/* -*- 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 "DOMSVGTransformList.h"

#include "mozilla/dom/SVGTransform.h"

#include "mozilla/dom/SVGMatrix.h"

#include "nsSVGAnimatedTransformList.h"

#include "nsSVGElement.h"

#include "mozilla/dom/SVGTransformListBinding.h"

#include "nsError.h"

#include <algorithm>

// local helper functions

namespace {

void UpdateListIndicesFromIndex(

  FallibleTArray<mozilla::dom::SVGTransform*>& 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 {

using namespace dom;

// We could use NS_IMPL_CYCLE_COLLECTION(, except that in Unlink() we need to

// clear our SVGAnimatedTransformList'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(DOMSVGTransformList)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DOMSVGTransformList)

  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(DOMSVGTransformList)

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAList)

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(DOMSVGTransformList)

  NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER

NS_IMPL_CYCLE_COLLECTION_TRACE_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(DOMSVGTransformList)

NS_IMPL_CYCLE_COLLECTING_RELEASE(DOMSVGTransformList)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMSVGTransformList)

  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY

  NS_INTERFACE_MAP_ENTRY(nsISupports)

NS_INTERFACE_MAP_END

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

// DOMSVGTransformList methods:

JSObject*

DOMSVGTransformList::WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto)

{

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

}

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

// Helper class: AutoChangeTransformListNotifier

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

// DidChangeTransformList.

class MOZ_RAII AutoChangeTransformListNotifier

{

public:

  explicit AutoChangeTransformListNotifier(DOMSVGTransformList* aTransformList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)

    : mTransformList(aTransformList)

  {

    MOZ_GUARD_OBJECT_NOTIFIER_INIT;

    MOZ_ASSERT(mTransformList, "Expecting non-null transformList");

    mEmptyOrOldValue =

      mTransformList->Element()->WillChangeTransformList();

  }

  ~AutoChangeTransformListNotifier()

  {

    mTransformList->Element()->DidChangeTransformList(mEmptyOrOldValue);

    if (mTransformList->IsAnimating()) {

      mTransformList->Element()->AnimationNeedsResample();

    }

  }

private:

  DOMSVGTransformList* const mTransformList;

  nsAttrValue          mEmptyOrOldValue;

  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER

};

void

DOMSVGTransformList::InternalListLengthWillChange(uint32_t aNewLength)

{

  uint32_t oldLength = mItems.Length();

  if (aNewLength > SVGTransform::MaxListIndex()) {

    // It's safe to get out of sync with our internal list as long as we have

    // FEWER items than it does.

    aNewLength = SVGTransform::MaxListIndex();

  }

  RefPtr<DOMSVGTransformList> 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;

  }

}

SVGTransformList&

DOMSVGTransformList::InternalList() const

{

  nsSVGAnimatedTransformList *alist = Element()->GetAnimatedTransformList();

  return IsAnimValList() && alist->mAnimVal ?

    *alist->mAnimVal :

    alist->mBaseVal;

}

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

void

DOMSVGTransformList::Clear(ErrorResult& error)

{

  if (IsAnimValList()) {

    error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);

    return;

  }

  if (LengthNoFlush() > 0) {

    AutoChangeTransformListNotifier notifier(this);

    // Notify any existing DOM items of removal *before* truncating the lists

    // so that they can find their SVGTransform internal counterparts and copy

    // their values. This also notifies the animVal list:

    mAList->InternalBaseValListWillChangeLengthTo(0);

    mItems.Clear();

    InternalList().Clear();

  }

}

already_AddRefed<SVGTransform>

DOMSVGTransformList::Initialize(SVGTransform& newItem, ErrorResult& error)

{

  if (IsAnimValList()) {

    error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);

    return nullptr;

  }

  // If newItem is already in a list 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<SVGTransform> domItem = &newItem;

  if (domItem->HasOwner()) {

    domItem = newItem.Clone();

  }

  Clear(error);

  MOZ_ASSERT(!error.Failed(), "How could this fail?");

  return InsertItemBefore(*domItem, 0, error);

}

already_AddRefed<SVGTransform>

DOMSVGTransformList::GetItem(uint32_t index, ErrorResult& error)

{

  bool found;

