Switched to using |AXPosition| for calculating word and line boundaries on Windows.

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 <stddef.h>
 
 #include <algorithm>
 
@@ skipping 508 matching lines @@
   // Some screen readers like Jaws and older versions of VoiceOver require a
   // value to be set in text fields with rich content, even though the same
   // information is available on the children.
   if (value.empty() &&
       (IsSimpleTextControl() || IsRichTextControl()) &&
       !IsNativeTextControl())
     value = GetInnerText();
   return value;
 }
 
-int BrowserAccessibility::GetLineStartBoundary(
-    int start,
-    ui::TextBoundaryDirection direction,
-    ui::AXTextAffinity affinity) const {
-  DCHECK_GE(start, 0);
-  DCHECK_LE(start, static_cast<int>(GetText().length()));
-
-  if (IsSimpleTextControl()) {
-    return ui::FindAccessibleTextBoundary(GetText(), GetLineStartOffsets(),
-                                          ui::LINE_BOUNDARY, start, direction,
-                                          affinity);
-  }
-
-  // Keeps track of the start offset of each consecutive line.
-  int line_start = 0;
-  // Keeps track of the length of each consecutive line.
-  int line_length = 0;
-  for (size_t i = 0; i < InternalChildCount(); ++i) {
-    const BrowserAccessibility* child = InternalGetChild(i);
-    DCHECK(child);
-    // Child objects are of length one, since they are represented by a
-    // single embedded object character. The exception is text-only objects.
-    int child_length = 1;
-    if (child->IsTextOnlyObject())
-      child_length = static_cast<int>(child->GetText().length());
-
-    // Determine if |start| is within this child. As a special case, if
-    // the affinity is upstream, then the cursor position between two
-    // lines belongs to the previous line.
-    bool start_index_within_child = start < child_length;
-    if (start == child_length &&
-        !child->IsNextSiblingOnSameLine() &&
-        affinity == ui::AX_TEXT_AFFINITY_UPSTREAM) {
-      start_index_within_child = true;
-    }
-
-    // Stop when we reach both the child containing our start offset and, in
-    // case we are searching forward, the child that is at the end of the line
-    // on which this object is located.
-    if (start_index_within_child && (direction == ui::BACKWARDS_DIRECTION ||
-                                     !child->IsNextSiblingOnSameLine())) {
-      // Recurse into the inline text boxes.
-      if (child->GetRole() == ui::AX_ROLE_STATIC_TEXT) {
-        switch (direction) {
-          case ui::FORWARDS_DIRECTION:
-            line_length += child->GetLineStartBoundary(
-                std::max(start, 0), direction, affinity);
-            break;
-          case ui::BACKWARDS_DIRECTION:
-            line_start += child->GetLineStartBoundary(
-                std::max(start, 0), direction, affinity);
-            break;
-        }
-      } else {
-        line_length += child_length;
-      }
-
-      break;
-    }
-    line_length += child_length;
-
-    if (!child->IsNextSiblingOnSameLine()) {
-      // We are on a new line.
-      line_start += line_length;
-      line_length = 0;
-    }
-
-    start -= child_length;
-  }
-
-  switch (direction) {
-    case ui::FORWARDS_DIRECTION:
-      return line_start + line_length;
-    case ui::BACKWARDS_DIRECTION:
-      return line_start;
-  }
-  NOTREACHED();
-  return 0;
-}
-
-int BrowserAccessibility::GetWordStartBoundary(
-    int start, ui::TextBoundaryDirection direction) const {
-  DCHECK_GE(start, -1);
-  // Special offset that indicates that a word boundary has not been found.
-  int word_start_not_found = static_cast<int>(GetText().size());
-  int word_start = word_start_not_found;
-
-  switch (GetRole()) {
-    case ui::AX_ROLE_STATIC_TEXT: {
-      int prev_word_start = word_start_not_found;
-      int child_start = 0;
-      int child_end = 0;
-
-      // Go through the inline text boxes.
-      for (size_t i = 0; i < InternalChildCount(); ++i) {
-        // The next child starts where the previous one ended.
-        child_start = child_end;
-        const BrowserAccessibility* child = InternalGetChild(i);
-        DCHECK_EQ(child->GetRole(), ui::AX_ROLE_INLINE_TEXT_BOX);
-        int child_len = static_cast<int>(child->GetText().size());
-        child_end += child_len; // End is one past the last character.
-
-        const std::vector<int32_t>& 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_t>::const_iterator iter = std::upper_bound(
-            word_starts.begin(), word_starts.end(), local_start);
-        if (iter != word_starts.end()) {
-          if (direction == ui::FORWARDS_DIRECTION) {
-            word_start = child_start + *iter;
-          } else if (direction == ui::BACKWARDS_DIRECTION) {
-            if (iter == word_starts.begin()) {
-              // Return the position of the last word in the previous child.
-              word_start = prev_word_start;
-            } else {
-              word_start = child_start + *(iter - 1);
-            }
-          } else {
-            NOTREACHED();
-          }
-          break;
-        }
-
-        // No word start that is greater than the requested offset has been
-        // found.
-        prev_word_start = child_start + *(iter - 1);
-        if (direction == ui::FORWARDS_DIRECTION) {
-          word_start = child_end;
-        } else if (direction == ui::BACKWARDS_DIRECTION) {
-          word_start = prev_word_start;
-        } else {
-          NOTREACHED();
-        }
-      }
-      return word_start;
-    }
-
-    case ui::AX_ROLE_LINE_BREAK:
-      // Words never start at a line break.
-      return word_start_not_found;
-
-    default:
-      // If there are no children, the word start boundary is still unknown or
-      // found previously depending on the direction.
-      if (!InternalChildCount())
-        return word_start_not_found;
-
-      const BrowserAccessibility* this_object = this;
-      // Standard text fields such as textarea have an embedded div inside them
-      // that should be skipped.
-      // TODO(nektar): This is fragile. Replace with code that flattens tree.
-      if (IsSimpleTextControl() && InternalChildCount() == 1) {
-        this_object = InternalGetChild(0);
-      }
-      int child_start = 0;
-      for (size_t i = 0; i < this_object->InternalChildCount(); ++i) {
-        BrowserAccessibility* child = this_object->InternalGetChild(i);
-        // Child objects are of length one, since they are represented by a
-        // single embedded object character. The exception is text-only objects.
-        int child_len = 1;
-        if (child->IsTextOnlyObject()) {
-          child_len = static_cast<int>(child->GetText().length());
-          int child_word_start = child->GetWordStartBoundary(start, direction);
-          if (child_word_start < child_len) {
-            // We have found a possible word boundary.
-            word_start = child_start + child_word_start;
-          }
-
-          // Decide when to stop searching.
-          if ((word_start != word_start_not_found &&
-               direction == ui::FORWARDS_DIRECTION) ||
-              (start < child_len && direction == ui::BACKWARDS_DIRECTION)) {
-            break;
-          }
-        }
-
-        child_start += child_len;
-        if (start >= child_len)
-          start -= child_len;
-        else
-          start = -1;
-      }
-      return word_start;
-  }
-}
-
 BrowserAccessibility* BrowserAccessibility::ApproximateHitTest(
     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 397 matching lines @@
   return name;
 }
 
