gecko-dev/dom/svg/DOMSVGPathSeg.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 "DOMSVGPathSeg.h"
#include "DOMSVGPathSegList.h"
#include "SVGAnimatedPathSegList.h"
#include "SVGElement.h"
#include "nsError.h"

// See the architecture comment in DOMSVGPathSegList.h.

namespace mozilla {

using namespace dom::SVGPathSeg_Binding;

// We could use NS_IMPL_CYCLE_COLLECTION(, except that in Unlink() we need to
// clear our list'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(DOMSVGPathSeg)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DOMSVGPathSeg)
  // We may not belong to a list, so we must null check tmp->mList.
  if (tmp->mList) {
    tmp->mList->ItemAt(tmp->mListIndex) = nullptr;
  }
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mList)
  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(DOMSVGPathSeg)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mList)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(DOMSVGPathSeg)
  NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_TRACE_END

NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(DOMSVGPathSeg, AddRef)
NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(DOMSVGPathSeg, Release)

//----------------------------------------------------------------------
// Helper class: AutoChangePathSegNotifier
// Stack-based helper class to pair calls to WillChangePathSegList
// and DidChangePathSegList.
class MOZ_RAII AutoChangePathSegNotifier {
 public:
  explicit AutoChangePathSegNotifier(
      DOMSVGPathSeg* aPathSeg MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : mPathSeg(aPathSeg) {
    MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    MOZ_ASSERT(mPathSeg, "Expecting non-null pathSeg");
    MOZ_ASSERT(mPathSeg->HasOwner(),
               "Expecting list to have an owner for notification");
    mEmptyOrOldValue = mPathSeg->Element()->WillChangePathSegList();
  }

  ~AutoChangePathSegNotifier() {
    mPathSeg->Element()->DidChangePathSegList(mEmptyOrOldValue);
    // Null check mPathSeg->mList, since DidChangePathSegList can run script,
    // potentially removing mPathSeg from its list.
    if (mPathSeg->mList && mPathSeg->mList->AttrIsAnimating()) {
      mPathSeg->Element()->AnimationNeedsResample();
    }
  }

 private:
  DOMSVGPathSeg* const mPathSeg;
  nsAttrValue mEmptyOrOldValue;
  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

DOMSVGPathSeg::DOMSVGPathSeg(DOMSVGPathSegList* aList, uint32_t aListIndex,
                             bool aIsAnimValItem)
    : mList(aList), mListIndex(aListIndex), mIsAnimValItem(aIsAnimValItem) {
  // These shifts are in sync with the members in the header.
  MOZ_ASSERT(aList && aListIndex <= MaxListIndex(), "bad arg");

  MOZ_ASSERT(IndexIsValid(), "Bad index for DOMSVGPathSeg!");
}

DOMSVGPathSeg::DOMSVGPathSeg()
    : mList(nullptr), mListIndex(0), mIsAnimValItem(false) {}

void DOMSVGPathSeg::InsertingIntoList(DOMSVGPathSegList* aList,
                                      uint32_t aListIndex,
                                      bool aIsAnimValItem) {
  MOZ_ASSERT(!HasOwner(), "Inserting item that is already in a list");

  mList = aList;
  mListIndex = aListIndex;
  mIsAnimValItem = aIsAnimValItem;

  MOZ_ASSERT(IndexIsValid(), "Bad index for DOMSVGPathSeg!");
}

void DOMSVGPathSeg::RemovingFromList() {
  uint32_t argCount = SVGPathSegUtils::ArgCountForType(Type());
  // InternalItem() + 1, because the args come after the encoded seg type
  memcpy(PtrToMemberArgs(), InternalItem() + 1, argCount * sizeof(float));
  mList = nullptr;
  mIsAnimValItem = false;
}

void DOMSVGPathSeg::ToSVGPathSegEncodedData(float* aRaw) {
  MOZ_ASSERT(aRaw, "null pointer");
  uint32_t argCount = SVGPathSegUtils::ArgCountForType(Type());
  if (IsInList()) {
    // 1 + argCount, because we're copying the encoded seg type and args
    memcpy(aRaw, InternalItem(), (1 + argCount) * sizeof(float));
  } else {
    aRaw[0] = SVGPathSegUtils::EncodeType(Type());
    // aRaw + 1, because the args go after the encoded seg type
    memcpy(aRaw + 1, PtrToMemberArgs(), argCount * sizeof(float));
  }
}

float* DOMSVGPathSeg::InternalItem() {
  uint32_t dataIndex = mList->mItems[mListIndex].mInternalDataIndex;
  return &(mList->InternalList().mData[dataIndex]);
}

#ifdef DEBUG
bool DOMSVGPathSeg::IndexIsValid() {
  SVGAnimatedPathSegList* alist = Element()->GetAnimPathSegList();
  return (mIsAnimValItem && mListIndex < alist->GetAnimValue().CountItems()) ||
         (!mIsAnimValItem && mListIndex < alist->GetBaseValue().CountItems());
}
#endif

