gecko/dom/animation/AnimationPlayer.cpp

/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* 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 "AnimationPlayer.h"
#include "AnimationUtils.h"
#include "mozilla/dom/AnimationPlayerBinding.h"
#include "AnimationCommon.h" // For AnimationPlayerCollection,
                             // CommonAnimationManager
#include "nsIDocument.h" // For nsIDocument
#include "nsIPresShell.h" // For nsIPresShell
#include "nsLayoutUtils.h" // For PostRestyleEvent (remove after bug 1073336)
#include "PendingPlayerTracker.h" // For PendingPlayerTracker

namespace mozilla {
namespace dom {

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(AnimationPlayer, mTimeline,
                                      mSource, mReady)
NS_IMPL_CYCLE_COLLECTING_ADDREF(AnimationPlayer)
NS_IMPL_CYCLE_COLLECTING_RELEASE(AnimationPlayer)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(AnimationPlayer)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

JSObject*
AnimationPlayer::WrapObject(JSContext* aCx)
{
  return dom::AnimationPlayerBinding::Wrap(aCx, this);
}

Nullable<TimeDuration>
AnimationPlayer::GetCurrentTime() const
{
  Nullable<TimeDuration> result;
  if (!mHoldTime.IsNull()) {
    result = mHoldTime;
    return result;
  }

  if (!mStartTime.IsNull()) {
    Nullable<TimeDuration> timelineTime = mTimeline->GetCurrentTime();
    if (!timelineTime.IsNull()) {
      result.SetValue(timelineTime.Value() - mStartTime.Value());
    }
  }
  return result;
}

AnimationPlayState
AnimationPlayer::PlayState() const
{
  if (mIsPending) {
    return AnimationPlayState::Pending;
  }

  Nullable<TimeDuration> currentTime = GetCurrentTime();
  if (currentTime.IsNull()) {
    return AnimationPlayState::Idle;
  }

  if (mStartTime.IsNull()) {
    return AnimationPlayState::Paused;
  }

  if (currentTime.Value() >= SourceContentEnd()) {
    return AnimationPlayState::Finished;
  }

  return AnimationPlayState::Running;
}

Promise*
AnimationPlayer::GetReady(ErrorResult& aRv)
{
  // Lazily create the ready promise if it doesn't exist
  if (!mReady) {
    nsIGlobalObject* global = mTimeline->GetParentObject();
    if (global) {
      mReady = Promise::Create(global, aRv);
      // The ready promise should be initially resolved
      if (mReady) {
        mReady->MaybeResolve(this);
      }
    }
  }
  if (!mReady) {
    aRv.Throw(NS_ERROR_FAILURE);
  }

  return mReady;
}

void
AnimationPlayer::Play()
{
  DoPlay();
  PostUpdate();
}

void
AnimationPlayer::Pause()
{
  DoPause();
  PostUpdate();
}

Nullable<double>
AnimationPlayer::GetStartTimeAsDouble() const
{
  return AnimationUtils::TimeDurationToDouble(mStartTime);
}

Nullable<double>
AnimationPlayer::GetCurrentTimeAsDouble() const
{
  return AnimationUtils::TimeDurationToDouble(GetCurrentTime());
}

void
AnimationPlayer::SetSource(Animation* aSource)
{
  if (mSource) {
    mSource->SetParentTime(Nullable<TimeDuration>());
  }
  mSource = aSource;
  if (mSource) {
    mSource->SetParentTime(GetCurrentTime());
  }
}

void
AnimationPlayer::Tick()
{
  if (mSource) {
    mSource->SetParentTime(GetCurrentTime());
  }
}

void
AnimationPlayer::ResolveStartTime()
{
  // Currently we only expect this method to be called when we are in the
  // middle of initiating/resuming playback so we should have an unresolved
  // start time to update and a fixed current time to seek to.
  MOZ_ASSERT(mStartTime.IsNull() && !mHoldTime.IsNull(),
             "Resolving the start time but we don't appear to be waiting"
             " to begin playback");

  Nullable<TimeDuration> readyTime = mTimeline->GetCurrentTime();
  // Bug 1096776: Once we support disappearing or inactive timelines we
  // will need special handling here.
  MOZ_ASSERT(!readyTime.IsNull(), "Missing or inactive timeline");
  mStartTime.SetValue(readyTime.Value() - mHoldTime.Value());
  mHoldTime.SetNull();

  if (mReady) {
    mReady->MaybeResolve(this);
  }
}

bool
AnimationPlayer::IsRunning() const
{
  if (IsPaused() || !GetSource() || GetSource()->IsFinishedTransition()) {
    return false;
  }

