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

third_party/WebKit/Source/core/animation/KeyframeInterpolation.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "core/animation/InvalidatableInterpolation.h"
+#include "core/animation/KeyframeInterpolation.h"
 
 #include "core/animation/InterpolationEnvironment.h"
 #include "core/animation/StringKeyframe.h"
 #include "core/css/resolver/StyleResolverState.h"
 #include <memory>
 
 namespace blink {
 
-void InvalidatableInterpolation::interpolate(int, double fraction)
+void KeyframeInterpolation::interpolateImpl()
 {
-    if (fraction == m_currentFraction)
-        return;
+    DCHECK(m_previousFraction != m_currentFraction);
 
-    if (m_currentFraction == 0 || m_currentFraction == 1 || fraction == 0 || fraction == 1)
+    if (m_previousFraction == 0 || m_previousFraction == 1 || m_currentFraction == 0 || m_currentFraction == 1)
         clearCache();
 
-    m_currentFraction = fraction;
+    m_previousFraction = m_currentFraction;
     if (m_isCached && m_cachedPairConversion)
-        m_cachedPairConversion->interpolateValue(fraction, m_cachedValue);
+        m_cachedPairConversion->interpolateValue(m_currentFraction, m_cachedValue);
     // We defer the interpolation to ensureValidInterpolation() if m_cachedPairConversion is null.
 }
 
-std::unique_ptr<PairwisePrimitiveInterpolation> InvalidatableInterpolation::maybeConvertPairwise(const InterpolationEnvironment& environment, const UnderlyingValueOwner& underlyingValueOwner) const
+std::unique_ptr<PairwisePrimitiveInterpolation> KeyframeInterpolation::maybeConvertPairwise(const InterpolationEnvironment& environment, const UnderlyingValueOwner& underlyingValueOwner) const
 {
-    ASSERT(m_currentFraction != 0 && m_currentFraction != 1);
+    DCHECK(m_currentFraction != 0 && m_currentFraction != 1);
     for (const auto& interpolationType : m_interpolationTypes) {
         if ((m_startKeyframe->isNeutral() || m_endKeyframe->isNeutral()) && (!underlyingValueOwner || underlyingValueOwner.type() != *interpolationType))
             continue;
         ConversionCheckers conversionCheckers;
         PairwiseInterpolationValue result = interpolationType->maybeConvertPairwise(*m_startKeyframe, *m_endKeyframe, environment, underlyingValueOwner.value(), conversionCheckers);
         addConversionCheckers(*interpolationType, conversionCheckers);
-        if (result) {
-            return PairwisePrimitiveInterpolation::create(*interpolationType,
-                std::move(result.startInterpolableValue),
-                std::move(result.endInterpolableValue),
-                result.nonInterpolableValue.release());
-        }
+        if (result)
+            return PairwisePrimitiveInterpolation::create(*interpolationType, std::move(result));
     }
     return nullptr;
 }
 
-std::unique_ptr<TypedInterpolationValue> InvalidatableInterpolation::convertSingleKeyframe(const PropertySpecificKeyframe& keyframe, const InterpolationEnvironment& environment, const UnderlyingValueOwner& underlyingValueOwner) const
+std::unique_ptr<TypedInterpolationValue> KeyframeInterpolation::convertSingleKeyframe(const PropertySpecificKeyframe& keyframe, const InterpolationEnvironment& environment, const UnderlyingValueOwner& underlyingValueOwner) const
 {
     if (keyframe.isNeutral() && !underlyingValueOwner)
         return nullptr;
     for (const auto& interpolationType : m_interpolationTypes) {
         if (keyframe.isNeutral() && underlyingValueOwner.type() != *interpolationType)
             continue;
         ConversionCheckers conversionCheckers;
         InterpolationValue result = interpolationType->maybeConvertSingle(keyframe, environment, underlyingValueOwner.value(), conversionCheckers);
         addConversionCheckers(*interpolationType, conversionCheckers);
         if (result)
-            return TypedInterpolationValue::create(*interpolationType, std::move(result.interpolableValue), result.nonInterpolableValue.release());
+            return TypedInterpolationValue::create(*interpolationType, std::move(result));
     }
-    ASSERT(keyframe.isNeutral());
+    DCHECK(keyframe.isNeutral());
     return nullptr;
 }
 
