gecko-dev/dom/svg/DOMSVGPointList.cpp
2015-12-03 03:18:00 +01:00

480 lines
14 KiB
C++

/* -*- 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 "DOMSVGPointList.h"
#include "DOMSVGPoint.h"
#include "nsError.h"
#include "SVGAnimatedPointList.h"
#include "nsCOMPtr.h"
#include "nsSVGAttrTearoffTable.h"
#include "nsContentUtils.h"
#include "mozilla/dom/SVGPointListBinding.h"
#include <algorithm>
// See the comment in this file's header.
// local helper functions
namespace {
void
UpdateListIndicesFromIndex(FallibleTArray<mozilla::nsISVGPoint*>& 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 {
static inline
nsSVGAttrTearoffTable<void, DOMSVGPointList>&
SVGPointListTearoffTable()
{
static nsSVGAttrTearoffTable<void, DOMSVGPointList>
sSVGPointListTearoffTable;
return sSVGPointListTearoffTable;
}
NS_IMPL_CYCLE_COLLECTION_CLASS(DOMSVGPointList)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DOMSVGPointList)
// 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(DOMSVGPointList)
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(DOMSVGPointList)
NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(DOMSVGPointList)
NS_IMPL_CYCLE_COLLECTING_RELEASE(DOMSVGPointList)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMSVGPointList)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
//----------------------------------------------------------------------
// Helper class: AutoChangePointListNotifier
// Stack-based helper class to pair calls to WillChangePointList and
// DidChangePointList.
class MOZ_RAII AutoChangePointListNotifier
{
public:
explicit AutoChangePointListNotifier(DOMSVGPointList* aPointList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: mPointList(aPointList)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
MOZ_ASSERT(mPointList, "Expecting non-null pointList");
mEmptyOrOldValue =
mPointList->Element()->WillChangePointList();
}
~AutoChangePointListNotifier()
{
mPointList->Element()->DidChangePointList(mEmptyOrOldValue);
if (mPointList->AttrIsAnimating()) {
mPointList->Element()->AnimationNeedsResample();
}
}
private:
DOMSVGPointList* const mPointList;
nsAttrValue mEmptyOrOldValue;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
/* static */ already_AddRefed<DOMSVGPointList>
DOMSVGPointList::GetDOMWrapper(void *aList,
nsSVGElement *aElement,
bool aIsAnimValList)
{
RefPtr<DOMSVGPointList> wrapper =
SVGPointListTearoffTable().GetTearoff(aList);
if (!wrapper) {
wrapper = new DOMSVGPointList(aElement, aIsAnimValList);
SVGPointListTearoffTable().AddTearoff(aList, wrapper);
}
return wrapper.forget();
}
/* static */ DOMSVGPointList*
DOMSVGPointList::GetDOMWrapperIfExists(void *aList)
{
return SVGPointListTearoffTable().GetTearoff(aList);
}
DOMSVGPointList::~DOMSVGPointList()
{
// 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();
SVGPointListTearoffTable().RemoveTearoff(key);
}
JSObject*
DOMSVGPointList::WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto)
{
return mozilla::dom::SVGPointListBinding::Wrap(cx, this, aGivenProto);
}
void
DOMSVGPointList::InternalListWillChangeTo(const SVGPointList& 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 too!
uint32_t oldLength = mItems.Length();
uint32_t newLength = aNewValue.Length();
if (newLength > nsISVGPoint::MaxListIndex()) {
// It's safe to get out of sync with our internal list as long as we have
// FEWER items than it does.
newLength = nsISVGPoint::MaxListIndex();
}
RefPtr<DOMSVGPointList> kungFuDeathGrip;
if (newLength < 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 = newLength; i < oldLength; ++i) {
if (mItems[i]) {
mItems[i]->RemovingFromList();
}
}
if (!mItems.SetLength(newLength, fallible)) {
// 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 < newLength; ++i) {
mItems[i] = nullptr;
}
}
bool
DOMSVGPointList::AttrIsAnimating() const
{
return InternalAList().IsAnimating();
}
bool
DOMSVGPointList::AnimListMirrorsBaseList() const
{
return GetDOMWrapperIfExists(InternalAList().GetAnimValKey()) &&
!AttrIsAnimating();
}
SVGPointList&
DOMSVGPointList::InternalList() const
{
SVGAnimatedPointList *alist = mElement->GetAnimatedPointList();
return mIsAnimValList && alist->IsAnimating() ? *alist->mAnimVal : alist->mBaseVal;
}
SVGAnimatedPointList&
DOMSVGPointList::InternalAList() const
{
MOZ_ASSERT(mElement->GetAnimatedPointList(), "Internal error");
return *mElement->GetAnimatedPointList();
}
// ----------------------------------------------------------------------------
// nsIDOMSVGPointList implementation:
void
DOMSVGPointList::Clear(ErrorResult& aError)
{
if (IsAnimValList()) {
aError.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return;
}
if (LengthNoFlush() > 0) {
AutoChangePointListNotifier 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(SVGPointList()); // clears mItems
if (!AttrIsAnimating()) {
// The anim val list is in sync with the base val list
DOMSVGPointList *animList =
GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
if (animList) {
animList->InternalListWillChangeTo(SVGPointList()); // clears its mItems
}
}
InternalList().Clear();
}
}
already_AddRefed<nsISVGPoint>
DOMSVGPointList::Initialize(nsISVGPoint& 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.
nsCOMPtr<nsISVGPoint> domItem = &aNewItem;
if (domItem->HasOwner() || domItem->IsReadonly() ||
domItem->IsTranslatePoint()) {
domItem = domItem->Copy(); // must do this before changing anything!
