1 // Copyright (c) 2010 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 "pdf/pdfium/pdfium_page.h"
6
7 #include <math.h>
8 #include <stddef.h>
9
10 #include <algorithm>
11 #include <memory>
12 #include <utility>
13
14 #include "base/logging.h"
15 #include "base/numerics/math_constants.h"
16 #include "base/numerics/safe_math.h"
17 #include "base/strings/string_number_conversions.h"
18 #include "base/strings/string_util.h"
19 #include "base/strings/utf_string_conversions.h"
20 #include "pdf/pdfium/pdfium_api_string_buffer_adapter.h"
21 #include "pdf/pdfium/pdfium_engine.h"
22 #include "pdf/pdfium/pdfium_unsupported_features.h"
23 #include "ppapi/c/private/ppb_pdf.h"
24 #include "printing/units.h"
25 #include "third_party/pdfium/public/cpp/fpdf_scopers.h"
26 #include "third_party/pdfium/public/fpdf_annot.h"
27 #include "third_party/pdfium/public/fpdf_catalog.h"
28
29 using printing::ConvertUnitDouble;
30 using printing::kPointsPerInch;
31 using printing::kPixelsPerInch;
32
33 namespace chrome_pdf {
34
35 namespace {
36
37 constexpr float k45DegreesInRadians = base::kPiFloat / 4;
38 constexpr float k90DegreesInRadians = base::kPiFloat / 2;
39 constexpr float k180DegreesInRadians = base::kPiFloat;
40 constexpr float k270DegreesInRadians = 3 * base::kPiFloat / 2;
41 constexpr float k360DegreesInRadians = 2 * base::kPiFloat;
42
43 PDFiumPage::IsValidLinkFunction g_is_valid_link_func_for_testing = nullptr;
44
45 // If the link cannot be converted to a pp::Var, then it is not possible to
46 // pass it to JS. In this case, ignore the link like other PDF viewers.
47 // See https://crbug.com/312882 for an example.
48 // TODO(crbug.com/702993): Get rid of the PPAPI usage here, as well as
49 // SetIsValidLinkFunctionForTesting() and related code.
IsValidLink(const std::string & url)50 bool IsValidLink(const std::string& url) {
51 return pp::Var(url).is_string();
52 }
53
FloatPageRectToPixelRect(FPDF_PAGE page,const pp::FloatRect & input)54 pp::FloatRect FloatPageRectToPixelRect(FPDF_PAGE page,
55 const pp::FloatRect& input) {
56 int output_width = FPDF_GetPageWidth(page);
57 int output_height = FPDF_GetPageHeight(page);
58
59 int min_x;
60 int min_y;
61 int max_x;
62 int max_y;
63 FPDF_BOOL ret = FPDF_PageToDevice(page, 0, 0, output_width, output_height, 0,
64 input.x(), input.y(), &min_x, &min_y);
65 DCHECK(ret);
66 ret = FPDF_PageToDevice(page, 0, 0, output_width, output_height, 0,
67 input.right(), input.bottom(), &max_x, &max_y);
68 DCHECK(ret);
69
70 if (max_x < min_x)
71 std::swap(min_x, max_x);
72 if (max_y < min_y)
73 std::swap(min_y, max_y);
74
75 pp::FloatRect output_rect(
76 ConvertUnitDouble(min_x, kPointsPerInch, kPixelsPerInch),
77 ConvertUnitDouble(min_y, kPointsPerInch, kPixelsPerInch),
78 ConvertUnitDouble(max_x - min_x, kPointsPerInch, kPixelsPerInch),
79 ConvertUnitDouble(max_y - min_y, kPointsPerInch, kPixelsPerInch));
80 return output_rect;
81 }
82
GetFloatCharRectInPixels(FPDF_PAGE page,FPDF_TEXTPAGE text_page,int index)83 pp::FloatRect GetFloatCharRectInPixels(FPDF_PAGE page,
84 FPDF_TEXTPAGE text_page,
85 int index) {
86 double left;
87 double right;
88 double bottom;
89 double top;
90 if (!FPDFText_GetCharBox(text_page, index, &left, &right, &bottom, &top))
91 return pp::FloatRect();
92
93 if (right < left)
94 std::swap(left, right);
95 if (bottom < top)
96 std::swap(top, bottom);
97 pp::FloatRect page_coords(left, top, right - left, bottom - top);
98 return FloatPageRectToPixelRect(page, page_coords);
99 }
100
GetFirstNonUnicodeWhiteSpaceCharIndex(FPDF_TEXTPAGE text_page,int start_char_index,int chars_count)101 int GetFirstNonUnicodeWhiteSpaceCharIndex(FPDF_TEXTPAGE text_page,
102 int start_char_index,
103 int chars_count) {
104 int i = start_char_index;
105 while (i < chars_count &&
106 base::IsUnicodeWhitespace(FPDFText_GetUnicode(text_page, i))) {
107 i++;
108 }
109 return i;
110 }
111
GetDirectionFromAngle(float angle)112 PP_PrivateDirection GetDirectionFromAngle(float angle) {
113 // Rotating the angle by 45 degrees to simplify the conditions statements.
114 // It's like if we rotated the whole cartesian coordinate system like below.
115 // X X
116 // X IV X
117 // X X
118 // X X
119 // X X
120 // III X I
121 // X X
122 // X X
123 // X X
124 // X II X
125 // X X
126
127 angle = fmodf(angle + k45DegreesInRadians, k360DegreesInRadians);
128 // Quadrant I.
129 if (angle >= 0 && angle <= k90DegreesInRadians)
130 return PP_PRIVATEDIRECTION_LTR;
131 // Quadrant II.
132 if (angle > k90DegreesInRadians && angle <= k180DegreesInRadians)
133 return PP_PRIVATEDIRECTION_TTB;
134 // Quadrant III.
135 if (angle > k180DegreesInRadians && angle <= k270DegreesInRadians)
136 return PP_PRIVATEDIRECTION_RTL;
137 // Quadrant IV.
138 return PP_PRIVATEDIRECTION_BTT;
139 }
140
GetDistanceBetweenPoints(const pp::FloatPoint & p1,const pp::FloatPoint & p2)141 float GetDistanceBetweenPoints(const pp::FloatPoint& p1,
142 const pp::FloatPoint& p2) {
143 pp::FloatPoint dist_vector = p1 - p2;
144 return sqrtf(powf(dist_vector.x(), 2) + powf(dist_vector.y(), 2));
145 }
146
AddCharSizeToAverageCharSize(pp::FloatSize new_size,pp::FloatSize * avg_size,int * count)147 void AddCharSizeToAverageCharSize(pp::FloatSize new_size,
148 pp::FloatSize* avg_size,
149 int* count) {
150 // Some characters sometimes have a bogus empty bounding box. We don't want
151 // them to impact the average.
152 if (!new_size.IsEmpty()) {
153 avg_size->set_width((avg_size->width() * *count + new_size.width()) /
154 (*count + 1));
155 avg_size->set_height((avg_size->height() * *count + new_size.height()) /
156 (*count + 1));
157 (*count)++;
158 }
159 }
160
GetRotatedCharWidth(float angle,const pp::FloatSize & size)161 float GetRotatedCharWidth(float angle, const pp::FloatSize& size) {
162 return fabsf(cosf(angle) * size.width()) + fabsf(sinf(angle) * size.height());
163 }
164
GetAngleOfVector(const pp::FloatPoint & v)165 float GetAngleOfVector(const pp::FloatPoint& v) {
166 float angle = atan2f(v.y(), v.x());
167 if (angle < 0)
168 angle += k360DegreesInRadians;
169 return angle;
170 }
171
GetAngleDifference(float a,float b)172 float GetAngleDifference(float a, float b) {
173 // This is either the difference or (360 - difference).
