1 files changed, 65 insertions, 0 deletions
diff --git a/dom/animation/ComputedTimingFunction.h b/dom/animation/ComputedTimingFunction.h
new file mode 100644
index 000000000..998097265
--- /dev/null
+++ b/dom/animation/ComputedTimingFunction.h
@@ -0,0 +1,65 @@
+/* -*- 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 mozilla_ComputedTimingFunction_h
+#define mozilla_ComputedTimingFunction_h
+
+#include "nsSMILKeySpline.h"  // nsSMILKeySpline
+#include "nsStyleStruct.h"    // nsTimingFunction
+
+namespace mozilla {
+
+class ComputedTimingFunction
+{
+public:
+  // BeforeFlag is used in step timing function.
+  // https://w3c.github.io/web-animations/#before-flag
+  enum class BeforeFlag {
+    Unset,
+    Set
+  };
+  void Init(const nsTimingFunction &aFunction);
+  double GetValue(double aPortion, BeforeFlag aBeforeFlag) const;
+  const nsSMILKeySpline* GetFunction() const
+  {
+    NS_ASSERTION(HasSpline(), "Type mismatch");
+    return &mTimingFunction;
+  }
+  nsTimingFunction::Type GetType() const { return mType; }
+  bool HasSpline() const { return nsTimingFunction::IsSplineType(mType); }
+  uint32_t GetSteps() const { return mSteps; }
+  bool operator==(const ComputedTimingFunction& aOther) const
+  {
+    return mType == aOther.mType &&
+           (HasSpline() ?
+            mTimingFunction == aOther.mTimingFunction :
+            mSteps == aOther.mSteps);
+  }
+  bool operator!=(const ComputedTimingFunction& aOther) const
+  {
+    return !(*this == aOther);
+  }
+  int32_t Compare(const ComputedTimingFunction& aRhs) const;
+  void AppendToString(nsAString& aResult) const;
+
+  static double GetPortion(const Maybe<ComputedTimingFunction>& aFunction,
+                           double aPortion,
+                           BeforeFlag aBeforeFlag)
+  {
+    return aFunction ? aFunction->GetValue(aPortion, aBeforeFlag) : aPortion;
+  }
+  static int32_t Compare(const Maybe<ComputedTimingFunction>& aLhs,
+                         const Maybe<ComputedTimingFunction>& aRhs);
+
+private:
+  nsTimingFunction::Type mType;
+  nsSMILKeySpline mTimingFunction;
+  uint32_t mSteps;
+};
+
+} // namespace mozilla
+
+#endif // mozilla_ComputedTimingFunction_h