  RefPtr<SVGTransform> item = IndexedGetter(index, found, error);

  if (!found) {

    error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);

  }

  return item.forget();

}

already_AddRefed<SVGTransform>

DOMSVGTransformList::IndexedGetter(uint32_t index, bool& found,

                                   ErrorResult& error)

{

  if (IsAnimValList()) {

    Element()->FlushAnimations();

  }

  found = index < LengthNoFlush();

  if (found) {

    return GetItemAt(index);

  }

  return nullptr;

}

already_AddRefed<SVGTransform>

DOMSVGTransformList::InsertItemBefore(SVGTransform& 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 >= SVGTransform::MaxListIndex()) {

    error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);

    return nullptr;

  }

  RefPtr<SVGTransform> domItem = &newItem;

  if (newItem.HasOwner()) {

    domItem = newItem.Clone(); // 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;

    }

  }

  AutoChangeTransformListNotifier notifier(this);

  // Now that we know we're inserting, keep animVal list in sync as necessary.

  MaybeInsertNullInAnimValListAt(index);

  InternalList().InsertItem(index, domItem->ToSVGTransform());

  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, index, IsAnimValList());

  UpdateListIndicesFromIndex(mItems, index + 1);

  return domItem.forget();

}

already_AddRefed<SVGTransform>

DOMSVGTransformList::ReplaceItem(SVGTransform& newItem,

                                 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;

  }

  RefPtr<SVGTransform> domItem = &newItem;

  if (newItem.HasOwner()) {

    domItem = newItem.Clone(); // must do this before changing anything!

  }

  AutoChangeTransformListNotifier 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->ToSVGTransform();

  mItems[index] = domItem;

  // This MUST come after the ToSVGPoint() call, otherwise that call

  // would end up reading bad data from InternalList()!

  domItem->InsertingIntoList(this, index, IsAnimValList());

  return domItem.forget();

}

already_AddRefed<SVGTransform>

DOMSVGTransformList::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;

  }

  AutoChangeTransformListNotifier 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:

  RefPtr<SVGTransform> result = GetItemAt(index);

  // Notify the DOM item of removal *before* modifying the lists so that the

  // DOM item can copy its *old* value:

  result->RemovingFromList();

  InternalList().RemoveItem(index);

  mItems.RemoveElementAt(index);

  UpdateListIndicesFromIndex(mItems, index);

  return result.forget();

}

already_AddRefed<SVGTransform>

DOMSVGTransformList::CreateSVGTransformFromMatrix(dom::SVGMatrix& matrix)

{

  RefPtr<SVGTransform> result = new SVGTransform(matrix.GetMatrix());

  return result.forget();

}

already_AddRefed<SVGTransform>

DOMSVGTransformList::Consolidate(ErrorResult& error)

{

  if (IsAnimValList()) {

    error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);

    return nullptr;

  }

  if (LengthNoFlush() == 0) {

    return nullptr;

  }

  // Note that SVG 1.1 says, "The consolidation operation creates new

  // SVGTransform object as the first and only item in the list" hence, even if

  // LengthNoFlush() == 1 we can't return that one item (after making it a

  // matrix type). We must orphan the existing item and then make a new one.

  // First calculate our matrix

  gfxMatrix mx = InternalList().GetConsolidationMatrix();

  // Then orphan the existing items

  Clear(error);

  MOZ_ASSERT(!error.Failed(), "How could this fail?");

  // And append the new transform

  RefPtr<SVGTransform> transform = new SVGTransform(mx);

  return InsertItemBefore(*transform, LengthNoFlush(), error);

}

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

// Implementation helpers:

already_AddRefed<SVGTransform>

DOMSVGTransformList::GetItemAt(uint32_t aIndex)

{

  MOZ_ASSERT(aIndex < mItems.Length());

  if (!mItems[aIndex]) {

    mItems[aIndex] = new SVGTransform(this, aIndex, IsAnimValList());

  }

  RefPtr<SVGTransform> result = mItems[aIndex];

  return result.forget();

}

void

DOMSVGTransformList::MaybeInsertNullInAnimValListAt(uint32_t aIndex)

{

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

  if (!AnimListMirrorsBaseList()) {

    return;

  }

  DOMSVGTransformList* 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

DOMSVGTransformList::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<DOMSVGTransformList> 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