174 float x = fmodf(fabsf(b - a), k360DegreesInRadians);
175 return x > k180DegreesInRadians ? k360DegreesInRadians - x : x;
176 }
177
FloatEquals(float f1,float f2)178 bool FloatEquals(float f1, float f2) {
179 // The idea behind this is to use this fraction of the larger of the
180 // two numbers as the limit of the difference. This breaks down near
181 // zero, so we reuse this as the minimum absolute size we will use
182 // for the base of the scale too.
183 static constexpr float kEpsilonScale = 0.00001f;
184 return fabsf(f1 - f2) <
185 kEpsilonScale * fmaxf(fmaxf(fabsf(f1), fabsf(f2)), kEpsilonScale);
186 }
187
188 using GetFormFieldPropertyFunction =
189 base::RepeatingCallback<unsigned long(unsigned short* buffer,
190 unsigned long buflen)>;
191
192 // Helper method to fetch string properties of form fields.
GetFormFieldProperty(GetFormFieldPropertyFunction function)193 std::string GetFormFieldProperty(GetFormFieldPropertyFunction function) {
194 base::string16 data;
195 size_t buffer_size = function.Run(nullptr, 0);
196 if (buffer_size > 0) {
197 PDFiumAPIStringBufferSizeInBytesAdapter<base::string16> api_string_adapter(
198 &data, buffer_size, true);
199 api_string_adapter.Close(function.Run(
200 reinterpret_cast<unsigned short*>(api_string_adapter.GetData()),
201 buffer_size));
202 }
203 return base::UTF16ToUTF8(data);
204 }
205
206 } // namespace
207
LinkTarget()208 PDFiumPage::LinkTarget::LinkTarget() : page(-1) {}
209
210 PDFiumPage::LinkTarget::LinkTarget(const LinkTarget& other) = default;
211
212 PDFiumPage::LinkTarget::~LinkTarget() = default;
213
PDFiumPage(PDFiumEngine * engine,int i)214 PDFiumPage::PDFiumPage(PDFiumEngine* engine, int i)
215 : engine_(engine), index_(i), available_(false) {}
216
217 PDFiumPage::PDFiumPage(PDFiumPage&& that) = default;
218
~PDFiumPage()219 PDFiumPage::~PDFiumPage() {
220 DCHECK_EQ(0, preventing_unload_count_);
221 }
222
223 // static
SetIsValidLinkFunctionForTesting(IsValidLinkFunction function)224 void PDFiumPage::SetIsValidLinkFunctionForTesting(
225 IsValidLinkFunction function) {
226 g_is_valid_link_func_for_testing = function;
227 }
228
Unload()229 void PDFiumPage::Unload() {
230 // Do not unload while in the middle of a load.
231 if (preventing_unload_count_)
232 return;
233
234 text_page_.reset();
235
236 if (page_) {
237 if (engine_->form()) {
238 FORM_OnBeforeClosePage(page(), engine_->form());
239 }
240 page_.reset();
241 }
242 }
243
GetPage()244 FPDF_PAGE PDFiumPage::GetPage() {
245 ScopedUnsupportedFeature scoped_unsupported_feature(engine_);
246 if (!available_)
247 return nullptr;
248 if (!page_) {
249 ScopedUnloadPreventer scoped_unload_preventer(this);
250 page_.reset(FPDF_LoadPage(engine_->doc(), index_));
251 if (page_ && engine_->form()) {
252 FORM_OnAfterLoadPage(page(), engine_->form());
253 }
254 }
255 return page();
256 }
257
GetTextPage()258 FPDF_TEXTPAGE PDFiumPage::GetTextPage() {
259 if (!available_)
260 return nullptr;
261 if (!text_page_) {
262 ScopedUnloadPreventer scoped_unload_preventer(this);
263 text_page_.reset(FPDFText_LoadPage(GetPage()));
264 }
265 return text_page();
266 }
267
CalculatePageObjectTextRunBreaks()268 void PDFiumPage::CalculatePageObjectTextRunBreaks() {
269 if (calculated_page_object_text_run_breaks_)
270 return;
271
272 calculated_page_object_text_run_breaks_ = true;
273 int chars_count = FPDFText_CountChars(GetTextPage());
274 if (chars_count == 0)
275 return;
276
277 CalculateLinks();
278 for (const auto& link : links_) {
279 if (link.start_char_index >= 0 && link.start_char_index < chars_count) {
280 page_object_text_run_breaks_.insert(link.start_char_index);
281 int next_text_run_break_index = link.start_char_index + link.char_count;
282 // Don't insert a break if the link is at the end of the page text.
283 if (next_text_run_break_index < chars_count) {
284 page_object_text_run_breaks_.insert(next_text_run_break_index);
285 }
286 }
287 }
288
289 PopulateAnnotations();
290 for (const auto& highlight : highlights_) {
291 if (highlight.start_char_index >= 0 &&
292 highlight.start_char_index < chars_count) {
293 page_object_text_run_breaks_.insert(highlight.start_char_index);
294 int next_text_run_break_index =
295 highlight.start_char_index + highlight.char_count;
296 // Don't insert a break if the highlight is at the end of the page text.
297 if (next_text_run_break_index < chars_count) {
298 page_object_text_run_breaks_.insert(next_text_run_break_index);
299 }
300 }
301 }
302 }
303
CalculateTextRunStyleInfo(int char_index,pp::PDF::PrivateAccessibilityTextStyleInfo * style_info)304 void PDFiumPage::CalculateTextRunStyleInfo(
305 int char_index,
306 pp::PDF::PrivateAccessibilityTextStyleInfo* style_info) {
307 FPDF_TEXTPAGE text_page = GetTextPage();
308 style_info->font_size = FPDFText_GetFontSize(text_page, char_index);
309
310 int flags = 0;
311 size_t buffer_size =
312 FPDFText_GetFontInfo(text_page, char_index, nullptr, 0, &flags);
313 if (buffer_size > 0) {
314 PDFiumAPIStringBufferAdapter<std::string> api_string_adapter(
315 &style_info->font_name, buffer_size, true);
316 void* data = api_string_adapter.GetData();
317 size_t bytes_written =
318 FPDFText_GetFontInfo(text_page, char_index, data, buffer_size, nullptr);
319 // Trim the null character.
320 api_string_adapter.Close(bytes_written);
321 }
322
323 style_info->font_weight = FPDFText_GetFontWeight(text_page, char_index);
324 // As defined in PDF 1.7 table 5.20.
325 constexpr int kFlagItalic = (1 << 6);
326 // Bold text is considered bold when greater than or equal to 700.
