Bug 1564128 part 1 - Add clone function for Animation and constructor for KeyframeEffect to copy properties but not the target. r=hiro

This is needed for copying animations from an original document to a static
clone during printing/print preview.

Differential Revision: https://phabricator.services.mozilla.com/D73139

dom/animation/Animation.cpp

@@ -83,6 +83,37 @@ class MOZ_RAII AutoMutationBatchForAnimation {
 //
 // ---------------------------------------------------------------------------
 
+/* static */
+already_AddRefed<Animation> Animation::ClonePausedAnimation(
+    nsIGlobalObject* aGlobal, const Animation& aOther, AnimationEffect& aEffect,
+    AnimationTimeline& aTimeline) {
+  RefPtr<Animation> animation = new Animation(aGlobal);
+  // Setup the timing.
+  animation->mTimeline = &aTimeline;
+  const Nullable<TimeDuration> timelineTime =
+      aTimeline.GetCurrentTimeAsDuration();
+  MOZ_ASSERT(!timelineTime.IsNull(), "Timeline not yet set");
+
+  const Nullable<TimeDuration> currentTime = aOther.GetCurrentTimeAsDuration();
+  animation->mHoldTime = currentTime;
+  if (!currentTime.IsNull()) {
+    animation->mPreviousCurrentTime = timelineTime;
+  }
+
+  animation->mPlaybackRate = aOther.mPlaybackRate;
+
+  // Setup the effect's link to this.
+  animation->mEffect = &aEffect;
+  animation->mEffect->SetAnimation(animation);
+
+  // We expect our relevance to be the same as the orginal.
+  animation->mIsRelevant = aOther.mIsRelevant;
+
+  animation->PostUpdate();
+  animation->mTimeline->NotifyAnimationUpdated(*animation);
+  return animation.forget();
+}
+
 NonOwningAnimationTarget Animation::GetTargetForAnimation() const {
   AnimationEffect* effect = GetEffect();
   NonOwningAnimationTarget target;

dom/animation/Animation.h

@@ -50,6 +50,14 @@ class Animation : public DOMEventTargetHelper,
   explicit Animation(nsIGlobalObject* aGlobal)
       : DOMEventTargetHelper(aGlobal), mAnimationIndex(sNextAnimationIndex++) {}
 
+  // Constructs a copy of |aOther| with a new effect and timeline.
+  // This is only intended to be used while making a static clone of a document
+  // during printing, and does not assume that |aOther| is in the same document
+  // as any of the other arguments.
+  static already_AddRefed<Animation> ClonePausedAnimation(
+      nsIGlobalObject* aGlobal, const Animation& aOther,
+      AnimationEffect& aEffect, AnimationTimeline& aTimeline);
+
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(Animation, DOMEventTargetHelper)
 

dom/animation/KeyframeEffect.cpp

@@ -90,8 +90,22 @@ KeyframeEffect::KeyframeEffect(Document* aDocument,
                                const KeyframeEffectParams& aOptions)
     : AnimationEffect(aDocument, std::move(aTiming)),
       mTarget(std::move(aTarget)),
-      mEffectOptions(aOptions),
-      mCumulativeChangeHint(nsChangeHint(0)) {}
+      mEffectOptions(aOptions) {}
+
+KeyframeEffect::KeyframeEffect(Document* aDocument,
+                               OwningAnimationTarget&& aTarget,
+                               const KeyframeEffect& aOther)
+    : AnimationEffect(aDocument, TimingParams{aOther.SpecifiedTiming()}),
+      mTarget(std::move(aTarget)),
+      mEffectOptions{aOther.IterationComposite(), aOther.Composite(),
+                     mTarget.mPseudoType},
+      mKeyframes(aOther.mKeyframes.Clone()),
+      mProperties(aOther.mProperties.Clone()),
+      mBaseValues(aOther.mBaseValues.Count()) {
+  for (auto iter = aOther.mBaseValues.ConstIter(); !iter.Done(); iter.Next()) {
+    mBaseValues.Put(iter.Key(), RefPtr{iter.Data()});
+  }
+}
 
 JSObject* KeyframeEffect::WrapObject(JSContext* aCx,
                                      JS::Handle<JSObject*> aGivenProto) {
@@ -1033,23 +1047,12 @@ already_AddRefed<KeyframeEffect> KeyframeEffect::Constructor(
   // aSource's TimingParams.
   // Note: we don't need to re-throw exceptions since the value specified on
   //       aSource's timing object can be assumed valid.
-  RefPtr<KeyframeEffect> effect = new KeyframeEffect(
-      doc, OwningAnimationTarget(aSource.mTarget),
-      TimingParams(aSource.SpecifiedTiming()), aSource.mEffectOptions);
+  RefPtr<KeyframeEffect> effect =
+      new KeyframeEffect(doc, OwningAnimationTarget{aSource.mTarget}, aSource);
   // Copy cumulative change hint. mCumulativeChangeHint should be the same as
   // the source one because both of targets are the same.
   effect->mCumulativeChangeHint = aSource.mCumulativeChangeHint;
 
-  // Copy aSource's keyframes and animation properties.
-  // Note: We don't call SetKeyframes directly, which might revise the
-  //       computed offsets and rebuild the animation properties.
-  effect->mKeyframes = aSource.mKeyframes.Clone();
-  effect->mProperties = aSource.mProperties.Clone();
-  for (auto iter = aSource.mBaseValues.ConstIter(); !iter.Done(); iter.Next()) {
-    // XXX Should this use non-const Iter() and then pass
-    // std::move(iter.Data())? Otherwise aSource might be a const&...
-    effect->mBaseValues.Put(iter.Key(), RefPtr{iter.Data()});
-  }
   return effect.forget();
 }
 

dom/animation/KeyframeEffect.h

@@ -111,6 +111,9 @@ class KeyframeEffect : public AnimationEffect {
   KeyframeEffect(Document* aDocument, OwningAnimationTarget&& aTarget,
                  TimingParams&& aTiming, const KeyframeEffectParams& aOptions);
 
+  KeyframeEffect(Document* aDocument, OwningAnimationTarget&& aTarget,
+                 const KeyframeEffect& aOther);
+
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(KeyframeEffect,
                                                          AnimationEffect)
@@ -454,7 +457,7 @@ class KeyframeEffect : public AnimationEffect {
   BaseValuesHashmap mBaseValues;
 
  private:
-  nsChangeHint mCumulativeChangeHint;
+  nsChangeHint mCumulativeChangeHint = nsChangeHint{0};
 
   void ComposeStyleRule(RawServoAnimationValueMap& aAnimationValues,
                         const AnimationProperty& aProperty,