Allows observers to be notified when layer animations complete.

ui/gfx/compositor/layer_animator.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/compositor/layer_animator.h"
 
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"

[sky, 2011/10/27 19:29:19]

don't need this since in header.

 #include "ui/base/animation/animation_container.h"
 #include "ui/gfx/compositor/compositor.h"
 #include "ui/gfx/compositor/layer.h"
-#include "ui/gfx/compositor/layer_animator_delegate.h"
+#include "ui/gfx/compositor/layer_animation_delegate.h"
+#include "ui/gfx/compositor/layer_animation_observer.h"
 #include "ui/gfx/compositor/layer_animation_sequence.h"
 
 namespace ui {
 
 class LayerAnimator;
 
 namespace {
 
 static const base::TimeDelta kDefaultTransitionDuration =
     base::TimeDelta::FromMilliseconds(200);
@@ skipping 24 matching lines @@
 
 // static
 LayerAnimator* LayerAnimator::CreateImplicitAnimator() {
   return new LayerAnimator(kDefaultTransitionDuration);
 }
 
 void LayerAnimator::SetTransform(const Transform& transform) {
   if (transition_duration_ == base::TimeDelta())
     delegate_->SetTransformFromAnimation(transform);
   else
-    StartAnimationElement(LayerAnimationElement::CreateTransformElement(
-        transform, transition_duration_));
+    StartAnimation(new LayerAnimationSequence(
+        LayerAnimationElement::CreateTransformElement(
+            transform, transition_duration_)));
 }
 
 Transform LayerAnimator::GetTargetTransform() const {
   LayerAnimationElement::TargetValue target;
   GetTargetValue(&target);
   return target.transform;
 }
 
 void LayerAnimator::SetBounds(const gfx::Rect& bounds) {
   if (transition_duration_ == base::TimeDelta())
     delegate_->SetBoundsFromAnimation(bounds);
   else
-    StartAnimationElement(LayerAnimationElement::CreateBoundsElement(
-        bounds, transition_duration_));
+    StartAnimation(new LayerAnimationSequence(
+        LayerAnimationElement::CreateBoundsElement(
+            bounds, transition_duration_)));
 }
 
 gfx::Rect LayerAnimator::GetTargetBounds() const {
   LayerAnimationElement::TargetValue target;
   GetTargetValue(&target);
   return target.bounds;
 }
 
 void LayerAnimator::SetOpacity(float opacity) {
   if (transition_duration_ == base::TimeDelta())
     delegate_->SetOpacityFromAnimation(opacity);
   else
-    StartAnimationElement(LayerAnimationElement::CreateOpacityElement(
-        opacity, transition_duration_));
+    StartAnimation(new LayerAnimationSequence(
+        LayerAnimationElement::CreateOpacityElement(
+            opacity, transition_duration_)));
 }
 
 float LayerAnimator::GetTargetOpacity() const {
   LayerAnimationElement::TargetValue target;
   GetTargetValue(&target);
   return target.opacity;
 }
 
-void LayerAnimator::SetDelegate(LayerAnimatorDelegate* delegate) {
+void LayerAnimator::SetDelegate(LayerAnimationDelegate* delegate) {
   DCHECK(delegate);
   delegate_ = delegate;
 }
 
 void LayerAnimator::StartAnimation(LayerAnimationSequence* animation) {
+  AddObserversToSequence(animation);
   if (!StartSequenceImmediately(animation)) {
     // Attempt to preempt a running animation.
     switch (preemption_strategy_) {
       case IMMEDIATELY_SET_NEW_TARGET:
         ImmediatelySetNewTarget(animation);
         break;
       case IMMEDIATELY_ANIMATE_TO_NEW_TARGET:
         ImmediatelyAnimateToNewTarget(animation);
         break;
       case ENQUEUE_NEW_ANIMATION:
         EnqueueNewAnimation(animation);
         break;
       case REPLACE_QUEUED_ANIMATIONS:
         ReplaceQueuedAnimations(animation);
         break;
       case BLEND_WITH_CURRENT_ANIMATION: {
         // TODO(vollick) Add support for blended sequences and use them here.
         NOTIMPLEMENTED();
         break;
       }
     }
   }
   FinishAnyAnimationWithZeroDuration();
   UpdateAnimationState();
 }
 
