Move LayoutObject::nextOffset/previousOffset() to editing utility

third_party/WebKit/Source/core/editing/EditingUtilities.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 524 matching lines @@
 Position lastEditablePositionBeforePositionInRoot(const Position& position, Node& highestRoot)
 {
     return lastEditablePositionBeforePositionInRootAlgorithm<EditingStrategy>(position, highestRoot);
 }
 
 PositionInFlatTree lastEditablePositionBeforePositionInRoot(const PositionInFlatTree& position, Node& highestRoot)
 {
     return lastEditablePositionBeforePositionInRootAlgorithm<EditingInFlatTreeStrategy>(position, highestRoot);
 }
 
-int uncheckedPreviousOffset(const Node* n, int current)
+int uncheckedPreviousOffset(const Node* node, int current)
 {
-    return n->layoutObject() ? n->layoutObject()->previousOffset(current) : current - 1;
+    if (!node->isTextNode())
+        return current - 1;
+    const String& text = toText(node)->data();
+    if (text.is8Bit())
+        return current - 1; // TODO(nona): Good to support CR x LF.
+    TextBreakIterator* iterator = cursorMovementIterator(text.characters16(), text.length());
+    if (!iterator)
+        return current - 1;
+    const int result = iterator->preceding(current);
+    return result == TextBreakDone ? current - 1 : result;
 }
 
 static int uncheckedPreviousOffsetForBackwardDeletion(const Node* n, int current)
 {
     return n->layoutObject() ? n->layoutObject()->previousOffsetForBackwardDeletion(current) : current - 1;
 }
 
-int uncheckedNextOffset(const Node* n, int current)
+int uncheckedNextOffset(const Node* node, int current)
 {
-    return n->layoutObject() ? n->layoutObject()->nextOffset(current) : current + 1;
+    if (!node->isTextNode())
+        return current + 1;
+    const String& text = toText(node)->data();
+    if (text.is8Bit())
+        return current + 1; // TODO(nona): Good to support CR x LF.
+    TextBreakIterator* iterator = cursorMovementIterator(text.characters16(), text.length());
+    if (!iterator)
+        return current + 1;
+    const int result = iterator->following(current);
+    return result == TextBreakDone ? current + 1 : result;
 }
 
 template <typename Strategy>
 PositionTemplate<Strategy> previousPositionOfAlgorithm(const PositionTemplate<Strategy>& position, PositionMoveType moveType)
 {
     Node* const node = position.anchorNode();
     if (!node)
         return position;
 
     const int offset = position.computeEditingOffset();
@@ skipping 1078 matching lines @@
     // instead of possibly at the end of the last node before the selection
     return mostForwardCaretPosition(visiblePosition.deepEquivalent());
 }
 
 bool isTextSecurityNode(const Node* node)
 {
     return node && node->layoutObject() && node->layoutObject()->style()->textSecurity() != TSNONE;
 }
 
 } // namespace blink