michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef NS_SMILVALUE_H_
michael@0: #define NS_SMILVALUE_H_
michael@0: 
michael@0: #include "nsISMILType.h"
michael@0: #include "nsSMILNullType.h"
michael@0: 
michael@0: /**
michael@0:  * Although objects of this type are generally only created on the stack and
michael@0:  * only exist during the taking of a new time sample, that's not always the
michael@0:  * case. The nsSMILValue objects obtained from attributes' base values are
michael@0:  * cached so that the SMIL engine can make certain optimizations during a
michael@0:  * sample if the base value has not changed since the last sample (potentially
michael@0:  * avoiding recomposing). These nsSMILValue objects typically live much longer
michael@0:  * than a single sample.
michael@0:  */
michael@0: class nsSMILValue
michael@0: {
michael@0: public:
michael@0:   nsSMILValue() : mU(), mType(nsSMILNullType::Singleton()) { }
michael@0:   explicit nsSMILValue(const nsISMILType* aType);
michael@0:   nsSMILValue(const nsSMILValue& aVal);
michael@0: 
michael@0:   ~nsSMILValue()
michael@0:   {
michael@0:     mType->Destroy(*this);
michael@0:   }
michael@0: 
michael@0:   const nsSMILValue& operator=(const nsSMILValue& aVal);
michael@0: 
michael@0:   // Equality operators. These are allowed to be conservative (return false
michael@0:   // more than you'd expect) - see comment above nsISMILType::IsEqual.
michael@0:   bool operator==(const nsSMILValue& aVal) const;
michael@0:   bool operator!=(const nsSMILValue& aVal) const {
michael@0:     return !(*this == aVal);
michael@0:   }
michael@0: 
michael@0:   bool IsNull() const
michael@0:   {
michael@0:     return (mType == nsSMILNullType::Singleton());
michael@0:   }
michael@0: 
michael@0:   // Swaps the member data (mU & mPtr) of |this| with |aOther|
michael@0:   void     Swap(nsSMILValue& aOther);
michael@0: 
michael@0:   nsresult Add(const nsSMILValue& aValueToAdd, uint32_t aCount = 1);
michael@0:   nsresult SandwichAdd(const nsSMILValue& aValueToAdd);
michael@0:   nsresult ComputeDistance(const nsSMILValue& aTo, double& aDistance) const;
michael@0:   nsresult Interpolate(const nsSMILValue& aEndVal,
michael@0:                        double aUnitDistance,
michael@0:                        nsSMILValue& aResult) const;
michael@0: 
michael@0:   union {
michael@0:     bool mBool;
michael@0:     uint64_t mUint;
michael@0:     int64_t mInt;
michael@0:     double mDouble;
michael@0:     struct {
michael@0:       float mAngle;
michael@0:       uint16_t mUnit;
michael@0:       uint16_t mOrientType;
michael@0:     } mOrient;
michael@0:     int32_t mIntPair[2];
michael@0:     float mNumberPair[2];
michael@0:     void* mPtr;
michael@0:   } mU;
michael@0:   const nsISMILType* mType;
michael@0: 
michael@0: protected:
michael@0:   void InitAndCheckPostcondition(const nsISMILType* aNewType);
michael@0:   void DestroyAndCheckPostcondition();
michael@0:   void DestroyAndReinit(const nsISMILType* aNewType);
michael@0: };
michael@0: 
michael@0: #endif  // NS_SMILVALUE_H_