327 constexpr int kStandardBoldValue = 700;
328 style_info->is_italic = (flags & kFlagItalic);
329 style_info->is_bold = style_info->font_weight >= kStandardBoldValue;
330 unsigned int fill_r;
331 unsigned int fill_g;
332 unsigned int fill_b;
333 unsigned int fill_a;
334 if (FPDFText_GetFillColor(text_page, char_index, &fill_r, &fill_g, &fill_b,
335 &fill_a)) {
336 style_info->fill_color = MakeARGB(fill_a, fill_r, fill_g, fill_b);
337 } else {
338 style_info->fill_color = MakeARGB(0xff, 0, 0, 0);
339 }
340
341 unsigned int stroke_r;
342 unsigned int stroke_g;
343 unsigned int stroke_b;
344 unsigned int stroke_a;
345 if (FPDFText_GetStrokeColor(text_page, char_index, &stroke_r, &stroke_g,
346 &stroke_b, &stroke_a)) {
347 style_info->stroke_color = MakeARGB(stroke_a, stroke_r, stroke_g, stroke_b);
348 } else {
349 style_info->stroke_color = MakeARGB(0xff, 0, 0, 0);
350 }
351
352 int render_mode = FPDFText_GetTextRenderMode(text_page, char_index);
353 if (render_mode < 0 || render_mode > PP_TEXTRENDERINGMODE_LAST) {
354 style_info->render_mode = PP_TEXTRENDERINGMODE_UNKNOWN;
355 } else {
356 style_info->render_mode = static_cast<PP_TextRenderingMode>(render_mode);
357 }
358 }
359
AreTextStyleEqual(int char_index,const pp::PDF::PrivateAccessibilityTextStyleInfo & style)360 bool PDFiumPage::AreTextStyleEqual(
361 int char_index,
362 const pp::PDF::PrivateAccessibilityTextStyleInfo& style) {
363 pp::PDF::PrivateAccessibilityTextStyleInfo char_style;
364 CalculateTextRunStyleInfo(char_index, &char_style);
365 return char_style.font_name == style.font_name &&
366 char_style.font_weight == style.font_weight &&
367 char_style.render_mode == style.render_mode &&
368 FloatEquals(char_style.font_size, style.font_size) &&
369 char_style.fill_color == style.fill_color &&
370 char_style.stroke_color == style.stroke_color &&
371 char_style.is_italic == style.is_italic &&
372 char_style.is_bold == style.is_bold;
373 }
374
375 base::Optional<pp::PDF::PrivateAccessibilityTextRunInfo>
GetTextRunInfo(int start_char_index)376 PDFiumPage::GetTextRunInfo(int start_char_index) {
377 FPDF_PAGE page = GetPage();
378 FPDF_TEXTPAGE text_page = GetTextPage();
379 int chars_count = FPDFText_CountChars(text_page);
380 // Check to make sure |start_char_index| is within bounds.
381 if (start_char_index < 0 || start_char_index >= chars_count)
382 return base::nullopt;
383
384 int actual_start_char_index = GetFirstNonUnicodeWhiteSpaceCharIndex(
385 text_page, start_char_index, chars_count);
386 // Check to see if GetFirstNonUnicodeWhiteSpaceCharIndex() iterated through
387 // all the characters.
388 if (actual_start_char_index >= chars_count) {
389 // If so, |info.len| needs to take the number of characters
390 // iterated into account.
391 DCHECK_GT(actual_start_char_index, start_char_index);
392 pp::PDF::PrivateAccessibilityTextRunInfo info;
393 info.len = chars_count - start_char_index;
394 info.bounds = pp::FloatRect();
395 info.direction = PP_PRIVATEDIRECTION_NONE;
396 return info;
397 }
398 int char_index = actual_start_char_index;
399
400 // Set text run's style info from the first character of the text run.
401 pp::PDF::PrivateAccessibilityTextRunInfo info;
402 CalculateTextRunStyleInfo(char_index, &info.style);
403
404 pp::FloatRect start_char_rect =
405 GetFloatCharRectInPixels(page, text_page, char_index);
406 float text_run_font_size = info.style.font_size;
407
408 // Heuristic: Initialize the average character size to one-third of the font
409 // size to avoid having the first few characters misrepresent the average.
410 // Without it, if a text run starts with a '.', its small bounding box could
411 // lead to a break in the text run after only one space. Ex: ". Hello World"
412 // would be split in two runs: "." and "Hello World".
413 double font_size_minimum = FPDFText_GetFontSize(text_page, char_index) / 3.0;
414 pp::FloatSize avg_char_size =
415 pp::FloatSize(font_size_minimum, font_size_minimum);
416 int non_whitespace_chars_count = 1;
417 AddCharSizeToAverageCharSize(start_char_rect.Floatsize(), &avg_char_size,
418 &non_whitespace_chars_count);
419
420 // Add first char to text run.
421 pp::FloatRect text_run_bounds = start_char_rect;
422 PP_PrivateDirection char_direction =
423 GetDirectionFromAngle(FPDFText_GetCharAngle(text_page, char_index));
424 if (char_index < chars_count)
425 char_index++;
426
427 pp::FloatRect prev_char_rect = start_char_rect;
428 float estimated_font_size =
429 std::max(start_char_rect.width(), start_char_rect.height());
430
431 // The angle of the vector starting at the first character center-point and
432 // ending at the current last character center-point.
433 float text_run_angle = 0;
434
435 CalculatePageObjectTextRunBreaks();
436 const auto breakpoint_iter =
437 std::lower_bound(page_object_text_run_breaks_.begin(),
438 page_object_text_run_breaks_.end(), char_index);
439 int breakpoint_index = breakpoint_iter != page_object_text_run_breaks_.end()
440 ? *breakpoint_iter
441 : -1;
442
443 // Continue adding characters until heuristics indicate we should end the text
444 // run.
445 while (char_index < chars_count) {
446 // Split a text run when it encounters a page object like links or images.
447 if (char_index == breakpoint_index)
448 break;
449
450 unsigned int character = FPDFText_GetUnicode(text_page, char_index);
451 pp::FloatRect char_rect =
452 GetFloatCharRectInPixels(page, text_page, char_index);
453
454 if (!base::IsUnicodeWhitespace(character)) {
455 // Heuristic: End the text run if the text style of the current character
456 // is different from the text run's style.
457 if (!AreTextStyleEqual(char_index, info.style))
458 break;
459
460 // Heuristic: End text run if character isn't going in the same direction.
461 if (char_direction !=
462 GetDirectionFromAngle(FPDFText_GetCharAngle(text_page, char_index)))
463 break;
464
465 // Heuristic: End the text run if the difference between the text run
466 // angle and the angle between the center-points of the previous and
467 // current characters is greater than 90 degrees.
468 float current_angle = GetAngleOfVector(char_rect.CenterPoint() -
469 prev_char_rect.CenterPoint());
470 if (start_char_rect != prev_char_rect) {
471 text_run_angle = GetAngleOfVector(prev_char_rect.CenterPoint() -
472 start_char_rect.CenterPoint());
473
474 if (GetAngleDifference(text_run_angle, current_angle) >
475 k90DegreesInRadians) {
476 break;
477 }
478 }
479
480 // Heuristic: End the text run if the center-point distance to the
481 // previous character is less than 2.5x the average character size.
482 AddCharSizeToAverageCharSize(char_rect.Floatsize(), &avg_char_size,
483 &non_whitespace_chars_count);
484
485 float avg_char_width = GetRotatedCharWidth(current_angle, avg_char_size);
486
487 float distance =
488 GetDistanceBetweenPoints(char_rect.CenterPoint(),
489 prev_char_rect.CenterPoint()) -
490 GetRotatedCharWidth(current_angle, char_rect.Floatsize()) / 2 -
491 GetRotatedCharWidth(current_angle, prev_char_rect.Floatsize()) / 2;
492
493 if (distance > 2.5f * avg_char_width)
494 break;
495
496 text_run_bounds = text_run_bounds.Union(char_rect);
497 prev_char_rect = char_rect;
498 }
499
500 if (!char_rect.IsEmpty()) {
501 // Update the estimated font size if needed.
