void
DOMSVGPathSegList::
MaybeInsertNullInAnimValListAt(uint32_t aIndex,
uint32_t aInternalIndex,
uint32_t aArgCountForItem)
{
NS_ABORT_IF_FALSE(!IsAnimValList(), "call from baseVal to animVal");
if (AttrIsAnimating()) {
// animVal not a clone of baseVal
return;
}
// The anim val list is in sync with the base val list
DOMSVGPathSegList *animVal =
GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
if (!animVal) {
// No animVal list wrapper
return;
}
NS_ABORT_IF_FALSE(animVal->mItems.Length() == mItems.Length(),
"animVal list not in sync!");
animVal->mItems.InsertElementAt(aIndex, ItemProxy(nullptr, aInternalIndex));
animVal->UpdateListIndicesFromIndex(aIndex + 1, 1 + aArgCountForItem);
}
NS_IMETHODIMP
DOMSVGPathSegList::InsertItemBefore(nsIDOMSVGPathSeg *aNewItem,
PRUint32 aIndex,
nsIDOMSVGPathSeg **_retval)
{
*_retval = nsnull;
if (IsAnimValList()) {
return NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR;
}
PRUint32 internalIndex;
if (aIndex < Length()) {
internalIndex = mItems[aIndex].mInternalDataIndex;
} else {
aIndex = Length();
internalIndex = InternalList().mData.Length();
}
if (aIndex >= DOMSVGPathSeg::MaxListIndex()) {
return NS_ERROR_DOM_INDEX_SIZE_ERR;
}
nsCOMPtr<DOMSVGPathSeg> domItem = do_QueryInterface(aNewItem);
if (!domItem) {
return NS_ERROR_DOM_SVG_WRONG_TYPE_ERR;
}
if (domItem->HasOwner()) {
domItem = domItem->Clone(); // must do this before changing anything!
}
PRUint32 argCount = SVGPathSegUtils::ArgCountForType(domItem->Type());
// Ensure we have enough memory so we can avoid complex error handling below:
if (!mItems.SetCapacity(mItems.Length() + 1) ||
!InternalList().mData.SetCapacity(InternalList().mData.Length() + 1 + argCount)) {
return NS_ERROR_OUT_OF_MEMORY;
}
// Now that we know we're inserting, keep animVal list in sync as necessary.
MaybeInsertNullInAnimValListAt(aIndex, internalIndex, argCount);
float segAsRaw[1 + NS_SVG_PATH_SEG_MAX_ARGS];
domItem->ToSVGPathSegEncodedData(segAsRaw);
InternalList().mData.InsertElementsAt(internalIndex, segAsRaw, 1 + argCount);
mItems.InsertElementAt(aIndex, ItemProxy(domItem.get(), internalIndex));
// This MUST come after the insertion into InternalList(), or else under the
// insertion into InternalList() the values read from domItem would be bad
// data from InternalList() itself!:
domItem->InsertingIntoList(this, aIndex, IsAnimValList());
UpdateListIndicesFromIndex(aIndex + 1, argCount + 1);
Element()->DidChangePathSegList(true);
if (AttrIsAnimating()) {
Element()->AnimationNeedsResample();
}
*_retval = domItem.forget().get();
return NS_OK;
}
already_AddRefed<DOMSVGPathSeg>
DOMSVGPathSegList::InsertItemBefore(DOMSVGPathSeg& aNewItem,
uint32_t aIndex,
ErrorResult& aError)
{
if (IsAnimValList()) {
aError.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
uint32_t internalIndex;
if (aIndex < LengthNoFlush()) {
internalIndex = mItems[aIndex].mInternalDataIndex;
} else {
aIndex = LengthNoFlush();
internalIndex = InternalList().mData.Length();
}
if (aIndex >= DOMSVGPathSeg::MaxListIndex()) {
aError.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
nsRefPtr<DOMSVGPathSeg> domItem = &aNewItem;
if (domItem->HasOwner()) {
domItem = domItem->Clone(); // must do this before changing anything!
}
uint32_t argCount = SVGPathSegUtils::ArgCountForType(domItem->Type());
// Ensure we have enough memory so we can avoid complex error handling below:
if (!mItems.SetCapacity(mItems.Length() + 1) ||
!InternalList().mData.SetCapacity(InternalList().mData.Length() + 1 + argCount)) {
aError.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
nsAttrValue emptyOrOldValue = Element()->WillChangePathSegList();
// Now that we know we're inserting, keep animVal list in sync as necessary.
