gecko-dev/dom/smil/nsSMILValue.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef NS_SMILVALUE_H_
#define NS_SMILVALUE_H_
#include "nsISMILType.h"
#include "nsSMILNullType.h"
/**
* Although objects of this type are generally only created on the stack and
* only exist during the taking of a new time sample, that's not always the
* case. The nsSMILValue objects obtained from attributes' base values are
* cached so that the SMIL engine can make certain optimizations during a
* sample if the base value has not changed since the last sample (potentially
* avoiding recomposing). These nsSMILValue objects typically live much longer
* than a single sample.
*/
class nsSMILValue
{
public:
nsSMILValue() : mU(), mType(nsSMILNullType::Singleton()) { }
explicit nsSMILValue(const nsISMILType* aType);
nsSMILValue(const nsSMILValue& aVal);
~nsSMILValue()
{
mType->Destroy(*this);
}
const nsSMILValue& operator=(const nsSMILValue& aVal);
// Equality operators. These are allowed to be conservative (return false
// more than you'd expect) - see comment above nsISMILType::IsEqual.
bool operator==(const nsSMILValue& aVal) const;
bool operator!=(const nsSMILValue& aVal) const {
return !(*this == aVal);
}
bool IsNull() const
{
return (mType == nsSMILNullType::Singleton());
}
// Swaps the member data (mU & mPtr) of |this| with |aOther|
void Swap(nsSMILValue& aOther);
nsresult Add(const nsSMILValue& aValueToAdd, uint32_t aCount = 1);
nsresult SandwichAdd(const nsSMILValue& aValueToAdd);
nsresult ComputeDistance(const nsSMILValue& aTo, double& aDistance) const;
nsresult Interpolate(const nsSMILValue& aEndVal,
double aUnitDistance,
nsSMILValue& aResult) const;
union {
bool mBool;
uint64_t mUint;
int64_t mInt;
double mDouble;
struct {
float mAngle;
uint16_t mUnit;
uint16_t mOrientType;
} mOrient;
int32_t mIntPair[2];
float mNumberPair[2];
void* mPtr;
} mU;
const nsISMILType* mType;
protected:
void InitAndCheckPostcondition(const nsISMILType* aNewType);
void DestroyAndCheckPostcondition();
void DestroyAndReinit(const nsISMILType* aNewType);
};
#endif // NS_SMILVALUE_H_