502 float char_largest_side = std::max(char_rect.height(), char_rect.width());
503 estimated_font_size = std::max(char_largest_side, estimated_font_size);
504 }
505
506 char_index++;
507 }
508
509 // Some PDFs have missing or obviously bogus font sizes; substitute the
510 // font size by the width or height (whichever's the largest) of the bigger
511 // character in the current text run.
512 if (text_run_font_size <= 1 || text_run_font_size < estimated_font_size / 2 ||
513 text_run_font_size > estimated_font_size * 2) {
514 text_run_font_size = estimated_font_size;
515 }
516
517 info.len = char_index - start_char_index;
518 info.style.font_size = text_run_font_size;
519 info.bounds = text_run_bounds;
520 // Infer text direction from first and last character of the text run. We
521 // can't base our decision on the character direction, since a character of a
522 // RTL language will have an angle of 0 when not rotated, just like a
523 // character in a LTR language.
524 info.direction = char_index - actual_start_char_index > 1
525 ? GetDirectionFromAngle(text_run_angle)
526 : PP_PRIVATEDIRECTION_NONE;
527 return info;
528 }
529
GetCharUnicode(int char_index)530 uint32_t PDFiumPage::GetCharUnicode(int char_index) {
531 FPDF_TEXTPAGE text_page = GetTextPage();
532 return FPDFText_GetUnicode(text_page, char_index);
533 }
534
GetCharBounds(int char_index)535 pp::FloatRect PDFiumPage::GetCharBounds(int char_index) {
536 FPDF_PAGE page = GetPage();
537 FPDF_TEXTPAGE text_page = GetTextPage();
538 return GetFloatCharRectInPixels(page, text_page, char_index);
539 }
540
GetLinkInfo()541 std::vector<PDFEngine::AccessibilityLinkInfo> PDFiumPage::GetLinkInfo() {
542 std::vector<PDFEngine::AccessibilityLinkInfo> link_info;
543 if (!available_)
544 return link_info;
545
546 CalculateLinks();
547
548 link_info.reserve(links_.size());
549 for (const Link& link : links_) {
550 PDFEngine::AccessibilityLinkInfo cur_info;
551 cur_info.url = link.target.url;
552 cur_info.start_char_index = link.start_char_index;
553 cur_info.char_count = link.char_count;
554
555 pp::Rect link_rect;
556 for (const auto& rect : link.bounding_rects)
557 link_rect = link_rect.Union(rect);
558 cur_info.bounds = pp::FloatRect(link_rect.x(), link_rect.y(),
559 link_rect.width(), link_rect.height());
560
561 link_info.push_back(std::move(cur_info));
562 }
563 return link_info;
564 }
565
GetImageInfo()566 std::vector<PDFEngine::AccessibilityImageInfo> PDFiumPage::GetImageInfo() {
567 std::vector<PDFEngine::AccessibilityImageInfo> image_info;
568 if (!available_)
569 return image_info;
570
571 CalculateImages();
572
573 image_info.reserve(images_.size());
574 for (const Image& image : images_) {
575 PDFEngine::AccessibilityImageInfo cur_info;
576 cur_info.alt_text = image.alt_text;
577 cur_info.bounds = pp::FloatRect(
578 image.bounding_rect.x(), image.bounding_rect.y(),
579 image.bounding_rect.width(), image.bounding_rect.height());
580 image_info.push_back(std::move(cur_info));
581 }
582 return image_info;
583 }
584
585 std::vector<PDFEngine::AccessibilityHighlightInfo>
GetHighlightInfo()586 PDFiumPage::GetHighlightInfo() {
587 std::vector<PDFEngine::AccessibilityHighlightInfo> highlight_info;
588 if (!available_)
589 return highlight_info;
590
591 PopulateAnnotations();
592
593 highlight_info.reserve(highlights_.size());
594 for (const Highlight& highlight : highlights_) {
595 PDFEngine::AccessibilityHighlightInfo cur_info;
596 cur_info.start_char_index = highlight.start_char_index;
597 cur_info.char_count = highlight.char_count;
598 cur_info.bounds = pp::FloatRect(
599 highlight.bounding_rect.x(), highlight.bounding_rect.y(),
600 highlight.bounding_rect.width(), highlight.bounding_rect.height());
601 cur_info.color = highlight.color;
602 highlight_info.push_back(std::move(cur_info));
603 }
604 return highlight_info;
605 }
606
607 std::vector<PDFEngine::AccessibilityTextFieldInfo>
GetTextFieldInfo()608 PDFiumPage::GetTextFieldInfo() {
609 std::vector<PDFEngine::AccessibilityTextFieldInfo> text_field_info;
610 if (!available_)
611 return text_field_info;
612
613 PopulateAnnotations();
614
615 text_field_info.reserve(text_fields_.size());
616 for (const TextField& text_field : text_fields_) {
617 PDFEngine::AccessibilityTextFieldInfo cur_info;
618 cur_info.name = text_field.name;
619 cur_info.value = text_field.value;
620 cur_info.is_read_only = !!(text_field.flags & FPDF_FORMFLAG_READONLY);
621 cur_info.is_required = !!(text_field.flags & FPDF_FORMFLAG_REQUIRED);
622 cur_info.is_password = !!(text_field.flags & FPDF_FORMFLAG_TEXT_PASSWORD);
623 cur_info.bounds = pp::FloatRect(
624 text_field.bounding_rect.x(), text_field.bounding_rect.y(),
625 text_field.bounding_rect.width(), text_field.bounding_rect.height());
626 text_field_info.push_back(std::move(cur_info));
627 }
628 return text_field_info;
629 }
630
GetLinkTargetAtIndex(int link_index,LinkTarget * target)631 PDFiumPage::Area PDFiumPage::GetLinkTargetAtIndex(int link_index,
632 LinkTarget* target) {
633 if (!available_ || link_index < 0)
634 return NONSELECTABLE_AREA;
635 CalculateLinks();
636 if (link_index >= static_cast<int>(links_.size()))
637 return NONSELECTABLE_AREA;
638 *target = links_[link_index].target;
639 return target->url.empty() ? DOCLINK_AREA : WEBLINK_AREA;
640 }
641
GetCharIndex(const pp::Point & point,PageOrientation orientation,int * char_index,int * form_type,LinkTarget * target)642 PDFiumPage::Area PDFiumPage::GetCharIndex(const pp::Point& point,
643 PageOrientation orientation,
644 int* char_index,
645 int* form_type,
646 LinkTarget* target) {
647 if (!available_)
648 return NONSELECTABLE_AREA;
649 pp::Point point2 = point - rect_.point();
650 double new_x;
651 double new_y;
652 FPDF_BOOL ret = FPDF_DeviceToPage(
653 GetPage(), 0, 0, rect_.width(), rect_.height(),
654 ToPDFiumRotation(orientation), point2.x(), point2.y(), &new_x, &new_y);
655 DCHECK(ret);
656
657 // hit detection tolerance, in points.
