Introduce composed tree version of rightPositionOf()

Source/core/editing/VisibleUnits.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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 2764 matching lines @@
 VisiblePosition leftPositionOf(const VisiblePosition& visiblePosition)
 {
     return leftPositionOfAlgorithm<EditingStrategy>(visiblePosition);
 }
 
 VisiblePositionInComposedTree leftPositionOf(const VisiblePositionInComposedTree& visiblePosition)
 {
     return leftPositionOfAlgorithm<EditingInComposedTreeStrategy>(visiblePosition);
 }
 
-static Position rightVisuallyDistinctCandidate(const VisiblePosition& visiblePosition)
+template <typename Strategy>
+static PositionAlgorithm<Strategy> rightVisuallyDistinctCandidate(const VisiblePositionTemplate<Strategy>& visiblePosition)
 {
-    const Position deepPosition = visiblePosition.deepEquivalent();
-    Position p = deepPosition;
+    const PositionAlgorithm<Strategy> deepPosition = visiblePosition.deepEquivalent();
+    PositionAlgorithm<Strategy> p = deepPosition;
     if (p.isNull())
-        return Position();
+        return PositionAlgorithm<Strategy>();
 
-    Position downstreamStart = mostForwardCaretPosition(p);
+    const PositionAlgorithm<Strategy> downstreamStart = mostForwardCaretPosition(p);
     TextDirection primaryDirection = primaryDirectionOf(*p.anchorNode());
     const TextAffinity affinity = visiblePosition.affinity();
 
     while (true) {
         InlineBoxPosition boxPosition = computeInlineBoxPosition(p, affinity, primaryDirection);
         InlineBox* box = boxPosition.inlineBox;
         int offset = boxPosition.offsetInBox;
         if (!box)
             return primaryDirection == LTR ? nextVisuallyDistinctCandidate(deepPosition) : previousVisuallyDistinctCandidate(deepPosition);
 
@@ skipping 17 matching lines @@
             int caretMinOffset = box->caretMinOffset();
             int caretMaxOffset = box->caretMaxOffset();
 
             if (offset > caretMinOffset && offset < caretMaxOffset)
                 break;
 
             if (box->isLeftToRightDirection() ? offset > caretMaxOffset : offset < caretMinOffset) {
                 // Overshot to the right.
                 InlineBox* nextBox = box->nextLeafChildIgnoringLineBreak();
                 if (!nextBox) {
-                    Position positionOnRight = primaryDirection == LTR ? nextVisuallyDistinctCandidate(deepPosition) : previousVisuallyDistinctCandidate(deepPosition);
+                    PositionAlgorithm<Strategy> positionOnRight = primaryDirection == LTR ? nextVisuallyDistinctCandidate(deepPosition) : previousVisuallyDistinctCandidate(deepPosition);
                     if (positionOnRight.isNull())
-                        return Position();
+                        return PositionAlgorithm<Strategy>();
 
                     InlineBox* boxOnRight = computeInlineBoxPosition(positionOnRight, affinity, primaryDirection).inlineBox;
                     if (boxOnRight && boxOnRight->root() == box->root())
-                        return Position();
+                        return PositionAlgorithm<Strategy>();
                     return positionOnRight;
                 }
 
                 // Reposition at the other logical position corresponding to our
                 // edge's visual position and go for another round.
                 box = nextBox;
                 layoutObject = &box->layoutObject();
                 offset = nextBox->caretLeftmostOffset();
                 continue;
             }
@@ skipping 47 matching lines @@
 
                 if (box->bidiLevel() > level) {
                     do {
                         nextBox = nextBox->nextLeafChild();
                     } while (nextBox && nextBox->bidiLevel() > level);
 
