Explicit animation support

ui/gfx/compositor/layer_animation_unittest.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 "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/time.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/rect.h"
+#include "ui/gfx/transform.h"
+#include "ui/gfx/compositor/layer_animation_delegate.h"
+#include "ui/gfx/compositor/layer_animation_element.h"
+#include "ui/gfx/compositor/layer_animation_sequence.h"
+#include "ui/gfx/compositor/layer_animator.h"
+
+namespace ui {
+
+namespace {
+
+void CheckApproximatelyEqual(const Transform& lhs,
+                             const Transform& rhs) {
+  for (int i = 0; i < 4; ++i) {
+    for (int j = 0; j < 4; ++j) {
+      EXPECT_FLOAT_EQ(lhs.matrix().get(i, j), rhs.matrix().get(i, j));
+    }
+  }
+}
+
+void CheckApproximatelyEqual(const gfx::Rect& lhs,
+                             const gfx::Rect& rhs) {
+  EXPECT_FLOAT_EQ(lhs.x(), rhs.x());
+  EXPECT_FLOAT_EQ(lhs.y(), rhs.y());
+  EXPECT_FLOAT_EQ(lhs.width(), rhs.width());
+  EXPECT_FLOAT_EQ(lhs.height(), rhs.height());
+}
+
+class DummyLayerAnimationDelegate : public LayerAnimationDelegate {
+ public:
+  DummyLayerAnimationDelegate() : opacity_(1.0f) {
+  }
+
+  virtual void SetBoundsFromAnimation(const gfx::Rect& bounds) OVERRIDE {
+    bounds_ = bounds;
+  }
+  virtual void SetTransformFromAnimation(const Transform& transform) OVERRIDE {
+    transform_ = transform;
+  }
+  virtual void SetOpacityFromAnimation(float opacity) OVERRIDE {
+    opacity_ = opacity;
+  }
+  virtual void ScheduleDrawForAnimation() OVERRIDE {
+  }
+  virtual const gfx::Rect& GetBoundsForAnimation() const OVERRIDE {
+    return bounds_;
+  }
+  virtual const Transform& GetTransformForAnimation() const OVERRIDE {
+    return transform_;
+  }
+  virtual const float GetOpacityForAnimation() const OVERRIDE {
+    return opacity_;
+  }
+
+ private:
+  gfx::Rect bounds_;
+  Transform transform_;
+  float opacity_;
+};
+
+TEST(LayerAnimationElementTest, TransformElement) {

[sky, 2011/10/19 00:06:33]

It's better form to create _unittest for each of the files you're going to test.
We sometimes don't do that if it's too hard to test each piece in isolation, but
that isn't the case here. You should be able to write tests for
LayerAnimationSequence and LayerAnimator in isolate of the rest, so that I would
separate out the two types of tests. If you need to share classes, like your
DummyLaerAnimationDelegate, move it into a .h/cc. See ui/aura/test/test* for
examples of shared classes.

+  DummyLayerAnimationDelegate delegate;
+  Transform start_transform, target_transform, middle_transform;
+  start_transform.SetRotate(-90);
+  target_transform.SetRotate(90);
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  scoped_ptr<LayerAnimationElement> element(
+      LayerAnimationElement::CreateTransformElement(target_transform, delta));
+
+  for (int i = 0; i < 2; ++i) {
+    delegate.SetTransformFromAnimation(start_transform);
+    element->Progress(0.0, &delegate);
+    CheckApproximatelyEqual(start_transform,
+                            delegate.GetTransformForAnimation());
+    element->Progress(0.5, &delegate);
+    CheckApproximatelyEqual(middle_transform,
+                            delegate.GetTransformForAnimation());
+    element->Progress(1.0, &delegate);
+    CheckApproximatelyEqual(target_transform,
+                            delegate.GetTransformForAnimation());
+  }
+
+  EXPECT_EQ(delta, element->Duration());
+}
+
+TEST(LayerAnimationElementTest, BoundsElement) {

[sky, 2011/10/19 00:06:33]

Add descriptions for each of your tests.