658 constexpr double kTolerance = 20.0;
659 int rv = FPDFText_GetCharIndexAtPos(GetTextPage(), new_x, new_y, kTolerance,
660 kTolerance);
661 *char_index = rv;
662
663 FPDF_LINK link = FPDFLink_GetLinkAtPoint(GetPage(), new_x, new_y);
664 int control =
665 FPDFPage_HasFormFieldAtPoint(engine_->form(), GetPage(), new_x, new_y);
666
667 // If there is a control and link at the same point, figure out their z-order
668 // to determine which is on top.
669 if (link && control > FPDF_FORMFIELD_UNKNOWN) {
670 int control_z_order = FPDFPage_FormFieldZOrderAtPoint(
671 engine_->form(), GetPage(), new_x, new_y);
672 int link_z_order = FPDFLink_GetLinkZOrderAtPoint(GetPage(), new_x, new_y);
673 DCHECK_NE(control_z_order, link_z_order);
674 if (control_z_order > link_z_order) {
675 *form_type = control;
676 return FormTypeToArea(*form_type);
677 }
678
679 // We don't handle all possible link types of the PDF. For example,
680 // launch actions, cross-document links, etc.
681 // In that case, GetLinkTarget() will return NONSELECTABLE_AREA
682 // and we should proceed with area detection.
683 Area area = GetLinkTarget(link, target);
684 if (area != NONSELECTABLE_AREA)
685 return area;
686 } else if (link) {
687 // We don't handle all possible link types of the PDF. For example,
688 // launch actions, cross-document links, etc.
689 // See identical block above.
690 Area area = GetLinkTarget(link, target);
691 if (area != NONSELECTABLE_AREA)
692 return area;
693 } else if (control > FPDF_FORMFIELD_UNKNOWN) {
694 *form_type = control;
695 return FormTypeToArea(*form_type);
696 }
697
698 if (rv < 0)
699 return NONSELECTABLE_AREA;
700
701 return GetLink(*char_index, target) != -1 ? WEBLINK_AREA : TEXT_AREA;
702 }
703
704 // static
FormTypeToArea(int form_type)705 PDFiumPage::Area PDFiumPage::FormTypeToArea(int form_type) {
706 switch (form_type) {
707 case FPDF_FORMFIELD_COMBOBOX:
708 case FPDF_FORMFIELD_TEXTFIELD:
709 #if defined(PDF_ENABLE_XFA)
710 // TODO(bug_353450): figure out selection and copying for XFA fields.
711 case FPDF_FORMFIELD_XFA_COMBOBOX:
712 case FPDF_FORMFIELD_XFA_TEXTFIELD:
713 #endif
714 return FORM_TEXT_AREA;
715 default:
716 return NONSELECTABLE_AREA;
717 }
718 }
719
GetCharAtIndex(int index)720 base::char16 PDFiumPage::GetCharAtIndex(int index) {
721 if (!available_)
722 return L'\0';
723 return static_cast<base::char16>(FPDFText_GetUnicode(GetTextPage(), index));
724 }
725
GetCharCount()726 int PDFiumPage::GetCharCount() {
727 if (!available_)
728 return 0;
729 return FPDFText_CountChars(GetTextPage());
730 }
731
IsCharIndexInBounds(int index)732 bool PDFiumPage::IsCharIndexInBounds(int index) {
733 return index >= 0 && index < GetCharCount();
734 }
735
GetLinkTarget(FPDF_LINK link,LinkTarget * target)736 PDFiumPage::Area PDFiumPage::GetLinkTarget(FPDF_LINK link, LinkTarget* target) {
737 FPDF_DEST dest_link = FPDFLink_GetDest(engine_->doc(), link);
738 if (dest_link)
739 return GetDestinationTarget(dest_link, target);
740
741 FPDF_ACTION action = FPDFLink_GetAction(link);
742 if (!action)
743 return NONSELECTABLE_AREA;
744
745 switch (FPDFAction_GetType(action)) {
746 case PDFACTION_GOTO: {
747 FPDF_DEST dest_action = FPDFAction_GetDest(engine_->doc(), action);
748 if (dest_action)
749 return GetDestinationTarget(dest_action, target);
750 // TODO(crbug.com/55776): We don't fully support all types of the
751 // in-document links.
752 return NONSELECTABLE_AREA;
753 }
754 case PDFACTION_URI:
755 return GetURITarget(action, target);
756 // TODO(crbug.com/767191): Support PDFACTION_LAUNCH.
757 // TODO(crbug.com/142344): Support PDFACTION_REMOTEGOTO.
758 case PDFACTION_LAUNCH:
759 case PDFACTION_REMOTEGOTO:
760 default:
761 return NONSELECTABLE_AREA;
762 }
763 }
764
GetDestinationTarget(FPDF_DEST destination,LinkTarget * target)765 PDFiumPage::Area PDFiumPage::GetDestinationTarget(FPDF_DEST destination,
766 LinkTarget* target) {
767 if (!target)
768 return NONSELECTABLE_AREA;
769
770 int page_index = FPDFDest_GetDestPageIndex(engine_->doc(), destination);
771 if (page_index < 0)
772 return NONSELECTABLE_AREA;
773
774 target->page = page_index;
775
776 base::Optional<gfx::PointF> xy;
777 GetPageDestinationTarget(destination, &xy, &target->zoom);
778 if (xy) {
779 gfx::PointF point = TransformPageToScreenXY(xy.value());
780 target->x_in_pixels = point.x();
781 target->y_in_pixels = point.y();
782 }
783
784 return DOCLINK_AREA;
785 }
786
GetPageDestinationTarget(FPDF_DEST destination,base::Optional<gfx::PointF> * xy,base::Optional<float> * zoom_value)787 void PDFiumPage::GetPageDestinationTarget(FPDF_DEST destination,
788 base::Optional<gfx::PointF>* xy,
789 base::Optional<float>* zoom_value) {
790 *xy = base::nullopt;
791 *zoom_value = base::nullopt;
792 if (!available_)
793 return;
794
795 FPDF_BOOL has_x_coord;
796 FPDF_BOOL has_y_coord;
797 FPDF_BOOL has_zoom;
798 FS_FLOAT x;
799 FS_FLOAT y;
800 FS_FLOAT zoom;
801 FPDF_BOOL success = FPDFDest_GetLocationInPage(
802 destination, &has_x_coord, &has_y_coord, &has_zoom, &x, &y, &zoom);
803
804 if (!success)
805 return;
806
807 if (has_x_coord && has_y_coord)
808 *xy = gfx::PointF(x, y);
809
810 if (has_zoom)
811 *zoom_value = zoom;
812 }
813
TransformPageToScreenXY(const gfx::PointF & xy)814 gfx::PointF PDFiumPage::TransformPageToScreenXY(const gfx::PointF& xy) {
815 if (!available_)
816 return gfx::PointF();
817
818 pp::FloatRect page_rect(xy.x(), xy.y(), 0, 0);
819 pp::FloatRect pixel_rect(FloatPageRectToPixelRect(GetPage(), page_rect));
820 return gfx::PointF(pixel_rect.x(), pixel_rect.y());
821 }
822
GetURITarget(FPDF_ACTION uri_action,LinkTarget * target) const823 PDFiumPage::Area PDFiumPage::GetURITarget(FPDF_ACTION uri_action,
824 LinkTarget* target) const {
825 if (target) {
826 size_t buffer_size =
827 FPDFAction_GetURIPath(engine_->doc(), uri_action, nullptr, 0);
828 if (buffer_size > 0) {
829 PDFiumAPIStringBufferAdapter<std::string> api_string_adapter(
830 &target->url, buffer_size, true);
831 void* data = api_string_adapter.GetData();
832 size_t bytes_written =
833 FPDFAction_GetURIPath(engine_->doc(), uri_action, data, buffer_size);
834 api_string_adapter.Close(bytes_written);
835 }
836 }
837 return WEBLINK_AREA;
838 }
839
GetLink(int char_index,LinkTarget * target)840 int PDFiumPage::GetLink(int char_index, LinkTarget* target) {
841 if (!available_)
842 return -1;
843
844 CalculateLinks();
845
846 // Get the bounding box of the rect again, since it might have moved because
847 // of the tolerance above.
