void
nsSMILAnimationFunction::ComposeResult(const nsISMILAttr& aSMILAttr,
nsSMILValue& aResult)
{
mHasChanged = false;
mPrevSampleWasSingleValueAnimation = false;
mWasSkippedInPrevSample = false;
// Skip animations that are inactive or in error
if (!IsActiveOrFrozen() || mErrorFlags != 0)
return;
// Get the animation values
nsSMILValueArray values;
nsresult rv = GetValues(aSMILAttr, values);
if (NS_FAILED(rv))
return;
// Check that we have the right number of keySplines and keyTimes
CheckValueListDependentAttrs(values.Length());
if (mErrorFlags != 0)
return;
// If this interval is active, we must have a non-negative mSampleTime
NS_ABORT_IF_FALSE(mSampleTime >= 0 || !mIsActive,
"Negative sample time for active animation");
NS_ABORT_IF_FALSE(mSimpleDuration.IsResolved() || mLastValue,
"Unresolved simple duration for active or frozen animation");
// If we want to add but don't have a base value then just fail outright.
// This can happen when we skipped getting the base value because there's an
// animation function in the sandwich that should replace it but that function
// failed unexpectedly.
bool isAdditive = IsAdditive();
if (isAdditive && aResult.IsNull())
return;
nsSMILValue result;
if (values.Length() == 1 && !IsToAnimation()) {
// Single-valued animation
result = values[0];
mPrevSampleWasSingleValueAnimation = true;
} else if (mLastValue) {
// Sampling last value
const nsSMILValue& last = values[values.Length() - 1];
result = last;
// See comment in AccumulateResult: to-animation does not accumulate
if (!IsToAnimation() && GetAccumulate() && mRepeatIteration) {
// If the target attribute type doesn't support addition Add will
// fail leaving result = last
result.Add(last, mRepeatIteration);
}
} else {
// Interpolation
if (NS_FAILED(InterpolateResult(values, result, aResult)))
return;
if (NS_FAILED(AccumulateResult(values, result)))
return;
}
// If additive animation isn't required or isn't supported, set the value.
if (!isAdditive || NS_FAILED(aResult.SandwichAdd(result))) {
aResult.Swap(result);
// Note: The old value of aResult is now in |result|, and it will get
// cleaned up when |result| goes out of scope, when this function returns.
}
}
