[unseasoned-pdf] Consolidate AccessibilityLinkInfo in pdf/

Use a single AccessibilityLinkInfo struct in pdf/ to fetch
accessibility data. The consolidation removes the need for two structs
and removes the overhead of conversion and copy from one struct to
another.

Bug: 1175023
Change-Id: I0ac87fda5766094f3c8477c9e1302234e6a498ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2690223
Commit-Queue: Ankit Kumar 🌪️ <ankk@microsoft.com>
Reviewed-by: Daniel Hosseinian <dhoss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#853462}

pdf/accessibility.cc

@@ -23,30 +23,6 @@ bool CompareTextRuns(const T& a, const T& b) {
   return a.text_range.index < b.text_range.index;
 }
 
-std::vector<AccessibilityLinkInfo> GetAccessibilityLinkInfo(
-    PDFEngine* engine,
-    int32_t page_index,
-    const std::vector<AccessibilityTextRunInfo>& text_runs) {
-  std::vector<PDFEngine::AccessibilityLinkInfo> engine_link_infos =
-      engine->GetLinkInfo(page_index);
-  std::vector<AccessibilityLinkInfo> link_infos;
-  link_infos.reserve(engine_link_infos.size());
-  for (size_t i = 0; i < engine_link_infos.size(); ++i) {
-    auto& cur_engine_info = engine_link_infos[i];
-    AccessibilityLinkInfo link_info;
-    link_info.url = std::move(cur_engine_info.url);
-    link_info.index_in_page = i;
-    link_info.bounds = cur_engine_info.bounds;
-    link_info.text_range = GetEnclosingTextRunRangeForCharRange(
-        text_runs, cur_engine_info.start_char_index,
-        cur_engine_info.char_count);
-    link_infos.push_back(std::move(link_info));
-  }
-  std::sort(link_infos.begin(), link_infos.end(),
-            CompareTextRuns<AccessibilityLinkInfo>);
-  return link_infos;
-}
-
 std::vector<AccessibilityImageInfo> GetAccessibilityImageInfo(
     PDFEngine* engine,
     int32_t page_index,
@@ -209,7 +185,7 @@ bool GetAccessibilityInfo(PDFEngine* engine,
   }
 
   page_info.text_run_count = text_runs.size();
-  page_objects.links = GetAccessibilityLinkInfo(engine, page_index, text_runs);
+  page_objects.links = engine->GetLinkInfo(page_index, text_runs);
   page_objects.images =
       GetAccessibilityImageInfo(engine, page_index, page_info.text_run_count);
   page_objects.highlights =

pdf/accessibility_helper.cc

@@ -1,4 +1,4 @@
-// Copyright 2021 The Chromium Authors. All rights reserved.
+// Copyright 2020 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -14,8 +14,6 @@
 
 namespace chrome_pdf {
 
-namespace {
-
 bool IsCharWithinTextRun(const AccessibilityTextRunInfo& text_run,
                          uint32_t text_run_start_char_index,
                          uint32_t char_index) {
@@ -23,20 +21,19 @@ bool IsCharWithinTextRun(const AccessibilityTextRunInfo& text_run,
          char_index - text_run_start_char_index < text_run.len;
 }
 
-}  // namespace
-
+// If a valid text run range is not found for the char range then return the
+// fallback value.
 AccessibilityTextRunRangeInfo GetEnclosingTextRunRangeForCharRange(
     const std::vector<AccessibilityTextRunInfo>& text_runs,
     int start_char_index,
     int char_count) {
   // Initialize with fallback value.
-  AccessibilityTextRunRangeInfo text_range = {
-      static_cast<uint32_t>(text_runs.size()), 0};
+  AccessibilityTextRunRangeInfo text_range = {text_runs.size(), 0};
   if (start_char_index < 0 || char_count <= 0)
     return text_range;
 