848 double left;
849 double right;
850 double bottom;
851 double top;
852 if (!FPDFText_GetCharBox(GetTextPage(), char_index, &left, &right, &bottom,
853 &top)) {
854 return -1;
855 }
856
857 pp::Point origin(PageToScreen(pp::Point(), 1.0, left, top, right, bottom,
858 PageOrientation::kOriginal)
859 .point());
860 for (size_t i = 0; i < links_.size(); ++i) {
861 for (const auto& rect : links_[i].bounding_rects) {
862 if (rect.Contains(origin)) {
863 if (target)
864 target->url = links_[i].target.url;
865 return i;
866 }
867 }
868 }
869 return -1;
870 }
871
CalculateLinks()872 void PDFiumPage::CalculateLinks() {
873 if (calculated_links_)
874 return;
875
876 calculated_links_ = true;
877 PopulateWebLinks();
878 PopulateAnnotationLinks();
879 }
880
PopulateWebLinks()881 void PDFiumPage::PopulateWebLinks() {
882 ScopedFPDFPageLink links(FPDFLink_LoadWebLinks(GetTextPage()));
883 int count = FPDFLink_CountWebLinks(links.get());
884 for (int i = 0; i < count; ++i) {
885 base::string16 url;
886 int url_length = FPDFLink_GetURL(links.get(), i, nullptr, 0);
887 if (url_length > 0) {
888 PDFiumAPIStringBufferAdapter<base::string16> api_string_adapter(
889 &url, url_length, true);
890 unsigned short* data =
891 reinterpret_cast<unsigned short*>(api_string_adapter.GetData());
892 int actual_length = FPDFLink_GetURL(links.get(), i, data, url_length);
893 api_string_adapter.Close(actual_length);
894 }
895 Link link;
896 link.target.url = base::UTF16ToUTF8(url);
897
898 IsValidLinkFunction is_valid_link_func =
899 g_is_valid_link_func_for_testing ? g_is_valid_link_func_for_testing
900 : &IsValidLink;
901 if (!is_valid_link_func(link.target.url))
902 continue;
903
904 // Make sure all the characters in the URL are valid per RFC 1738.
905 // http://crbug.com/340326 has a sample bad PDF.
906 // GURL does not work correctly, e.g. it just strips \t \r \n.
907 bool is_invalid_url = false;
908 for (size_t j = 0; j < link.target.url.length(); ++j) {
909 // Control characters are not allowed.
910 // 0x7F is also a control character.
911 // 0x80 and above are not in US-ASCII.
912 if (link.target.url[j] < ' ' || link.target.url[j] >= '\x7F') {
913 is_invalid_url = true;
914 break;
915 }
916 }
917 if (is_invalid_url)
918 continue;
919
920 int rect_count = FPDFLink_CountRects(links.get(), i);
921 for (int j = 0; j < rect_count; ++j) {
922 double left;
923 double top;
924 double right;
925 double bottom;
926 FPDFLink_GetRect(links.get(), i, j, &left, &top, &right, &bottom);
927 pp::Rect rect = PageToScreen(pp::Point(), 1.0, left, top, right, bottom,
928 PageOrientation::kOriginal);
929 if (rect.IsEmpty())
930 continue;
931 link.bounding_rects.push_back(rect);
932 }
933 FPDF_BOOL is_link_over_text = FPDFLink_GetTextRange(
934 links.get(), i, &link.start_char_index, &link.char_count);
935 DCHECK(is_link_over_text);
936 links_.push_back(link);
937 }
938 }
939
PopulateAnnotationLinks()940 void PDFiumPage::PopulateAnnotationLinks() {
941 int start_pos = 0;
942 FPDF_LINK link_annot;
943 FPDF_PAGE page = GetPage();
944 while (FPDFLink_Enumerate(page, &start_pos, &link_annot)) {
945 Link link;
946 Area area = GetLinkTarget(link_annot, &link.target);
947 if (area == NONSELECTABLE_AREA)
948 continue;
949
950 FS_RECTF link_rect;
951 if (!FPDFLink_GetAnnotRect(link_annot, &link_rect))
952 continue;
953
954 // The horizontal/vertical coordinates in PDF Links could be
955 // flipped. Swap the coordinates before further processing.
956 if (link_rect.right < link_rect.left)
957 std::swap(link_rect.right, link_rect.left);
958 if (link_rect.bottom > link_rect.top)
959 std::swap(link_rect.bottom, link_rect.top);
960
961 int quad_point_count = FPDFLink_CountQuadPoints(link_annot);
962 // Calculate the bounds of link using the quad points data.
963 // If quad points for link is not present then use
964 // |link_rect| to calculate the bounds instead.
965 if (quad_point_count > 0) {
966 for (int i = 0; i < quad_point_count; ++i) {
967 FS_QUADPOINTSF point;
968 if (FPDFLink_GetQuadPoints(link_annot, i, &point)) {
969 // PDF Specifications: Quadpoints start from bottom left (x1, y1) and
970 // runs counter clockwise.
971 link.bounding_rects.push_back(
972 PageToScreen(pp::Point(), 1.0, point.x4, point.y4, point.x2,
973 point.y2, PageOrientation::kOriginal));
974 }
975 }
976 } else {
977 link.bounding_rects.push_back(PageToScreen(
978 pp::Point(), 1.0, link_rect.left, link_rect.top, link_rect.right,
979 link_rect.bottom, PageOrientation::kOriginal));
980 }
981
982 // Calculate underlying text range of link.
983 GetUnderlyingTextRangeForRect(
984 pp::FloatRect(link_rect.left, link_rect.bottom,
985 std::abs(link_rect.right - link_rect.left),
986 std::abs(link_rect.bottom - link_rect.top)),
987 &link.start_char_index, &link.char_count);
988 links_.emplace_back(link);
989 }
990 }
991
CalculateImages()992 void PDFiumPage::CalculateImages() {
993 if (calculated_images_)
994 return;
995
996 calculated_images_ = true;
997 FPDF_PAGE page = GetPage();
998 int page_object_count = FPDFPage_CountObjects(page);
999 MarkedContentIdToImageMap marked_content_id_image_map;
1000 bool is_tagged = FPDFCatalog_IsTagged(engine_->doc());
1001 for (int i = 0; i < page_object_count; ++i) {
1002 FPDF_PAGEOBJECT page_object = FPDFPage_GetObject(page, i);
1003 if (FPDFPageObj_GetType(page_object) != FPDF_PAGEOBJ_IMAGE)
1004 continue;
1005 float left;
1006 float top;
1007 float right;
1008 float bottom;
1009 FPDF_BOOL ret =
1010 FPDFPageObj_GetBounds(page_object, &left, &bottom, &right, &top);
1011 DCHECK(ret);
1012 Image image;
1013 image.bounding_rect = PageToScreen(pp::Point(), 1.0, left, top, right,
1014 bottom, PageOrientation::kOriginal);
1015
1016 if (is_tagged) {
1017 // Collect all marked content IDs for image objects so that they can
1018 // later be used to retrieve alt text from struct tree for the page.