-void InvalidatableInterpolation::addConversionCheckers(const InterpolationType& type, ConversionCheckers& conversionCheckers) const
+void KeyframeInterpolation::addConversionCheckers(const InterpolationType& type, ConversionCheckers& conversionCheckers) const
 {
     for (size_t i = 0; i < conversionCheckers.size(); i++) {
         conversionCheckers[i]->setType(type);
         m_conversionCheckers.append(std::move(conversionCheckers[i]));
     }
 }
 
-std::unique_ptr<TypedInterpolationValue> InvalidatableInterpolation::maybeConvertUnderlyingValue(const InterpolationEnvironment& environment) const
+std::unique_ptr<TypedInterpolationValue> KeyframeInterpolation::maybeConvertUnderlyingValue(const InterpolationEnvironment& environment) const
 {
     for (const auto& interpolationType : m_interpolationTypes) {
         InterpolationValue result = interpolationType->maybeConvertUnderlyingValue(environment);
         if (result)
-            return TypedInterpolationValue::create(*interpolationType, std::move(result.interpolableValue), result.nonInterpolableValue.release());
+            return TypedInterpolationValue::create(*interpolationType, std::move(result));
     }
     return nullptr;
 }
 
-bool InvalidatableInterpolation::dependsOnUnderlyingValue() const
+bool KeyframeInterpolation::dependsOnUnderlyingValue() const
 {
     return (m_startKeyframe->underlyingFraction() != 0 && m_currentFraction != 1) || (m_endKeyframe->underlyingFraction() != 0 && m_currentFraction != 0);
 }
 
-bool InvalidatableInterpolation::isNeutralKeyframeActive() const
+bool KeyframeInterpolation::isNeutralKeyframeActive() const
 {
     return (m_startKeyframe->isNeutral() && m_currentFraction != 1) || (m_endKeyframe->isNeutral() && m_currentFraction != 0);
 }
 
-void InvalidatableInterpolation::clearCache() const
+void KeyframeInterpolation::clearCache() const
 {
     m_isCached = false;
     m_cachedPairConversion.reset();
     m_conversionCheckers.clear();
     m_cachedValue.reset();
 }
 
-bool InvalidatableInterpolation::isCacheValid(const InterpolationEnvironment& environment, const UnderlyingValueOwner& underlyingValueOwner) const
+bool KeyframeInterpolation::isCacheValid(const InterpolationEnvironment& environment, const UnderlyingValueOwner& underlyingValueOwner) const
 {
     if (!m_isCached)
         return false;
     if (isNeutralKeyframeActive()) {
         if (m_cachedPairConversion && m_cachedPairConversion->isFlip())
             return false;
         // Pairwise interpolation can never happen between different InterpolationTypes, neutral values always represent the underlying value.
         if (!underlyingValueOwner || !m_cachedValue || m_cachedValue->type() != underlyingValueOwner.type())
             return false;
     }
     for (const auto& checker : m_conversionCheckers) {
         if (!checker->isValid(environment, underlyingValueOwner.value()))
             return false;
     }
     return true;
 }
 
-const TypedInterpolationValue* InvalidatableInterpolation::ensureValidInterpolation(const InterpolationEnvironment& environment, const UnderlyingValueOwner& underlyingValueOwner) const
+const TypedInterpolationValue* KeyframeInterpolation::ensureValidInterpolation(const InterpolationEnvironment& environment, const UnderlyingValueOwner& underlyingValueOwner) const
 {
-    ASSERT(!std::isnan(m_currentFraction));
+    DCHECK(!std::isnan(m_currentFraction));
     if (isCacheValid(environment, underlyingValueOwner))
         return m_cachedValue.get();
     clearCache();
     if (m_currentFraction == 0) {
         m_cachedValue = convertSingleKeyframe(*m_startKeyframe, environment, underlyingValueOwner);
     } else if (m_currentFraction == 1) {
         m_cachedValue = convertSingleKeyframe(*m_endKeyframe, environment, underlyingValueOwner);
     } else {
         std::unique_ptr<PairwisePrimitiveInterpolation> pairwiseConversion = maybeConvertPairwise(environment, underlyingValueOwner);
         if (pairwiseConversion) {
             m_cachedValue = pairwiseConversion->initialValue();
             m_cachedPairConversion = std::move(pairwiseConversion);
         } else {
             m_cachedPairConversion = FlipPrimitiveInterpolation::create(
                 convertSingleKeyframe(*m_startKeyframe, environment, underlyingValueOwner),
                 convertSingleKeyframe(*m_endKeyframe, environment, underlyingValueOwner));
         }
         m_cachedPairConversion->interpolateValue(m_currentFraction, m_cachedValue);
     }
     m_isCached = true;
     return m_cachedValue.get();
 }
 
