFeed = false;
506       }
507     } else {
508       IsContainPreChar = false;
509       IsAddLineFeed = true;
510     }
511   }
512   return strText;
513 }
514 
GetTextByRect(const CFX_FloatRect & rect) const515 WideString CPDF_TextPage::GetTextByRect(const CFX_FloatRect& rect) const {
516   return GetTextByPredicate([&rect](const CharInfo& charinfo) {
517     return IsRectIntersect(rect, charinfo.char_box());
518   });
519 }
520 
GetTextByObject(const CPDF_TextObject * pTextObj) const521 WideString CPDF_TextPage::GetTextByObject(
522     const CPDF_TextObject* pTextObj) const {
523   return GetTextByPredicate([pTextObj](const CharInfo& charinfo) {
524     return charinfo.text_object() == pTextObj;
525   });
526 }
527 
GetCharInfo(size_t index) const528 const CPDF_TextPage::CharInfo& CPDF_TextPage::GetCharInfo(size_t index) const {
529   CHECK_LT(index, m_CharList.size());
530   return m_CharList[index];
531 }
532 
GetCharInfo(size_t index)533 CPDF_TextPage::CharInfo& CPDF_TextPage::GetCharInfo(size_t index) {
534   CHECK_LT(index, m_CharList.size());
535   return m_CharList[index];
536 }
537 
GetCharFontSize(size_t index) const538 float CPDF_TextPage::GetCharFontSize(size_t index) const {
539   CHECK_LT(index, m_CharList.size());
540   return GetFontSize(m_CharList[index].text_object());
541 }
542 
GetCharLooseBounds(size_t index) const543 CFX_FloatRect CPDF_TextPage::GetCharLooseBounds(size_t index) const {
544   return GetLooseBounds(GetCharInfo(index));
545 }
546 
GetPageText(int start,int count) const547 WideString CPDF_TextPage::GetPageText(int start, int count) const {
548   if (start < 0 || start >= CountChars() || count <= 0 || m_CharList.empty() ||
549       m_TextBuf.IsEmpty()) {
550     return WideString();
551   }
552 
553   const int count_chars = CountChars();
554   int text_start = TextIndexFromCharIndex(start);
555 
556   // If the character at |start| is a non-printing character, then
557   // TextIndexFromCharIndex will return -1, so scan ahead to the first printing
558   // character.
559   while (text_start < 0) {
560     if (start >= count_chars)
561       return WideString();
562     start++;
563     text_start = TextIndexFromCharIndex(start);
564   }
565 
566   count = std::min(count, count_chars - start);
567 
568   int last = start + count - 1;
569   int text_last = TextIndexFromCharIndex(last);
570 
571   // If the character at |last| is a non-printing character, then
572   // TextIndexFromCharIndex will return -1, so scan back to the last printing
573   // character.
574   while (text_last < 0) {
575     if (last < text_start)
576       return WideString();
577 
578     last--;
579     text_last = TextIndexFromCharIndex(last);
580   }
581 
582   if (text_last < text_start)
583     return WideString();
584 
585   int text_count = text_last - text_start + 1;
586 
587   return WideString(m_TextBuf.AsStringView().Substr(text_start, text_count));
588 }
589 
CountRects(int start,int nCount)590 int CPDF_TextPage::CountRects(int start, int nCount) {
591   if (start < 0)
592     return -1;
593 
594   m_SelRects = GetRectArray(start, nCount);
595   return fxcrt::CollectionSize<int>(m_SelRects);
596 }
597 
GetRect(int rectIndex,CFX_FloatRect * pRect) const598 bool CPDF_TextPage::GetRect(int rectIndex, CFX_FloatRect* pRect) const {
599   if (!fxcrt::IndexInBounds(m_SelRects, rectIndex))
600     return false;
601 
602   *pRect = m_SelRects[rectIndex];
603   return true;
604 }
605 
FindTextlineFlowOrientation() const606 CPDF_TextPage::TextOrientation CPDF_TextPage::FindTextlineFlowOrientation()
607     const {
608   const int32_t nPageWidth = static_cast<int32_t>(m_pPage->GetPageWidth());
609   const int32_t nPageHeight = static_cast<int32_t>(m_pPage->GetPageHeight());
610   if (nPageWidth <= 0 || nPageHeight <= 0)
611     return TextOrientation::kUnknown;
612 
613   std::vector<bool> nHorizontalMask(nPageWidth);
614   std::vector<bool> nVerticalMask(nPageHeight);
615   float fLineHeight = 0.0f;
616   int32_t nStartH = nPageWidth;
617   int32_t nEndH = 0;
618   int32_t nStartV = nPageHeight;
619   int32_t nEndV = 0;
620   for (const auto& pPageObj : *m_pPage) {
621     if (!pPageObj->IsActive() || !pPageObj->IsText()) {
622       continue;
623     }
624 
625     int32_t minH = static_cast<int32_t>(
626         std::clamp<float>(pPageObj->GetRect().left, 0.0f, nPageWidth));
627     int32_t maxH = static_cast<int32_t>(
628         std::clamp<float>(pPageObj->GetRect().right, 0.0f, nPageWidth));
629     int32_t minV = static_cast<int32_t>(
630         std::clamp<float>(pPageObj->GetRect().bottom, 0.0f, nPageHeight));
631     int32_t maxV = static_cast<int32_t>(
632         std::clamp<float>(pPageObj->GetRect().top, 0.0f, nPageHeight));
633     if (minH >= maxH || minV >= maxV)
634       continue;
635 
636     for (int32_t i = minH; i < maxH; ++i)
637       nHorizontalMask[i] = true;
638     for (int32_t i = minV; i < maxV; ++i)
639       nVerticalMask[i] = true;