////////////////////////////////////////////////////////////////////////
// Implementation of DOMSVGPathSeg sub-classes below this point

#define IMPL_PROP_WITH_TYPE(segName, propName, index, type)             \
  type DOMSVGPathSeg##segName::propName() {                             \
    if (mIsAnimValItem && HasOwner()) {                                 \
      Element()->FlushAnimations(); /* May make HasOwner() == false */  \
    }                                                                   \
    return type(HasOwner() ? InternalItem()[1 + index] : mArgs[index]); \
  }                                                                     \
  void DOMSVGPathSeg##segName::Set##propName(type a##propName,          \
                                             ErrorResult& rv) {         \
    if (mIsAnimValItem) {                                               \
      rv.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);               \
      return;                                                           \
    }                                                                   \
    if (HasOwner()) {                                                   \
      if (InternalItem()[1 + index] == float(a##propName)) {            \
        return;                                                         \
      }                                                                 \
      AutoChangePathSegNotifier notifier(this);                         \
      InternalItem()[1 + index] = float(a##propName);                   \
    } else {                                                            \
      mArgs[index] = float(a##propName);                                \
    }                                                                   \
  }

// For float, the normal type of arguments
#define IMPL_FLOAT_PROP(segName, propName, index) \
  IMPL_PROP_WITH_TYPE(segName, propName, index, float)

// For the boolean flags in arc commands
#define IMPL_BOOL_PROP(segName, propName, index) \
  IMPL_PROP_WITH_TYPE(segName, propName, index, bool)

///////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(MovetoAbs, X, 0)
IMPL_FLOAT_PROP(MovetoAbs, Y, 1)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(MovetoRel, X, 0)
IMPL_FLOAT_PROP(MovetoRel, Y, 1)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(LinetoAbs, X, 0)
IMPL_FLOAT_PROP(LinetoAbs, Y, 1)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(LinetoRel, X, 0)
IMPL_FLOAT_PROP(LinetoRel, Y, 1)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(CurvetoCubicAbs, X1, 0)
IMPL_FLOAT_PROP(CurvetoCubicAbs, Y1, 1)
IMPL_FLOAT_PROP(CurvetoCubicAbs, X2, 2)
IMPL_FLOAT_PROP(CurvetoCubicAbs, Y2, 3)
IMPL_FLOAT_PROP(CurvetoCubicAbs, X, 4)
IMPL_FLOAT_PROP(CurvetoCubicAbs, Y, 5)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(CurvetoCubicRel, X1, 0)
IMPL_FLOAT_PROP(CurvetoCubicRel, Y1, 1)
IMPL_FLOAT_PROP(CurvetoCubicRel, X2, 2)
IMPL_FLOAT_PROP(CurvetoCubicRel, Y2, 3)
IMPL_FLOAT_PROP(CurvetoCubicRel, X, 4)
IMPL_FLOAT_PROP(CurvetoCubicRel, Y, 5)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(CurvetoQuadraticAbs, X1, 0)
IMPL_FLOAT_PROP(CurvetoQuadraticAbs, Y1, 1)
IMPL_FLOAT_PROP(CurvetoQuadraticAbs, X, 2)
IMPL_FLOAT_PROP(CurvetoQuadraticAbs, Y, 3)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(CurvetoQuadraticRel, X1, 0)
IMPL_FLOAT_PROP(CurvetoQuadraticRel, Y1, 1)
IMPL_FLOAT_PROP(CurvetoQuadraticRel, X, 2)
IMPL_FLOAT_PROP(CurvetoQuadraticRel, Y, 3)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(ArcAbs, R1, 0)
IMPL_FLOAT_PROP(ArcAbs, R2, 1)
IMPL_FLOAT_PROP(ArcAbs, Angle, 2)
IMPL_BOOL_PROP(ArcAbs, LargeArcFlag, 3)
IMPL_BOOL_PROP(ArcAbs, SweepFlag, 4)
IMPL_FLOAT_PROP(ArcAbs, X, 5)
IMPL_FLOAT_PROP(ArcAbs, Y, 6)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(ArcRel, R1, 0)
IMPL_FLOAT_PROP(ArcRel, R2, 1)
IMPL_FLOAT_PROP(ArcRel, Angle, 2)
IMPL_BOOL_PROP(ArcRel, LargeArcFlag, 3)
IMPL_BOOL_PROP(ArcRel, SweepFlag, 4)
IMPL_FLOAT_PROP(ArcRel, X, 5)
IMPL_FLOAT_PROP(ArcRel, Y, 6)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(LinetoHorizontalAbs, X, 0)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(LinetoHorizontalRel, X, 0)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(LinetoVerticalAbs, Y, 0)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(LinetoVerticalRel, Y, 0)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(CurvetoCubicSmoothAbs, X2, 0)
IMPL_FLOAT_PROP(CurvetoCubicSmoothAbs, Y2, 1)
IMPL_FLOAT_PROP(CurvetoCubicSmoothAbs, X, 2)
IMPL_FLOAT_PROP(CurvetoCubicSmoothAbs, Y, 3)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(CurvetoCubicSmoothRel, X2, 0)
IMPL_FLOAT_PROP(CurvetoCubicSmoothRel, Y2, 1)
IMPL_FLOAT_PROP(CurvetoCubicSmoothRel, X, 2)
IMPL_FLOAT_PROP(CurvetoCubicSmoothRel, Y, 3)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(CurvetoQuadraticSmoothAbs, X, 0)
IMPL_FLOAT_PROP(CurvetoQuadraticSmoothAbs, Y, 1)