 std::vector<int> BrowserAccessibility::GetLineStartOffsets() const {
   if (!instance_active())
     return std::vector<int>();
   return node()->GetOrComputeLineStartOffsets();
 }
 
 BrowserAccessibility::AXPlatformPositionInstance
-BrowserAccessibility::CreatePositionAt(int offset) const {
+BrowserAccessibility::CreatePositionAt(int offset,
+                                       ui::AXTextAffinity affinity) const {
   DCHECK(manager_);
-  return AXPlatformPosition::CreateTextPosition(
-      manager_->ax_tree_id(), GetId(), offset, ui::AX_TEXT_AFFINITY_DOWNSTREAM);
+  return AXPlatformPosition::CreateTextPosition(manager_->ax_tree_id(), GetId(),
+                                                offset, affinity);
 }
 
 base::string16 BrowserAccessibility::GetInnerText() const {
   if (IsTextOnlyObject())
     return GetString16Attribute(ui::AX_ATTR_NAME);
 
   base::string16 text;
   for (size_t i = 0; i < InternalChildCount(); ++i)
     text += InternalGetChild(i)->GetInnerText();
   return text;
@@ skipping 118 matching lines @@
     const ui::AXActionData& data) {
   NOTREACHED();
   return false;
 }
 
 void BrowserAccessibility::DoDefaultAction() {
   NOTREACHED();
 }
 
 }  // namespace content