Add composition support for SVG Web Animation of x, y, dx, dy attributes

third_party/WebKit/Source/core/animation/LengthSVGInterpolation.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/LengthSVGInterpolation.h"
-
-#include "core/css/CSSHelper.h"
-#include "core/svg/SVGAnimatedLength.h"
-#include "core/svg/SVGAnimatedLengthList.h"
-#include "core/svg/SVGElement.h"
-#include "core/svg/SVGLengthContext.h"
-#include "wtf/StdLibExtras.h"
-
-namespace blink {
-
-PassRefPtrWillBeRawPtr<SVGLengthList> LengthSVGInterpolation::createList(const SVGAnimatedPropertyBase& attribute)
-{
-    ASSERT(attribute.type() == AnimatedLengthList);
-    const SVGAnimatedLengthList& animatedLengthList = static_cast<const SVGAnimatedLengthList&>(attribute);
-    return SVGLengthList::create(animatedLengthList.currentValue()->unitMode());
-}
-
-PassRefPtr<LengthSVGInterpolation> LengthSVGInterpolation::create(SVGPropertyBase* start, SVGPropertyBase* end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute)
-{
-    NonInterpolableType modeData;
-    OwnPtr<InterpolableValue> startValue = toInterpolableValue(toSVGLength(start), attribute.get(), &modeData);
-    OwnPtr<InterpolableValue> endValue = toInterpolableValue(toSVGLength(end), attribute.get(), nullptr);
-    return adoptRef(new LengthSVGInterpolation(startValue.release(), endValue.release(), attribute, modeData));
-}
-
-namespace {
-
-void populateModeData(const SVGAnimatedPropertyBase* attribute, LengthSVGInterpolation::NonInterpolableType* ptrModeData)
-{
-    switch (attribute->type()) {
-    case AnimatedLength: {
-        const SVGAnimatedLength& animatedLength = static_cast<const SVGAnimatedLength&>(*attribute);
-        ptrModeData->unitMode = animatedLength.currentValue()->unitMode();
-        break;
-    }
-    case AnimatedLengthList: {
-        const SVGAnimatedLengthList& animatedLengthList = static_cast<const SVGAnimatedLengthList&>(*attribute);
-        ptrModeData->unitMode = animatedLengthList.currentValue()->unitMode();
-        break;
-    }
-    default:
-        ASSERT_NOT_REACHED();
-    }
-}
-
-enum LengthInterpolatedUnit {
-    LengthInterpolatedNumber,
-    LengthInterpolatedPercentage,
-    LengthInterpolatedEMS,
-    LengthInterpolatedEXS,
-    LengthInterpolatedREMS,
-    LengthInterpolatedCHS,
-};
-
-static const CSSPrimitiveValue::UnitType unitTypes[] = {
-    CSSPrimitiveValue::UnitType::UserUnits,
-    CSSPrimitiveValue::UnitType::Percentage,
-    CSSPrimitiveValue::UnitType::Ems,
-    CSSPrimitiveValue::UnitType::Exs,
-    CSSPrimitiveValue::UnitType::Rems,
-    CSSPrimitiveValue::UnitType::Chs
-};
-
-const size_t numLengthInterpolatedUnits = WTF_ARRAY_LENGTH(unitTypes);
-
-LengthInterpolatedUnit convertToInterpolatedUnit(CSSPrimitiveValue::UnitType unitType, double& value)
-{
-    switch (unitType) {
-    case CSSPrimitiveValue::UnitType::Unknown:
-    default:
-        ASSERT_NOT_REACHED();
-    case CSSPrimitiveValue::UnitType::Pixels:
-    case CSSPrimitiveValue::UnitType::Number:
-        return LengthInterpolatedNumber;
-    case CSSPrimitiveValue::UnitType::Percentage:
-        return LengthInterpolatedPercentage;
-    case CSSPrimitiveValue::UnitType::Ems:
-        return LengthInterpolatedEMS;
-    case CSSPrimitiveValue::UnitType::Exs:
-        return LengthInterpolatedEXS;
-    case CSSPrimitiveValue::UnitType::Centimeters:
-        value *= cssPixelsPerCentimeter;
-        return LengthInterpolatedNumber;
-    case CSSPrimitiveValue::UnitType::Millimeters:
-        value *= cssPixelsPerMillimeter;
-        return LengthInterpolatedNumber;
-    case CSSPrimitiveValue::UnitType::Inches:
-        value *= cssPixelsPerInch;
-        return LengthInterpolatedNumber;
-    case CSSPrimitiveValue::UnitType::Points:
-        value *= cssPixelsPerPoint;
-        return LengthInterpolatedNumber;
-    case CSSPrimitiveValue::UnitType::Picas:
-        value *= cssPixelsPerPica;
-        return LengthInterpolatedNumber;
-    case CSSPrimitiveValue::UnitType::UserUnits:
-        return LengthInterpolatedNumber;
-    case CSSPrimitiveValue::UnitType::Rems:
-        return LengthInterpolatedREMS;
-    case CSSPrimitiveValue::UnitType::Chs:
-        return LengthInterpolatedCHS;
-    }
-}
-
-} // namespace
-
-PassOwnPtr<InterpolableValue> LengthSVGInterpolation::toInterpolableValue(SVGLength* length, const SVGAnimatedPropertyBase* attribute, NonInterpolableType* ptrModeData)
-{
-    if (ptrModeData)
-        populateModeData(attribute, ptrModeData);
-
-    double value = length->valueInSpecifiedUnits();
-    LengthInterpolatedUnit unitType = convertToInterpolatedUnit(length->typeWithCalcResolved(), value);
-
-    double values[numLengthInterpolatedUnits] = { };
-    values[unitType] = value;
-
-    OwnPtr<InterpolableList> listOfValues = InterpolableList::create(numLengthInterpolatedUnits);
-    for (size_t i = 0; i < numLengthInterpolatedUnits; ++i)
-        listOfValues->set(i, InterpolableNumber::create(values[i]));
-    return listOfValues.release();
-}
-
-PassRefPtrWillBeRawPtr<SVGLength> LengthSVGInterpolation::fromInterpolableValue(const InterpolableValue& interpolableValue, const NonInterpolableType& modeData, const SVGElement* element, const QualifiedName& attributeName)
-{
-    const InterpolableList& listOfValues = toInterpolableList(interpolableValue);
-    ASSERT(element);
-
-    double value = 0;
-    CSSPrimitiveValue::UnitType unitType = CSSPrimitiveValue::UnitType::UserUnits;
-    unsigned unitTypeCount = 0;
-    // We optimise for the common case where only one unit type is involved.
-    for (size_t i = 0; i < numLengthInterpolatedUnits; i++) {
-        double entry = toInterpolableNumber(listOfValues.get(i))->value();
-        if (!entry)
-            continue;
-        unitTypeCount++;
-        if (unitTypeCount > 1)
-            break;
-
-        value = entry;
-        unitType = unitTypes[i];
-    }
-
-    if (unitTypeCount > 1) {
-        value = 0;
-        unitType = CSSPrimitiveValue::UnitType::UserUnits;
-
-        // SVGLength does not support calc expressions, so we convert to canonical units.
-        SVGLengthContext lengthContext(element);
-        for (size_t i = 0; i < numLengthInterpolatedUnits; i++) {
-            double entry = toInterpolableNumber(listOfValues.get(i))->value();
-            if (entry)
-                value += lengthContext.convertValueToUserUnits(entry, modeData.unitMode, unitTypes[i]);
-        }
-    }
-
-    if (SVGLength::negativeValuesForbiddenForAnimatedLengthAttribute(attributeName) && value < 0)
-        value = 0;
-
-    RefPtrWillBeRawPtr<SVGLength> result = SVGLength::create(modeData.unitMode); // defaults to the length 0
-    result->newValueSpecifiedUnits(unitType, value);
-    return result.release();
-}
-
-PassRefPtrWillBeRawPtr<SVGPropertyBase> LengthSVGInterpolation::interpolatedValue(SVGElement& targetElement) const
-{
-    return fromInterpolableValue(*m_cachedValue, m_modeData, &targetElement, attributeName());
-}
-
-}