640 
641     nStartH = std::min(nStartH, minH);
642     nEndH = std::max(nEndH, maxH);
643     nStartV = std::min(nStartV, minV);
644     nEndV = std::max(nEndV, maxV);
645 
646     if (fLineHeight <= 0.0f)
647       fLineHeight = pPageObj->GetRect().Height();
648   }
649   const int32_t nDoubleLineHeight = 2 * fLineHeight;
650   if ((nEndV - nStartV) < nDoubleLineHeight)
651     return TextOrientation::kHorizontal;
652   if ((nEndH - nStartH) < nDoubleLineHeight)
653     return TextOrientation::kVertical;
654 
655   const float nSumH = MaskPercentFilled(nHorizontalMask, nStartH, nEndH);
656   if (nSumH > 0.8f)
657     return TextOrientation::kHorizontal;
658 
659   const float nSumV = MaskPercentFilled(nVerticalMask, nStartV, nEndV);
660   if (nSumH > nSumV)
661     return TextOrientation::kHorizontal;
662   if (nSumH < nSumV)
663     return TextOrientation::kVertical;
664   return TextOrientation::kUnknown;
665 }
666 
AppendGeneratedCharacter(wchar_t unicode,const CFX_Matrix & form_matrix,bool use_temp_buffer)667 void CPDF_TextPage::AppendGeneratedCharacter(wchar_t unicode,
668                                              const CFX_Matrix& form_matrix,
669                                              bool use_temp_buffer) {
670   std::optional<CharInfo> charinfo = GenerateCharInfo(unicode, form_matrix);
671   if (!charinfo.has_value()) {
672     return;
673   }
674 
675   if (use_temp_buffer) {
676     m_TempTextBuf.AppendChar(unicode);
677     m_TempCharList.push_back(charinfo.value());
678   } else {
679     m_TextBuf.AppendChar(unicode);
680     m_CharList.push_back(charinfo.value());
681   }
682 }
683 
ProcessObject()684 void CPDF_TextPage::ProcessObject() {
685   if (m_pPage->GetActivePageObjectCount() == 0) {
686     return;
687   }
688 
689   m_TextlineDir = FindTextlineFlowOrientation();
690   for (auto it = m_pPage->begin(); it != m_pPage->end(); ++it) {
691     CPDF_PageObject* pObj = it->get();
692     if (!pObj->IsActive()) {
693       continue;
694     }
695 
696     if (pObj->IsText()) {
697       ProcessTextObject(pObj->AsText(), CFX_Matrix(), m_pPage, it);
698     } else if (pObj->IsForm()) {
699       ProcessFormObject(pObj->AsForm(), CFX_Matrix());
700     }
701   }
702   for (const auto& obj : mTextObjects)
703     ProcessTextObject(obj);
704 
705   mTextObjects.clear();
706   CloseTempLine();
707 }
708 
ProcessFormObject(CPDF_FormObject * pFormObj,const CFX_Matrix & form_matrix)709 void CPDF_TextPage::ProcessFormObject(CPDF_FormObject* pFormObj,
710                                       const CFX_Matrix& form_matrix) {
711   CFX_Matrix curFormMatrix = pFormObj->form_matrix() * form_matrix;
712   const CPDF_PageObjectHolder* pHolder = pFormObj->form();
713   for (auto it = pHolder->begin(); it != pHolder->end(); ++it) {
714     CPDF_PageObject* pPageObj = it->get();
715     if (!pPageObj->IsActive()) {
716       continue;
717     }
718 
719     if (pPageObj->IsText()) {
720       ProcessTextObject(pPageObj->AsText(), curFormMatrix, pHolder, it);
721     } else if (pPageObj->IsForm()) {
722       ProcessFormObject(pPageObj->AsForm(), curFormMatrix);
723     }
724   }
725 }
726 
AddCharInfoByLRDirection(wchar_t wChar,const CharInfo & info)727 void CPDF_TextPage::AddCharInfoByLRDirection(wchar_t wChar,
728                                              const CharInfo& info) {
729   CharInfo info2 = info;
730   if (IsControlChar(info2)) {
731     m_CharList.push_back(info2);
732     return;
733   }
734   DataVector<wchar_t> normalized;
735   if (wChar >= 0xFB00 && wChar <= 0xFB06)
736     normalized = GetUnicodeNormalization(wChar);
737   if (normalized.empty()) {
738     m_TextBuf.AppendChar(wChar);
739     m_CharList.push_back(info2);
740     return;
741   }
742   info2.set_char_type(CharType::kPiece);
743   for (wchar_t normalized_char : normalized) {
744     info2.set_unicode(normalized_char);
745     m_TextBuf.AppendChar(normalized_char);
746     m_CharList.push_back(info2);
747   }
748 }
749 
AddCharInfoByRLDirection(wchar_t wChar,const CharInfo & info)750 void CPDF_TextPage::AddCharInfoByRLDirection(wchar_t wChar,
751                                              const CharInfo& info) {
752   CharInfo info2 = info;
753   if (IsControlChar(info2)) {
754     m_CharList.push_back(info2);
755     return;
756   }
757   wChar = pdfium::unicode::GetMirrorChar(wChar);
758   DataVector<wchar_t> normalized = GetUnicodeNormalization(wChar);
759   if (normalized.empty()) {
760     info2.set_unicode(wChar);
761     m_TextBuf.AppendChar(wChar);
762     m_CharList.push_back(info2);
763     return;
764   }
765   info2.set_char_type(CharType::kPiece);
766   for (wchar_t normalized_char : normalized) {
767     info2.set_unicode(normalized_char);
768     m_TextBuf.AppendChar(normalized_char);
769     m_CharList.push_back(info2);
770   }
771 }
772 
CloseTempLine()773 void CPDF_TextPage::CloseTempLine() {
774   if (m_TempCharList.empty())
775     return;
776 
