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-rw-r--r--dom/svg/DOMSVGPathSegList.cpp537
1 files changed, 537 insertions, 0 deletions
diff --git a/dom/svg/DOMSVGPathSegList.cpp b/dom/svg/DOMSVGPathSegList.cpp
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+++ b/dom/svg/DOMSVGPathSegList.cpp
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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/. */
+
+#include "DOMSVGPathSegList.h"
+
+#include "DOMSVGPathSeg.h"
+#include "nsError.h"
+#include "SVGAnimatedPathSegList.h"
+#include "SVGAttrTearoffTable.h"
+#include "SVGPathSegUtils.h"
+#include "mozilla/dom/SVGElement.h"
+#include "mozilla/dom/SVGPathElement.h"
+#include "mozilla/dom/SVGPathSegListBinding.h"
+#include "mozilla/RefPtr.h"
+
+// See the comment in this file's header.
+
+namespace mozilla::dom {
+
+static inline SVGAttrTearoffTable<void, DOMSVGPathSegList>&
+SVGPathSegListTearoffTable() {
+ static SVGAttrTearoffTable<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.
+ tmp->RemoveFromTearoffTable();
+ 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_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
+
+/* static */
+already_AddRefed<DOMSVGPathSegList> DOMSVGPathSegList::GetDOMWrapper(
+ void* aList, SVGPathElement* aElement) {
+ RefPtr<DOMSVGPathSegList> wrapper =
+ SVGPathSegListTearoffTable().GetTearoff(aList);
+ if (!wrapper) {
+ wrapper = new DOMSVGPathSegList(
+ aElement, aElement->GetAnimPathSegList()->GetAnimValKey() == aList);
+ SVGPathSegListTearoffTable().AddTearoff(aList, wrapper);
+ }
+ return wrapper.forget();
+}
+
+/* static */
+DOMSVGPathSegList* DOMSVGPathSegList::GetDOMWrapperIfExists(void* aList) {
+ return SVGPathSegListTearoffTable().GetTearoff(aList);
+}
+
+void DOMSVGPathSegList::RemoveFromTearoffTable() {
+ // 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);
+}
+
+DOMSVGPathSegList::~DOMSVGPathSegList() { RemoveFromTearoffTable(); }
+
+JSObject* DOMSVGPathSegList::WrapObject(JSContext* cx,
+ JS::Handle<JSObject*> aGivenProto) {
+ return mozilla::dom::SVGPathSegList_Binding::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
+ // MOZ_ASSERT_UNREACHABLE 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::dom