1019 FPDF_IMAGEOBJ_METADATA image_metadata;
1020 if (FPDFImageObj_GetImageMetadata(page_object, page, &image_metadata)) {
1021 int marked_content_id = image_metadata.marked_content_id;
1022 if (marked_content_id >= 0) {
1023 // If |marked_content_id| is already present, ignore the one being
1024 // inserted.
1025 marked_content_id_image_map.insert(
1026 {marked_content_id, images_.size()});
1027 }
1028 }
1029 }
1030 images_.push_back(image);
1031 }
1032
1033 if (!marked_content_id_image_map.empty())
1034 PopulateImageAltText(marked_content_id_image_map);
1035 }
1036
PopulateImageAltText(const MarkedContentIdToImageMap & marked_content_id_image_map)1037 void PDFiumPage::PopulateImageAltText(
1038 const MarkedContentIdToImageMap& marked_content_id_image_map) {
1039 ScopedFPDFStructTree struct_tree(FPDF_StructTree_GetForPage(GetPage()));
1040 if (!struct_tree)
1041 return;
1042
1043 std::set<FPDF_STRUCTELEMENT> visited_elements;
1044 int tree_children_count = FPDF_StructTree_CountChildren(struct_tree.get());
1045 for (int i = 0; i < tree_children_count; ++i) {
1046 FPDF_STRUCTELEMENT current_element =
1047 FPDF_StructTree_GetChildAtIndex(struct_tree.get(), i);
1048 PopulateImageAltTextForStructElement(marked_content_id_image_map,
1049 current_element, &visited_elements);
1050 }
1051 }
1052
PopulateImageAltTextForStructElement(const MarkedContentIdToImageMap & marked_content_id_image_map,FPDF_STRUCTELEMENT current_element,std::set<FPDF_STRUCTELEMENT> * visited_elements)1053 void PDFiumPage::PopulateImageAltTextForStructElement(
1054 const MarkedContentIdToImageMap& marked_content_id_image_map,
1055 FPDF_STRUCTELEMENT current_element,
1056 std::set<FPDF_STRUCTELEMENT>* visited_elements) {
1057 if (!current_element)
1058 return;
1059
1060 bool inserted = visited_elements->insert(current_element).second;
1061 if (!inserted)
1062 return;
1063
1064 int marked_content_id =
1065 FPDF_StructElement_GetMarkedContentID(current_element);
1066 if (marked_content_id >= 0) {
1067 auto it = marked_content_id_image_map.find(marked_content_id);
1068 if (it != marked_content_id_image_map.end() &&
1069 images_[it->second].alt_text.empty()) {
1070 size_t buffer_size =
1071 FPDF_StructElement_GetAltText(current_element, nullptr, 0);
1072 if (buffer_size > 0) {
1073 base::string16 alt_text;
1074 PDFiumAPIStringBufferSizeInBytesAdapter<base::string16>
1075 api_string_adapter(&alt_text, buffer_size, true);
1076 api_string_adapter.Close(FPDF_StructElement_GetAltText(
1077 current_element, api_string_adapter.GetData(), buffer_size));
1078 images_[it->second].alt_text = base::UTF16ToUTF8(alt_text);
1079 }
1080 }
1081 }
1082 int children_count = FPDF_StructElement_CountChildren(current_element);
1083 for (int i = 0; i < children_count; ++i) {
1084 FPDF_STRUCTELEMENT child =
1085 FPDF_StructElement_GetChildAtIndex(current_element, i);
1086 PopulateImageAltTextForStructElement(marked_content_id_image_map, child,
1087 visited_elements);
1088 }
1089 }
1090
PopulateAnnotations()1091 void PDFiumPage::PopulateAnnotations() {
1092 if (calculated_annotations_)
1093 return;
1094
1095 FPDF_PAGE page = GetPage();
1096 if (!page)
1097 return;
1098
1099 int annotation_count = FPDFPage_GetAnnotCount(page);
1100 for (int i = 0; i < annotation_count; ++i) {
1101 ScopedFPDFAnnotation annot(FPDFPage_GetAnnot(page, i));
1102 DCHECK(annot);
1103 FPDF_ANNOTATION_SUBTYPE subtype = FPDFAnnot_GetSubtype(annot.get());
1104
1105 switch (subtype) {
1106 case FPDF_ANNOT_HIGHLIGHT: {
1107 PopulateHighlight(annot.get());
1108 break;
1109 }
1110 case FPDF_ANNOT_WIDGET: {
1111 // TODO(crbug.com/1030242): Populate other types of form fields too.
1112 if (FPDFAnnot_GetFormFieldType(engine_->form(), annot.get()) ==
1113 FPDF_FORMFIELD_TEXTFIELD) {
1114 PopulateTextField(annot.get());
1115 }
1116 break;
1117 }
1118 default:
1119 break;
1120 }
1121 }
1122 calculated_annotations_ = true;
1123 }
1124
PopulateHighlight(FPDF_ANNOTATION annot)1125 void PDFiumPage::PopulateHighlight(FPDF_ANNOTATION annot) {
1126 DCHECK(annot);
1127 DCHECK_EQ(FPDFAnnot_GetSubtype(annot), FPDF_ANNOT_HIGHLIGHT);
1128
1129 FS_RECTF rect;
1130 if (!FPDFAnnot_GetRect(annot, &rect))
1131 return;
1132
1133 Highlight highlight;
1134 // We use the bounding box of the highlight as the bounding rect.
1135 highlight.bounding_rect =
1136 PageToScreen(pp::Point(), 1.0, rect.left, rect.top, rect.right,
1137 rect.bottom, PageOrientation::kOriginal);
1138 GetUnderlyingTextRangeForRect(
1139 pp::FloatRect(rect.left, rect.bottom, std::abs(rect.right - rect.left),
1140 std::abs(rect.bottom - rect.top)),
1141 &highlight.start_char_index, &highlight.char_count);
1142
1143 // Retrieve the color of the highlight.
1144 unsigned int color_r;
1145 unsigned int color_g;
1146 unsigned int color_b;
1147 unsigned int color_a;
1148 FPDF_PAGEOBJECT page_object = FPDFAnnot_GetObject(annot, 0);
1149 if (FPDFPageObj_GetFillColor(page_object, &color_r, &color_g, &color_b,
1150 &color_a)) {
1151 highlight.color = MakeARGB(color_a, color_r, color_g, color_b);
1152 } else {
1153 // Set the same default color as in pdfium. See calls to
1154 // GetColorStringWithDefault() in CPVT_GenerateAP::Generate*AP() in
1155 // pdfium.
