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DOMSVGPointList.cpp (14196B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #include "DOMSVGPointList.h"
      8 
      9 #include <algorithm>
     10 
     11 #include "DOMSVGPoint.h"
     12 #include "SVGAnimatedPointList.h"
     13 #include "SVGAttrTearoffTable.h"
     14 #include "SVGPolyElement.h"
     15 #include "mozilla/dom/SVGElement.h"
     16 #include "mozilla/dom/SVGPointListBinding.h"
     17 #include "nsContentUtils.h"
     18 #include "nsError.h"
     19 
     20 // See the comment in this file's header.
     21 
     22 // local helper functions
     23 namespace {
     24 
     25 void UpdateListIndicesFromIndex(
     26    FallibleTArray<mozilla::dom::DOMSVGPoint*>& aItemsArray,
     27    uint32_t aStartingIndex) {
     28  uint32_t length = aItemsArray.Length();
     29 
     30  for (uint32_t i = aStartingIndex; i < length; ++i) {
     31    if (aItemsArray[i]) {
     32      aItemsArray[i]->UpdateListIndex(i);
     33    }
     34  }
     35 }
     36 
     37 }  // namespace
     38 
     39 namespace mozilla::dom {
     40 
     41 static inline SVGAttrTearoffTable<void, DOMSVGPointList>&
     42 SVGPointListTearoffTable() {
     43  static SVGAttrTearoffTable<void, DOMSVGPointList> sSVGPointListTearoffTable;
     44  return sSVGPointListTearoffTable;
     45 }
     46 
     47 NS_IMPL_CYCLE_COLLECTION_CLASS(DOMSVGPointList)
     48 
     49 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DOMSVGPointList)
     50  // No unlinking of mElement, we'd need to null out the value pointer (the
     51  // object it points to is held by the element) and null-check it everywhere.
     52  tmp->RemoveFromTearoffTable();
     53  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
     54 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
     55 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(DOMSVGPointList)
     56  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mElement)
     57 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
     58 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(DOMSVGPointList)
     59  NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
     60 NS_IMPL_CYCLE_COLLECTION_TRACE_END
     61 
     62 NS_IMPL_CYCLE_COLLECTING_ADDREF(DOMSVGPointList)
     63 NS_IMPL_CYCLE_COLLECTING_RELEASE(DOMSVGPointList)
     64 
     65 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMSVGPointList)
     66  NS_INTERFACE_MAP_ENTRY_CONCRETE(DOMSVGPointList)
     67  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
     68  NS_INTERFACE_MAP_ENTRY(nsISupports)
     69 NS_INTERFACE_MAP_END
     70 
     71 /* static */
     72 already_AddRefed<DOMSVGPointList> DOMSVGPointList::GetDOMWrapper(
     73    void* aList, SVGPolyElement* aElement) {
     74  RefPtr<DOMSVGPointList> wrapper =
     75      SVGPointListTearoffTable().GetTearoff(aList);
     76  if (!wrapper) {
     77    wrapper = new DOMSVGPointList(
     78        aElement, aElement->GetAnimatedPointList()->GetAnimValKey() == aList);
     79    SVGPointListTearoffTable().AddTearoff(aList, wrapper);
     80  }
     81  return wrapper.forget();
     82 }
     83 
     84 /* static */
     85 DOMSVGPointList* DOMSVGPointList::GetDOMWrapperIfExists(void* aList) {
     86  return SVGPointListTearoffTable().GetTearoff(aList);
     87 }
     88 
     89 void DOMSVGPointList::RemoveFromTearoffTable() {
     90  // Called from Unlink and the destructor.
     91  //
     92  // There are now no longer any references to us held by script or list items.
     93  // Note we must use GetAnimValKey/GetBaseValKey here, NOT InternalList()!
     94  if (mIsInTearoffTable) {
     95    void* key = mIsAnimValList ? InternalAList().GetAnimValKey()
     96                               : InternalAList().GetBaseValKey();
     97    SVGPointListTearoffTable().RemoveTearoff(key);
     98    mIsInTearoffTable = false;
     99  }
    100 }
    101 
    102 DOMSVGPointList::~DOMSVGPointList() { RemoveFromTearoffTable(); }
    103 
    104 JSObject* DOMSVGPointList::WrapObject(JSContext* cx,
    105                                      JS::Handle<JSObject*> aGivenProto) {
    106  return mozilla::dom::SVGPointList_Binding::Wrap(cx, this, aGivenProto);
    107 }
    108 
    109 void DOMSVGPointList::InternalListWillChangeTo(const SVGPointList& aNewValue) {
    110  // When the number of items in our internal counterpart changes, we MUST stay
    111  // in sync. Everything in the scary comment in
    112  // DOMSVGLengthList::InternalBaseValListWillChangeTo applies here too!
