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

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

-// Copyright 2014 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/Interpolation.h"
-
-#include <memory>
-
-namespace blink {
-
-namespace {
-
-bool typesMatch(const InterpolableValue* start, const InterpolableValue* end)
-{
-    if (start == end)
-        return true;
-    if (start->isNumber())
-        return end->isNumber();
-    if (start->isBool())
-        return end->isBool();
-    if (start->isAnimatableValue())
-        return end->isAnimatableValue();
-    if (!(start->isList() && end->isList()))
-        return false;
-    const InterpolableList* startList = toInterpolableList(start);
-    const InterpolableList* endList = toInterpolableList(end);
-    if (startList->length() != endList->length())
-        return false;
-    for (size_t i = 0; i < startList->length(); ++i) {
-        if (!typesMatch(startList->get(i), endList->get(i)))
-            return false;
-    }
-    return true;
-}
-
-} // namespace
-
-Interpolation::Interpolation(std::unique_ptr<InterpolableValue> start, std::unique_ptr<InterpolableValue> end)
-    : m_start(std::move(start))
-    , m_end(std::move(end))
-    , m_cachedFraction(0)
-    , m_cachedIteration(0)
-    , m_cachedValue(m_start ? m_start->clone() : nullptr)
-{
-    RELEASE_ASSERT(typesMatch(m_start.get(), m_end.get()));
-}
-
-Interpolation::~Interpolation()
-{
-}
-
-void Interpolation::interpolate(int iteration, double fraction)
-{
-    if (m_cachedFraction != fraction || m_cachedIteration != iteration) {
-        m_start->interpolate(*m_end, fraction, *m_cachedValue);
-        m_cachedIteration = iteration;
-        m_cachedFraction = fraction;
-    }
-}
-
-} // namespace blink