Make non-null VisibleSelections creatable only by createVisibleSelection[Deprecated]

third_party/WebKit/Source/core/editing/VisibleSelection.h

 /*
  * Copyright (C) 2004 Apple Computer, 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 31 matching lines @@
 class SelectionAdjuster;
 
 const TextAffinity SelDefaultAffinity = TextAffinity::Downstream;
 enum SelectionDirection { DirectionForward, DirectionBackward, DirectionRight, DirectionLeft };
 
 template <typename Strategy>
 class CORE_TEMPLATE_CLASS_EXPORT VisibleSelectionTemplate {
     DISALLOW_NEW();
 public:
     VisibleSelectionTemplate();
-    VisibleSelectionTemplate(const PositionTemplate<Strategy>&, TextAffinity, bool isDirectional = false);
-    VisibleSelectionTemplate(const PositionTemplate<Strategy>& base, const PositionTemplate<Strategy>& extent, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
-    explicit VisibleSelectionTemplate(const EphemeralRangeTemplate<Strategy>&, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
-
-    explicit VisibleSelectionTemplate(const VisiblePositionTemplate<Strategy>&, bool isDirectional = false);
-    VisibleSelectionTemplate(const VisiblePositionTemplate<Strategy>&, const VisiblePositionTemplate<Strategy>&, bool isDirectional = false);
-
-    explicit VisibleSelectionTemplate(const PositionWithAffinityTemplate<Strategy>&, bool isDirectional = false);
-
     VisibleSelectionTemplate(const VisibleSelectionTemplate&);
     VisibleSelectionTemplate& operator=(const VisibleSelectionTemplate&);
 
+    // Note: |create()| should be used only by |createVisibleSelection| and
+    // |selectionFromContentsOfNode|.
+    // TODO(xiaochengh): Use enum class instead of boolean parameter.

[yosin_UTC9, 2016/09/30 01:20:35]

Once Selection class introduced, we don't need to use enum class.

We would write as:
Selection::Builder builder;
builder.collapse(base).extend(extent)
  .setIsDirectional(true)
  .setAffinity(TextAffinity::Downstream);
VisibleSelection selection = createVisibleSelectionDeprecated(builder.build());

Until C++ introduce named parameter, builder patter is useful.

+    static VisibleSelectionTemplate create(const PositionTemplate<Strategy>& base, const PositionTemplate<Strategy>& extent, TextAffinity, bool isDirectional);
+
     static VisibleSelectionTemplate selectionFromContentsOfNode(Node*);
 
     SelectionType getSelectionType() const { return m_selectionType; }
 
     void setAffinity(TextAffinity affinity) { m_affinity = affinity; }
     TextAffinity affinity() const { return m_affinity; }
 
     void setBase(const PositionTemplate<Strategy>&);
     void setBase(const VisiblePositionTemplate<Strategy>&);
     void setExtent(const PositionTemplate<Strategy>&);
@@ skipping 58 matching lines @@
     void validatePositionsIfNeeded();
 
 #ifndef NDEBUG
     void showTreeForThis() const;
 #endif
     static void PrintTo(const VisibleSelectionTemplate&, std::ostream*);
 
 private:
     friend class SelectionAdjuster;
 
+    VisibleSelectionTemplate(const PositionTemplate<Strategy>& base, const PositionTemplate<Strategy>& extent, TextAffinity, bool isDirectional);
+
     void validate(TextGranularity = CharacterGranularity);
 
     // Support methods for validate()
     void setBaseAndExtentToDeepEquivalents();
     void adjustSelectionToAvoidCrossingShadowBoundaries();
     void adjustSelectionToAvoidCrossingEditingBoundaries();
     void setEndRespectingGranularity(TextGranularity);
     void setStartRespectingGranularity(TextGranularity);
     void updateSelectionType();
 
@@ skipping 25 matching lines @@
     // of |m_hasTrailingWhitespace|.
     bool m_hasTrailingWhitespace : 1;
 };
 
 extern template class CORE_EXTERN_TEMPLATE_EXPORT VisibleSelectionTemplate<EditingStrategy>;
 extern template class CORE_EXTERN_TEMPLATE_EXPORT VisibleSelectionTemplate<EditingInFlatTreeStrategy>;
 
 using VisibleSelection = VisibleSelectionTemplate<EditingStrategy>;
 using VisibleSelectionInFlatTree = VisibleSelectionTemplate<EditingInFlatTreeStrategy>;
 
+// TODO(xiaochengh): Introduce builder class to get rid of these overloads.
+CORE_EXPORT VisibleSelection createVisibleSelection(const Position&, TextAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelection(const Position& base, const Position& extent, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelection(const EphemeralRange&, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelection(const VisiblePosition&, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelection(const VisiblePosition&, const VisiblePosition&, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelection(const PositionWithAffinity&, bool isDirectional = false);
+
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelection(const PositionInFlatTree&, TextAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelection(const PositionInFlatTree& base, const PositionInFlatTree& extent, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelection(const EphemeralRangeInFlatTree&, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelection(const VisiblePositionInFlatTree&, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelection(const VisiblePositionInFlatTree&, const VisiblePositionInFlatTree&, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelection(const PositionInFlatTreeWithAffinity&, bool isDirectional = false);
+
+// Callers of these functions should ensure clean layout by themselves and then
+// switch to the proper versions (to be introduced).
+CORE_EXPORT VisibleSelection createVisibleSelectionDeprecated(const Position&, TextAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelectionDeprecated(const Position& base, const Position& extent, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelectionDeprecated(const EphemeralRange&, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelectionDeprecated(const VisiblePosition&, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelectionDeprecated(const VisiblePosition&, const VisiblePosition&, bool isDirectional = false);
+CORE_EXPORT VisibleSelection createVisibleSelectionDeprecated(const PositionWithAffinity&, bool isDirectional = false);
+
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelectionDeprecated(const PositionInFlatTree&, TextAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelectionDeprecated(const PositionInFlatTree& base, const PositionInFlatTree& extent, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelectionDeprecated(const EphemeralRangeInFlatTree&, TextAffinity = SelDefaultAffinity, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelectionDeprecated(const VisiblePositionInFlatTree&, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelectionDeprecated(const VisiblePositionInFlatTree&, const VisiblePositionInFlatTree&, bool isDirectional = false);
+CORE_EXPORT VisibleSelectionInFlatTree createVisibleSelectionDeprecated(const PositionInFlatTreeWithAffinity&, bool isDirectional = false);
+
 // We don't yet support multi-range selections, so we only ever have one range
 // to return.
 CORE_EXPORT EphemeralRange firstEphemeralRangeOf(const VisibleSelection&);
 
 // TODO(sof): move more firstRangeOf() uses to be over EphemeralRange instead.
 CORE_EXPORT Range* firstRangeOf(const VisibleSelection&);
 
 CORE_EXPORT std::ostream& operator<<(std::ostream&, const VisibleSelection&);
 CORE_EXPORT std::ostream& operator<<(std::ostream&, const VisibleSelectionInFlatTree&);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::VisibleSelection&);
 void showTree(const blink::VisibleSelection*);
 void showTree(const blink::VisibleSelectionInFlatTree&);
 void showTree(const blink::VisibleSelectionInFlatTree*);
 #endif
 
 #endif // VisibleSelection_h