fune/dom/svg/SVGTransformableElement.cpp

/* -*- 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 "SVGTransformableElement.h"

#include "DOMSVGAnimatedTransformList.h"
#include "mozilla/dom/MutationEventBinding.h"
#include "nsContentUtils.h"
#include "nsIFrame.h"

using namespace mozilla::gfx;

namespace mozilla::dom {

already_AddRefed<DOMSVGAnimatedTransformList>
SVGTransformableElement::Transform() {
  // We're creating a DOM wrapper, so we must tell GetAnimatedTransformList
  // to allocate the DOMSVGAnimatedTransformList if it hasn't already done so:
  return DOMSVGAnimatedTransformList::GetDOMWrapper(
      GetAnimatedTransformList(DO_ALLOCATE), this);
}

//----------------------------------------------------------------------
// nsIContent methods

nsChangeHint SVGTransformableElement::GetAttributeChangeHint(
    const nsAtom* aAttribute, int32_t aModType) const {
  nsChangeHint retval =
      SVGElement::GetAttributeChangeHint(aAttribute, aModType);
  if (aAttribute == nsGkAtoms::transform ||
      aAttribute == nsGkAtoms::mozAnimateMotionDummyAttr) {
    nsIFrame* frame = GetPrimaryFrame();
    retval |= nsChangeHint_InvalidateRenderingObservers;
    if (!frame || frame->HasAnyStateBits(NS_FRAME_IS_NONDISPLAY)) {
      return retval;
    }

    bool isAdditionOrRemoval = false;
    if (aModType == MutationEvent_Binding::ADDITION ||
        aModType == MutationEvent_Binding::REMOVAL) {
      isAdditionOrRemoval = true;
    } else {
      MOZ_ASSERT(aModType == MutationEvent_Binding::MODIFICATION,
                 "Unknown modification type.");
      if (!mTransforms || !mTransforms->HasTransform()) {
        // New value is empty, treat as removal.
        // FIXME: Should we just rely on CreatedOrRemovedOnLastChange?
        isAdditionOrRemoval = true;
      } else if (mTransforms->CreatedOrRemovedOnLastChange()) {
        // Old value was empty, treat as addition.
        isAdditionOrRemoval = true;
      }
    }

    if (isAdditionOrRemoval) {
      retval |= nsChangeHint_ComprehensiveAddOrRemoveTransform;
    } else {
      // We just assume the old and new transforms are different.
      retval |= nsChangeHint_UpdatePostTransformOverflow |
                nsChangeHint_UpdateTransformLayer;
    }
  }
  return retval;
}

bool SVGTransformableElement::IsEventAttributeNameInternal(nsAtom* aName) {
  return nsContentUtils::IsEventAttributeName(aName, EventNameType_SVGGraphic);
}

//----------------------------------------------------------------------
// SVGElement overrides

gfxMatrix SVGTransformableElement::PrependLocalTransformsTo(
    const gfxMatrix& aMatrix, SVGTransformTypes aWhich) const {
  if (aWhich == eChildToUserSpace) {
    // We don't have any eUserSpaceToParent transforms. (Sub-classes that do
    // must override this function and handle that themselves.)
    return aMatrix;
  }
  return GetUserToParentTransform(mAnimateMotionTransform.get(),
                                  mTransforms.get()) *
         aMatrix;
}

const gfx::Matrix* SVGTransformableElement::GetAnimateMotionTransform() const {
  return mAnimateMotionTransform.get();
}

void SVGTransformableElement::SetAnimateMotionTransform(
    const gfx::Matrix* aMatrix) {
  if ((!aMatrix && !mAnimateMotionTransform) ||
      (aMatrix && mAnimateMotionTransform &&
       aMatrix->FuzzyEquals(*mAnimateMotionTransform))) {
    return;
  }
  bool transformSet = mTransforms && mTransforms->IsExplicitlySet();
  bool prevSet = mAnimateMotionTransform || transformSet;
  mAnimateMotionTransform =
      aMatrix ? MakeUnique<gfx::Matrix>(*aMatrix) : nullptr;
  bool nowSet = mAnimateMotionTransform || transformSet;
  int32_t modType;
  if (prevSet && !nowSet) {
    modType = MutationEvent_Binding::REMOVAL;
  } else if (!prevSet && nowSet) {
    modType = MutationEvent_Binding::ADDITION;
  } else {
    modType = MutationEvent_Binding::MODIFICATION;
  }
  DidAnimateTransformList(modType);
  nsIFrame* frame = GetPrimaryFrame();
  if (frame) {
    // If the result of this transform and any other transforms on this frame
    // is the identity matrix, then DoApplyRenderingChangeToTree won't handle
    // our nsChangeHint_UpdateTransformLayer hint since aFrame->IsTransformed()
    // will return false. That's fine, but we still need to schedule a repaint,
    // and that won't otherwise happen. Since it's cheap to call SchedulePaint,
    // we don't bother to check IsTransformed().
    frame->SchedulePaint();
  }
}

SVGAnimatedTransformList* SVGTransformableElement::GetAnimatedTransformList(
    uint32_t aFlags) {
  if (!mTransforms && (aFlags & DO_ALLOCATE)) {
    mTransforms = MakeUnique<SVGAnimatedTransformList>();
  }
  return mTransforms.get();
}

/* static */
gfxMatrix SVGTransformableElement::GetUserToParentTransform(
    const gfx::Matrix* aAnimateMotionTransform,
    const SVGAnimatedTransformList* aTransforms) {
  gfxMatrix result;

  if (aAnimateMotionTransform) {
    result.PreMultiply(ThebesMatrix(*aAnimateMotionTransform));
  }

  if (aTransforms) {
    result.PreMultiply(aTransforms->GetAnimValue().GetConsolidationMatrix());
  }

  return result;
}

}  // namespace mozilla::dom