  ComputedTiming computedTiming = GetSource()->GetComputedTiming();
  return computedTiming.mPhase == ComputedTiming::AnimationPhase_Active;
}

bool
AnimationPlayer::CanThrottle() const
{
  if (!mSource ||
      mSource->IsFinishedTransition() ||
      mSource->Properties().IsEmpty()) {
    return true;
  }

  if (!mIsRunningOnCompositor) {
    return false;
  }

  if (PlayState() != AnimationPlayState::Finished) {
    // Unfinished animations can be throttled.
    return true;
  }

  // The animation has finished but, if this is the first sample since
  // finishing, we need an unthrottled sample so we can apply the correct
  // end-of-animation behavior on the main thread (either removing the
  // animation style or applying the fill mode).
  return mIsPreviousStateFinished;
}

void
AnimationPlayer::ComposeStyle(nsRefPtr<css::AnimValuesStyleRule>& aStyleRule,
                              nsCSSPropertySet& aSetProperties,
                              bool& aNeedsRefreshes)
{
  if (!mSource || mSource->IsFinishedTransition()) {
    return;
  }

  AnimationPlayState playState = PlayState();
  if (playState == AnimationPlayState::Running ||
      playState == AnimationPlayState::Pending) {
    aNeedsRefreshes = true;
  }

  mSource->ComposeStyle(aStyleRule, aSetProperties);

  mIsPreviousStateFinished = (playState == AnimationPlayState::Finished);
}

void
AnimationPlayer::DoPlay()
{
  // FIXME: When we implement finishing behavior (bug 1074630) we will
  // need to pass a flag so that when we start playing due to a change in
  // animation-play-state we *don't* trigger finishing behavior.

  Nullable<TimeDuration> currentTime = GetCurrentTime();
  if (currentTime.IsNull()) {
    mHoldTime.SetValue(TimeDuration(0));
  } else if (mHoldTime.IsNull()) {
    // If the hold time is null, we are already playing normally
    return;
  }

  // Create a new pending ready promise
  nsIGlobalObject* global = mTimeline->GetParentObject();
  if (global) {
    ErrorResult rv;
    mReady = Promise::Create(global, rv);
  }

  ResolveStartTime();
}

void
AnimationPlayer::DoPause()
{
  if (IsPaused()) {
    return;
  }
  // Mark this as no longer running on the compositor so that next time
  // we update animations we won't throttle them and will have a chance
  // to remove the animation from any layer it might be on.
  mIsRunningOnCompositor = false;

  // Bug 927349 - check for null result here and go to pending state
  mHoldTime = GetCurrentTime();
  mStartTime.SetNull();
}

void
AnimationPlayer::FlushStyle() const
{
  nsIDocument* doc = GetRenderedDocument();
  if (doc) {
    doc->FlushPendingNotifications(Flush_Style);
  }
}

void
AnimationPlayer::PostUpdate()
{
  AnimationPlayerCollection* collection = GetCollection();
  if (collection) {
    collection->NotifyPlayerUpdated();
  }
}

StickyTimeDuration
AnimationPlayer::SourceContentEnd() const
{
  if (!mSource) {
    return StickyTimeDuration(0);
  }

  return mSource->Timing().mDelay
         + mSource->GetComputedTiming().mActiveDuration;
}

nsIDocument*
AnimationPlayer::GetRenderedDocument() const
{
  if (!mSource) {
    return nullptr;
  }

  Element* targetElement;
  nsCSSPseudoElements::Type pseudoType;
  mSource->GetTarget(targetElement, pseudoType);
  if (!targetElement) {
    return nullptr;
  }

  return targetElement->GetComposedDoc();
}

nsPresContext*
AnimationPlayer::GetPresContext() const
{
  nsIDocument* doc = GetRenderedDocument();
  if (!doc) {
    return nullptr;
  }
  nsIPresShell* shell = doc->GetShell();
  if (!shell) {
    return nullptr;
  }
  return shell->GetPresContext();
}

AnimationPlayerCollection*
AnimationPlayer::GetCollection() const
{
  css::CommonAnimationManager* manager = GetAnimationManager();
  if (!manager) {
    return nullptr;
  }
  MOZ_ASSERT(mSource, "A player with an animation manager must have a source");

  Element* targetElement;
  nsCSSPseudoElements::Type targetPseudoType;
  mSource->GetTarget(targetElement, targetPseudoType);
  MOZ_ASSERT(targetElement,
             "A player with an animation manager must have a target");

  return manager->GetAnimationPlayers(targetElement, targetPseudoType, false);
}

} // namespace dom
} // namespace mozilla