-  const base::CheckedNumeric<uint32_t> checked_end_char_index =
-      base::MakeCheckedNum(char_count) - 1 + start_char_index;
+  base::CheckedNumeric<uint32_t> checked_end_char_index = char_count - 1;
+  checked_end_char_index += start_char_index;
   if (!checked_end_char_index.IsValid())
     return text_range;
   uint32_t end_char_index = checked_end_char_index.ValueOrDie();

pdf/accessibility_helper.h

@@ -1,4 +1,4 @@
-// Copyright 2021 The Chromium Authors. All rights reserved.
+// Copyright 2020 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -12,9 +12,6 @@ namespace chrome_pdf {
 struct AccessibilityTextRunInfo;
 struct AccessibilityTextRunRangeInfo;
 
-// Find the text run range encompassing the char range denoted by
-// |start_char_index| and |char_count|. If a valid text run range is not found
-// for the char range then return the fallback value.
 AccessibilityTextRunRangeInfo GetEnclosingTextRunRangeForCharRange(
     const std::vector<AccessibilityTextRunInfo>& text_runs,
     int start_char_index,

pdf/pdf_engine.h

@@ -60,6 +60,7 @@ namespace chrome_pdf {
 class InputEvent;
 class Thumbnail;
 class UrlLoader;
+struct AccessibilityLinkInfo;
 struct AccessibilityTextRunInfo;
 struct DocumentAttachmentInfo;
 struct DocumentMetadata;
@@ -282,17 +283,6 @@ class PDFEngine {
         const base::Location& from_here = base::Location::Current()) = 0;
   };
 
-  struct AccessibilityLinkInfo {
-    AccessibilityLinkInfo();
-    AccessibilityLinkInfo(const AccessibilityLinkInfo& that);
-    ~AccessibilityLinkInfo();
-
-    std::string url;
-    int start_char_index;
-    int char_count;
-    gfx::RectF bounds;
-  };
-
   struct AccessibilityImageInfo {
     AccessibilityImageInfo();
     AccessibilityImageInfo(const AccessibilityImageInfo& that);
@@ -440,7 +430,9 @@ class PDFEngine {
       int start_char_index) = 0;
   // For all the links on page |page_index|, get their urls, underlying text
   // ranges and bounding boxes.
-  virtual std::vector<AccessibilityLinkInfo> GetLinkInfo(int page_index) = 0;
+  virtual std::vector<AccessibilityLinkInfo> GetLinkInfo(
+      int page_index,
+      const std::vector<AccessibilityTextRunInfo>& text_runs) = 0;
   // For all the images in page |page_index|, get their alt texts and bounding
   // boxes.
   virtual std::vector<AccessibilityImageInfo> GetImageInfo(int page_index) = 0;

pdf/pdfium/pdfium_engine.cc

@@ -515,13 +515,6 @@ void ShutdownSDK() {
 #endif  // defined(PDF_ENABLE_V8)
 }
 
-PDFEngine::AccessibilityLinkInfo::AccessibilityLinkInfo() = default;
-
-PDFEngine::AccessibilityLinkInfo::AccessibilityLinkInfo(
-    const AccessibilityLinkInfo& that) = default;
-
-PDFEngine::AccessibilityLinkInfo::~AccessibilityLinkInfo() = default;
-
 PDFEngine::AccessibilityImageInfo::AccessibilityImageInfo() = default;
 
 PDFEngine::AccessibilityImageInfo::AccessibilityImageInfo(
@@ -2606,10 +2599,11 @@ base::Optional<AccessibilityTextRunInfo> PDFiumEngine::GetTextRunInfo(
   return info;
 }
 
-std::vector<PDFEngine::AccessibilityLinkInfo> PDFiumEngine::GetLinkInfo(
-    int page_index) {
+std::vector<AccessibilityLinkInfo> PDFiumEngine::GetLinkInfo(
+    int page_index,
+    const std::vector<AccessibilityTextRunInfo>& text_runs) {
   DCHECK(PageIndexInBounds(page_index));
-  return pages_[page_index]->GetLinkInfo();
+  return pages_[page_index]->GetLinkInfo(text_runs);
 }
 
