text: /*
   * 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.
  G*     * Redistributions in binary form must reproduce the above
   * copyright notice, this list of conditions and the following disclaimer
   * in the documentation and/or other materials provided with the
   * distribution.
   *     * Neither the name of Google Inc. nor the names of its
   * contributors may be used to endorse or promote products derived from
   * this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (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 SVGAnimatedProperty_h
  #define SVGAnimatedProperty_h
  
  #include "bindings/core/v8/ExceptionStatePlaceholder.h"
  #include "bindings/core/v8/ScriptWrappable.h"
  #include "core/dom/ExceptionCode.h"
  #include "core/svg/SVGParsingError.h"
  #include "core/svg/properties/SVGPropertyInfo.h"
  #include "core/svg/properties/SVGPropertyTearOff.h"
  #include "platform/heap/Handle.h"
  #include "wtf/Noncopyable.h"
  #include "wtf/PassRefPtr.h"
  #include "wtf/RefCounted.h"
  
  namespace blink {
  
  class SVGElement;
  
  class SVGAnimatedPropertyBase : public RefCountedWillBeGarbageCollectedFinalized<SVGAnimatedPropertyBase>, public ScriptWrappable {
      DEFINE_WRAPPERTYPEINFO_NOT_REACHED();
      WTF_MAKE_NONCOPYABLE(SVGAnimatedPropertyBase);
  public:
      virtual ~SVGAnimatedPropertyBase();
  
      virtual SVGPropertyBase* currentValueBase() = 0;
      virtual bool isAnimating() const = 0;
  
      virtual PassRefPtrWillBeRawPtr<SVGPropertyBase> createAnimatedValue() = 0;
      virtual void setAnimatedValue(PassRefPtrWillBeRawPtr<SVGPropertyBase>) = 0;
      virtual void animationEnded();
  
      virtual void setBaseValueAsString(const String& value, SVGParsingError& parseError) = 0;
      virtual bool needsSynchronizeAttribute() = 0;
      virtual void synchronizeAttribute();
  
      AnimatedPropertyType type() const
      {
          return m_type;
      }
  
      SVGElement* contextElement() const
      {
          return m_contextElement;
      }
  
      const QualifiedName& attributeName() const
      {
          return m_attributeName;
      }
  
      bool isReadOnly() const
      {
          return m_isReadOnly;
      }
  
      void setReadOnly()
      {
          m_isReadOnly = true;
      }
  
      bool isSpecified() const;
  
      virtual void trace(Visitor* visitor)
      {
          visitor->trace(m_contextElement);
      }
  
  protected:
      SVGAnimatedPropertyBase(AnimatedPropertyType, SVGElement*, const QualifiedName& attributeName);
  
  private:
      const AnimatedPropertyType m_type;
      bool m_isReadOnly;
  
      // This reference is kept alive from V8 wrapper
      RawPtrWillBeMember<SVGElement> m_contextElement;
  
      const QualifiedName& m_attributeName;
  };
  
  template <typename Property>
  class SVGAnimatedPropertyCommon : public SVGAnimatedPropertyBase {
  public:
      Property* baseValue()
      {
          return m_baseValue.get();
      }
  
      Property* currentValue()
      {
          return m_currentValue ? m_currentValue.get() : m_baseValue.get();
      }
  
      const Property* currentValue() const
      {
          return const_cast<SVGAnimatedPropertyCommon*>(this)->currentValue();
      }
  
      virtual SVGPropertyBase* currentValueBase() override
      {
          return currentValue();
      }
  
      virtual bool isAnimating() const override
      {
          return m_currentValue;
      }
  
      void setBaseValueAsString(const String& value, SVGParsingError& parseError) override
      {
          TrackExceptionState es;
  
          m_baseValue->setValueAsString(value, es);
  
          if (es.hadException())
              parseError = ParsingAttributeFailedError;
      }
  
      virtual PassRefPtrWillBeRawPtr<SVGPropertyBase> createAnimatedValue() override
      {
          return m_baseValue->clone();
      }
  
      virtual void setAnimatedValue(PassRefPtrWillBeRawPtr<SVGPropertyBase> passValue) override
      {
          RefPtrWillBeRawPtr<SVGPropertyBase> value = passValue;
          ASSERT(value->type() == Property::classType());
          m_currentValue = static_pointer_cast<Property>(value.release());
      }
  
      virtual void animationEnded() override
      {
          m_currentValue.clear();
  
          SVGAnimatedPropertyBase::animationEnded();
      }
  
      virtual void trace(Visitor* visitor) override
      {
          visitor->trace(m_baseValue);
          visitor->trace(m_currentValue);
          SVGAnimatedPropertyBase::trace(visitor);
      }
  
  protected:
      SVGAnimatedPropertyCommon(SVGElement* contextElement, const QualifiedName& attributeName, PassRefPtrWillBeRawPtr<Property> initialValue)
          : SVGAnimatedPropertyBase(Property::classType(), contextElement, attributeName)
          , m_baseValue(initialValue)
      {
      }
  
  private:
      RefPtrWillBeMember<Property> m_baseValue;
      RefPtrWillBeMember<Property> m_currentValue;
  };
  
