Introduce enum class TextAffinity as replacement of enum EAffinity

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 12 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef VisiblePosition_h
 #define VisiblePosition_h
 
 #include "core/CoreExport.h"
 #include "core/editing/EditingBoundary.h"
 #include "core/editing/EphemeralRange.h"
 #include "core/editing/PositionWithAffinity.h"
+#include "core/editing/TextAffinity.h"
 #include "platform/heap/Handle.h"
 #include "platform/text/TextDirection.h"
 
 namespace blink {
 
 // VisiblePosition default affinity is downstream because
 // the callers do not really care (they just want the
 // deep position without regard to line position), and this
 // is cheaper than UPSTREAM
-#define VP_DEFAULT_AFFINITY DOWNSTREAM
+#define VP_DEFAULT_AFFINITY TextAffinity::Downstream
 
 // Callers who do not know where on the line the position is,
 // but would like UPSTREAM if at a line break or DOWNSTREAM
 // otherwise, need a clear way to specify that.  The
 // constructors auto-correct UPSTREAM to DOWNSTREAM if the
 // position is not at a line break.
-#define VP_UPSTREAM_IF_POSSIBLE UPSTREAM
+#define VP_UPSTREAM_IF_POSSIBLE TextAffinity::Upstream
 
 class InlineBox;
 class Range;
 
 // |VisiblePosition| is an immutable object representing "canonical position"
 // with affinity.
 //
 // "canonical position" is roughly equivalent to a position where we can place
 // caret, see |canonicalPosition()| for actual definition.
 //
 // "affinity" represents a place of caret at wrapped line. UPSTREAM affinity
 // means caret is placed at end of line. DOWNSTREAM affinity means caret is
 // placed at start of line.
 //
 // Example of affinity:
 //    abc^def where "^" represent |Position|
 // 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) { }
-    explicit VisiblePosition(const Position&, EAffinity = VP_DEFAULT_AFFINITY);
-    explicit VisiblePosition(const PositionInComposedTree&, EAffinity = VP_DEFAULT_AFFINITY);
+    explicit VisiblePosition(const Position&, TextAffinity = VP_DEFAULT_AFFINITY);
+    explicit VisiblePosition(const PositionInComposedTree&, TextAffinity = VP_DEFAULT_AFFINITY);
     explicit VisiblePosition(const PositionWithAffinity&);
 
     // 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); }
-    EAffinity affinity() const { ASSERT(m_affinity == UPSTREAM || m_affinity == DOWNSTREAM); return m_affinity; }
+    TextAffinity affinity() const { return m_affinity; }
 
     // next() and previous() will increment/decrement by a character cluster.
     VisiblePosition next(EditingBoundaryCrossingRule = CanCrossEditingBoundary) const;
     VisiblePosition previous(EditingBoundaryCrossingRule = CanCrossEditingBoundary) const;
     VisiblePosition honorEditingBoundaryAtOrBefore(const VisiblePosition&) const;
     VisiblePosition honorEditingBoundaryAtOrAfter(const VisiblePosition&) const;
     VisiblePosition skipToStartOfEditingBoundary(const VisiblePosition&) const;
     VisiblePosition skipToEndOfEditingBoundary(const VisiblePosition&) const;
 
     VisiblePosition left() const;
@@ skipping 16 matching lines @@
     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>&, EAffinity);
+    void init(const PositionAlgorithm<Strategy>&, TextAffinity);
 
     Position leftVisuallyDistinctCandidate() const;
     Position rightVisuallyDistinctCandidate() const;
 
     Position m_deepPosition;
-    EAffinity m_affinity;
+    TextAffinity m_affinity;
 };
 
 // TODO(yosin) We should move |computeInlineBoxPosition()| to "VisibleUnits.h"
 // with |Position| version.
 inline InlineBoxPosition computeInlineBoxPosition(const VisiblePosition& position)
 {
     return position.deepEquivalent().computeInlineBoxPosition(position.affinity());
 }
 
 EphemeralRange makeRange(const VisiblePosition&, const VisiblePosition&);
 
 CORE_EXPORT Position canonicalPositionOf(const Position&);
 CORE_EXPORT PositionInComposedTree canonicalPositionOf(const PositionInComposedTree&);
 PositionWithAffinity honorEditingBoundaryAtOrBeforeOf(const PositionWithAffinity&, const Position& anchor);
 PositionInComposedTreeWithAffinity honorEditingBoundaryAtOrBeforeOf(const PositionInComposedTreeWithAffinity&, const PositionInComposedTree& anchor);
 
 } // 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