    113 
    114  uint32_t oldLength = mItems.Length();
    115 
    116  uint32_t newLength = aNewValue.Length();
    117  if (newLength > DOMSVGPoint::MaxListIndex()) {
    118    // It's safe to get out of sync with our internal list as long as we have
    119    // FEWER items than it does.
    120    newLength = DOMSVGPoint::MaxListIndex();
    121  }
    122 
    123  RefPtr<DOMSVGPointList> kungFuDeathGrip;
    124  if (newLength < oldLength) {
    125    // RemovingFromList() might clear last reference to |this|.
    126    // Retain a temporary reference to keep from dying before returning.
    127    kungFuDeathGrip = this;
    128  }
    129 
    130  // If our length will decrease, notify the items that will be removed:
    131  for (uint32_t i = newLength; i < oldLength; ++i) {
    132    if (mItems[i]) {
    133      mItems[i]->RemovingFromList();
    134    }
    135  }
    136 
    137  if (!mItems.SetLength(newLength, fallible)) {
    138    // We silently ignore SetLength OOM failure since being out of sync is safe
    139    // so long as we have *fewer* items than our internal list.
    140    mItems.Clear();
    141    return;
    142  }
    143 
    144  // If our length has increased, null out the new pointers:
    145  for (uint32_t i = oldLength; i < newLength; ++i) {
    146    mItems[i] = nullptr;
    147  }
    148 }
    149 
    150 bool DOMSVGPointList::AttrIsAnimating() const {
    151  return InternalAList().IsAnimating();
    152 }
    153 
    154 bool DOMSVGPointList::AnimListMirrorsBaseList() const {
    155  return GetDOMWrapperIfExists(InternalAList().GetAnimValKey()) &&
    156         !AttrIsAnimating();
    157 }
    158 
    159 SVGPointList& DOMSVGPointList::InternalList() const {
    160  SVGAnimatedPointList* alist = mElement->GetAnimatedPointList();
    161  return mIsAnimValList && alist->IsAnimating() ? *alist->mAnimVal
    162                                                : alist->mBaseVal;
    163 }
    164 
    165 SVGAnimatedPointList& DOMSVGPointList::InternalAList() const {
    166  MOZ_ASSERT(mElement->GetAnimatedPointList(), "Internal error");
    167  return *mElement->GetAnimatedPointList();
    168 }
    169 
    170 // ----------------------------------------------------------------------------
    171 // nsIDOMSVGPointList implementation:
    172 
    173 void DOMSVGPointList::Clear(ErrorResult& aRv) {
    174  if (IsAnimValList()) {
    175    aRv.ThrowNoModificationAllowedError("Animated values cannot be set");
    176    return;
    177  }
    178 
    179  if (LengthNoFlush() > 0) {
    180    AutoChangePointListNotifier notifier(this);
    181    // DOM list items that are to be removed must be removed before we change
    182    // the internal list, otherwise they wouldn't be able to copy their
    183    // internal counterparts' values!
    184 
    185    InternalListWillChangeTo(SVGPointList());  // clears mItems
    186 
    187    if (!AttrIsAnimating()) {
    188      // The anim val list is in sync with the base val list
    189      DOMSVGPointList* animList =
    190          GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
    191      if (animList) {
    192        animList->InternalListWillChangeTo(
    193            SVGPointList());  // clears its mItems
    194      }
    195    }
    196 
    197    InternalList().Clear();
    198  }
    199 }
    200 
    201 already_AddRefed<DOMSVGPoint> DOMSVGPointList::Initialize(DOMSVGPoint& aNewItem,
    202                                                          ErrorResult& aRv) {
    203  if (IsAnimValList()) {
    204    aRv.ThrowNoModificationAllowedError("Animated values cannot be set");
    205    return nullptr;
    206  }
    207 
    208  // If aNewItem is already in a list we should insert a clone of aNewItem,
    209  // and for consistency, this should happen even if *this* is the list that
    210  // aNewItem is currently in. Note that in the case of aNewItem being in this
    211  // list, the Clear() call before the InsertItemBefore() call would remove it
    212  // from this list, and so the InsertItemBefore() call would not insert a
    213  // clone of aNewItem, it would actually insert aNewItem. To prevent that
    214  // from happening we have to do the clone here, if necessary.
