Introduce visiblePositionOf() for Position and PositionInComposedTree

Source/core/editing/VisiblePosition.h

 /*
  * Copyright (C) 2004, 2008 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 55 matching lines @@
 // When above text line wrapped after "abc"
 //    abc|  UPSTREAM |VisiblePosition|
 //    |def  DOWNSTREAM |VisiblePosition|
 //
 // NOTE: UPSTREAM affinity will be used only if pos is at end of a wrapped line,
 // otherwise it will be converted to DOWNSTREAM.
 class CORE_EXPORT VisiblePosition final {
     DISALLOW_ALLOCATION();
 public:
     VisiblePosition() : m_affinity(VP_DEFAULT_AFFINITY) { }
+
+    // TODO(yosin) We should use |visiblePositionOf()| instead of constructor,
+    // and make constructors to have private accessibility, since constructors
+    // aren't simple, e.g. they update layout tree.
     explicit VisiblePosition(const Position&, TextAffinity = VP_DEFAULT_AFFINITY);
-    explicit VisiblePosition(const PositionInComposedTree&, TextAffinity = VP_DEFAULT_AFFINITY);
     explicit VisiblePosition(const PositionWithAffinity&);
 
+    // Node: Other than |visiblePositionOf()|, we should not use
+    // |createWithoutCanonicalization()|.
+    static VisiblePosition createWithoutCanonicalization(const PositionWithAffinity& canonicalized);
+
     // Intentionally delete |operator==()| and |operator!=()| for reducing
     // compilation error message.
     // TODO(yosin) We'll have |equals()| when we have use cases of checking
     // equality of both position and affinity.
     bool operator==(const VisiblePosition&) const = delete;
     bool operator!=(const VisiblePosition&) const = delete;
 
     bool isNull() const { return m_deepPosition.isNull(); }
     bool isNotNull() const { return m_deepPosition.isNotNull(); }
     bool isOrphan() const { return m_deepPosition.isOrphan(); }
 
     Position deepEquivalent() const { return m_deepPosition; }
     Position toParentAnchoredPosition() const { return deepEquivalent().parentAnchoredEquivalent(); }
     PositionWithAffinity toPositionWithAffinity() const { return PositionWithAffinity(m_deepPosition, m_affinity); }
     TextAffinity affinity() const { return m_affinity; }
 
     // TODO(yosin) This does not handle [table, 0] correctly.
     Element* rootEditableElement() const { return m_deepPosition.isNotNull() ? m_deepPosition.anchorNode()->rootEditableElement() : 0; }
 
     DECLARE_TRACE();
 
 #ifndef NDEBUG
     void debugPosition(const char* msg = "") const;
     void formatForDebugger(char* buffer, unsigned length) const;
     void showTreeForThis() const;
 #endif
 
 private:
-    template<typename Strategy>
-    void init(const PositionAlgorithm<Strategy>&, TextAffinity);
-
+    // TODO(yosin) We should use |PositionWithAffinity| to make
+    // |toPositionWithAffinity()| simpler.
     Position m_deepPosition;
     TextAffinity m_affinity;
 };
 
 // TODO(yosin) We should move |absoluteCaretBoundsOf()| to "VisibleUnits.cpp".
 // Bounds of (possibly transformed) caret in absolute coords
 CORE_EXPORT IntRect absoluteCaretBoundsOf(const VisiblePosition&);
 
 // Abs x/y position of the caret ignoring transforms.
 // TODO(yosin) navigation with transforms should be smarter.
 // TODO(yosin) We should move a glboal funciton
 // |lineDirectionPointForBlockDirectionNavigationOf()| to "FrameSelection.h"
 // as static function.
 int lineDirectionPointForBlockDirectionNavigationOf(const VisiblePosition&);
 
 // TODO(yosin) We should move |leftPositionOf()| and |rightPositionOf()| to
 // "VisibleUnits.cpp".
 VisiblePosition leftPositionOf(const VisiblePosition&);
 VisiblePosition rightPositionOf(const VisiblePosition&);
 
 CORE_EXPORT Position canonicalPositionOf(const Position&);
 CORE_EXPORT PositionInComposedTree canonicalPositionOf(const PositionInComposedTree&);
+
 // TODO(yosin) We should move |characterAfter()| and |characterBefore()| to
 // "VisibleUnits.cpp"
 UChar32 characterAfter(const VisiblePosition&);
 UChar32 characterBefore(const VisiblePosition&);
 
 // TODO(yosin) We should move |honorEditingBoundaryAtOr{Before,After} to
 // "VisibleUnits.cpp" as static function.
 // next() and previous() will increment/decrement by a character cluster.
 VisiblePosition honorEditingBoundaryAtOrBefore(const VisiblePosition&, const Position& anchor);
 PositionWithAffinity honorEditingBoundaryAtOrBeforeOf(const PositionWithAffinity&, const Position& anchor);
 PositionInComposedTreeWithAffinity honorEditingBoundaryAtOrBeforeOf(const PositionInComposedTreeWithAffinity&, const PositionInComposedTree& anchor);
 VisiblePosition honorEditingBoundaryAtOrAfter(const VisiblePosition&, const Position& anchor);
 
 // TODO(yosin) We should move |nextPositionOf()| to "VisibleUnits.cpp".
 VisiblePosition nextPositionOf(const VisiblePosition&, EditingBoundaryCrossingRule = CanCrossEditingBoundary);
 // TODO(yosin) We should move |previousPositionOf()| to "VisibleUnits.cpp"
 VisiblePosition previousPositionOf(const VisiblePosition&, EditingBoundaryCrossingRule = CanCrossEditingBoundary);
 
+CORE_EXPORT VisiblePosition visiblePositionOf(const Position&, TextAffinity = VP_DEFAULT_AFFINITY);
+CORE_EXPORT VisiblePosition visiblePositionOf(const PositionInComposedTree&, TextAffinity = VP_DEFAULT_AFFINITY);
+
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::VisiblePosition*);
 void showTree(const blink::VisiblePosition&);
 #endif
 
 #endif // VisiblePosition_h