 void LayerAnimator::ScheduleAnimation(LayerAnimationSequence* animation) {
+  AddObserversToSequence(animation);
   if (is_animating()) {
     animation_queue_.push_back(make_linked_ptr(animation));
     ProcessQueue();
   } else {
     StartSequenceImmediately(animation);
   }
   UpdateAnimationState();
 }
 
 void LayerAnimator::ScheduleTogether(
@@ skipping 16 matching lines @@
 
   // These animations (provided they don't animate any common properties) will
   // now animate together if trivially scheduled.
   for (iter = animations.begin(); iter != animations.end(); ++iter) {
     ScheduleAnimation(*iter);
   }
 
   UpdateAnimationState();
 }
 
-void LayerAnimator::StartAnimationElement(LayerAnimationElement* animation) {
-  StartAnimation(new LayerAnimationSequence(animation));
-}
-
-void LayerAnimator::ScheduleAnimationElement(LayerAnimationElement* animation) {
-  ScheduleAnimation(new LayerAnimationSequence(animation));
-}
-
-void LayerAnimator::ScheduleElementsTogether(
-    const std::vector<LayerAnimationElement*>& animations) {
-  std::vector<LayerAnimationSequence*> sequences;
-  for (size_t i = 0; i < animations.size(); ++i)
-    sequences.push_back(new LayerAnimationSequence(animations[i]));
-  ScheduleTogether(sequences);
-}
-
 void LayerAnimator::StopAnimatingProperty(
     LayerAnimationElement::AnimatableProperty property) {
   while (true) {
     RunningAnimation* running = GetRunningAnimation(property);
     if (!running)
       break;
     FinishAnimation(running->sequence);
   }
 }
 
 void LayerAnimator::StopAnimating() {
   while (is_animating())
     FinishAnimation(running_animations_[0].sequence);
 }
 
+void LayerAnimator::AddObserver(LayerAnimationObserver* observer) {
+  if (!observers_.HasObserver(observer))
+    observers_.AddObserver(observer);
+}
+
+void LayerAnimator::RemoveObserver(LayerAnimationObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 LayerAnimator::ScopedSettings::ScopedSettings(LayerAnimator* animator)
     : animator_(animator),
       old_transition_duration_(animator->transition_duration_) {
   SetTransitionDuration(kDefaultTransitionDuration);
 }
 
 LayerAnimator::ScopedSettings::~ScopedSettings() {
   animator_->transition_duration_ = old_transition_duration_;
+  for (size_t i = 0; i < observers_.size(); ++i)
+    animator_->RemoveObserver(observers_[i]);
+}
+
+void LayerAnimator::ScopedSettings::AddObserver(
+    LayerAnimationObserver* observer) {
+  observers_.push_back(observer);
+  animator_->AddObserver(observer);

[sky, 2011/10/27 19:29:19]

I believe this means the observer is notified of every sequence created.
Shouldn't it just be the last one that gets created?

 }
 
 void LayerAnimator::ScopedSettings::SetTransitionDuration(
     base::TimeDelta duration) {
   animator_->transition_duration_ = duration;
 }
 
 // LayerAnimator private -------------------------------------------------------
 
 void LayerAnimator::Step(base::TimeTicks now) {
@@ skipping 56 matching lines @@
        queue_iter != animation_queue_.end(); ++queue_iter) {
     if ((*queue_iter) == sequence) {
       animation_queue_.erase(queue_iter);
       break;
     }
   }
 }
 
 void LayerAnimator::FinishAnimation(LayerAnimationSequence* sequence) {
   sequence->Progress(sequence->duration(), delegate());
-  delegate()->OnLayerAnimationEnded(sequence);
+  NotifyAnimationEnded(sequence);
   RemoveAnimation(sequence);
   ProcessQueue();
   UpdateAnimationState();
 }
 