    215 
    216  RefPtr<DOMSVGPoint> domItem = &aNewItem;
    217  if (domItem->HasOwner()) {
    218    domItem = domItem->Copy();  // must do this before changing anything!
    219  }
    220 
    221  ErrorResult rv;
    222  Clear(rv);
    223  MOZ_ASSERT(!rv.Failed());
    224  return InsertItemBefore(*domItem, 0, aRv);
    225 }
    226 
    227 already_AddRefed<DOMSVGPoint> DOMSVGPointList::GetItem(uint32_t index,
    228                                                       ErrorResult& aRv) {
    229  bool found;
    230  RefPtr<DOMSVGPoint> item = IndexedGetter(index, found, aRv);
    231  if (!found) {
    232    aRv.ThrowIndexSizeError("Index out of range");
    233  }
    234  return item.forget();
    235 }
    236 
    237 already_AddRefed<DOMSVGPoint> DOMSVGPointList::IndexedGetter(uint32_t aIndex,
    238                                                             bool& aFound,
    239                                                             ErrorResult& aRv) {
    240  if (IsAnimValList()) {
    241    Element()->FlushAnimations();
    242  }
    243  aFound = aIndex < LengthNoFlush();
    244  if (aFound) {
    245    return GetItemAt(aIndex);
    246  }
    247  return nullptr;
    248 }
    249 
    250 already_AddRefed<DOMSVGPoint> DOMSVGPointList::InsertItemBefore(
    251    DOMSVGPoint& aNewItem, uint32_t aIndex, ErrorResult& aRv) {
    252  if (IsAnimValList()) {
    253    aRv.ThrowNoModificationAllowedError("Animated values cannot be set");
    254    return nullptr;
    255  }
    256 
    257  aIndex = std::min(aIndex, LengthNoFlush());
    258  if (aIndex >= DOMSVGPoint::MaxListIndex()) {
    259    aRv.ThrowIndexSizeError("Index out of range");
    260    return nullptr;
    261  }
    262 
    263  RefPtr<DOMSVGPoint> domItem = &aNewItem;
    264  if (domItem->HasOwner()) {
    265    domItem = domItem->Copy();  // must do this before changing anything!
    266  }
    267 
    268  // Ensure we have enough memory so we can avoid complex error handling below:
    269  if (!mItems.SetCapacity(mItems.Length() + 1, fallible) ||
    270      !InternalList().SetCapacity(InternalList().Length() + 1)) {
    271    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
    272    return nullptr;
    273  }
    274  if (AnimListMirrorsBaseList()) {
    275    DOMSVGPointList* animVal =
    276        GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
    277    MOZ_ASSERT(animVal, "animVal must be a valid pointer");
    278    if (!animVal->mItems.SetCapacity(animVal->mItems.Length() + 1, fallible)) {
    279      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
    280      return nullptr;
    281    }
    282  }
    283 
    284  AutoChangePointListNotifier notifier(this);
    285  // Now that we know we're inserting, keep animVal list in sync as necessary.
    286  MaybeInsertNullInAnimValListAt(aIndex);
    287 
    288  InternalList().InsertItem(aIndex, domItem->ToSVGPoint());
    289  MOZ_ALWAYS_TRUE(mItems.InsertElementAt(aIndex, domItem, fallible));
    290 
    291  // This MUST come after the insertion into InternalList(), or else under the
    292  // insertion into InternalList() the values read from domItem would be bad
    293  // data from InternalList() itself!:
    294  domItem->InsertingIntoList(this, aIndex, IsAnimValList());
    295 
    296  UpdateListIndicesFromIndex(mItems, aIndex + 1);
    297 
    298  return domItem.forget();
    299 }
    300 
    301 already_AddRefed<DOMSVGPoint> DOMSVGPointList::ReplaceItem(
    302    DOMSVGPoint& aNewItem, uint32_t aIndex, ErrorResult& aRv) {
    303  if (IsAnimValList()) {
    304    aRv.ThrowNoModificationAllowedError("Animated values cannot be set");
    305    return nullptr;
    306  }
    307 
    308  if (aIndex >= LengthNoFlush()) {
    309    aRv.ThrowIndexSizeError("Index out of range");
    310    return nullptr;
    311  }
    312 
    313  RefPtr<DOMSVGPoint> domItem = &aNewItem;
    314  if (domItem->HasOwner()) {
    315    domItem = domItem->Copy();  // must do this before changing anything!
