Fixed IAccessibleText::TextAtOffset with IA2_TEXT_BOUNDARY_WORD to return text that spans from the …

content/browser/accessibility/browser_accessibility.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/accessibility/browser_accessibility.h"
 
+#include <algorithm>
+
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/common/accessibility_messages.h"
+#include "ui/accessibility/ax_text_utils.h"
 
 namespace content {
 
 #if !defined(OS_MACOSX) && \
     !defined(OS_WIN) && \
     !defined(OS_ANDROID)
 // We have subclassess of BrowserAccessibility on Mac and Win. For any other
 // platform, instantiate the base class.
 // static
 BrowserAccessibility* BrowserAccessibility::Create() {
@@ skipping 277 matching lines @@
     const {
   gfx::Rect bounds = GetLocalBoundsForRange(start, len);
 
   // Adjust the bounds by the top left corner of the containing view's bounds
   // in screen coordinates.
   bounds.Offset(manager_->GetViewBounds().OffsetFromOrigin());
 
   return bounds;
 }
 
+int BrowserAccessibility::GetWordStartBoundary(
+    int start, ui::TextBoundaryDirection direction) const {
+  int prev_word_start = 0;
+  int word_start = 0;
+  if (GetRole() != ui::AX_ROLE_STATIC_TEXT) {
+    int prev_child_y = -1;
+    for (size_t i = 0; i < InternalChildCount(); ++i) {
+      BrowserAccessibility* child = InternalGetChild(i);
+      int child_len = child->GetStaticTextLenRecursive();
+      int child_word_start = child->GetWordStartBoundary(start, direction);
+      word_start += child_word_start;
+      if (child_word_start != child_len)
+          break;
+      gfx::Rect child_rect = child->GetLocation();
+      int child_y = child_rect.y();
+      if (prev_child_y == -1)
+          prev_child_y = child_y;
+      if (prev_child_y != child_y) {
+        child_len += 1;
+        word_start += 1;
+        prev_child_y = child_y;
+      }
+      start -= child_len;
+    }
+    return word_start;
+  }
+
+  int child_start = 0;
+  int child_end = 0;
+  for (size_t i = 0; i < InternalChildCount(); ++i) {
+    // The next child starts where the previous one ended.
+    child_start = child_end;
+    BrowserAccessibility* child = InternalGetChild(i);
+    DCHECK_EQ(child->GetRole(), ui::AX_ROLE_INLINE_TEXT_BOX);
+    std::string child_text;
+    child->GetStringAttribute(ui::AX_ATTR_VALUE, &child_text);

[dmazzoni, 2015/02/20 18:16:21]

Minor nit: it's slightly better to write:

const std::string& child_text = child->GetStringAttribute(ui::AX_ATTR_VALUE);
because then it doesn't need to make a copy of the string.

+    int child_len = static_cast<int>(child_text.size());
+    child_end += child_len; // End is one past the last character.
+
+    const std::vector<int32>& word_starts = child->GetIntListAttribute(
+        ui::AX_ATTR_WORD_STARTS);
+    if (word_starts.empty()) {
+      word_start = child_end;
+      continue;
+    }
+
+    int local_start = start - child_start;
+    std::vector<int32>::const_iterator iter = std::upper_bound(
+        word_starts.cbegin(), word_starts.cend(), local_start);
+    if (iter != word_starts.cend()) {
+      if (direction == ui::FORWARDS_DIRECTION) {
+        word_start = child_start + *iter;
+      } else if (direction == ui::BACKWARDS_DIRECTION) {

[dmazzoni, 2015/02/20 18:16:21]

nit: handle the case where direction is not FORWARDS or BACKWARDS, maybe with
NOTREACHED().

+        if (iter == word_starts.cbegin()) {
+          // Return the position of the last word in the previous child.
+          word_start = prev_word_start;
+        } else {
+          word_start = child_start + *(iter - 1);
+        }
+      }
+      break;
+    }
+    prev_word_start = *(iter - 1);
+    word_start = child_end;
+  }
+
+  return word_start;
+}
+
 BrowserAccessibility* BrowserAccessibility::BrowserAccessibilityForPoint(
     const gfx::Point& point) {
   // The best result found that's a child of this object.
   BrowserAccessibility* child_result = NULL;
   // The best result that's an indirect descendant like grandchild, etc.
   BrowserAccessibility* descendant_result = NULL;
 
   // Walk the children recursively looking for the BrowserAccessibility that
   // most tightly encloses the specified point. Walk backwards so that in
   // the absence of any other information, we assume the object that occurs
@@ skipping 389 matching lines @@
       }
       need_to_offset_web_area = true;
     }
     parent = parent->GetParentForBoundsCalculation();
   }
 
   return bounds;
 }
 
 }  // namespace content