1156 highlight.color = MakeARGB(255, 255, 255, 0);
1157 }
1158
1159 highlights_.push_back(std::move(highlight));
1160 }
1161
PopulateTextField(FPDF_ANNOTATION annot)1162 void PDFiumPage::PopulateTextField(FPDF_ANNOTATION annot) {
1163 DCHECK(annot);
1164 FPDF_FORMHANDLE form_handle = engine_->form();
1165 DCHECK_EQ(FPDFAnnot_GetFormFieldType(form_handle, annot),
1166 FPDF_FORMFIELD_TEXTFIELD);
1167
1168 FS_RECTF rect;
1169 if (!FPDFAnnot_GetRect(annot, &rect))
1170 return;
1171
1172 TextField text_field;
1173 // We use the bounding box of the text field as the bounding rect.
1174 text_field.bounding_rect =
1175 PageToScreen(pp::Point(), 1.0, rect.left, rect.top, rect.right,
1176 rect.bottom, PageOrientation::kOriginal);
1177 text_field.value = GetFormFieldProperty(
1178 base::BindRepeating(FPDFAnnot_GetFormFieldValue, form_handle, annot));
1179 text_field.name = GetFormFieldProperty(
1180 base::BindRepeating(FPDFAnnot_GetFormFieldName, form_handle, annot));
1181 text_field.flags = FPDFAnnot_GetFormFieldFlags(form_handle, annot);
1182 text_fields_.push_back(std::move(text_field));
1183 }
1184
GetUnderlyingTextRangeForRect(const pp::FloatRect & rect,int * start_index,int * char_len)1185 bool PDFiumPage::GetUnderlyingTextRangeForRect(const pp::FloatRect& rect,
1186 int* start_index,
1187 int* char_len) {
1188 if (!available_)
1189 return false;
1190
1191 FPDF_TEXTPAGE text_page = GetTextPage();
1192 int char_count = FPDFText_CountChars(text_page);
1193 if (char_count <= 0)
1194 return false;
1195
1196 int start_char_index = -1;
1197 int cur_char_count = 0;
1198
1199 // Iterate over page text to find such continuous characters whose mid-points
1200 // lie inside the rectangle.
1201 for (int i = 0; i < char_count; ++i) {
1202 double char_left;
1203 double char_right;
1204 double char_bottom;
1205 double char_top;
1206 if (!FPDFText_GetCharBox(text_page, i, &char_left, &char_right,
1207 &char_bottom, &char_top)) {
1208 break;
1209 }
1210
1211 float xmid = (char_left + char_right) / 2;
1212 float ymid = (char_top + char_bottom) / 2;
1213 if (rect.Contains(xmid, ymid)) {
1214 if (start_char_index == -1)
1215 start_char_index = i;
1216 ++cur_char_count;
1217 } else if (start_char_index != -1) {
1218 break;
1219 }
1220 }
1221
1222 if (cur_char_count == 0)
1223 return false;
1224
1225 *char_len = cur_char_count;
1226 *start_index = start_char_index;
1227 return true;
1228 }
1229
PageToScreen(const pp::Point & offset,double zoom,double left,double top,double right,double bottom,PageOrientation orientation) const1230 pp::Rect PDFiumPage::PageToScreen(const pp::Point& offset,
1231 double zoom,
1232 double left,
1233 double top,
1234 double right,
1235 double bottom,
1236 PageOrientation orientation) const {
1237 if (!available_)
1238 return pp::Rect();
1239
1240 double start_x = (rect_.x() - offset.x()) * zoom;
1241 double start_y = (rect_.y() - offset.y()) * zoom;
1242 double size_x = rect_.width() * zoom;
1243 double size_y = rect_.height() * zoom;
1244 if (!base::IsValueInRangeForNumericType<int>(start_x) ||
1245 !base::IsValueInRangeForNumericType<int>(start_y) ||
1246 !base::IsValueInRangeForNumericType<int>(size_x) ||
1247 !base::IsValueInRangeForNumericType<int>(size_y)) {
1248 return pp::Rect();
1249 }
1250
1251 int new_left;
1252 int new_top;
1253 int new_right;
1254 int new_bottom;
1255 FPDF_BOOL ret = FPDF_PageToDevice(
1256 page(), static_cast<int>(start_x), static_cast<int>(start_y),
1257 static_cast<int>(ceil(size_x)), static_cast<int>(ceil(size_y)),
1258 ToPDFiumRotation(orientation), left, top, &new_left, &new_top);
1259 DCHECK(ret);
1260 ret = FPDF_PageToDevice(
1261 page(), static_cast<int>(start_x), static_cast<int>(start_y),
1262 static_cast<int>(ceil(size_x)), static_cast<int>(ceil(size_y)),
1263 ToPDFiumRotation(orientation), right, bottom, &new_right, &new_bottom);
1264 DCHECK(ret);
1265
1266 // If the PDF is rotated, the horizontal/vertical coordinates could be
1267 // flipped. See
1268 // http://www.netl.doe.gov/publications/proceedings/03/ubc/presentations/Goeckner-pres.pdf
1269 if (new_right < new_left)
1270 std::swap(new_right, new_left);
1271 if (new_bottom < new_top)
1272 std::swap(new_bottom, new_top);
1273
1274 base::CheckedNumeric<int32_t> new_size_x = new_right;
1275 new_size_x -= new_left;
1276 new_size_x += 1;
1277 base::CheckedNumeric<int32_t> new_size_y = new_bottom;
1278 new_size_y -= new_top;
1279 new_size_y += 1;
1280 if (!new_size_x.IsValid() || !new_size_y.IsValid())
1281 return pp::Rect();
1282
1283 return pp::Rect(new_left, new_top, new_size_x.ValueOrDie(),
1284 new_size_y.ValueOrDie());
1285 }
1286
ScopedUnloadPreventer(PDFiumPage * page)1287 PDFiumPage::ScopedUnloadPreventer::ScopedUnloadPreventer(PDFiumPage* page)
1288 : page_(page) {
1289 page_->preventing_unload_count_++;
1290 }
1291
~ScopedUnloadPreventer()1292 PDFiumPage::ScopedUnloadPreventer::~ScopedUnloadPreventer() {
1293 page_->preventing_unload_count_--;
1294 }
1295
1296 PDFiumPage::Link::Link() = default;
1297
1298 PDFiumPage::Link::Link(const Link& that) = default;
1299
1300 PDFiumPage::Link::~Link() = default;
1301
1302 PDFiumPage::Image::Image() = default;
1303
1304 PDFiumPage::Image::Image(const Image& that) = default;
1305
1306 PDFiumPage::Image::~Image() = default;
1307
1308 PDFiumPage::Highlight::Highlight() = default;
1309
1310 PDFiumPage::Highlight::Highlight(const Highlight& that) = default;
1311
1312 PDFiumPage::Highlight::~Highlight() = default;
1313
1314 PDFiumPage::TextField::TextField() = default;
1315
1316 PDFiumPage::TextField::TextField(const TextField& that) = default;
1317
1318 PDFiumPage::TextField::~TextField() = default;
1319
ToPDFiumRotation(PageOrientation orientation)1320 int ToPDFiumRotation(PageOrientation orientation) {
1321 // Could static_cast<int>(orientation), but using an exhaustive switch will
1322 // trigger an error if we ever change the definition of PageOrientation.
1323 switch (orientation) {
1324 case PageOrientation::kOriginal:
1325 return 0;
1326 case PageOrientation::kClockwise90:
1327 return 1;
1328 case PageOrientation::kClockwise180:
1329 return 2;
1330 case PageOrientation::kClockwise270:
1331 return 3;
1332 }
1333 NOTREACHED();
1334 return 0;
1335 }
1336
1337 } // namespace chrome_pdf
1338