Avoid duplicate functions/code in core/editing: computeDistance

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 2041 matching lines @@
   TextControlElement* textControl = enclosingTextControl(position);
   return isHTMLInputElement(textControl) &&
          toHTMLInputElement(textControl)->type() == InputTypeNames::password;
 }
 
 bool isTextSecurityNode(const Node* node) {
   return node && node->layoutObject() &&
          node->layoutObject()->style()->textSecurity() != TSNONE;
 }
 
+// If current position is at grapheme boundary, return 0; otherwise, return the
+// distance to its nearest left grapheme boundary.
+size_t computeDistanceToLeftGraphemeBoundary(const Position& position) {
+  const Position& adjustedPosition = previousPositionOf(
+      nextPositionOf(position, PositionMoveType::GraphemeCluster),
+      PositionMoveType::GraphemeCluster);
+  DCHECK_EQ(position.anchorNode(), adjustedPosition.anchorNode());
+  DCHECK_GE(position.computeOffsetInContainerNode(),
+            adjustedPosition.computeOffsetInContainerNode());
+  return static_cast<size_t>(position.computeOffsetInContainerNode() -
+                             adjustedPosition.computeOffsetInContainerNode());
+}
+
+// If current position is at grapheme boundary, return 0; otherwise, return the
+// distance to its nearest right grapheme boundary.
+size_t computeDistanceToRightGraphemeBoundary(const Position& position) {
+  const Position& adjustedPosition = nextPositionOf(
+      previousPositionOf(position, PositionMoveType::GraphemeCluster),
+      PositionMoveType::GraphemeCluster);
+  DCHECK_EQ(position.anchorNode(), adjustedPosition.anchorNode());
+  DCHECK_GE(adjustedPosition.computeOffsetInContainerNode(),
+            position.computeOffsetInContainerNode());
+  return static_cast<size_t>(adjustedPosition.computeOffsetInContainerNode() -
+                             position.computeOffsetInContainerNode());
+}
+
 const StaticRangeVector* targetRangesForInputEvent(const Node& node) {
   // TODO(xiaochengh): The use of updateStyleAndLayoutIgnorePendingStylesheets
   // needs to be audited. see http://crbug.com/590369 for more details.
   node.document().updateStyleAndLayoutIgnorePendingStylesheets();
   if (!hasRichlyEditableStyle(node))
     return nullptr;
   const EphemeralRange& range =
       firstEphemeralRangeOf(node.document()
                                 .frame()
                                 ->selection()
@@ skipping 88 matching lines @@
         return InputType::DeleteSoftLineBackward;
       if (granularity == ParagraphBoundary)
         return InputType::DeleteHardLineBackward;
       return InputType::DeleteContentBackward;
     default:
       return InputType::None;
   }
 }
 
 }  // namespace blink