777   WideString str = m_TempTextBuf.MakeString();
778   bool bPrevSpace = false;
779   for (size_t i = 0; i < str.GetLength(); ++i) {
780     if (str[i] != ' ') {
781       bPrevSpace = false;
782       continue;
783     }
784     if (bPrevSpace) {
785       m_TempTextBuf.Delete(i, 1);
786       m_TempCharList.erase(m_TempCharList.begin() + i);
787       str.Delete(i);
788       --i;
789     }
790     bPrevSpace = true;
791   }
792   CFX_BidiString bidi(str);
793   if (m_rtl)
794     bidi.SetOverallDirectionRight();
795   CFX_BidiChar::Direction eCurrentDirection = bidi.OverallDirection();
796   for (const auto& segment : bidi) {
797     if (segment.direction == CFX_BidiChar::Direction::kRight ||
798         (segment.direction == CFX_BidiChar::Direction::kNeutral &&
799          eCurrentDirection == CFX_BidiChar::Direction::kRight)) {
800       eCurrentDirection = CFX_BidiChar::Direction::kRight;
801       for (int m = segment.start + segment.count; m > segment.start; --m)
802         AddCharInfoByRLDirection(str[m - 1], m_TempCharList[m - 1]);
803     } else {
804       if (segment.direction != CFX_BidiChar::Direction::kLeftWeak) {
805         eCurrentDirection = CFX_BidiChar::Direction::kLeft;
806       }
807       for (int m = segment.start; m < segment.start + segment.count; ++m)
808         AddCharInfoByLRDirection(str[m], m_TempCharList[m]);
809     }
810   }
811   m_TempCharList.clear();
812   m_TempTextBuf.Delete(0, m_TempTextBuf.GetLength());
813 }
814 
ProcessTextObject(CPDF_TextObject * pTextObj,const CFX_Matrix & form_matrix,const CPDF_PageObjectHolder * pObjList,CPDF_PageObjectHolder::const_iterator ObjPos)815 void CPDF_TextPage::ProcessTextObject(
816     CPDF_TextObject* pTextObj,
817     const CFX_Matrix& form_matrix,
818     const CPDF_PageObjectHolder* pObjList,
819     CPDF_PageObjectHolder::const_iterator ObjPos) {
820   if (fabs(pTextObj->GetRect().Width()) < kSizeEpsilon)
821     return;
822 
823   size_t count = mTextObjects.size();
824   TransformedTextObject new_obj;
825   new_obj.m_pTextObj = pTextObj;
826   new_obj.m_formMatrix = form_matrix;
827   if (count == 0) {
828     mTextObjects.push_back(new_obj);
829     return;
830   }
831   if (IsSameAsPreTextObject(pTextObj, pObjList, ObjPos))
832     return;
833 
834   TransformedTextObject prev_obj = mTextObjects[count - 1];
835   size_t nItem = prev_obj.m_pTextObj->CountItems();
836   if (nItem == 0)
837     return;
838 
839   CPDF_TextObject::Item item = prev_obj.m_pTextObj->GetItemInfo(nItem - 1);
840   float prev_width =
841       GetCharWidth(item.m_CharCode, prev_obj.m_pTextObj->GetFont().Get()) *
842       prev_obj.m_pTextObj->GetFontSize() / 1000;
843 
844   CFX_Matrix prev_matrix =
845       prev_obj.m_pTextObj->GetTextMatrix() * prev_obj.m_formMatrix;
846   prev_width = prev_matrix.TransformDistance(fabs(prev_width));
847   item = pTextObj->GetItemInfo(0);
848   float this_width = GetCharWidth(item.m_CharCode, pTextObj->GetFont().Get()) *
849                      pTextObj->GetFontSize() / 1000;
850   this_width = fabs(this_width);
851 
852   CFX_Matrix this_matrix = pTextObj->GetTextMatrix() * form_matrix;
853   this_width = this_matrix.TransformDistance(fabs(this_width));
854 
855   float threshold = std::max(prev_width, this_width) / 4;
856   CFX_PointF prev_pos = m_DisplayMatrix.Transform(
857       prev_obj.m_formMatrix.Transform(prev_obj.m_pTextObj->GetPos()));
858   CFX_PointF this_pos =
859       m_DisplayMatrix.Transform(form_matrix.Transform(pTextObj->GetPos()));
860   if (fabs(this_pos.y - prev_pos.y) > threshold * 2) {
861     for (size_t i = 0; i < count; ++i)
862       ProcessTextObject(mTextObjects[i]);
863     mTextObjects.clear();
864     mTextObjects.push_back(new_obj);
865     return;
866   }
867 
868   for (size_t i = count; i > 0; --i) {
869     TransformedTextObject prev_text_obj = mTextObjects[i - 1];
870     CFX_PointF new_prev_pos =
871         m_DisplayMatrix.Transform(prev_text_obj.m_formMatrix.Transform(
872             prev_text_obj.m_pTextObj->GetPos()));
873     if (this_pos.x >= new_prev_pos.x) {
874       mTextObjects.insert(mTextObjects.begin() + i, new_obj);
875       return;
876     }
877   }
878   mTextObjects.insert(mTextObjects.begin(), new_obj);
879 }
880 
PreMarkedContent(const CPDF_TextObject * pTextObj)881 CPDF_TextPage::MarkedContentState CPDF_TextPage::PreMarkedContent(
882     const CPDF_TextObject* pTextObj) {
883   const CPDF_ContentMarks* pMarks = pTextObj->GetContentMarks();
884   const size_t nContentMarks = pMarks->CountItems();
885   if (nContentMarks == 0)
886     return MarkedContentState::kPass;
887 
888   WideString actual_text;
889   bool bExist = false;
890   RetainPtr<const CPDF_Dictionary> pDict;
891   for (size_t i = 0; i < nContentMarks; ++i) {
892     const CPDF_ContentMarkItem* item = pMarks->GetItem(i);
893     pDict = item->GetParam();
894     if (!pDict)
895       continue;
896     RetainPtr<const CPDF_String> temp = pDict->GetStringFor("ActualText");
