C++ DOMSVGPathSegList类代码示例

void
DOMSVGPathSegList::
  MaybeInsertNullInAnimValListAt(uint32_t aIndex,
                                 uint32_t aInternalIndex,
                                 uint32_t aArgCountForItem)
{
  NS_ABORT_IF_FALSE(!IsAnimValList(), "call from baseVal to animVal");

  if (AttrIsAnimating()) {
    // animVal not a clone of baseVal
    return;
  }

  // The anim val list is in sync with the base val list
  DOMSVGPathSegList *animVal =
    GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
  if (!animVal) {
    // No animVal list wrapper
    return;
  }

  NS_ABORT_IF_FALSE(animVal->mItems.Length() == mItems.Length(),
                    "animVal list not in sync!");

  animVal->mItems.InsertElementAt(aIndex, ItemProxy(nullptr, aInternalIndex));

  animVal->UpdateListIndicesFromIndex(aIndex + 1, 1 + aArgCountForItem);
}

nsresult
SVGAnimatedPathSegList::SetAnimValue(const SVGPathData& aNewAnimValue,
                                     nsSVGElement *aElement)
{
  // Note that a new animation may totally change the number of items in the
  // animVal list, either replacing what was essentially a mirror of the
  // baseVal list, or else replacing and overriding an existing animation.
  // Unfortunately it is not possible for us to reliably distinguish between
  // calls to this method that are setting a new sample for an existing
  // animation, and calls that are setting the first sample of an animation
  // that will override an existing animation. In the case of DOMSVGPathSegList
  // the InternalListWillChangeTo method is not virtually free as it is for the
  // other DOM list classes, so this is a shame. We'd quite like to be able to
  // skip the call if possible.

  // We must send these notifications *before* changing mAnimVal! (See above.)

  DOMSVGPathSegList *domWrapper =
    DOMSVGPathSegList::GetDOMWrapperIfExists(GetAnimValKey());
  if (domWrapper) {
    domWrapper->InternalListWillChangeTo(aNewAnimValue);
  }
  if (!mAnimVal) {
    mAnimVal = new SVGPathData();
  }
  nsresult rv = mAnimVal->CopyFrom(aNewAnimValue);
  if (NS_FAILED(rv)) {
    // OOM. We clear the animation and, importantly, ClearAnimValue() ensures
    // that mAnimVal's DOM wrapper (if any) is kept in sync!
    ClearAnimValue(aElement);
  }
  aElement->DidAnimatePathSegList();
  return rv;
}

void
DOMSVGPathSegList::Clear(ErrorResult& aError)
{
  if (IsAnimValList()) {
    aError.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
    return;
  }

  if (LengthNoFlush() > 0) {
    nsAttrValue emptyOrOldValue = Element()->WillChangePathSegList();
    // 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(SVGPathData()); // clears mItems

    if (!AttrIsAnimating()) {
      // The anim val list is in sync with the base val list
      DOMSVGPathSegList *animList =
        GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
      if (animList) {
        animList->InternalListWillChangeTo(SVGPathData()); // clears its mItems
      }
    }

    InternalList().Clear();
    Element()->DidChangePathSegList(emptyOrOldValue);
    if (AttrIsAnimating()) {
      Element()->AnimationNeedsResample();
    }
  }
}

NS_IMETHODIMP
DOMSVGPathSegList::Clear()
{
  if (IsAnimValList()) {
    return NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR;
  }

  if (Length() > 0) {
    // 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(SVGPathData()); // clears mItems

    if (!AttrIsAnimating()) {
      // The anim val list is in sync with the base val list
      DOMSVGPathSegList *animList =
        GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
      if (animList) {
        animList->InternalListWillChangeTo(SVGPathData()); // clears its mItems
      }
    }

    InternalList().Clear();
    Element()->DidChangePathSegList(PR_TRUE);
#ifdef MOZ_SMIL
    if (AttrIsAnimating()) {
      Element()->AnimationNeedsResample();
    }
#endif
  }
  return NS_OK;
}

void
DOMSVGPathSegList::
  MaybeRemoveItemFromAnimValListAt(PRUint32 aIndex,
                                   PRUint32 aArgCountForItem)
{
  NS_ABORT_IF_FALSE(!IsAnimValList(), "call from baseVal to animVal");

  if (AttrIsAnimating()) {
    // animVal not a clone of baseVal
    return;
  }

  DOMSVGPathSegList *animVal =
    GetDOMWrapperIfExists(InternalAList().GetAnimValKey());
  if (!animVal) {
    // No animVal list wrapper
    return;
  }

  NS_ABORT_IF_FALSE(animVal->mItems.Length() == mItems.Length(),
                    "animVal list not in sync!");

  if (animVal->ItemAt(aIndex)) {
    animVal->ItemAt(aIndex)->RemovingFromList();
  }
  animVal->mItems.RemoveElementAt(aIndex);

  animVal->UpdateListIndicesFromIndex(aIndex, -(1 + aArgCountForItem));
}

void
SVGAnimatedPathSegList::ClearAnimValue(nsSVGElement *aElement)
{
  // We must send these notifications *before* changing mAnimVal! (See above.)

  DOMSVGPathSegList *domWrapper =
    DOMSVGPathSegList::GetDOMWrapperIfExists(GetAnimValKey());
  if (domWrapper) {
    // When all animation ends, animVal simply mirrors baseVal, which may have
    // a different number of items to the last active animated value.
    //
    domWrapper->InternalListWillChangeTo(mBaseVal);
  }
  mAnimVal = nullptr;
  aElement->DidAnimatePathSegList();
}

void DOMSVGPathSegList::MaybeInsertNullInAnimValListAt(
    uint32_t aIndex, uint32_t aInternalIndex, uint32_t aArgCountForItem) {
  MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal");

  if (!AnimListMirrorsBaseList()) {
    return;
  }

  // The anim val list is in sync with the base val list
  DOMSVGPathSegList* 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, ItemProxy(nullptr, aInternalIndex), fallible));

  animVal->UpdateListIndicesFromIndex(aIndex + 1, 1 + aArgCountForItem);
}