gecko-dev/dom/svg/DOMSVGLengthList.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "DOMSVGLengthList.h"
#include "DOMSVGLength.h"
#include "nsError.h"
#include "SVGAnimatedLengthList.h"
#include "nsCOMPtr.h"
#include "mozilla/dom/SVGLengthListBinding.h"
#include <algorithm>
// See the comment in this file's header.
// local helper functions
namespace {
using mozilla::DOMSVGLength;
void UpdateListIndicesFromIndex(FallibleTArray<DOMSVGLength*>& aItemsArray,
uint32_t aStartingIndex)
{
uint32_t length = aItemsArray.Length();
for (uint32_t i = aStartingIndex; i < length; ++i) {
if (aItemsArray[i]) {
aItemsArray[i]->UpdateListIndex(i);
}
}
}
} // namespace
namespace mozilla {
// We could use NS_IMPL_CYCLE_COLLECTION(, except that in Unlink() we need to
// clear our DOMSVGAnimatedLengthList's weak ref to us to be safe. (The other
// option would be to not unlink and rely on the breaking of the other edges in
// the cycle, as NS_SVG_VAL_IMPL_CYCLE_COLLECTION does.)
NS_IMPL_CYCLE_COLLECTION_CLASS(DOMSVGLengthList)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DOMSVGLengthList)
if (tmp->mAList) {
if (tmp->IsAnimValList()) {
tmp->mAList->mAnimVal = nullptr;
} else {
tmp->mAList->mBaseVal = nullptr;
}
NS_IMPL_CYCLE_COLLECTION_UNLINK(mAList)
}
NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(DOMSVGLengthList)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAList)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(DOMSVGLengthList)
NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(DOMSVGLengthList)
NS_IMPL_CYCLE_COLLECTING_RELEASE(DOMSVGLengthList)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMSVGLengthList)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
JSObject*
DOMSVGLengthList::WrapObject(JSContext *cx)
{
return mozilla::dom::SVGLengthListBinding::Wrap(cx, this);
}
//----------------------------------------------------------------------
// Helper class: AutoChangeLengthListNotifier
// Stack-based helper class to pair calls to WillChangeLengthList and
// DidChangeLengthList.
class MOZ_STACK_CLASS AutoChangeLengthListNotifier
{
public:
explicit AutoChangeLengthListNotifier(DOMSVGLengthList* aLengthList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: mLengthList(aLengthList)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
MOZ_ASSERT(mLengthList, "Expecting non-null lengthList");
mEmptyOrOldValue =
mLengthList->Element()->WillChangeLengthList(mLengthList->AttrEnum());
}
~AutoChangeLengthListNotifier()
{
mLengthList->Element()->DidChangeLengthList(mLengthList->AttrEnum(),
mEmptyOrOldValue);
if (mLengthList->IsAnimating()) {
mLengthList->Element()->AnimationNeedsResample();
}
}
private:
DOMSVGLengthList* const mLengthList;
nsAttrValue mEmptyOrOldValue;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
void
DOMSVGLengthList::InternalListLengthWillChange(uint32_t aNewLength)
{
uint32_t oldLength = mItems.Length();
if (aNewLength > DOMSVGLength::MaxListIndex()) {
// It's safe to get out of sync with our internal list as long as we have
// FEWER items than it does.
aNewLength = DOMSVGLength::MaxListIndex();
}
nsRefPtr<DOMSVGLengthList> kungFuDeathGrip;
if (aNewLength < oldLength) {
// RemovingFromList() might clear last reference to |this|.
// Retain a temporary reference to keep from dying before returning.
kungFuDeathGrip = this;
}
// If our length will decrease, notify the items that will be removed:
for (uint32_t i = aNewLength; i < oldLength; ++i) {
if (mItems[i]) {
mItems[i]->RemovingFromList();
}
}
if (!mItems.SetLength(aNewLength)) {
// We silently ignore SetLength OOM failure since being out of sync is safe
// so long as we have *fewer* items than our internal list.
mItems.Clear();
return;
}
// If our length has increased, null out the new pointers:
for (uint32_t i = oldLength; i < aNewLength; ++i) {
mItems[i] = nullptr;
}
}
SVGLengthList&
DOMSVGLengthList::InternalList() const
{
SVGAnimatedLengthList *alist = Element()->GetAnimatedLengthList(AttrEnum());
return IsAnimValList() && alist->mAnimVal ? *alist->mAnimVal : alist->mBaseVal;
}
// ----------------------------------------------------------------------------
void
DOMSVGLengthList::Clear(ErrorResult& aError)
{
if (IsAnimValList()) {
aError.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return;
}
if (LengthNoFlush() > 0) {
AutoChangeLengthListNotifier notifier(this);
// Notify any existing DOM items of removal *before* truncating the lists
// so that they can find their SVGLength internal counterparts and copy
// their values. This also notifies the animVal list:
mAList->InternalBaseValListWillChangeTo(SVGLengthList());
mItems.Clear();
InternalList().Clear();
}
}
already_AddRefed<DOMSVGLength>
DOMSVGLengthList::Initialize(DOMSVGLength& newItem,
ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
// If newItem already has an owner or is reflecting an attribute, we should
// insert a clone of newItem, and for consistency, this should happen even if
// *this* is the list that newItem is currently in. Note that in the case of
// newItem 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 newItem, it would actually insert newItem. To
// prevent that from happening we have to do the clone here, if necessary.