897     if (temp) {
898       bExist = true;
899       actual_text = temp->GetUnicodeText();
900     }
901   }
902   if (!bExist)
903     return MarkedContentState::kPass;
904 
905   if (m_pPrevTextObj) {
906     const CPDF_ContentMarks* pPrevMarks = m_pPrevTextObj->GetContentMarks();
907     if (pPrevMarks->CountItems() == nContentMarks &&
908         pPrevMarks->GetItem(nContentMarks - 1)->GetParam() == pDict) {
909       return MarkedContentState::kDone;
910     }
911   }
912 
913   if (actual_text.IsEmpty()) {
914     return MarkedContentState::kPass;
915   }
916 
917   RetainPtr<CPDF_Font> pFont = pTextObj->GetFont();
918   bExist = false;
919   for (size_t i = 0; i < actual_text.GetLength(); ++i) {
920     if (pFont->CharCodeFromUnicode(actual_text[i]) !=
921         CPDF_Font::kInvalidCharCode) {
922       bExist = true;
923       break;
924     }
925   }
926   if (!bExist)
927     return MarkedContentState::kPass;
928 
929   bExist = false;
930   for (size_t i = 0; i < actual_text.GetLength(); ++i) {
931     wchar_t wChar = actual_text[i];
932     if ((wChar > 0x80 && wChar < 0xFFFD) || (wChar <= 0x80 && isprint(wChar))) {
933       bExist = true;
934       break;
935     }
936   }
937   if (!bExist)
938     return MarkedContentState::kDone;
939 
940   return MarkedContentState::kDelay;
941 }
942 
ProcessMarkedContent(const TransformedTextObject & obj)943 void CPDF_TextPage::ProcessMarkedContent(const TransformedTextObject& obj) {
944   CPDF_TextObject* const pTextObj = obj.m_pTextObj;
945   const CPDF_ContentMarks* pMarks = pTextObj->GetContentMarks();
946   const size_t nContentMarks = pMarks->CountItems();
947   WideString actual_text;
948   for (size_t n = 0; n < nContentMarks; ++n) {
949     const CPDF_ContentMarkItem* item = pMarks->GetItem(n);
950     RetainPtr<const CPDF_Dictionary> pDict = item->GetParam();
951     if (pDict) {
952       actual_text = pDict->GetUnicodeTextFor("ActualText");
953     }
954   }
955   if (actual_text.IsEmpty()) {
956     return;
957   }
958 
959   const bool bR2L = IsRightToLeft(*pTextObj);
960   CFX_Matrix matrix = pTextObj->GetTextMatrix() * obj.m_formMatrix;
961   CFX_FloatRect rect = pTextObj->GetRect();
962   float step = 0;
963 
964   if (bR2L) {
965     rect.left = rect.right - (rect.Width() / actual_text.GetLength());
966     step = -rect.Width();
967   } else {
968     rect.right = rect.left + (rect.Width() / actual_text.GetLength());
969     step = rect.Width();
970   }
971 
972   RetainPtr<CPDF_Font> const font = pTextObj->GetFont();
973   for (size_t k = 0; k < actual_text.GetLength(); ++k) {
974     wchar_t wChar = actual_text[k];
975     if (wChar <= 0x80 && !isprint(wChar)) {
976       wChar = 0x20;
977     }
978     if (wChar >= 0xFFFD) {
979       continue;
980     }
981 
982     CFX_FloatRect char_box(rect);
983     char_box.Translate(k * step, 0);
984     m_TempCharList.push_back(
985         CharInfo(CharType::kPiece, font->CharCodeFromUnicode(wChar), wChar,
986                  pTextObj->GetPos(), char_box, matrix, pTextObj));
987   }
988 }
989 
FindPreviousTextObject()990 void CPDF_TextPage::FindPreviousTextObject() {
991   const CharInfo* pPrevCharInfo = GetPrevCharInfo();
992   if (!pPrevCharInfo)
993     return;
994 
995   if (pPrevCharInfo->text_object()) {
996     m_pPrevTextObj = pPrevCharInfo->text_object();
997   }
998 }
999 
SwapTempTextBuf(size_t iCharListStartAppend,size_t iBufStartAppend)1000 void CPDF_TextPage::SwapTempTextBuf(size_t iCharListStartAppend,
1001                                     size_t iBufStartAppend) {
1002   DCHECK(!m_TempCharList.empty());
1003   if (iCharListStartAppend < m_TempCharList.size()) {
1004     auto fwd = m_TempCharList.begin() + iCharListStartAppend;
1005     auto rev = m_TempCharList.end() - 1;
1006     for (; fwd < rev; ++fwd, --rev) {
1007       std::swap(*fwd, *rev);
1008     }
1009   }
1010   pdfium::span<wchar_t> temp_span = m_TempTextBuf.GetWideSpan();
1011   DCHECK(!temp_span.empty());
1012   if (iBufStartAppend < temp_span.size()) {
1013     pdfium::span<wchar_t> reverse_span = temp_span.subspan(iBufStartAppend);
1014     std::reverse(reverse_span.begin(), reverse_span.end());
1015   }
1016 }
1017 
ProcessTextObject(const TransformedTextObject & obj)1018 void CPDF_TextPage::ProcessTextObject(const TransformedTextObject& obj) {
1019   CPDF_TextObject* const pTextObj = obj.m_pTextObj;
1020   if (fabs(pTextObj->GetRect().Width()) < kSizeEpsilon) {
1021     return;
1022   }
1023 
1024   const CFX_Matrix form_matrix = obj.m_formMatrix;
1025   const MarkedContentState ePreMKC = PreMarkedContent(pTextObj);
1026   if (ePreMKC == MarkedContentState::kDone) {
1027     m_pPrevTextObj = pTextObj;
1028     m_PrevMatrix = form_matrix;
1029     return;
1030   }
1031 
1032   if (m_pPrevTextObj) {
1033     GenerateCharacter type = ProcessInsertObject(pTextObj, form_matrix);
1034     if (type == GenerateCharacter::kLineBreak) {
1035       m_CurlineRect = pTextObj->GetRect();