 std::vector<PDFEngine::AccessibilityImageInfo> PDFiumEngine::GetImageInfo(

pdf/pdfium/pdfium_engine.h

@@ -141,7 +141,9 @@ class PDFiumEngine : public PDFEngine,
   base::Optional<AccessibilityTextRunInfo> GetTextRunInfo(
       int page_index,
       int start_char_index) override;
-  std::vector<AccessibilityLinkInfo> GetLinkInfo(int page_index) override;
+  std::vector<AccessibilityLinkInfo> GetLinkInfo(
+      int page_index,
+      const std::vector<AccessibilityTextRunInfo>& text_runs) override;
   std::vector<AccessibilityImageInfo> GetImageInfo(int page_index) override;
   std::vector<AccessibilityHighlightInfo> GetHighlightInfo(
       int page_index) override;

pdf/pdfium/pdfium_page.cc

@@ -21,6 +21,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "pdf/accessibility_helper.h"
 #include "pdf/accessibility_structs.h"
 #include "pdf/pdfium/pdfium_api_string_buffer_adapter.h"
 #include "pdf/pdfium/pdfium_engine.h"
@@ -256,6 +257,11 @@ bool IsRadioButtonOrCheckBox(int button_type) {
          button_type == FPDF_FORMFIELD_RADIOBUTTON;
 }
 
+template <typename T>
+bool CompareTextRuns(const T& a, const T& b) {
+  return a.text_range.index < b.text_range.index;
+}
+
 }  // namespace
 
 PDFiumPage::LinkTarget::LinkTarget() : page(-1) {}
@@ -611,19 +617,22 @@ gfx::RectF PDFiumPage::GetCharBounds(int char_index) {
   return GetFloatCharRectInPixels(page, text_page, char_index);
 }
 
-std::vector<PDFEngine::AccessibilityLinkInfo> PDFiumPage::GetLinkInfo() {
-  std::vector<PDFEngine::AccessibilityLinkInfo> link_info;
+std::vector<AccessibilityLinkInfo> PDFiumPage::GetLinkInfo(
+    const std::vector<AccessibilityTextRunInfo>& text_runs) {
+  std::vector<AccessibilityLinkInfo> link_info;
   if (!available_)
     return link_info;
 
   CalculateLinks();
 
   link_info.reserve(links_.size());
-  for (const Link& link : links_) {
-    PDFEngine::AccessibilityLinkInfo cur_info;
+  for (size_t i = 0; i < links_.size(); ++i) {
+    const Link& link = links_[i];
+    AccessibilityLinkInfo cur_info;
     cur_info.url = link.target.url;
-    cur_info.start_char_index = link.start_char_index;
-    cur_info.char_count = link.char_count;
+    cur_info.index_in_page = i;
+    cur_info.text_range = GetEnclosingTextRunRangeForCharRange(
+        text_runs, link.start_char_index, link.char_count);
 
     gfx::Rect link_rect;
     for (const auto& rect : link.bounding_rects)
@@ -633,6 +642,9 @@ std::vector<PDFEngine::AccessibilityLinkInfo> PDFiumPage::GetLinkInfo() {
 
     link_info.push_back(std::move(cur_info));
   }
+
+  std::sort(link_info.begin(), link_info.end(),
+            CompareTextRuns<AccessibilityLinkInfo>);
   return link_info;
 }
 

pdf/pdfium/pdfium_page.h

@@ -34,6 +34,7 @@ namespace chrome_pdf {
 
 class PDFiumEngine;
 class Thumbnail;
+struct AccessibilityLinkInfo;
 struct AccessibilityTextRunInfo;
 struct AccessibilityTextStyleInfo;
 
@@ -64,7 +65,8 @@ class PDFiumPage {
   gfx::RectF GetCharBounds(int char_index);
   // For all the links on the page, get their urls, underlying text ranges and
   // bounding boxes.
-  std::vector<PDFEngine::AccessibilityLinkInfo> GetLinkInfo();
+  std::vector<AccessibilityLinkInfo> GetLinkInfo(
+      const std::vector<AccessibilityTextRunInfo>& text_runs);
   // For all the images on the page, get their alt texts and bounding boxes.
   std::vector<PDFEngine::AccessibilityImageInfo> GetImageInfo();
   // For all the highlights on the page, get their underlying text ranges and