MaybeInsertNullInAnimValListAt(aIndex, internalIndex, argCount);
float segAsRaw[1 + NS_SVG_PATH_SEG_MAX_ARGS];
domItem->ToSVGPathSegEncodedData(segAsRaw);
InternalList().mData.InsertElementsAt(internalIndex, segAsRaw, 1 + argCount);
mItems.InsertElementAt(aIndex, ItemProxy(domItem.get(), internalIndex));
// This MUST come after the insertion into InternalList(), or else under the
// insertion into InternalList() the values read from domItem would be bad
// data from InternalList() itself!:
domItem->InsertingIntoList(this, aIndex, IsAnimValList());
UpdateListIndicesFromIndex(aIndex + 1, argCount + 1);
Element()->DidChangePathSegList(emptyOrOldValue);
if (AttrIsAnimating()) {
Element()->AnimationNeedsResample();
}
return domItem.forget();
}
void
DOMSVGPathSegList::InternalListWillChangeTo(const SVGPathData& aNewValue)
{
// When the number of items in our internal counterpart changes, we MUST stay
// in sync. Everything in the scary comment in
// DOMSVGLengthList::InternalBaseValListWillChangeTo applies here just as
// much, but we have the additional issue that failing to stay in sync would
// mean that - assuming we aren't reading bad memory - we would likely end up
// decoding command types from argument floats when looking in our
// SVGPathData's data array! Either way, we'll likely then go down
// NS_NOTREACHED code paths, or end up reading/setting more bad memory!!
// The only time that our other DOM list type implementations remove items is
// if those items become surplus items due to an attribute change or SMIL
// animation sample shortening the list. In general though, they try to keep
// their existing DOM items, even when things change. To be consistent, we'd
// really like to do the same thing. However, because different types of path
// segment correspond to different DOMSVGPathSeg subclasses, the type of
// items in our list are generally not the same, which makes this harder for
// us. We have to remove DOM segments if their type is not the same as the
// type of the new internal segment at their index.
//
// We also need to sync up mInternalDataIndex, but since we need to loop over
// all the items in the new list checking types anyway, that's almost
// insignificant in terms of overhead.
//
// Note that this method is called on every single SMIL animation resample
// and we have no way to short circuit the overhead since we don't have a
// way to tell if the call is due to a new animation, or a resample of an
// existing animation (when the number and type of items would be the same).
// (Note that a new animation could start overriding an existing animation at
// any time, so checking IsAnimating() wouldn't work.) Because we get called
// on every sample, it would not be acceptable alternative to throw away all
// our items and let them be recreated lazily, since that would break what
// script sees!
uint32_t length = mItems.Length();
uint32_t index = 0;
uint32_t dataLength = aNewValue.mData.Length();
uint32_t dataIndex = 0; // index into aNewValue's raw data array
uint32_t newSegType;
nsRefPtr<DOMSVGPathSegList> kungFuDeathGrip;
if (length) {
// RemovingFromList() might clear last reference to |this|.
// Retain a temporary reference to keep from dying before returning.
//
// NOTE: For path-seg lists (unlike other list types), we have to do this
// *whenever our list is nonempty* (even if we're growing in length).
// That's because the path-seg-type of any segment could differ between old
// list vs. new list, which will make us destroy & recreate that segment,
// which could remove the last reference to us.
//
// (We explicitly *don't* want to create a kungFuDeathGrip in the length=0
// case, though, because we do hit this code inside our constructor before
// any other owning references have been added, and at that point, the
// deathgrip-removal would make us die before we exit our constructor.)
kungFuDeathGrip = this;
}
while (index < length && dataIndex < dataLength) {
newSegType = SVGPathSegUtils::DecodeType(aNewValue.mData[dataIndex]);
if (ItemAt(index) && ItemAt(index)->Type() != newSegType) {
ItemAt(index)->RemovingFromList();
ItemAt(index) = nullptr;
}
// Only after the RemovingFromList() can we touch mInternalDataIndex!
mItems[index].mInternalDataIndex = dataIndex;
++index;
dataIndex += 1 + SVGPathSegUtils::ArgCountForType(newSegType);
}
NS_ABORT_IF_FALSE((index == length && dataIndex <= dataLength) ||
(index <= length && dataIndex == dataLength),
"very bad - list corruption?");
if (index < length) {
// aNewValue has fewer items than our previous internal counterpart
uint32_t newLength = index;
// Remove excess items from the list:
for (; index < length; ++index) {
if (ItemAt(index)) {
ItemAt(index)->RemovingFromList();
ItemAt(index) = nullptr;
}
}
// Only now may we truncate mItems
mItems.SetLength(newLength);
} else if (dataIndex < dataLength) {
// aNewValue has more items than our previous internal counterpart
// Sync mItems:
while (dataIndex < dataLength) {
if (mItems.Length() &&
mItems.Length() - 1 > DOMSVGPathSeg::MaxListIndex()) {
// It's safe to get out of sync with our internal list as long as we
// have FEWER items than it does.
return;
}
if (!mItems.AppendElement(ItemProxy(nullptr, dataIndex))) {
// OOM
ErrorResult rv;
Clear(rv);
MOZ_ASSERT(!rv.Failed());
return;
}
dataIndex += 1 + SVGPathSegUtils::ArgCountForType(SVGPathSegUtils::DecodeType(aNewValue.mData[dataIndex]));
}
}
NS_ABORT_IF_FALSE(dataIndex == dataLength, "Serious processing error");
NS_ABORT_IF_FALSE(index == length, "Serious counting error");
}
