/* -*- 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 "nsSMILInstanceTime.h"

#include "nsSMILInterval.h"

#include "nsSMILTimeValueSpec.h"

#include "mozilla/AutoRestore.h"

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

// Implementation

nsSMILInstanceTime::nsSMILInstanceTime(const nsSMILTimeValue& aTime,

                                       nsSMILInstanceTimeSource aSource,

                                       nsSMILTimeValueSpec* aCreator,

                                       nsSMILInterval* aBaseInterval)

  : mTime(aTime),

    mFlags(0),

    mVisited(false),

    mFixedEndpointRefCnt(0),

    mSerial(0),

    mCreator(aCreator),

    mBaseInterval(nullptr) // This will get set to aBaseInterval in a call to

                          // SetBaseInterval() at end of constructor

{

  switch (aSource) {

    case SOURCE_NONE:

      // No special flags

      break;

    case SOURCE_DOM:

      mFlags = kDynamic | kFromDOM;

      break;

    case SOURCE_SYNCBASE:

      mFlags = kMayUpdate;

      break;

    case SOURCE_EVENT:

      mFlags = kDynamic;

      break;

  }

  SetBaseInterval(aBaseInterval);

}

nsSMILInstanceTime::~nsSMILInstanceTime()

{

  MOZ_ASSERT(!mBaseInterval,

             "Destroying instance time without first calling Unlink()");

  MOZ_ASSERT(mFixedEndpointRefCnt == 0,

             "Destroying instance time that is still used as the fixed "

             "endpoint of an interval");

}

void

nsSMILInstanceTime::Unlink()

{

  RefPtr<nsSMILInstanceTime> deathGrip(this);

  if (mBaseInterval) {

    mBaseInterval->RemoveDependentTime(*this);

    mBaseInterval = nullptr;

  }

  mCreator = nullptr;

}

void

nsSMILInstanceTime::HandleChangedInterval(

    const nsSMILTimeContainer* aSrcContainer,

    bool aBeginObjectChanged,

    bool aEndObjectChanged)

{

  // It's possible a sequence of notifications might cause our base interval to

  // be updated and then deleted. Furthermore, the delete might happen whilst

  // we're still in the queue to be notified of the change. In any case, if we

  // don't have a base interval, just ignore the change.

  if (!mBaseInterval)

    return;

  MOZ_ASSERT(mCreator, "Base interval is set but creator is not.");

  if (mVisited) {

    // Break the cycle here

    Unlink();

    return;

  }

  bool objectChanged = mCreator->DependsOnBegin() ? aBeginObjectChanged :

                                                      aEndObjectChanged;

  RefPtr<nsSMILInstanceTime> deathGrip(this);

  mozilla::AutoRestore<bool> setVisited(mVisited);

  mVisited = true;

  mCreator->HandleChangedInstanceTime(*GetBaseTime(), aSrcContainer, *this,

                                      objectChanged);

}

void

nsSMILInstanceTime::HandleDeletedInterval()

{

  MOZ_ASSERT(mBaseInterval,

             "Got call to HandleDeletedInterval on an independent instance "

             "time");

  MOZ_ASSERT(mCreator, "Base interval is set but creator is not");

  mBaseInterval = nullptr;

  mFlags &= ~kMayUpdate; // Can't update without a base interval

  RefPtr<nsSMILInstanceTime> deathGrip(this);

  mCreator->HandleDeletedInstanceTime(*this);

  mCreator = nullptr;

}

void

nsSMILInstanceTime::HandleFilteredInterval()

{

  MOZ_ASSERT(mBaseInterval,

             "Got call to HandleFilteredInterval on an independent instance "

             "time");

  mBaseInterval = nullptr;

  mFlags &= ~kMayUpdate; // Can't update without a base interval

  mCreator = nullptr;

}

bool

nsSMILInstanceTime::ShouldPreserve() const

{

  return mFixedEndpointRefCnt > 0 || (mFlags & kWasDynamicEndpoint);

}

void

nsSMILInstanceTime::UnmarkShouldPreserve()

{

  mFlags &= ~kWasDynamicEndpoint;

}

void

nsSMILInstanceTime::AddRefFixedEndpoint()

{

  MOZ_ASSERT(mFixedEndpointRefCnt < UINT16_MAX,

             "Fixed endpoint reference count upper limit reached");

  ++mFixedEndpointRefCnt;

  mFlags &= ~kMayUpdate; // Once fixed, always fixed

}

void

nsSMILInstanceTime::ReleaseFixedEndpoint()

{

  MOZ_ASSERT(mFixedEndpointRefCnt > 0, "Duplicate release");

  --mFixedEndpointRefCnt;

  if (mFixedEndpointRefCnt == 0 && IsDynamic()) {

    mFlags |= kWasDynamicEndpoint;

  }

}

bool

nsSMILInstanceTime::IsDependentOn(const nsSMILInstanceTime& aOther) const

{

  if (mVisited)

    return false;

  const nsSMILInstanceTime* myBaseTime = GetBaseTime();

  if (!myBaseTime)

    return false;

  if (myBaseTime == &aOther)

    return true;

  mozilla::AutoRestore<bool> setVisited(mVisited);

  mVisited = true;

  return myBaseTime->IsDependentOn(aOther);

}

const nsSMILInstanceTime*

nsSMILInstanceTime::GetBaseTime() const

{

  if (!mBaseInterval) {

    return nullptr;

  }

  MOZ_ASSERT(mCreator, "Base interval is set but there is no creator.");

  if (!mCreator) {

    return nullptr;

  }

  return mCreator->DependsOnBegin() ? mBaseInterval->Begin() :

                                      mBaseInterval->End();

}

void

nsSMILInstanceTime::SetBaseInterval(nsSMILInterval* aBaseInterval)

{

  MOZ_ASSERT(!mBaseInterval,

             "Attempting to reassociate an instance time with a different "

             "interval.");

  if (aBaseInterval) {

    MOZ_ASSERT(mCreator,

               "Attempting to create a dependent instance time without "

               "reference to the creating nsSMILTimeValueSpec object.");

    if (!mCreator)

      return;

    aBaseInterval->AddDependentTime(*this);

  }

  mBaseInterval = aBaseInterval;

}