                     if (!nextBox || nextBox->bidiLevel() < level)
                         continue;
                 }
             } else {
-                // Trailing edge of a secondary run. Set to the leading edge of
-                // the entire run.
+                // Trailing edge of a secondary run. Set to the leading edge of the entire run.
                 while (true) {
                     while (InlineBox* prevBox = box->prevLeafChild()) {
                         if (prevBox->bidiLevel() < level)
                             break;
                         box = prevBox;
                     }
                     if (box->bidiLevel() == level)
                         break;
                     level = box->bidiLevel();
                     while (InlineBox* nextBox = box->nextLeafChild()) {
                         if (nextBox->bidiLevel() < level)
                             break;
                         box = nextBox;
                     }
                     if (box->bidiLevel() == level)
                         break;
                     level = box->bidiLevel();
                 }
                 layoutObject = &box->layoutObject();
                 offset = primaryDirection == LTR ? box->caretMaxOffset() : box->caretMinOffset();
             }
             break;
         }
 
-        p = Position::editingPositionOf(layoutObject->node(), offset);
+        p = PositionAlgorithm<Strategy>::editingPositionOf(layoutObject->node(), offset);
 
         if ((isVisuallyEquivalentCandidate(p) && mostForwardCaretPosition(p) != downstreamStart) || p.atStartOfTree() || p.atEndOfTree())
             return p;
 
         ASSERT(p != deepPosition);
     }
 }
 
-VisiblePosition rightPositionOf(const VisiblePosition& visiblePosition)
+template <typename Strategy>
+static VisiblePositionTemplate<Strategy> rightPositionOfAlgorithm(const VisiblePositionTemplate<Strategy>& visiblePosition)
 {
-    const Position pos = rightVisuallyDistinctCandidate(visiblePosition);
-    // TODO(yosin) Why can't we move left from the last position in a tree?
+    const PositionAlgorithm<Strategy> pos = rightVisuallyDistinctCandidate(visiblePosition);
+    // FIXME: Why can't we move left from the last position in a tree?
     if (pos.atStartOfTree() || pos.atEndOfTree())
-        return VisiblePosition();
+        return VisiblePositionTemplate<Strategy>();
 
-    VisiblePosition right = createVisiblePosition(pos);
+    const VisiblePositionTemplate<Strategy> right = createVisiblePosition(pos);
     ASSERT(right.deepEquivalent() != visiblePosition.deepEquivalent());
 
     return directionOfEnclosingBlock(right.deepEquivalent()) == LTR ? honorEditingBoundaryAtOrAfter(right, visiblePosition.deepEquivalent()) : honorEditingBoundaryAtOrBefore(right, visiblePosition.deepEquivalent());
 }
 
+VisiblePosition rightPositionOf(const VisiblePosition& visiblePosition)
+{
+    return rightPositionOfAlgorithm<EditingStrategy>(visiblePosition);
+}
+
+VisiblePositionInComposedTree rightPositionOf(const VisiblePositionInComposedTree& visiblePosition)
+{
+    return rightPositionOfAlgorithm<EditingInComposedTreeStrategy>(visiblePosition);
+}
+
 template <typename Strategy>
 static VisiblePositionTemplate<Strategy> nextPositionOfAlgorithm(const VisiblePositionTemplate<Strategy>& visiblePosition, EditingBoundaryCrossingRule rule)
 {
     const VisiblePositionTemplate<Strategy> next = createVisiblePosition(nextVisuallyDistinctCandidate(visiblePosition.deepEquivalent()), visiblePosition.affinity());
 
     switch (rule) {
     case CanCrossEditingBoundary:
         return next;
     case CannotCrossEditingBoundary:
         return honorEditingBoundaryAtOrAfter(next, visiblePosition.deepEquivalent());
@@ skipping 64 matching lines @@
         return honorEditingBoundaryAtOrBefore(prev, visiblePosition.deepEquivalent());
     case CanSkipOverEditingBoundary:
         return skipToStartOfEditingBoundary(prev, visiblePosition.deepEquivalent());
     }
 
     ASSERT_NOT_REACHED();
     return honorEditingBoundaryAtOrBefore(prev, visiblePosition.deepEquivalent());
 }
 
 } // namespace blink