1036     } else {
1037       m_CurlineRect.Union(pTextObj->GetRect());
1038     }
1039 
1040     if (!ProcessGenerateCharacter(type, pTextObj, form_matrix)) {
1041       return;
1042     }
1043   } else {
1044     m_CurlineRect = pTextObj->GetRect();
1045   }
1046 
1047   if (ePreMKC == MarkedContentState::kDelay) {
1048     ProcessMarkedContent(obj);
1049     m_pPrevTextObj = pTextObj;
1050     m_PrevMatrix = form_matrix;
1051     return;
1052   }
1053 
1054   m_pPrevTextObj = pTextObj;
1055   m_PrevMatrix = form_matrix;
1056 
1057   const bool bR2L = IsRightToLeft(*pTextObj);
1058   const CFX_Matrix matrix = pTextObj->GetTextMatrix() * form_matrix;
1059   const bool bIsBidiAndMirrorInverse =
1060       bR2L && (matrix.a * matrix.d - matrix.b * matrix.c) < 0;
1061   const size_t iBufStartAppend = m_TempTextBuf.GetLength();
1062   const size_t iCharListStartAppend = m_TempCharList.size();
1063 
1064   ProcessTextObjectItems(pTextObj, form_matrix, matrix);
1065   if (bIsBidiAndMirrorInverse) {
1066     SwapTempTextBuf(iCharListStartAppend, iBufStartAppend);
1067   }
1068 }
1069 
GetTextObjectWritingMode(const CPDF_TextObject * pTextObj) const1070 CPDF_TextPage::TextOrientation CPDF_TextPage::GetTextObjectWritingMode(
1071     const CPDF_TextObject* pTextObj) const {
1072   size_t nChars = pTextObj->CountChars();
1073   if (nChars <= 1)
1074     return m_TextlineDir;
1075 
1076   CPDF_TextObject::Item first = pTextObj->GetCharInfo(0);
1077   CPDF_TextObject::Item last = pTextObj->GetCharInfo(nChars - 1);
1078   CFX_Matrix text_matrix = pTextObj->GetTextMatrix();
1079   first.m_Origin = text_matrix.Transform(first.m_Origin);
1080   last.m_Origin = text_matrix.Transform(last.m_Origin);
1081 
1082   static constexpr float kEpsilon = 0.0001f;
1083   float dX = fabs(last.m_Origin.x - first.m_Origin.x);
1084   float dY = fabs(last.m_Origin.y - first.m_Origin.y);
1085   if (dX <= kEpsilon && dY <= kEpsilon)
1086     return TextOrientation::kUnknown;
1087 
1088   static constexpr float kThreshold = 0.0872f;
1089   CFX_VectorF v(dX, dY);
1090   v.Normalize();
1091   bool bXUnderThreshold = v.x <= kThreshold;
1092   if (v.y <= kThreshold)
1093     return bXUnderThreshold ? m_TextlineDir : TextOrientation::kHorizontal;
1094   return bXUnderThreshold ? TextOrientation::kVertical : m_TextlineDir;
1095 }
1096 
IsHyphen(wchar_t curChar) const1097 bool CPDF_TextPage::IsHyphen(wchar_t curChar) const {
1098   WideStringView curText = m_TempTextBuf.AsStringView();
1099   if (curText.IsEmpty())
1100     curText = m_TextBuf.AsStringView();
1101 
1102   if (curText.IsEmpty())
1103     return false;
1104 
1105   auto iter = curText.rbegin();
1106   for (; (iter + 1) != curText.rend() && *iter == 0x20; ++iter) {
1107     // Do nothing
1108   }
1109 
1110   if (!IsHyphenCode(*iter))
1111     return false;
1112 
1113   if ((iter + 1) != curText.rend()) {
1114     iter++;
1115     if (FXSYS_iswalpha(*iter) && FXSYS_iswalnum(curChar))
1116       return true;
1117   }
1118 
1119   const CharInfo* pPrevCharInfo = GetPrevCharInfo();
1120   return pPrevCharInfo && pPrevCharInfo->char_type() == CharType::kPiece &&
1121          IsHyphenCode(pPrevCharInfo->unicode());
1122 }
1123 
GetPrevCharInfo() const1124 const CPDF_TextPage::CharInfo* CPDF_TextPage::GetPrevCharInfo() const {
1125   if (!m_TempCharList.empty())
1126     return &m_TempCharList.back();
1127   return !m_CharList.empty() ? &m_CharList.back() : nullptr;
1128 }
1129 
ProcessInsertObject(const CPDF_TextObject * pObj,const CFX_Matrix & form_matrix)1130 CPDF_TextPage::GenerateCharacter CPDF_TextPage::ProcessInsertObject(
1131     const CPDF_TextObject* pObj,
1132     const CFX_Matrix& form_matrix) {
1133   FindPreviousTextObject();
1134   TextOrientation WritingMode = GetTextObjectWritingMode(pObj);
1135   if (WritingMode == TextOrientation::kUnknown)
1136     WritingMode = GetTextObjectWritingMode(m_pPrevTextObj);
1137 
1138   size_t nItem = m_pPrevTextObj->CountItems();
1139   if (nItem == 0)
1140     return GenerateCharacter::kNone;
1141 
1142   CPDF_TextObject::Item PrevItem = m_pPrevTextObj->GetItemInfo(nItem - 1);
1143   CPDF_TextObject::Item item = pObj->GetItemInfo(0);
1144   const CFX_FloatRect& this_rect = pObj->GetRect();
1145   const CFX_FloatRect& prev_rect = m_pPrevTextObj->GetRect();
1146   WideString unicode = pObj->GetFont()->UnicodeFromCharCode(item.m_CharCode);
1147   if (unicode.IsEmpty()) {
1148     unicode += static_cast<wchar_t>(item.m_CharCode);
1149   }
1150 
1151   wchar_t curChar = unicode[0];
1152   if (WritingMode == TextOrientation::kHorizontal) {
1153     if (EndHorizontalLine(this_rect, prev_rect)) {
1154       return IsHyphen(curChar) ? GenerateCharacter::kHyphen
1155                                : GenerateCharacter::kLineBreak;
1156     }
1157   } else if (WritingMode == TextOrientation::kVertical) {
1158     if (EndVerticalLine(this_rect, prev_rect, m_CurlineRect,
