WIP: Implement CSS transitions on top of InterpolationTypes instead of AnimatableValues

third_party/WebKit/Source/core/animation/EffectModel.h

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef EffectModel_h
 #define EffectModel_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/CSSPropertyNames.h"
 #include "core/CoreExport.h"
+#include "core/animation/AnimationEffect.h"
 #include "core/animation/PropertyHandle.h"
 #include "platform/heap/Handle.h"
 #include "wtf/HashMap.h"
 
 namespace blink {
 
 class Interpolation;
 
 // Time independent representation of an Animation's content.
 // Can be sampled for the active pairs of Keyframes (represented by Interpolations) at a given time fraction.
 class CORE_EXPORT EffectModel : public GarbageCollectedFinalized<EffectModel>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
     enum CompositeOperation {
         CompositeReplace,
         CompositeAdd,
     };
 
-    EffectModel() { }
     virtual ~EffectModel() { }
-    virtual bool sample(int iteration, double fraction, double iterationDuration, Vector<RefPtr<Interpolation>>&) const = 0;
 
-    virtual bool affects(PropertyHandle) const { return false; }
-    virtual bool isTransformRelatedEffect() const { return false; }
+    bool sample(int iteration, double fraction, double iterationDuration, Vector<RefPtr<Interpolation>>& result) const
+    {
+        DCHECK_GE(iteration, 0);
+        DCHECK(!isNull(fraction));
+        bool changed = iteration != m_lastIteration || fraction != m_lastFraction || iterationDuration != m_lastIterationDuration;
+        m_lastIteration = iteration;
+        m_lastFraction = fraction;
+        m_lastIterationDuration = iterationDuration;
+        sampleImpl(iteration, fraction, iterationDuration, result);
+        return changed;
+    }
+
+    virtual bool affects(PropertyHandle) const = 0;
+    bool isTransformRelatedEffect() const
+    {
+        return affects(PropertyHandle(CSSPropertyTransform))
+            || affects(PropertyHandle(CSSPropertyRotate))
+            || affects(PropertyHandle(CSSPropertyScale))
+            || affects(PropertyHandle(CSSPropertyTranslate));
+    }
+
     virtual bool isKeyframeEffectModel() const { return false; }
+    virtual bool isTransitionEffectModel() const { return false; }
 
     DEFINE_INLINE_VIRTUAL_TRACE() { }
+
+protected:
+    EffectModel()
+        : m_lastIteration(0)
+        , m_lastFraction(nullValue())
+        , m_lastIterationDuration(0)
+    { }
+
+    virtual void sampleImpl(int iteration, double fraction, double iterationDuration, Vector<RefPtr<Interpolation>>&) const = 0;
+
+    void clearLastFraction() const { m_lastFraction = nullValue(); }
+
+private:
+    mutable int m_lastIteration;
+    mutable double m_lastFraction;
+    mutable double m_lastIterationDuration;
 };
 
 } // namespace blink
 
 #endif // EffectModel_h