-void InvalidatableInterpolation::setFlagIfInheritUsed(InterpolationEnvironment& environment) const
+void KeyframeInterpolation::setFlagIfInheritUsed(InterpolationEnvironment& environment) const
 {
     if (!m_property.isCSSProperty() && !m_property.isPresentationAttribute())
         return;
     if (!environment.state().parentStyle())
         return;
     const CSSValue* startValue = toCSSPropertySpecificKeyframe(*m_startKeyframe).value();
     const CSSValue* endValue = toCSSPropertySpecificKeyframe(*m_endKeyframe).value();
     if ((startValue && startValue->isInheritedValue())
         || (endValue && endValue->isInheritedValue())) {
         environment.state().parentStyle()->setHasExplicitlyInheritedProperties();
     }
 }
 
-double InvalidatableInterpolation::underlyingFraction() const
+double KeyframeInterpolation::underlyingFraction() const
 {
     if (m_currentFraction == 0)
         return m_startKeyframe->underlyingFraction();
     if (m_currentFraction == 1)
         return m_endKeyframe->underlyingFraction();
     return m_cachedPairConversion->interpolateUnderlyingFraction(m_startKeyframe->underlyingFraction(), m_endKeyframe->underlyingFraction(), m_currentFraction);
 }
 
-void InvalidatableInterpolation::applyStack(const ActiveInterpolations& interpolations, InterpolationEnvironment& environment)
+void KeyframeInterpolation::applyStack(const ActiveInterpolations& interpolations, InterpolationEnvironment& environment)
 {
-    ASSERT(!interpolations.isEmpty());
+    DCHECK(!interpolations.isEmpty());
     size_t startingIndex = 0;
 
     // Compute the underlying value to composite onto.
     UnderlyingValueOwner underlyingValueOwner;
-    const InvalidatableInterpolation& firstInterpolation = toInvalidatableInterpolation(*interpolations.at(startingIndex));
+    const KeyframeInterpolation& firstInterpolation = toKeyframeInterpolation(*interpolations.at(startingIndex));
     if (firstInterpolation.dependsOnUnderlyingValue()) {
         underlyingValueOwner.set(firstInterpolation.maybeConvertUnderlyingValue(environment));
     } else {
         const TypedInterpolationValue* firstValue = firstInterpolation.ensureValidInterpolation(environment, underlyingValueOwner);
         // Fast path for replace interpolations that are the only one to apply.
         if (interpolations.size() == 1) {
             if (firstValue) {
                 firstInterpolation.setFlagIfInheritUsed(environment);
                 firstValue->type().apply(firstValue->interpolableValue(), firstValue->getNonInterpolableValue(), environment);
             }
             return;
         }
         underlyingValueOwner.set(firstValue);
         startingIndex++;
     }
 
     // Composite interpolations onto the underlying value.
     bool shouldApply = false;
     for (size_t i = startingIndex; i < interpolations.size(); i++) {
-        const InvalidatableInterpolation& currentInterpolation = toInvalidatableInterpolation(*interpolations.at(i));
-        ASSERT(currentInterpolation.dependsOnUnderlyingValue());
+        const KeyframeInterpolation& currentInterpolation = toKeyframeInterpolation(*interpolations.at(i));
+        DCHECK(currentInterpolation.dependsOnUnderlyingValue());
         const TypedInterpolationValue* currentValue = currentInterpolation.ensureValidInterpolation(environment, underlyingValueOwner);
         if (!currentValue)
             continue;
         shouldApply = true;
         currentInterpolation.setFlagIfInheritUsed(environment);
         double underlyingFraction = currentInterpolation.underlyingFraction();
         if (underlyingFraction == 0 || !underlyingValueOwner || underlyingValueOwner.type() != currentValue->type())
             underlyingValueOwner.set(currentValue);
         else
             currentValue->type().composite(underlyingValueOwner, underlyingFraction, currentValue->value(), currentInterpolation.m_currentFraction);
     }
 
     if (shouldApply && underlyingValueOwner)
         underlyingValueOwner.type().apply(*underlyingValueOwner.value().interpolableValue, underlyingValueOwner.value().nonInterpolableValue.get(), environment);
 }
 
 } // namespace blink