Introduce isVisuallyEquivalentCandidate() as replacement of PositionAlgorithm::isCandidate()

Source/core/editing/VisiblePosition.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Portions Copyright (c) 2011 Motorola Mobility, 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
@@ skipping 235 matching lines @@
                     level = box->bidiLevel();
                 }
                 layoutObject = &box->layoutObject();
                 offset = primaryDirection == LTR ? box->caretMinOffset() : box->caretMaxOffset();
             }
             break;
         }
 
         p = Position::editingPositionOf(layoutObject->node(), offset);
 
-        if ((p.isCandidate() && p.downstream() != downstreamStart) || p.atStartOfTree() || p.atEndOfTree())
+        if ((isVisuallyEquivalentCandidate(p) && p.downstream() != downstreamStart) || p.atStartOfTree() || p.atEndOfTree())
             return p;
 
         ASSERT(p != m_deepPosition);
     }
 }
 
 VisiblePosition VisiblePosition::left() const
 {
     Position pos = leftVisuallyDistinctCandidate();
     // FIXME: Why can't we move left from the last position in a tree?
@@ skipping 141 matching lines @@
                     level = box->bidiLevel();
                 }
                 layoutObject = &box->layoutObject();
                 offset = primaryDirection == LTR ? box->caretMaxOffset() : box->caretMinOffset();
             }
             break;
         }
 
         p = Position::editingPositionOf(layoutObject->node(), offset);
 
-        if ((p.isCandidate() && p.downstream() != downstreamStart) || p.atStartOfTree() || p.atEndOfTree())
+        if ((isVisuallyEquivalentCandidate(p) && p.downstream() != downstreamStart) || p.atStartOfTree() || p.atEndOfTree())
             return p;
 
         ASSERT(p != m_deepPosition);
     }
 }
 
 VisiblePosition VisiblePosition::right() const
 {
     Position pos = rightVisuallyDistinctCandidate();
     // FIXME: Why can't we move left from the last position in a tree?
@@ skipping 112 matching lines @@
 
     // That must mean that |pos| is not editable. Return the next position after pos that is in the same editable region as this position
     return firstEditableVisiblePositionAfterPositionInRoot(pos.deepEquivalent(), highestRoot);
 }
 
 template <typename PositionType>
 static PositionType canonicalizeCandidate(const PositionType& candidate)
 {
     if (candidate.isNull())
         return PositionType();
-    ASSERT(candidate.isCandidate());
+    ASSERT(isVisuallyEquivalentCandidate(candidate));
     PositionType upstream = candidate.upstream();
-    if (upstream.isCandidate())
+    if (isVisuallyEquivalentCandidate(upstream))
         return upstream;
     return candidate;
 }
 
 template <typename PositionType>
 static PositionType canonicalPosition(const PositionType& passedPosition)
 {
     // Sometimes updating selection positions can be extremely expensive and occur
     // frequently.  Often calling preventDefault on mousedown events can avoid
     // doing unnecessary text selection work.  http://crbug.com/472258.
@@ skipping 11 matching lines @@
     // unless the affinity is upstream.
     if (position.isNull())
         return PositionType();
 
     ASSERT(position.document());
     position.document()->updateLayoutIgnorePendingStylesheets();
 
     Node* node = position.computeContainerNode();
 
     PositionType candidate = position.upstream();
-    if (candidate.isCandidate())
+    if (isVisuallyEquivalentCandidate(candidate))
         return candidate;
     candidate = position.downstream();
-    if (candidate.isCandidate())
+    if (isVisuallyEquivalentCandidate(candidate))
         return candidate;
 
     // When neither upstream or downstream gets us to a candidate (upstream/downstream won't leave
     // blocks or enter new ones), we search forward and backward until we find one.
     PositionType next = canonicalizeCandidate(nextCandidate(position));
     PositionType prev = canonicalizeCandidate(previousCandidate(position));
     Node* nextNode = next.anchorNode();
     Node* prevNode = prev.anchorNode();
 
     // The new position must be in the same editable element. Enforce that first.
@@ skipping 170 matching lines @@
     else
         fprintf(stderr, "Cannot showTree for (nil) VisiblePosition.\n");
 }
 
 void showTree(const blink::VisiblePosition& vpos)
 {
     vpos.showTreeForThis();
 }
 
 #endif