nsRefPtr<DOMSVGLength> domItem = &newItem;
if (!domItem) {
error.Throw(NS_ERROR_DOM_SVG_WRONG_TYPE_ERR);
return nullptr;
}
if (domItem->HasOwner() || domItem->IsReflectingAttribute()) {
domItem = domItem->Copy();
}
ErrorResult rv;
Clear(rv);
MOZ_ASSERT(!rv.Failed());
return InsertItemBefore(*domItem, 0, error);
}
already_AddRefed<DOMSVGLength>
DOMSVGLengthList::GetItem(uint32_t index, ErrorResult& error)
{
bool found;
nsRefPtr<DOMSVGLength> item = IndexedGetter(index, found, error);
if (!found) {
error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
}
return item.forget();
}
already_AddRefed<DOMSVGLength>
DOMSVGLengthList::IndexedGetter(uint32_t index, bool& found, ErrorResult& error)
{
if (IsAnimValList()) {
Element()->FlushAnimations();
}
found = index < LengthNoFlush();
if (found) {
return GetItemAt(index);
}
return nullptr;
}
already_AddRefed<DOMSVGLength>
DOMSVGLengthList::InsertItemBefore(DOMSVGLength& newItem,
uint32_t index,
ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
index = std::min(index, LengthNoFlush());
if (index >= DOMSVGLength::MaxListIndex()) {
error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
nsRefPtr<DOMSVGLength> domItem = &newItem;
if (!domItem) {
error.Throw(NS_ERROR_DOM_SVG_WRONG_TYPE_ERR);
return nullptr;
}
if (domItem->HasOwner() || domItem->IsReflectingAttribute()) {
domItem = domItem->Copy(); // must do this before changing anything!
}
// Ensure we have enough memory so we can avoid complex error handling below:
if (!mItems.SetCapacity(mItems.Length() + 1) ||
!InternalList().SetCapacity(InternalList().Length() + 1)) {
error.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
AutoChangeLengthListNotifier notifier(this);
// Now that we know we're inserting, keep animVal list in sync as necessary.
MaybeInsertNullInAnimValListAt(index);
InternalList().InsertItem(index, domItem->ToSVGLength());
mItems.InsertElementAt(index, domItem.get());
// 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, AttrEnum(), index, IsAnimValList());
UpdateListIndicesFromIndex(mItems, index + 1);
return domItem.forget();
}
already_AddRefed<DOMSVGLength>
DOMSVGLengthList::ReplaceItem(DOMSVGLength& newItem,
uint32_t index,
ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
nsRefPtr<DOMSVGLength> domItem = &newItem;
if (!domItem) {
error.Throw(NS_ERROR_DOM_SVG_WRONG_TYPE_ERR);
return nullptr;
}
if (index >= LengthNoFlush()) {
error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
if (domItem->HasOwner() || domItem->IsReflectingAttribute()) {
domItem = domItem->Copy(); // must do this before changing anything!
}
AutoChangeLengthListNotifier notifier(this);
if (mItems[index]) {
// Notify any existing DOM item of removal *before* modifying the lists so
// that the DOM item can copy the *old* value at its index:
mItems[index]->RemovingFromList();
}
InternalList()[index] = domItem->ToSVGLength();
mItems[index] = domItem;
// This MUST come after the ToSVGPoint() call, otherwise that call
// would end up reading bad data from InternalList()!
domItem->InsertingIntoList(this, AttrEnum(), index, IsAnimValList());
return domItem.forget();
}
already_AddRefed<DOMSVGLength>
DOMSVGLengthList::RemoveItem(uint32_t index,
ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
if (index >= LengthNoFlush()) {
error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
AutoChangeLengthListNotifier notifier(this);
// 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(index);
// We have to return the removed item, so get it, creating it if necessary:
nsCOMPtr<DOMSVGLength> result = GetItemAt(index);
// Notify the DOM item of removal *before* modifying the lists so that the
// DOM item can copy its *old* value:
mItems[index]->RemovingFromList();
InternalList().RemoveItem(index);
mItems.RemoveElementAt(index);
UpdateListIndicesFromIndex(mItems, index);
return result.forget();
}
already_AddRefed<DOMSVGLength>
DOMSVGLengthList::GetItemAt(uint32_t aIndex)
{
MOZ_ASSERT(aIndex < mItems.Length());
if (!mItems[aIndex]) {
mItems[aIndex] = new DOMSVGLength(this, AttrEnum(), aIndex, IsAnimValList());
}
nsRefPtr<DOMSVGLength> result = mItems[aIndex];
return result.forget();
}
void
DOMSVGLengthList::MaybeInsertNullInAnimValListAt(uint32_t aIndex)
{
MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal");
DOMSVGLengthList* animVal = mAList->mAnimVal;
if (!animVal || mAList->IsAnimating()) {
// No animVal list wrapper, or animVal not a clone of baseVal
return;
}
MOZ_ASSERT(animVal->mItems.Length() == mItems.Length(),
"animVal list not in sync!");
animVal->mItems.InsertElementAt(aIndex, static_cast<DOMSVGLength*>(nullptr));
UpdateListIndicesFromIndex(animVal->mItems, aIndex + 1);
}
void
DOMSVGLengthList::MaybeRemoveItemFromAnimValListAt(uint32_t aIndex)
{
MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal");
// 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.
nsRefPtr<DOMSVGLengthList> animVal = mAList->mAnimVal;
if (!animVal || mAList->IsAnimating()) {
// No animVal list wrapper, or animVal not a clone of baseVal
return;
}
MOZ_ASSERT(animVal->mItems.Length() == mItems.Length(),
"animVal list not in sync!");
if (animVal->mItems[aIndex]) {
animVal->mItems[aIndex]->RemovingFromList();
}
animVal->mItems.RemoveElementAt(aIndex);
UpdateListIndicesFromIndex(animVal->mItems, aIndex);
}
} // namespace mozilla