Replace AnimatableValues with ComputedStyle references for CSS Transitions

third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 627 matching lines @@
   // applyMatchedProperties system.
   if (state.update.ActiveInterpolationsForAnimations().Contains(property) ||
       (state.animating_element->GetElementAnimations() &&
        state.animating_element->GetElementAnimations()
            ->CssAnimations()
            .previous_active_interpolations_for_animations_.Contains(
                property))) {
     return;
   }
 
-  RefPtr<AnimatableValue> to = nullptr;
   const RunningTransition* interrupted_transition = nullptr;
   if (state.active_transitions) {
     TransitionMap::const_iterator active_transition_iter =
         state.active_transitions->find(property);
     if (active_transition_iter != state.active_transitions->end()) {
       const RunningTransition* running_transition =
           &active_transition_iter->value;
-      to = CSSAnimatableValueFactory::Create(property, state.style);
-      const AnimatableValue* active_to = running_transition->to.Get();
-      if (to->Equals(active_to))
+      if (CSSPropertyEquality::PropertiesEqual(property, state.style,
+                                               *running_transition->to)) {
         return;
+      }
       state.update.CancelTransition(property);
       DCHECK(!state.animating_element->GetElementAnimations() ||
              !state.animating_element->GetElementAnimations()
                   ->IsAnimationStyleChange());
 
-      if (to->Equals(
-              running_transition->reversing_adjusted_start_value.Get())) {
+      if (CSSPropertyEquality::PropertiesEqual(
+              property, state.style,
+              *running_transition->reversing_adjusted_start_value)) {
         interrupted_transition = running_transition;
       }
     }
   }
 
   const PropertyRegistry* registry =
       state.animating_element->GetDocument().GetPropertyRegistry();
-
   if (property.IsCSSCustomProperty()) {
-    if (!registry || !registry->Registration(property.CustomPropertyName()) ||
-        CSSPropertyEquality::RegisteredCustomPropertiesEqual(
-            property.CustomPropertyName(), state.old_style, state.style)) {
+    if (!registry || !registry->Registration(property.CustomPropertyName())) {
       return;
     }
-  } else if (CSSPropertyEquality::PropertiesEqual(
-                 property.CssProperty(), state.old_style, state.style)) {
+  }
+
+  if (CSSPropertyEquality::PropertiesEqual(property, state.old_style,
+                                           state.style)) {
     return;
   }
 
-  if (!to)
-    to = CSSAnimatableValueFactory::Create(property, state.style);
-  RefPtr<AnimatableValue> from =
-      CSSAnimatableValueFactory::Create(property, state.old_style);
-
   CSSInterpolationTypesMap map(registry);
   InterpolationEnvironment old_environment(map, state.old_style);
   InterpolationEnvironment new_environment(map, state.style);
   InterpolationValue start = nullptr;
   InterpolationValue end = nullptr;
   const InterpolationType* transition_type = nullptr;
   for (const auto& interpolation_type : map.Get(property)) {
     start = interpolation_type->MaybeConvertUnderlyingValue(old_environment);
     if (!start) {
       continue;
@@ skipping 22 matching lines @@
   if (timing.start_delay + timing.iteration_duration <= 0) {
     // We may have started a transition in a prior CSSTransitionData update,
     // this CSSTransitionData update needs to override them.
     // TODO(alancutter): Just iterate over the CSSTransitionDatas in reverse and
     // skip any properties that have already been visited so we don't need to
     // "undo" work like this.
     state.update.UnstartTransition(property);
     return;
   }
 
-  AnimatableValue* reversing_adjusted_start_value = from.Get();
+  const ComputedStyle* reversing_adjusted_start_value = &state.old_style;
   double reversing_shortening_factor = 1;
   if (interrupted_transition) {
     const double interrupted_progress =
         interrupted_transition->animation->effect()->Progress();
     if (!std::isnan(interrupted_progress)) {
       reversing_adjusted_start_value = interrupted_transition->to.Get();
       reversing_shortening_factor =
           clampTo((interrupted_progress *
                    interrupted_transition->reversing_shortening_factor) +
                       (1 - interrupted_transition->reversing_shortening_factor),
@@ skipping 34 matching lines @@
 
   RefPtr<TransitionKeyframe> end_keyframe =
       TransitionKeyframe::Create(property);
   end_keyframe->SetValue(TypedInterpolationValue::Create(
       *transition_type, end.interpolable_value->Clone(),
       end.non_interpolable_value));
   end_keyframe->SetOffset(1);
   keyframes.push_back(end_keyframe);
 
   if (CompositorAnimations::IsCompositableProperty(property.CssProperty())) {
+    RefPtr<AnimatableValue> from =
+        CSSAnimatableValueFactory::Create(property, state.old_style);
+    RefPtr<AnimatableValue> to =
+        CSSAnimatableValueFactory::Create(property, state.style);
     delay_keyframe->SetCompositorValue(from);
     start_keyframe->SetCompositorValue(from);
     end_keyframe->SetCompositorValue(to);
   }
 
   TransitionKeyframeEffectModel* model =
       TransitionKeyframeEffectModel::Create(keyframes);
-  state.update.StartTransition(property, from.Get(), to.Get(),
+  if (!state.cloned_style) {
+    state.cloned_style = ComputedStyle::Clone(state.style);

[Eric Willigers, 2017/05/24 05:43:58]

Why is safe to not always overwrite?

[alancutter (OOO until 2018), 2017/05/24 06:34:44]

This cloned style is shared between transitions that start at the same time for
the same element.

+  }
+  state.update.StartTransition(property, &state.old_style, state.cloned_style,
                                reversing_adjusted_start_value,
                                reversing_shortening_factor,
                                *InertEffect::Create(model, timing, false, 0));
   DCHECK(!state.animating_element->GetElementAnimations() ||
          !state.animating_element->GetElementAnimations()
               ->IsAnimationStyleChange());
 }
 
 void CSSAnimations::CalculateTransitionUpdateForCustomProperty(
     TransitionUpdateState& state,
@@ skipping 63 matching lines @@
 
   const bool animation_style_recalc =
       element_animations && element_animations->IsAnimationStyleChange();
 
   HashSet<PropertyHandle> listed_properties;
   bool any_transition_had_transition_all = false;
   const LayoutObject* layout_object = animating_element->GetLayoutObject();
   if (!animation_style_recalc && style.Display() != EDisplay::kNone &&
       layout_object && layout_object->Style() && transition_data) {
     TransitionUpdateState state = {
-        update,          animating_element,  *layout_object->Style(),
-        style,           active_transitions, listed_properties,
-        *transition_data};
+        update,  animating_element,  *layout_object->Style(), style,
+        nullptr, active_transitions, listed_properties,       *transition_data};

[Eric Willigers, 2017/05/24 05:43:58]

Why the spaces?

[alancutter (OOO until 2018), 2017/05/24 06:34:44]

This is what git cl format does.

 
     for (size_t transition_index = 0;
          transition_index < transition_data->PropertyList().size();
          ++transition_index) {
       const CSSTransitionData::TransitionProperty& transition_property =
           transition_data->PropertyList()[transition_index];
       if (transition_property.unresolved_property == CSSPropertyAll) {
         any_transition_had_transition_all = true;
       }
       if (property_pass == PropertyPass::kCustom) {
@@ skipping 338 matching lines @@
              IsCustomPropertyHandle);
 }
 
 DEFINE_TRACE(CSSAnimations) {
   visitor->Trace(transitions_);
   visitor->Trace(pending_update_);
   visitor->Trace(running_animations_);
 }
 
 }  // namespace blink