  // Implementation of SVGAnimatedProperty which uses primitive types.
  // This is for classes which return primitive type for its "animVal".
  // Examples are SVGAnimatedBoolean, SVGAnimatedNumber, etc.
  template <typename Property, typename TearOffType = typename Property::TearOffType, typename PrimitiveType = typename Property::PrimitiveType>
  class SVGAnimatedProperty : public SVGAnimatedPropertyCommon<Property> {
  public:
      virtual bool needsSynchronizeAttribute() override
      {
          // DOM attribute synchronization is only needed if tear-off is being touched from javascript or the property is being animated.
          // This prevents unnecessary attribute creation on target element.
          return m_baseValueUpdated || this->isAnimating();
      }
  
      virtual void synchronizeAttribute() override
      {
          SVGAnimatedPropertyBase::synchronizeAttribute();
          m_baseValueUpdated = false;
      }
  
      // SVGAnimated* DOM Spec implementations:
  
      // baseVal()/setBaseVal()/animVal() are only to be used from SVG DOM implementation.
      // Use currentValue() from C++ code.
      PrimitiveType baseVal()
      {
          return this->baseValue()->value();
      }
  
      void setBaseVal(PrimitiveType value, blink::ExceptionState& exceptionState)
      {
          if (this->isReadOnly()) {
              exceptionState.throwDOMException(NoModificationAllowedError, "The attribute is read-only.");
              return;
          }
  
          this->baseValue()->setValue(value);
          m_baseValueUpdated = true;
  
          ASSERT(this->attributeName() != QualifiedName::null());
          this->contextElement()->invalidateSVGAttributes();
          this->contextElement()->svgAttributeChanged(this->attributeName());
      }
  
      PrimitiveType animVal()
      {
          return this->currentValue()->value();
      }
  
  protected:
      SVGAnimatedProperty(SVGElement* contextElement, const QualifiedName& attributeName, PassRefPtrWillBeRawPtr<Property> initialValue)
          : SVGAnimatedPropertyCommon<Property>(contextElement, attributeName, initialValue)
          , m_baseValueUpdated(false)
      {
      }
  
      bool m_baseValueUpdated;
  };
  
  // Implementation of SVGAnimatedProperty which uses tear-off value types.
  // These classes has "void" for its PrimitiveType.
  // This is for classes which return special type for its "animVal".
  // Examples are SVGAnimatedLength, SVGAnimatedRect, SVGAnimated*List, etc.
  template <typename Property, typename TearOffType>
  class SVGAnimatedProperty<Property, TearOffType, void> : public SVGAnimatedPropertyCommon<Property> {
  public:
      static PassRefPtrWillBeRawPtr<SVGAnimatedProperty<Property> > create(SVGElement* contextElement, const QualifiedName& attributeName, PassRefPtrWillBeRawPtr<Property> initialValue)
      {
          return adoptRefWillBeNoop(new SVGAnimatedProperty<Property>(contextElement, attributeName, initialValue));
      }
  
      virtual void setAnimatedValue(PassRefPtrWillBeRawPtr<SVGPropertyBase> value) override
      {
          SVGAnimatedPropertyCommon<Property>::setAnimatedValue(value);
          updateAnimValTearOffIfNeeded();
      }
  
      virtual void animationEnded() override
      {
          SVGAnimatedPropertyCommon<Property>::animationEnded();
          updateAnimValTearOffIfNeeded();
      }
  
      virtual bool needsSynchronizeAttribute() override
      {
          // DOM attribute synchronization is only needed if tear-off is being touched from javascript or the property is being animated.
          // This prevents unnecessary attribute creation on target element.
          return m_baseValTearOff || this->isAnimating();
      }
  
      // SVGAnimated* DOM Spec implementations:
  
      // baseVal()/animVal() are only to be used from SVG DOM implementation.
      // Use currentValue() from C++ code.
      virtual TearOffType* baseVal()
      {
          if (!m_baseValTearOff) {
              m_baseValTearOff = TearOffType::create(this->baseValue(), this->contextElement(), PropertyIsNotAnimVal, this->attributeName());
              if (this->isReadOnly())
                  m_baseValTearOff->setIsReadOnlyProperty();
          }
  
          return m_baseValTearOff.get();
      }
  
      TearOffType* animVal()
      {
          if (!m_animValTearOff)
              m_animValTearOff = TearOffType::create(this->currentValue(), this->contextElement(), PropertyIsAnimVal, this->attributeName());
  
          return m_animValTearOff.get();
      }
  
      virtual void trace(Visitor* visitor) override
      {
          visitor->trace(m_baseValTearOff);
          visitor->trace(m_animValTearOff);
          SVGAnimatedPropertyCommon<Property>::trace(visitor);
      }
  
  protected:
      SVGAnimatedProperty(SVGElement* contextElement, const QualifiedName& attributeName, PassRefPtrWillBeRawPtr<Property> initialValue)
          : SVGAnimatedPropertyCommon<Property>(contextElement, attributeName, initialValue)
      {
      }
  
  private:
      void updateAnimValTearOffIfNeeded()
      {
          if (m_animValTearOff)
              m_animValTearOff->setTarget(this->currentValue());
      }
  
      // When still (not animated):
      //     Both m_animValTearOff and m_baseValTearOff target m_baseValue.
      // When animated:
      //     m_animValTearOff targets m_currentValue.
      //     m_baseValTearOff targets m_baseValue.
      RefPtrWillBeMember<TearOffType> m_baseValTearOff;
      RefPtrWillBeMember<TearOffType> m_animValTearOff;
  };
  
  } // namespace blink
  
  #endif // SVGAnimatedProperty_h
  