}
ErrorResult rv;
Clear(rv);
MOZ_ASSERT(!rv.Failed());
return InsertItemBefore(*domItem, 0, aError);
}
already_AddRefed<nsISVGPoint>
DOMSVGPointList::GetItem(uint32_t index, ErrorResult& error)
{
bool found;
RefPtr<nsISVGPoint> item = IndexedGetter(index, found, error);
if (!found) {
error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
}
return item.forget();
}
already_AddRefed<nsISVGPoint>
DOMSVGPointList::IndexedGetter(uint32_t aIndex, bool& aFound,
ErrorResult& aError)
{
if (IsAnimValList()) {
Element()->FlushAnimations();
}
aFound = aIndex < LengthNoFlush();
if (aFound) {
return GetItemAt(aIndex);
}
return nullptr;
}
already_AddRefed<nsISVGPoint>
DOMSVGPointList::InsertItemBefore(nsISVGPoint& aNewItem, uint32_t aIndex,
ErrorResult& aError)
{
if (IsAnimValList()) {
aError.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
aIndex = std::min(aIndex, LengthNoFlush());
if (aIndex >= nsISVGPoint::MaxListIndex()) {
aError.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
nsCOMPtr<nsISVGPoint> domItem = &aNewItem;
if (domItem->HasOwner() || domItem->IsReadonly() ||
domItem->IsTranslatePoint()) {
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, fallible) ||
!InternalList().SetCapacity(InternalList().Length() + 1)) {
aError.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
if (AnimListMirrorsBaseList()) {
DOMSVGPointList *animVal =
GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
MOZ_ASSERT(animVal, "animVal must be a valid pointer");
if (!animVal->mItems.SetCapacity(
animVal->mItems.Length() + 1, fallible)) {
aError.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
}
AutoChangePointListNotifier notifier(this);
// Now that we know we're inserting, keep animVal list in sync as necessary.
MaybeInsertNullInAnimValListAt(aIndex);
InternalList().InsertItem(aIndex, domItem->ToSVGPoint());
MOZ_ALWAYS_TRUE(mItems.InsertElementAt(aIndex, domItem, 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(mItems, aIndex + 1);
return domItem.forget();
}
already_AddRefed<nsISVGPoint>
DOMSVGPointList::ReplaceItem(nsISVGPoint& 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;
}
nsCOMPtr<nsISVGPoint> domItem = &aNewItem;
if (domItem->HasOwner() || domItem->IsReadonly() ||
domItem->IsTranslatePoint()) {
domItem = domItem->Copy(); // must do this before changing anything!
}
AutoChangePointListNotifier notifier(this);
if (mItems[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:
mItems[aIndex]->RemovingFromList();
}
InternalList()[aIndex] = domItem->ToSVGPoint();
mItems[aIndex] = domItem;
// This MUST come after the ToSVGPoint() call, otherwise that call
// would end up reading bad data from InternalList()!
domItem->InsertingIntoList(this, aIndex, IsAnimValList());
return domItem.forget();
}
already_AddRefed<nsISVGPoint>
DOMSVGPointList::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;
}
AutoChangePointListNotifier 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(aIndex);
// We have to return the removed item, so get it, creating it if necessary:
RefPtr<nsISVGPoint> result = GetItemAt(aIndex);
// Notify the DOM item of removal *before* modifying the lists so that the
// DOM item can copy its *old* value:
mItems[aIndex]->RemovingFromList();
InternalList().RemoveItem(aIndex);
mItems.RemoveElementAt(aIndex);
UpdateListIndicesFromIndex(mItems, aIndex);
return result.forget();
}
already_AddRefed<nsISVGPoint>
DOMSVGPointList::GetItemAt(uint32_t aIndex)
{
MOZ_ASSERT(aIndex < mItems.Length());
if (!mItems[aIndex]) {
mItems[aIndex] = new DOMSVGPoint(this, aIndex, IsAnimValList());
}
RefPtr<nsISVGPoint> result = mItems[aIndex];
return result.forget();
}
void
DOMSVGPointList::MaybeInsertNullInAnimValListAt(uint32_t aIndex)
{
MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal");
if (!AnimListMirrorsBaseList()) {
return;
}
// The anim val list is in sync with the base val list
DOMSVGPointList *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, nullptr, fallible));
UpdateListIndicesFromIndex(animVal->mItems, aIndex + 1);
}
void
DOMSVGPointList::MaybeRemoveItemFromAnimValListAt(uint32_t aIndex)
{
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<DOMSVGPointList> 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->mItems[aIndex]) {
animVal->mItems[aIndex]->RemovingFromList();
}
animVal->mItems.RemoveElementAt(aIndex);
UpdateListIndicesFromIndex(animVal->mItems, aIndex);
}
} // namespace mozilla