+  DummyLayerAnimationDelegate delegate;
+  gfx::Rect start, target, middle;
+  start = target = middle = gfx::Rect(0, 0, 50, 50);
+  start.set_x(-90);
+  target.set_x(90);
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  scoped_ptr<LayerAnimationElement> element(
+      LayerAnimationElement::CreateBoundsElement(target, delta));
+
+  for (int i = 0; i < 2; ++i) {
+    delegate.SetBoundsFromAnimation(start);
+    element->Progress(0.0, &delegate);
+    CheckApproximatelyEqual(start, delegate.GetBoundsForAnimation());
+    element->Progress(0.5, &delegate);
+    CheckApproximatelyEqual(middle, delegate.GetBoundsForAnimation());
+    element->Progress(1.0, &delegate);
+    CheckApproximatelyEqual(target, delegate.GetBoundsForAnimation());
+  }
+
+  EXPECT_EQ(delta, element->Duration());
+}
+
+TEST(LayerAnimationElementTest, OpacityElement) {
+  DummyLayerAnimationDelegate delegate;
+  float start = 0.0;
+  float middle = 0.5;
+  float target = 1.0;
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+  scoped_ptr<LayerAnimationElement> element(
+      LayerAnimationElement::CreateOpacityElement(target, delta));
+
+  for (int i = 0; i < 2; ++i) {
+    delegate.SetOpacityFromAnimation(start);
+    element->Progress(0.0, &delegate);
+    EXPECT_FLOAT_EQ(start, delegate.GetOpacityForAnimation());
+    element->Progress(0.5, &delegate);
+    EXPECT_FLOAT_EQ(middle, delegate.GetOpacityForAnimation());
+    element->Progress(1.0, &delegate);
+    EXPECT_FLOAT_EQ(target, delegate.GetOpacityForAnimation());
+  }
+
+  EXPECT_EQ(delta, element->Duration());
+}
+
+TEST(LayerAnimationElementTest, PauseElement) {
+  LayerAnimationElement::AnimatableProperties properties;
+  properties.insert(LayerAnimationElement::TRANSFORM);
+  properties.insert(LayerAnimationElement::BOUNDS);
+  properties.insert(LayerAnimationElement::OPACITY);
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  scoped_ptr<LayerAnimationElement> element(
+      LayerAnimationElement::CreatePauseElement(properties, delta));
+
+  DummyLayerAnimationDelegate delegate;
+  DummyLayerAnimationDelegate copy = delegate;
+
+  element->Progress(1.0, &delegate);
+
+  // Nothing should have changed.
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(),
+                          copy.GetBoundsForAnimation());
+  CheckApproximatelyEqual(delegate.GetTransformForAnimation(),
+                          copy.GetTransformForAnimation());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(),
+                  copy.GetOpacityForAnimation());
+
+  // Pause should last for |delta|.
+  EXPECT_EQ(delta, element->Duration());
+}
+
+TEST(LayerAnimationSequenceTest, NoElement) {
+  LayerAnimationSequence sequence;
+  EXPECT_EQ(sequence.duration(), base::TimeDelta());
+  EXPECT_TRUE(sequence.properties().size() == 0);
+  LayerAnimationElement::AnimatableProperties properties;
+  EXPECT_FALSE(sequence.HasCommonProperty(properties));
+}
+
+TEST(LayerAnimationSequenceTest, SingleElement) {
+  LayerAnimationSequence sequence;
+  DummyLayerAnimationDelegate delegate;
+  float start = 0.0;
+  float middle = 0.5;
+  float target = 1.0;
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+  sequence.AddElement(
+      LayerAnimationElement::CreateOpacityElement(target, delta));
+
+  for (int i = 0; i < 2; ++i) {
+    delegate.SetOpacityFromAnimation(start);
+    sequence.Progress(base::TimeDelta::FromMilliseconds(0), &delegate);
