/* -*- 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_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::SVGPointList_Binding::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