gecko/content/smil/nsSMILValue.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2012-05-21 04:12:37 -07:00
/* 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/. */
#include "nsSMILValue.h"
#include "nsDebug.h"
#include <string.h>
//----------------------------------------------------------------------
// Public methods
nsSMILValue::nsSMILValue(const nsISMILType* aType)
: mType(&nsSMILNullType::sSingleton)
{
if (!aType) {
NS_ERROR("Trying to construct nsSMILValue with null mType pointer");
return;
}
InitAndCheckPostcondition(aType);
}
nsSMILValue::nsSMILValue(const nsSMILValue& aVal)
: mType(&nsSMILNullType::sSingleton)
{
InitAndCheckPostcondition(aVal.mType);
mType->Assign(*this, aVal);
}
const nsSMILValue&
nsSMILValue::operator=(const nsSMILValue& aVal)
{
if (&aVal == this)
return *this;
if (mType != aVal.mType) {
DestroyAndReinit(aVal.mType);
}
mType->Assign(*this, aVal);
return *this;
}
bool
nsSMILValue::operator==(const nsSMILValue& aVal) const
{
if (&aVal == this)
return true;
return mType == aVal.mType && mType->IsEqual(*this, aVal);
}
void
nsSMILValue::Swap(nsSMILValue& aOther)
{
nsSMILValue tmp;
memcpy(&tmp, &aOther, sizeof(nsSMILValue)); // tmp = aOther
memcpy(&aOther, this, sizeof(nsSMILValue)); // aOther = this
memcpy(this, &tmp, sizeof(nsSMILValue)); // this = tmp
// |tmp| is about to die -- we need to clear its mType, so that its
// destructor doesn't muck with the data we just transferred out of it.
tmp.mType = &nsSMILNullType::sSingleton;
}
nsresult
nsSMILValue::Add(const nsSMILValue& aValueToAdd, PRUint32 aCount)
{
if (aValueToAdd.mType != mType) {
NS_ERROR("Trying to add incompatible types");
return NS_ERROR_FAILURE;
}
return mType->Add(*this, aValueToAdd, aCount);
}
nsresult
nsSMILValue::SandwichAdd(const nsSMILValue& aValueToAdd)
{
if (aValueToAdd.mType != mType) {
NS_ERROR("Trying to add incompatible types");
return NS_ERROR_FAILURE;
}
return mType->SandwichAdd(*this, aValueToAdd);
}
nsresult
nsSMILValue::ComputeDistance(const nsSMILValue& aTo, double& aDistance) const
{
if (aTo.mType != mType) {
NS_ERROR("Trying to calculate distance between incompatible types");
return NS_ERROR_FAILURE;
}
return mType->ComputeDistance(*this, aTo, aDistance);
}
nsresult
nsSMILValue::Interpolate(const nsSMILValue& aEndVal,
double aUnitDistance,
nsSMILValue& aResult) const
{
if (aEndVal.mType != mType) {
NS_ERROR("Trying to interpolate between incompatible types");
return NS_ERROR_FAILURE;
}
if (aResult.mType != mType) {
// Outparam has wrong type
aResult.DestroyAndReinit(mType);
}
return mType->Interpolate(*this, aEndVal, aUnitDistance, aResult);
}
//----------------------------------------------------------------------
// Helper methods
// Wrappers for nsISMILType::Init & ::Destroy that verify their postconditions
void
nsSMILValue::InitAndCheckPostcondition(const nsISMILType* aNewType)
{
aNewType->Init(*this);
NS_ABORT_IF_FALSE(mType == aNewType,
"Post-condition of Init failed. nsSMILValue is invalid");
}
void
nsSMILValue::DestroyAndCheckPostcondition()
{
mType->Destroy(*this);
NS_ABORT_IF_FALSE(IsNull(), "Post-condition of Destroy failed. "
"nsSMILValue not null after destroying");
}
void
nsSMILValue::DestroyAndReinit(const nsISMILType* aNewType)
{
DestroyAndCheckPostcondition();
InitAndCheckPostcondition(aNewType);
}