1159                         pObj->GetFontSize(), m_pPrevTextObj->GetFontSize())) {
1160       return IsHyphen(curChar) ? GenerateCharacter::kHyphen
1161                                : GenerateCharacter::kLineBreak;
1162     }
1163   }
1164 
1165   float last_pos = PrevItem.m_Origin.x;
1166   int nLastWidth =
1167       GetCharWidth(PrevItem.m_CharCode, m_pPrevTextObj->GetFont().Get());
1168   float last_width = nLastWidth * m_pPrevTextObj->GetFontSize() / 1000;
1169   last_width = fabs(last_width);
1170   int nThisWidth = GetCharWidth(item.m_CharCode, pObj->GetFont().Get());
1171   float this_width = fabs(nThisWidth * pObj->GetFontSize() / 1000);
1172   float threshold = std::max(last_width, this_width) / 4;
1173 
1174   CFX_Matrix prev_matrix = m_pPrevTextObj->GetTextMatrix() * m_PrevMatrix;
1175   CFX_Matrix prev_reverse = prev_matrix.GetInverse();
1176 
1177   CFX_PointF pos =
1178       prev_reverse.Transform(form_matrix.Transform(pObj->GetPos()));
1179   if (last_width < this_width)
1180     threshold = prev_reverse.TransformDistance(threshold);
1181 
1182   bool bNewline = false;
1183   if (WritingMode == TextOrientation::kHorizontal) {
1184     CFX_FloatRect rect = m_pPrevTextObj->GetRect();
1185     float rect_height = rect.Height();
1186     rect.Normalize();
1187     if ((rect.IsEmpty() && rect_height > 5) ||
1188         ((pos.y > threshold * 2 || pos.y < threshold * -3) &&
1189          (fabs(pos.y) >= 1 || fabs(pos.y) > fabs(pos.x)))) {
1190       bNewline = true;
1191       if (nItem > 1) {
1192         CPDF_TextObject::Item tempItem = m_pPrevTextObj->GetItemInfo(0);
1193         CFX_Matrix m = m_pPrevTextObj->GetTextMatrix();
1194         if (PrevItem.m_Origin.x > tempItem.m_Origin.x &&
1195             m_DisplayMatrix.a > 0.9 && m_DisplayMatrix.b < 0.1 &&
1196             m_DisplayMatrix.c < 0.1 && m_DisplayMatrix.d < -0.9 && m.b < 0.1 &&
1197             m.c < 0.1) {
1198           CFX_FloatRect re(0, m_pPrevTextObj->GetRect().bottom, 1000,
1199                            m_pPrevTextObj->GetRect().top);
1200           if (re.Contains(pObj->GetPos())) {
1201             bNewline = false;
1202           } else {
1203             if (CFX_FloatRect(0, pObj->GetRect().bottom, 1000,
1204                               pObj->GetRect().top)
1205                     .Contains(m_pPrevTextObj->GetPos())) {
1206               bNewline = false;
1207             }
1208           }
1209         }
1210       }
1211     }
1212   }
1213   if (bNewline) {
1214     return IsHyphen(curChar) ? GenerateCharacter::kHyphen
1215                              : GenerateCharacter::kLineBreak;
1216   }
1217 
1218   if (pObj->CountChars() == 1 && IsHyphenCode(curChar) && IsHyphen(curChar))
1219     return GenerateCharacter::kHyphen;
1220 
1221   if (curChar == L' ')
1222     return GenerateCharacter::kNone;
1223 
1224   WideString PrevStr =
1225       m_pPrevTextObj->GetFont()->UnicodeFromCharCode(PrevItem.m_CharCode);
1226   wchar_t preChar = PrevStr.Back();
1227   if (preChar == L' ')
1228     return GenerateCharacter::kNone;
1229 
1230   CFX_Matrix matrix = pObj->GetTextMatrix() * form_matrix;
1231   float threshold2 = std::max(nLastWidth, nThisWidth);
1232   threshold2 = NormalizeThreshold(threshold2, 400, 700, 800);
1233   if (nLastWidth >= nThisWidth) {
1234     threshold2 *= fabs(m_pPrevTextObj->GetFontSize());
1235   } else {
1236     threshold2 *= fabs(pObj->GetFontSize());
1237     threshold2 = matrix.TransformDistance(threshold2);
1238     threshold2 = prev_reverse.TransformDistance(threshold2);
1239   }
1240   threshold2 /= 1000;
1241   if ((threshold2 < 1.4881 && threshold2 > 1.4879) ||
1242       (threshold2 < 1.39001 && threshold2 > 1.38999)) {
1243     threshold2 *= 1.5;
1244   }
1245   return GenerateSpace(pos, last_pos, this_width, last_width, threshold2)
1246              ? GenerateCharacter::kSpace
1247              : GenerateCharacter::kNone;
1248 }
1249 
ProcessGenerateCharacter(GenerateCharacter type,const CPDF_TextObject * text_object,const CFX_Matrix & form_matrix)1250 bool CPDF_TextPage::ProcessGenerateCharacter(GenerateCharacter type,
1251                                              const CPDF_TextObject* text_object,
1252                                              const CFX_Matrix& form_matrix) {
1253   switch (type) {
1254     case GenerateCharacter::kNone:
1255       return true;
1256     case GenerateCharacter::kSpace: {
1257       AppendGeneratedCharacter(L' ', form_matrix, /*use_temp_buffer=*/true);
1258       return true;
1259     }
1260     case GenerateCharacter::kLineBreak:
1261       CloseTempLine();
1262       if (m_TextBuf.GetSize()) {
1263         AppendGeneratedCharacter(L'\r', form_matrix, /*use_temp_buffer=*/false);
1264         AppendGeneratedCharacter(L'\n', form_matrix, /*use_temp_buffer=*/false);
1265       }
1266       return true;
1267     case GenerateCharacter::kHyphen:
1268       if (text_object->CountChars() == 1) {
1269         CPDF_TextObject::Item item = text_object->GetCharInfo(0);
