/* -*- 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 "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_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, JS::Handle<JSObject*> aGivenProto)

{

  return mozilla::dom::SVGLengthList_Binding::Wrap(cx, this, aGivenProto);

}

//----------------------------------------------------------------------

// Helper class: AutoChangeLengthListNotifier

// Stack-based helper class to pair calls to WillChangeLengthList and

// DidChangeLengthList.

class MOZ_RAII 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();

  }

  RefPtr<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, 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 < 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.

  RefPtr<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;

  RefPtr<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;

  }

  RefPtr<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, fallible) ||

      !InternalList().SetCapacity(InternalList().Length() + 1)) {

    error.Throw(NS_ERROR_OUT_OF_MEMORY);

    return nullptr;

  }

  if (AnimListMirrorsBaseList()) {

    if (!mAList->mAnimVal->mItems.SetCapacity(

          mAList->mAnimVal->mItems.Length() + 1, fallible)) {

      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());

  MOZ_ALWAYS_TRUE(mItems.InsertElementAt(index, domItem.get(), 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, 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;

  }

  RefPtr<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());

  }

  RefPtr<DOMSVGLength> result = mItems[aIndex];

  return result.forget();

}

void

DOMSVGLengthList::MaybeInsertNullInAnimValListAt(uint32_t aIndex)

{

  MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal");

  if (!AnimListMirrorsBaseList()) {

    return;

  }

  DOMSVGLengthList* animVal = mAList->mAnimVal;

  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

DOMSVGLengthList::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<DOMSVGLengthList> animVal = mAList->mAnimVal;

  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