De-templatize ui::AXPosition

ui/accessibility/ax_range.h

Index: ui/accessibility/ax_range.h
diff --git a/ui/accessibility/ax_range.h b/ui/accessibility/ax_range.h
index 914f350d3a74d292ccaa90ca4531dc0c6c3739c5..4acbd893deab58bf71840a33adecb7470028faa8 100644
--- a/ui/accessibility/ax_range.h
+++ b/ui/accessibility/ax_range.h
@@ -9,6 +9,8 @@
 #include <utility>
 
 #include "base/strings/string16.h"
+#include "ui/accessibility/ax_export.h"
+#include "ui/accessibility/ax_position.h"
 
 namespace ui {
 
@@ -16,69 +18,29 @@ namespace ui {
 //
 // In order to avoid any confusion regarding whether a deep or a shallow copy is
 // being performed, this class can be moved but not copied.
-template <class AXPositionType>
-class AXRange {
+class AX_EXPORT AXAbstractRange {
  public:
-  AXRange()
-      : anchor_(AXPositionType::CreateNullPosition()),
-        focus_(AXPositionType::CreateNullPosition()) {}
-
-  AXRange(std::unique_ptr<AXPositionType> anchor,
-          std::unique_ptr<AXPositionType> focus) {
-    if (anchor) {
-      anchor_ = std::move(anchor);
-    } else {
-      anchor_ = AXPositionType::CreateNullPosition();
-    }
-    if (focus) {
-      focus_ = std::move(focus);
-    } else {
-      focus = AXPositionType::CreateNullPosition();
-    }
-  }
-
-  AXRange(const AXRange& other) = delete;
+  AXAbstractRange(std::unique_ptr<AXPositionBase> anchor,
+                  std::unique_ptr<AXPositionBase> focus);
+  AXAbstractRange(AXAbstractRange&& other);
 
-  AXRange(AXRange&& other) : AXRange() {
-    anchor_.swap(other.anchor_);
-    focus_.swap(other.focus_);
-  }
+  AXAbstractRange(const AXAbstractRange& other) = delete;
+  AXAbstractRange& operator=(const AXAbstractRange& other) = delete;
+  AXAbstractRange& operator=(AXAbstractRange&& other) = delete;
 
-  AXRange& operator=(const AXRange& other) = delete;
-
-  AXRange& operator=(const AXRange&& other) {
-    if (this != other) {
-      anchor_ = AXPositionType::CreateNullPosition();
-      focus_ = AXPositionType::CreateNullPosition();
-      anchor_.swap(other.anchor_);
-      focus_.swap(other.focus_);
-    }
-    return *this;
-  }
-
-  virtual ~AXRange() {}
+  ~AXAbstractRange();
 
   bool IsNull() const {
     return !anchor_ || !focus_ || anchor_->IsNullPosition() ||
            focus_->IsNullPosition();
   }
 
-  AXPositionType* anchor() const {
-    DCHECK(anchor_);
-    return anchor_.get();
-  }
-
-  AXPositionType* focus() const {
-    DCHECK(focus_);
-    return focus_.get();
-  }
-
   base::string16 GetText() const {
     base::string16 text;
     if (IsNull())
       return text;
 
-    std::unique_ptr<AXPositionType> start, end;
+    std::unique_ptr<AXPositionBase> start, end;
     if (*anchor_ < *focus_) {
       start = anchor_->AsLeafTextPosition();
       end = focus_->AsLeafTextPosition();
@@ -106,9 +68,44 @@ class AXRange {
     return text.substr(0, text_length);
   }
 
+  AXPositionBase* anchor() const { return anchor_.get(); }
+  AXPositionBase* focus() const { return focus_.get(); }
+
+ protected:
+  std::unique_ptr<AXPositionBase> anchor_;
+  std::unique_ptr<AXPositionBase> focus_;
+};
+
+template <class AXPositionType>
+class AXRange : public AXAbstractRange {
+ public:
+  AXRange() : AXAbstractRange(CreateNull(), CreateNull()) {}
+  AXRange(std::unique_ptr<AXPositionType> anchor,
+          std::unique_ptr<AXPositionType> focus)
+      : AXAbstractRange(anchor ? AsBase(std::move(anchor)) : CreateNull(),
+                        focus ? AsBase(std::move(focus)) : CreateNull()) {}
+  AXRange(AXRange&& other) = default;
+
+  AXRange(const AXRange& other) = delete;
+  AXRange& operator=(const AXRange& other) = delete;
+  AXRange& operator=(AXRange&& other) = delete;
+
+  typename AXPositionType::ConcreteNodeType* GetAnchorNode() const {
+    return static_cast<AXPositionType*>(anchor_.get())->GetAnchor();
+  }
+  typename AXPositionType::ConcreteNodeType* GetFocusNode() const {
+    return static_cast<AXPositionType*>(focus_.get())->GetAnchor();
+  }
+
  private:
-  std::unique_ptr<AXPositionType> anchor_;
-  std::unique_ptr<AXPositionType> focus_;
+  static std::unique_ptr<AXPositionBase> AsBase(
+      std::unique_ptr<AXPositionType> concrete) {
+    return base::WrapUnique<AXPositionBase>(concrete.release());
+  }
+
+  static std::unique_ptr<AXPositionBase> CreateNull() {
+    return AsBase(AXPositionType::CreateConcreteNullPosition());
+  }
 };
 
 }  // namespace ui