 void LayerAnimator::FinishAnyAnimationWithZeroDuration() {
   // Special case: if we've started a 0 duration animation, just finish it now
   // and get rid of it. Note at each iteration of the loop, we either increment
   // i or remove an element from running_animations_, so
   // running_animations_.size() - i is always decreasing and we are always
   // progressing towards the termination of the loop.
   for (size_t i = 0; i < running_animations_.size();) {
     if (running_animations_[i].sequence->duration() == base::TimeDelta()) {
       running_animations_[i].sequence->Progress(
           running_animations_[i].sequence->duration(), delegate());
-      delegate()->OnLayerAnimationEnded(running_animations_[i].sequence);
+      NotifyAnimationEnded(running_animations_[i].sequence);

[sky, 2011/10/27 19:29:19]

Can't progress recognize it's at the end and notify observers itself?

       RemoveAnimation(running_animations_[i].sequence);
     } else {
       ++i;
     }
   }
   ProcessQueue();
   UpdateAnimationState();
 }
 
 void LayerAnimator::ClearAnimations() {
@@ skipping 42 matching lines @@
   // progress towards the loop terminating.
   for (size_t i = 0; i < running_animations_.size();) {
     if (running_animations_[i].sequence->HasCommonProperty(
             sequence->properties())) {
       // Finish the animation.
       if (abort){
         running_animations_[i].sequence->Abort();
       } else {
         running_animations_[i].sequence->Progress(
             running_animations_[i].sequence->duration(), delegate());
-        delegate()->OnLayerAnimationEnded(running_animations_[i].sequence);
+        NotifyAnimationEnded(running_animations_[i].sequence);
       }
       RemoveAnimation(running_animations_[i].sequence);
     } else {
       ++i;
     }
   }
 
   // Same for the queued animations. See comment above about loop termination.
   for (size_t i = 0; i < animation_queue_.size();) {
     if (animation_queue_[i]->HasCommonProperty(sequence->properties())) {
       // Finish the animation.
       if (abort)
         animation_queue_[i]->Abort();
       else
         animation_queue_[i]->Progress(animation_queue_[i]->duration(),
                                       delegate());
       RemoveAnimation(animation_queue_[i].get());
     } else {
       ++i;
     }
   }
 }
 
 void LayerAnimator::ImmediatelySetNewTarget(LayerAnimationSequence* sequence) {
   const bool abort = false;
   RemoveAllAnimationsWithACommonProperty(sequence, abort);
   sequence->Progress(sequence->duration(), delegate());
-  delegate()->OnLayerAnimationEnded(sequence);
+  NotifyAnimationEnded(sequence);
   RemoveAnimation(sequence);
 }
 
 void LayerAnimator::ImmediatelyAnimateToNewTarget(
     LayerAnimationSequence* sequence) {
   const bool abort = true;
   RemoveAllAnimationsWithACommonProperty(sequence, abort);
   AddToQueueIfNotPresent(sequence);
   StartSequenceImmediately(sequence);
 }
@@ skipping 95 matching lines @@
 }
 
 void LayerAnimator::GetTargetValue(
     LayerAnimationElement::TargetValue* target) const {
   for (RunningAnimations::const_iterator iter = running_animations_.begin();
        iter != running_animations_.end(); ++iter) {
     (*iter).sequence->GetTargetValue(target);
   }
 }
 
+void LayerAnimator::NotifyAnimationEnded(LayerAnimationSequence* sequence) {
+  sequence->NotifyEnded();
+}
+
+void LayerAnimator::AddObserversToSequence(LayerAnimationSequence* sequence) {
+  if (observers_.might_have_observers()) {
+    ObserverListBase<LayerAnimationObserver>::Iterator it(observers_);
+    LayerAnimationObserver* obs;
+    while ((obs = it.GetNext()) != NULL)
+      sequence->AddObserver(obs);
+  }
+}
+
 }  // namespace ui