diff options
Diffstat (limited to 'dom/svg/DOMSVGPathSegList.cpp')
| -rw-r--r-- | dom/svg/DOMSVGPathSegList.cpp | 607 |
1 files changed, 607 insertions, 0 deletions
diff --git a/dom/svg/DOMSVGPathSegList.cpp b/dom/svg/DOMSVGPathSegList.cpp new file mode 100644 index 000000000..edacdfc93 --- /dev/null +++ b/dom/svg/DOMSVGPathSegList.cpp @@ -0,0 +1,607 @@ +/* -*- 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/. */ + +#include "nsSVGElement.h" +#include "DOMSVGPathSegList.h" +#include "DOMSVGPathSeg.h" +#include "nsError.h" +#include "SVGAnimatedPathSegList.h" +#include "nsCOMPtr.h" +#include "nsSVGAttrTearoffTable.h" +#include "SVGPathSegUtils.h" +#include "mozilla/dom/SVGPathSegListBinding.h" + +// See the comment in this file's header. + +namespace mozilla { + + static inline +nsSVGAttrTearoffTable<void, DOMSVGPathSegList>& +SVGPathSegListTearoffTable() +{ + static nsSVGAttrTearoffTable<void, DOMSVGPathSegList> + sSVGPathSegListTearoffTable; + return sSVGPathSegListTearoffTable; +} + +NS_IMPL_CYCLE_COLLECTION_CLASS(DOMSVGPathSegList) + +NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DOMSVGPathSegList) + // No unlinking of mElement, we'd need to null out the value pointer (the + // object it points to is held by the element) and null-check it everywhere. + NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER +NS_IMPL_CYCLE_COLLECTION_UNLINK_END +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(DOMSVGPathSegList) + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mElement) + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END +NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(DOMSVGPathSegList) + NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER +NS_IMPL_CYCLE_COLLECTION_TRACE_END + +NS_IMPL_CYCLE_COLLECTING_ADDREF(DOMSVGPathSegList) +NS_IMPL_CYCLE_COLLECTING_RELEASE(DOMSVGPathSegList) + +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMSVGPathSegList) + NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY + NS_INTERFACE_MAP_ENTRY(nsISupports) +NS_INTERFACE_MAP_END + + +//---------------------------------------------------------------------- +// Helper class: AutoChangePathSegListNotifier +// Stack-based helper class to pair calls to WillChangePathSegList and +// DidChangePathSegList. +class MOZ_RAII AutoChangePathSegListNotifier +{ +public: + explicit AutoChangePathSegListNotifier(DOMSVGPathSegList* aPathSegList MOZ_GUARD_OBJECT_NOTIFIER_PARAM) + : mPathSegList(aPathSegList) + { + MOZ_GUARD_OBJECT_NOTIFIER_INIT; + MOZ_ASSERT(mPathSegList, "Expecting non-null pathSegList"); + mEmptyOrOldValue = + mPathSegList->Element()->WillChangePathSegList(); + } + + ~AutoChangePathSegListNotifier() + { + mPathSegList->Element()->DidChangePathSegList(mEmptyOrOldValue); + if (mPathSegList->AttrIsAnimating()) { + mPathSegList->Element()->AnimationNeedsResample(); + } + } + +private: + DOMSVGPathSegList* const mPathSegList; + nsAttrValue mEmptyOrOldValue; + MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER +}; + +/* static */ already_AddRefed<DOMSVGPathSegList> +DOMSVGPathSegList::GetDOMWrapper(void *aList, + nsSVGElement *aElement, + bool aIsAnimValList) +{ + RefPtr<DOMSVGPathSegList> wrapper = + SVGPathSegListTearoffTable().GetTearoff(aList); + if (!wrapper) { + wrapper = new DOMSVGPathSegList(aElement, aIsAnimValList); + SVGPathSegListTearoffTable().AddTearoff(aList, wrapper); + } + return wrapper.forget(); +} + +/* static */ DOMSVGPathSegList* +DOMSVGPathSegList::GetDOMWrapperIfExists(void *aList) +{ + return SVGPathSegListTearoffTable().GetTearoff(aList); +} + +DOMSVGPathSegList::~DOMSVGPathSegList() +{ + // There are now no longer any references to us held by script or list items. + // Note we must use