1270         WideString unicode =
1271             text_object->GetFont()->UnicodeFromCharCode(item.m_CharCode);
1272         if (unicode.IsEmpty()) {
1273           unicode += static_cast<wchar_t>(item.m_CharCode);
1274         }
1275         wchar_t curChar = unicode[0];
1276         if (IsHyphenCode(curChar)) {
1277           return false;
1278         }
1279       }
1280       while (m_TempTextBuf.GetSize() > 0 &&
1281              m_TempTextBuf.AsStringView().Back() == 0x20) {
1282         m_TempTextBuf.Delete(m_TempTextBuf.GetLength() - 1, 1);
1283         m_TempCharList.pop_back();
1284       }
1285       CharInfo& charinfo = m_TempCharList.back();
1286       m_TempTextBuf.Delete(m_TempTextBuf.GetLength() - 1, 1);
1287       charinfo.set_char_type(CharType::kHyphen);
1288       charinfo.set_unicode(0x2);
1289       m_TempTextBuf.AppendChar(0xfffe);
1290       return true;
1291   }
1292   NOTREACHED_NORETURN();
1293 }
1294 
ProcessTextObjectItems(CPDF_TextObject * text_object,const CFX_Matrix & form_matrix,const CFX_Matrix & matrix)1295 void CPDF_TextPage::ProcessTextObjectItems(CPDF_TextObject* text_object,
1296                                            const CFX_Matrix& form_matrix,
1297                                            const CFX_Matrix& matrix) {
1298   const float base_space = CalculateBaseSpace(text_object, matrix) +
1299                            CalculateBaseSpaceAdjustment(text_object, matrix);
1300   RetainPtr<CPDF_Font> const font = text_object->GetFont();
1301 
1302   float spacing = 0;
1303   const size_t nItems = text_object->CountItems();
1304   for (size_t i = 0; i < nItems; ++i) {
1305     CPDF_TextObject::Item item = text_object->GetItemInfo(i);
1306     if (item.m_CharCode == 0xffffffff) {
1307       WideString str = m_TempTextBuf.MakeString();
1308       if (str.IsEmpty()) {
1309         str = m_TextBuf.AsStringView();
1310       }
1311       if (!str.IsEmpty() && str.Back() != L' ') {
1312         float fontsize_h = text_object->text_state().GetFontSizeH();
1313         spacing = -fontsize_h * item.m_Origin.x / 1000;
1314       }
1315       continue;
1316     }
1317 
1318     spacing -= base_space;
1319 
1320     if (spacing && i > 0) {
1321       const float threshold = CalculateSpaceThreshold(
1322           font, text_object->text_state().GetFontSizeH(), item.m_CharCode);
1323       if (threshold && spacing && spacing >= threshold) {
1324         m_TempTextBuf.AppendChar(L' ');
1325         CFX_PointF origin = matrix.Transform(item.m_Origin);
1326         m_TempCharList.push_back(CharInfo(
1327             CharType::kGenerated, CPDF_Font::kInvalidCharCode, L' ', origin,
1328             CFX_FloatRect(origin.x, origin.y, origin.x, origin.y), form_matrix,
1329             text_object));
1330       }
1331       if (item.m_CharCode == CPDF_Font::kInvalidCharCode) {
1332         continue;
1333       }
1334     }
1335 
1336     spacing = 0;
1337     WideString unicode = font->UnicodeFromCharCode(item.m_CharCode);
1338     CharType char_type = CharType::kNormal;
1339     if (unicode.IsEmpty() && item.m_CharCode) {
1340       unicode += static_cast<wchar_t>(item.m_CharCode);
1341       char_type = CharType::kNotUnicode;
1342     }
1343 
1344     const FX_RECT rect = font->GetCharBBox(item.m_CharCode);
1345     const float fFontSize = text_object->GetFontSize() / 1000;
1346     CFX_FloatRect char_box(rect.left * fFontSize + item.m_Origin.x,
1347                            rect.bottom * fFontSize + item.m_Origin.y,
1348                            rect.right * fFontSize + item.m_Origin.x,
1349                            rect.top * fFontSize + item.m_Origin.y);
1350     if (fabsf(char_box.top - char_box.bottom) < kSizeEpsilon) {
1351       char_box.top = char_box.bottom + fFontSize;
1352     }
1353     if (fabsf(char_box.right - char_box.left) < kSizeEpsilon) {
1354       char_box.right =
1355           char_box.left + text_object->GetCharWidth(item.m_CharCode);
1356     }
1357     char_box = matrix.TransformRect(char_box);
1358 
1359     CharInfo charinfo(char_type, item.m_CharCode, 0,
1360                       matrix.Transform(item.m_Origin), char_box, matrix,
1361                       text_object);
1362     if (unicode.IsEmpty()) {
1363       m_TempCharList.push_back(charinfo);
1364       m_TempTextBuf.AppendChar(0xfffe);
1365       continue;
1366     }
1367 
1368     bool add_unicode = true;
1369     const int count = std::min(fxcrt::CollectionSize<int>(m_TempCharList), 7);
1370     constexpr float kTextCharRatioGapDelta = 0.07f;
1371     float threshold = charinfo.matrix().TransformXDistance(
1372         kTextCharRatioGapDelta * text_object->GetFontSize());
1373     for (int n = fxcrt::CollectionSize<int>(m_TempCharList);
1374          n > fxcrt::CollectionSize<int>(m_TempCharList) - count; --n) {
1375       const CharInfo& charinfo1 = m_TempCharList[n - 1];
1376       CFX_PointF diff = charinfo1.origin() - charinfo.origin();
