1 files changed, 44 insertions, 0 deletions
diff --git a/dom/smil/SMILNullType.h b/dom/smil/SMILNullType.h
new file mode 100644
index 0000000000..83f69b2478
--- /dev/null
+++ b/dom/smil/SMILNullType.h
@@ -0,0 +1,44 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DOM_SMIL_SMILNULLTYPE_H_
+#define DOM_SMIL_SMILNULLTYPE_H_
+
+#include "mozilla/Attributes.h"
+#include "mozilla/SMILType.h"
+
+namespace mozilla {
+
+class SMILNullType : public SMILType {
+ public:
+  // Singleton for SMILValue objects to hold onto.
+  static SMILNullType* Singleton();
+
+ protected:
+  // SMILType Methods
+  // -------------------
+  void Init(SMILValue& aValue) const override {}
+  void Destroy(SMILValue& aValue) const override {}
+  nsresult Assign(SMILValue& aDest, const SMILValue& aSrc) const override;
+
+  // The remaining methods should never be called, so although they're very
+  // simple they don't need to be inline.
+  bool IsEqual(const SMILValue& aLeft, const SMILValue& aRight) const override;
+  nsresult Add(SMILValue& aDest, const SMILValue& aValueToAdd,
+               uint32_t aCount) const override;
+  nsresult ComputeDistance(const SMILValue& aFrom, const SMILValue& aTo,
+                           double& aDistance) const override;
+  nsresult Interpolate(const SMILValue& aStartVal, const SMILValue& aEndVal,
+                       double aUnitDistance, SMILValue& aResult) const override;
+
+ private:
+  // Private constructor: prevent instances beyond my singleton.
+  constexpr SMILNullType() = default;
+};
+
+}  // namespace mozilla
+
+#endif  // DOM_SMIL_SMILNULLTYPE_H_