    316  }
    317 
    318  AutoChangePointListNotifier notifier(this);
    319  if (mItems[aIndex]) {
    320    // Notify any existing DOM item of removal *before* modifying the lists so
    321    // that the DOM item can copy the *old* value at its index:
    322    mItems[aIndex]->RemovingFromList();
    323  }
    324 
    325  InternalList()[aIndex] = domItem->ToSVGPoint();
    326  mItems[aIndex] = domItem;
    327 
    328  // This MUST come after the ToSVGPoint() call, otherwise that call
    329  // would end up reading bad data from InternalList()!
    330  domItem->InsertingIntoList(this, aIndex, IsAnimValList());
    331 
    332  return domItem.forget();
    333 }
    334 
    335 already_AddRefed<DOMSVGPoint> DOMSVGPointList::RemoveItem(uint32_t aIndex,
    336                                                          ErrorResult& aRv) {
    337  if (IsAnimValList()) {
    338    aRv.ThrowNoModificationAllowedError("Animated values cannot be set");
    339    return nullptr;
    340  }
    341 
    342  if (aIndex >= LengthNoFlush()) {
    343    aRv.ThrowIndexSizeError("Index out of range");
    344    return nullptr;
    345  }
    346 
    347  AutoChangePointListNotifier notifier(this);
    348  // Now that we know we're removing, keep animVal list in sync as necessary.
    349  // Do this *before* touching InternalList() so the removed item can get its
    350  // internal value.
    351  MaybeRemoveItemFromAnimValListAt(aIndex);
    352 
    353  // We have to return the removed item, so get it, creating it if necessary:
    354  RefPtr<DOMSVGPoint> result = GetItemAt(aIndex);
    355 
    356  // Notify the DOM item of removal *before* modifying the lists so that the
    357  // DOM item can copy its *old* value:
    358  mItems[aIndex]->RemovingFromList();
    359 
    360  InternalList().RemoveItem(aIndex);
    361  mItems.RemoveElementAt(aIndex);
    362 
    363  UpdateListIndicesFromIndex(mItems, aIndex);
    364 
    365  return result.forget();
    366 }
    367 
    368 already_AddRefed<DOMSVGPoint> DOMSVGPointList::GetItemAt(uint32_t aIndex) {
    369  MOZ_ASSERT(aIndex < mItems.Length());
    370 
    371  if (!mItems[aIndex]) {
    372    mItems[aIndex] = new DOMSVGPoint(this, aIndex, IsAnimValList());
    373  }
    374  RefPtr<DOMSVGPoint> result = mItems[aIndex];
    375  return result.forget();
    376 }
    377 
    378 void DOMSVGPointList::MaybeInsertNullInAnimValListAt(uint32_t aIndex) {
    379  MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal");
    380 
    381  if (!AnimListMirrorsBaseList()) {
    382    return;
    383  }
    384 
    385  // The anim val list is in sync with the base val list
    386  DOMSVGPointList* animVal =
    387      GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
    388 
    389  MOZ_ASSERT(animVal, "AnimListMirrorsBaseList() promised a non-null animVal");
    390  MOZ_ASSERT(animVal->mItems.Length() == mItems.Length(),
    391             "animVal list not in sync!");
    392  MOZ_ALWAYS_TRUE(animVal->mItems.InsertElementAt(aIndex, nullptr, fallible));
    393 
    394  UpdateListIndicesFromIndex(animVal->mItems, aIndex + 1);
    395 }
    396 
    397 void DOMSVGPointList::MaybeRemoveItemFromAnimValListAt(uint32_t aIndex) {
    398  MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal");
    399 
    400  if (!AnimListMirrorsBaseList()) {
    401    return;
    402  }
    403 
    404  // This needs to be a strong reference; otherwise, the RemovingFromList call
    405  // below might drop the last reference to animVal before we're done with it.
    406  RefPtr<DOMSVGPointList> animVal =
    407      GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
    408 
    409  MOZ_ASSERT(animVal, "AnimListMirrorsBaseList() promised a non-null animVal");
    410  MOZ_ASSERT(animVal->mItems.Length() == mItems.Length(),
    411             "animVal list not in sync!");
    412 
    413  if (animVal->mItems[aIndex]) {
    414    animVal->mItems[aIndex]->RemovingFromList();
    415  }
    416  animVal->mItems.RemoveElementAt(aIndex);
    417 
    418  UpdateListIndicesFromIndex(animVal->mItems, aIndex);
    419 }
    420 
    421 }  // namespace mozilla::dom