1377       if (charinfo1.char_code() == charinfo.char_code() &&
1378           charinfo1.text_object()->GetFont() ==
1379               charinfo.text_object()->GetFont() &&
1380           fabs(diff.x) < threshold && fabs(diff.y) < threshold) {
1381         add_unicode = false;
1382         break;
1383       }
1384     }
1385     if (add_unicode) {
1386       for (wchar_t c : unicode) {
1387         charinfo.set_unicode(c);
1388         m_TempTextBuf.AppendChar(c ? c : 0xfffe);
1389         m_TempCharList.push_back(charinfo);
1390       }
1391     } else if (i == 0) {
1392       WideString str = m_TempTextBuf.MakeString();
1393       if (!str.IsEmpty() && str.Back() == L' ') {
1394         m_TempTextBuf.Delete(m_TempTextBuf.GetLength() - 1, 1);
1395         m_TempCharList.pop_back();
1396       }
1397     }
1398   }
1399 }
1400 
IsSameTextObject(CPDF_TextObject * pTextObj1,CPDF_TextObject * pTextObj2) const1401 bool CPDF_TextPage::IsSameTextObject(CPDF_TextObject* pTextObj1,
1402                                      CPDF_TextObject* pTextObj2) const {
1403   if (!pTextObj1 || !pTextObj2)
1404     return false;
1405 
1406   CFX_FloatRect rcPreObj = pTextObj2->GetRect();
1407   const CFX_FloatRect& rcCurObj = pTextObj1->GetRect();
1408   if (rcPreObj.IsEmpty() && rcCurObj.IsEmpty()) {
1409     float dbXdif = fabs(rcPreObj.left - rcCurObj.left);
1410     size_t nCount = m_CharList.size();
1411     if (nCount >= 2) {
1412       float dbSpace = m_CharList[nCount - 2].char_box().Width();
1413       if (dbXdif > dbSpace)
1414         return false;
1415     }
1416   }
1417   if (!rcPreObj.IsEmpty() || !rcCurObj.IsEmpty()) {
1418     rcPreObj.Intersect(rcCurObj);
1419     if (rcPreObj.IsEmpty())
1420       return false;
1421     if (fabs(rcPreObj.Width() - rcCurObj.Width()) > rcCurObj.Width() / 2) {
1422       return false;
1423     }
1424     if (pTextObj2->GetFontSize() != pTextObj1->GetFontSize())
1425       return false;
1426   }
1427 
1428   size_t nPreCount = pTextObj2->CountItems();
1429   if (nPreCount != pTextObj1->CountItems())
1430     return false;
1431 
1432   // If both objects have no items, consider them same.
1433   if (nPreCount == 0)
1434     return true;
1435 
1436   CPDF_TextObject::Item itemPer;
1437   CPDF_TextObject::Item itemCur;
1438   for (size_t i = 0; i < nPreCount; ++i) {
1439     itemPer = pTextObj2->GetItemInfo(i);
1440     itemCur = pTextObj1->GetItemInfo(i);
1441     if (itemCur.m_CharCode != itemPer.m_CharCode)
1442       return false;
1443   }
1444 
1445   CFX_PointF diff = pTextObj1->GetPos() - pTextObj2->GetPos();
1446   float font_size = pTextObj2->GetFontSize();
1447   float char_size =
1448       GetCharWidth(itemPer.m_CharCode, pTextObj2->GetFont().Get());
1449   float max_pre_size =
1450       std::max(std::max(rcPreObj.Height(), rcPreObj.Width()), font_size);
1451   return fabs(diff.x) <= 0.9 * char_size * font_size / 1000 &&
1452          fabs(diff.y) <= max_pre_size / 8;
1453 }
1454 
IsSameAsPreTextObject(CPDF_TextObject * pTextObj,const CPDF_PageObjectHolder * pObjList,CPDF_PageObjectHolder::const_iterator iter) const1455 bool CPDF_TextPage::IsSameAsPreTextObject(
1456     CPDF_TextObject* pTextObj,
1457     const CPDF_PageObjectHolder* pObjList,
1458     CPDF_PageObjectHolder::const_iterator iter) const {
1459   int i = 0;
1460   while (i < 5 && iter != pObjList->begin()) {
1461     --iter;
1462     CPDF_PageObject* pOtherObj = iter->get();
1463     if (pOtherObj == pTextObj || !pOtherObj->IsText())
1464       continue;
1465     if (IsSameTextObject(pOtherObj->AsText(), pTextObj))
1466       return true;
1467     ++i;
1468   }
1469   return false;
1470 }
1471 
GenerateCharInfo(wchar_t unicode,const CFX_Matrix & form_matrix)1472 std::optional<CPDF_TextPage::CharInfo> CPDF_TextPage::GenerateCharInfo(
1473     wchar_t unicode,
1474     const CFX_Matrix& form_matrix) {
1475   const CharInfo* pPrevCharInfo = GetPrevCharInfo();
1476   if (!pPrevCharInfo) {
1477     return std::nullopt;
1478   }
1479 
1480   int pre_width = 0;
1481   if (pPrevCharInfo->text_object() &&
1482       pPrevCharInfo->char_code() != CPDF_Font::kInvalidCharCode) {
1483     pre_width = GetCharWidth(pPrevCharInfo->char_code(),
1484                              pPrevCharInfo->text_object()->GetFont().Get());
1485   }
1486 
1487   float fFontSize = pPrevCharInfo->text_object()
1488                         ? pPrevCharInfo->text_object()->GetFontSize()
1489                         : pPrevCharInfo->char_box().Height();
1490   if (!fFontSize)
1491     fFontSize = kDefaultFontSize;
1492 
1493   CFX_PointF origin(pPrevCharInfo->origin().x + pre_width * (fFontSize) / 1000,
1494                     pPrevCharInfo->origin().y);
1495   return CharInfo(CharType::kGenerated, CPDF_Font::kInvalidCharCode, unicode,
1496                   origin, CFX_FloatRect(origin.x, origin.y, origin.x, origin.y),
1497                   form_matrix, /*text_object=*/nullptr);
1498 }
1499