GetAnimValKey/GetBaseValKey here, NOT InternalList()! + void *key = mIsAnimValList ? + InternalAList().GetAnimValKey() : + InternalAList().GetBaseValKey(); + SVGPathSegListTearoffTable().RemoveTearoff(key); +} + +JSObject* +DOMSVGPathSegList::WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto) +{ + return mozilla::dom::SVGPathSegListBinding::Wrap(cx, this, aGivenProto); +} + +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; + + RefPtr<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); + } + + MOZ_ASSERT((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.TruncateLength(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), fallible)) { + // OOM + ErrorResult rv; + Clear(rv); + MOZ_ASSERT(!rv.Failed()); + return; + } + dataIndex += 1 + SVGPathSegUtils::ArgCountForType(SVGPathSegUtils::DecodeType(aNewValue.mData[dataIndex])); + } + } + + MOZ_ASSERT(dataIndex == dataLength, "Serious processing error"); + MOZ_ASSERT(index == length, "Serious counting error"); +} + +bool +DOMSVGPathSegList::AttrIsAnimating() const +{ + return InternalAList().IsAnimating(); +} + +bool +DOMSVGPathSegList::AnimListMirrorsBaseList() const +{ + return GetDOMWrapperIfExists(InternalAList().GetAnimValKey()) && + !AttrIsAnimating(); +} + +SVGPathData& +DOMSVGPathSegList::InternalList() const +{ + SVGAnimatedPathSegList *alist = mElement->GetAnimPathSegList(); + return mIsAnimValList && alist->IsAnimating() ? *alist->mAnimVal : alist->mBaseVal; +} + +SVGAnimatedPathSegList& +DOMSVGPathSegList::InternalAList() const +{ + MOZ_ASSERT(mElement->GetAnimPathSegList(), "Internal error"); + return *mElement->GetAnimPathSegList(); +} + +// ---------------------------------------------------------------------------- +// nsIDOMSVGPathSegList implementation: + +void +DOMSVGPathSegList::Clear(ErrorResult& aError) +{ + if (IsAnimValList()) { + aError.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR); + return; + } + + if (LengthNoFlush() > 0) { + AutoChangePathSegListNotifier notifier(this); + // DOM list items that are to be removed must be removed before we change + // the internal list, otherwise they wouldn't be able to copy their + // internal counterparts' values! + + InternalListWillChangeTo(SVGPathData()); // clears mItems + + if (!AttrIsAnimating()) { + // The anim val list is in sync with the base val list + DOMSVGPathSegList *animList = + GetDOMWrapperIfExists(InternalAList().GetAnimValKey()); + if (animList) { + animList->InternalListWillChangeTo(SVGPathData()); // clears its mItems + } + } + + InternalList().Clear(); + } +} + +already_AddRefed<DOMSVGPathSeg> +DOMSVGPathSegList::Initialize(DOMSVGPathSeg& aNewItem, ErrorResult& aError) +{ + if (IsAnimValList()) { + aError.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR); + return nullptr; + } + + // If aNewItem is already in a list we should insert a clone of aNewItem, + // and for consistency, this should happen even if *this* is the list that + // aNewItem is currently in. Note that in the case of aNewItem being in this + // list, the Clear() call before the InsertItemBefore() call would remove it + // from this list, and so the InsertItemBefore() call would not insert a + // clone of aNewItem, it would actually insert aNewItem. To prevent that + // from happening we have to do the clone here, if necessary. + + RefPtr<DOMSVGPathSeg> domItem = &aNewItem; + if (aNewItem.HasOwner()) { + domItem = aNewItem.Clone(); + } + + Clear(aError); + MOZ_ASSERT(!aError.Failed(), "How could this fail?"); + return InsertItemBefore(*domItem, 0, aError); +} + +already_AddRefed<DOMSVGPathSeg> +DOMSVGPathSegList::GetItem(uint32_t index, ErrorResult& error) +{ + bool found; + RefPtr<DOMSVGPathSeg> item = IndexedGetter(index, found, error); + if (!found) { + error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR); + } + return item.forget(); +} + +already_AddRefed<DOMSVGPathSeg> +DOMSVGPathSegList::IndexedGetter(uint32_t aIndex, bool& aFound, + ErrorResult& aError) +{ + if (IsAnimValList()) { + Element()->FlushAnimations(); + } + aFound = aIndex < LengthNoFlush(); + if (aFound) { + return GetItemAt(aIndex); + } + return nullptr; +} + +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; + } + + RefPtr<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, fallible) || + !InternalList().mData.SetCapacity(InternalList().mData.Length() + 1 + argCount, + fallible)) { + aError.Throw(NS_ERROR_OUT_OF_MEMORY); + return nullptr; + } + if (AnimListMirrorsBaseList()) { + DOMSVGPathSegList *animVal = + GetDOMWrapperIfExists(InternalAList().GetAnimValKey()); + MOZ_ASSERT(animVal, "animVal should be a valid pointer"); + if (!animVal->mItems.SetCapacity( + animVal->mItems.Length() + 1, fallible)) { + aError.Throw(NS_ERROR_OUT_OF_MEMORY); + return nullptr; + } + } + + AutoChangePathSegListNotifier notifier(this); + // 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); + + MOZ_ALWAYS_TRUE(InternalList().mData.InsertElementsAt(internalIndex, + segAsRaw, + 1 + argCount, + fallible)); + MOZ_ALWAYS_TRUE(mItems.InsertElementAt(aIndex, + ItemProxy(domItem.get(), + internalIndex), + fallible)); + + // 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); + + return domItem.forget(); +} + +already_AddRefed<DOMSVGPathSeg> +DOMSVGPathSegList::ReplaceItem(DOMSVGPathSeg& aNewItem, + uint32_t aIndex, + ErrorResult& aError) +{ + if (IsAnimValList()) { + aError.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR); + return nullptr; + } + + if (aIndex >= LengthNoFlush()) { + aError.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR); + return nullptr; + } + + RefPtr<DOMSVGPathSeg> domItem = &aNewItem; + if (domItem->HasOwner()) { + domItem = domItem->Clone(); // must do this before changing anything! + } + + AutoChangePathSegListNotifier notifier(this); + if (ItemAt(aIndex)) { + // Notify any existing DOM item of removal *before* modifying the lists so + // that the DOM item can copy the *old* value at its index: + ItemAt(aIndex)->RemovingFromList(); + } + + uint32_t internalIndex = mItems[aIndex].mInternalDataIndex; + // We use InternalList() to get oldArgCount since we may not have a DOM + // wrapper at the index being replaced. + uint32_t oldType = SVGPathSegUtils::DecodeType(InternalList().mData[internalIndex]); + + // NOTE: ArgCountForType returns a (small) unsigned value, but we're + // intentionally putting it in a signed variable, because we're going to + // subtract these values and might produce something negative. + int32_t oldArgCount = SVGPathSegUtils::ArgCountForType(oldType); + int32_t newArgCount = SVGPathSegUtils::ArgCountForType(domItem->Type()); + + float segAsRaw[1 + NS_SVG_PATH_SEG_MAX_ARGS]; + domItem->ToSVGPathSegEncodedData(segAsRaw); + + if (!InternalList().mData.ReplaceElementsAt(internalIndex, 1 + oldArgCount, + segAsRaw, 1 + newArgCount, + fallible)) { + aError.Throw(NS_ERROR_OUT_OF_MEMORY); + return nullptr; + } + ItemAt(aIndex) = domItem; + + // This MUST come after the ToSVGPathSegEncodedData call, otherwise that call + // would end up reading bad data from InternalList()! + domItem->InsertingIntoList(this, aIndex, IsAnimValList()); + + int32_t delta = newArgCount - oldArgCount; + if (delta != 0) { + for (uint32_t i = aIndex + 1; i < LengthNoFlush(); ++i) { + mItems[i].mInternalDataIndex += delta; + } + } + + return domItem.forget(); +} + +already_AddRefed<DOMSVGPathSeg> +DOMSVGPathSegList::RemoveItem(uint32_t aIndex, + ErrorResult& aError) +{ + if (IsAnimValList()) { + aError.