////////////////////////////////////////////////////////////////////////

IMPL_FLOAT_PROP(CurvetoQuadraticSmoothRel, X, 0)
IMPL_FLOAT_PROP(CurvetoQuadraticSmoothRel, Y, 1)

// This must come after DOMSVGPathSegClosePath et. al. have been declared.
/* static */
DOMSVGPathSeg* DOMSVGPathSeg::CreateFor(DOMSVGPathSegList* aList,
                                        uint32_t aListIndex,
                                        bool aIsAnimValItem) {
  uint32_t dataIndex = aList->mItems[aListIndex].mInternalDataIndex;
  float* data = &aList->InternalList().mData[dataIndex];
  uint32_t type = SVGPathSegUtils::DecodeType(data[0]);

  switch (type) {
    case PATHSEG_CLOSEPATH:
      return new DOMSVGPathSegClosePath(aList, aListIndex, aIsAnimValItem);
    case PATHSEG_MOVETO_ABS:
      return new DOMSVGPathSegMovetoAbs(aList, aListIndex, aIsAnimValItem);
    case PATHSEG_MOVETO_REL:
      return new DOMSVGPathSegMovetoRel(aList, aListIndex, aIsAnimValItem);
    case PATHSEG_LINETO_ABS:
      return new DOMSVGPathSegLinetoAbs(aList, aListIndex, aIsAnimValItem);
    case PATHSEG_LINETO_REL:
      return new DOMSVGPathSegLinetoRel(aList, aListIndex, aIsAnimValItem);
    case PATHSEG_CURVETO_CUBIC_ABS:
      return new DOMSVGPathSegCurvetoCubicAbs(aList, aListIndex,
                                              aIsAnimValItem);
    case PATHSEG_CURVETO_CUBIC_REL:
      return new DOMSVGPathSegCurvetoCubicRel(aList, aListIndex,
                                              aIsAnimValItem);
    case PATHSEG_CURVETO_QUADRATIC_ABS:
      return new DOMSVGPathSegCurvetoQuadraticAbs(aList, aListIndex,
                                                  aIsAnimValItem);
    case PATHSEG_CURVETO_QUADRATIC_REL:
      return new DOMSVGPathSegCurvetoQuadraticRel(aList, aListIndex,
                                                  aIsAnimValItem);
    case PATHSEG_ARC_ABS:
      return new DOMSVGPathSegArcAbs(aList, aListIndex, aIsAnimValItem);
    case PATHSEG_ARC_REL:
      return new DOMSVGPathSegArcRel(aList, aListIndex, aIsAnimValItem);
    case PATHSEG_LINETO_HORIZONTAL_ABS:
      return new DOMSVGPathSegLinetoHorizontalAbs(aList, aListIndex,
                                                  aIsAnimValItem);
    case PATHSEG_LINETO_HORIZONTAL_REL:
      return new DOMSVGPathSegLinetoHorizontalRel(aList, aListIndex,
                                                  aIsAnimValItem);
    case PATHSEG_LINETO_VERTICAL_ABS:
      return new DOMSVGPathSegLinetoVerticalAbs(aList, aListIndex,
                                                aIsAnimValItem);
    case PATHSEG_LINETO_VERTICAL_REL:
      return new DOMSVGPathSegLinetoVerticalRel(aList, aListIndex,
                                                aIsAnimValItem);
    case PATHSEG_CURVETO_CUBIC_SMOOTH_ABS:
      return new DOMSVGPathSegCurvetoCubicSmoothAbs(aList, aListIndex,
                                                    aIsAnimValItem);
    case PATHSEG_CURVETO_CUBIC_SMOOTH_REL:
      return new DOMSVGPathSegCurvetoCubicSmoothRel(aList, aListIndex,
                                                    aIsAnimValItem);
    case PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS:
      return new DOMSVGPathSegCurvetoQuadraticSmoothAbs(aList, aListIndex,
                                                        aIsAnimValItem);
    case PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL:
      return new DOMSVGPathSegCurvetoQuadraticSmoothRel(aList, aListIndex,
                                                        aIsAnimValItem);
    default:
      MOZ_ASSERT_UNREACHABLE("Invalid path segment type");
      return nullptr;
  }
}

}  // namespace mozilla