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR); + return nullptr; + } + + if (aIndex >= LengthNoFlush()) { + aError.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR); + return nullptr; + } + // We have to return the removed item, so get it, creating it if necessary: + RefPtr<DOMSVGPathSeg> result = GetItemAt(aIndex); + + AutoChangePathSegListNotifier notifier(this); + // Notify the DOM item of removal *before* modifying the lists so that the + // DOM item can copy its *old* value: + ItemAt(aIndex)->RemovingFromList(); + + uint32_t internalIndex = mItems[aIndex].mInternalDataIndex; + uint32_t segType = SVGPathSegUtils::DecodeType(InternalList().mData[internalIndex]); + // NOTE: ArgCountForType returns a (small) unsigned value, but we're + // intentionally putting it in a signed value, because we're going to + // negate it, and you can't negate an unsigned value. + int32_t argCount = SVGPathSegUtils::ArgCountForType(segType); + + // Now that we know we're removing, keep animVal list in sync as necessary. + // Do this *before* touching InternalList() so the removed item can get its + // internal value. + MaybeRemoveItemFromAnimValListAt(aIndex, argCount); + + InternalList().mData.RemoveElementsAt(internalIndex, 1 + argCount); + mItems.RemoveElementAt(aIndex); + + UpdateListIndicesFromIndex(aIndex, -(argCount + 1)); + + return result.forget(); +} + +already_AddRefed<DOMSVGPathSeg> +DOMSVGPathSegList::GetItemAt(uint32_t aIndex) +{ + MOZ_ASSERT(aIndex < mItems.Length()); + + if (!ItemAt(aIndex)) { + ItemAt(aIndex) = DOMSVGPathSeg::CreateFor(this, aIndex, IsAnimValList()); + } + RefPtr<DOMSVGPathSeg> result = ItemAt(aIndex); + return result.forget(); +} + +void +DOMSVGPathSegList:: + MaybeInsertNullInAnimValListAt(uint32_t aIndex, + uint32_t aInternalIndex, + uint32_t aArgCountForItem) +{ + MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal"); + + if (!AnimListMirrorsBaseList()) { + return; + } + + // The anim val list is in sync with the base val list + DOMSVGPathSegList *animVal = + GetDOMWrapperIfExists(InternalAList().GetAnimValKey()); + + MOZ_ASSERT(animVal, "AnimListMirrorsBaseList() promised a non-null animVal"); + MOZ_ASSERT(animVal->mItems.Length() == mItems.Length(), + "animVal list not in sync!"); + MOZ_ALWAYS_TRUE(animVal->mItems.InsertElementAt(aIndex, + ItemProxy(nullptr, + aInternalIndex), + fallible)); + + animVal->UpdateListIndicesFromIndex(aIndex + 1, 1 + aArgCountForItem); +} + +void +DOMSVGPathSegList:: + MaybeRemoveItemFromAnimValListAt(uint32_t aIndex, + int32_t aArgCountForItem) +{ + MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal"); + + if (!AnimListMirrorsBaseList()) { + return; + } + + // This needs to be a strong reference; otherwise, the RemovingFromList call + // below might drop the last reference to animVal before we're done with it. + RefPtr<DOMSVGPathSegList> animVal = + GetDOMWrapperIfExists(InternalAList().GetAnimValKey()); + + MOZ_ASSERT(animVal, "AnimListMirrorsBaseList() promised a non-null animVal"); + MOZ_ASSERT(animVal->mItems.Length() == mItems.Length(), + "animVal list not in sync!"); + + if (animVal->ItemAt(aIndex)) { + animVal->ItemAt(aIndex)->RemovingFromList(); + } + animVal->mItems.RemoveElementAt(aIndex); + + animVal->UpdateListIndicesFromIndex(aIndex, -(1 + aArgCountForItem)); +} + +void +DOMSVGPathSegList::UpdateListIndicesFromIndex(uint32_t aStartingIndex, + int32_t aInternalDataIndexDelta) +{ + uint32_t length = mItems.Length(); + + for (uint32_t i = aStartingIndex; i < length; ++i) { + mItems[i].mInternalDataIndex += aInternalDataIndexDelta; + if (ItemAt(i)) { + ItemAt(i)->UpdateListIndex(i); + } + } +} + +} // namespace mozilla |