+    EXPECT_FLOAT_EQ(start, delegate.GetOpacityForAnimation());
+    sequence.Progress(base::TimeDelta::FromMilliseconds(500), &delegate);
+    EXPECT_FLOAT_EQ(middle, delegate.GetOpacityForAnimation());
+    sequence.Progress(base::TimeDelta::FromMilliseconds(1000), &delegate);
+    EXPECT_FLOAT_EQ(target, delegate.GetOpacityForAnimation());
+  }
+
+  EXPECT_TRUE(sequence.properties().size() == 1);
+  EXPECT_TRUE(sequence.properties().find(LayerAnimationElement::OPACITY) !=
+              sequence.properties().end());
+  EXPECT_EQ(delta, sequence.duration());
+}
+
+TEST(LayerAnimationSequenceTest, MultipleElement) {
+  LayerAnimationSequence sequence;
+  DummyLayerAnimationDelegate delegate;
+  float start_opacity = 0.0;
+  float middle_opacity = 0.5;
+  float target_opacity = 1.0;
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+  sequence.AddElement(
+      LayerAnimationElement::CreateOpacityElement(target_opacity, delta));
+
+  // Pause bounds for a second.
+  LayerAnimationElement::AnimatableProperties properties;
+  properties.insert(LayerAnimationElement::BOUNDS);
+
+  sequence.AddElement(
+      LayerAnimationElement::CreatePauseElement(properties, delta));
+
+  Transform start_transform, target_transform, middle_transform;
+  start_transform.SetRotate(-90);
+  target_transform.SetRotate(90);
+
+  sequence.AddElement(
+      LayerAnimationElement::CreateTransformElement(target_transform, delta));
+
+  for (int i = 0; i < 2; ++i) {
+    delegate.SetOpacityFromAnimation(start_opacity);
+    delegate.SetTransformFromAnimation(start_transform);
+
+    sequence.Progress(base::TimeDelta::FromMilliseconds(0), &delegate);
+    EXPECT_FLOAT_EQ(start_opacity, delegate.GetOpacityForAnimation());
+    sequence.Progress(base::TimeDelta::FromMilliseconds(500), &delegate);
+    EXPECT_FLOAT_EQ(middle_opacity, delegate.GetOpacityForAnimation());
+    sequence.Progress(base::TimeDelta::FromMilliseconds(1000), &delegate);
+    EXPECT_FLOAT_EQ(target_opacity, delegate.GetOpacityForAnimation());
+    DummyLayerAnimationDelegate copy = delegate;
+
+    // In the middle of the pause -- nothing should have changed.
+    sequence.Progress(base::TimeDelta::FromMilliseconds(1500), &delegate);
+    CheckApproximatelyEqual(delegate.GetBoundsForAnimation(),
+                            copy.GetBoundsForAnimation());
+    CheckApproximatelyEqual(delegate.GetTransformForAnimation(),
+                            copy.GetTransformForAnimation());
+    EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(),
+                    copy.GetOpacityForAnimation());
+
+
+    sequence.Progress(base::TimeDelta::FromMilliseconds(2000), &delegate);
+    CheckApproximatelyEqual(start_transform,
+                            delegate.GetTransformForAnimation());
+    sequence.Progress(base::TimeDelta::FromMilliseconds(2500), &delegate);
+    CheckApproximatelyEqual(middle_transform,
+                            delegate.GetTransformForAnimation());
+    sequence.Progress(base::TimeDelta::FromMilliseconds(3000), &delegate);
+    CheckApproximatelyEqual(target_transform,
+                            delegate.GetTransformForAnimation());
+  }
+
+  EXPECT_TRUE(sequence.properties().size() == 3);
+  EXPECT_TRUE(sequence.properties().find(LayerAnimationElement::OPACITY) !=
+              sequence.properties().end());
+  EXPECT_TRUE(sequence.properties().find(LayerAnimationElement::TRANSFORM) !=
+              sequence.properties().end());
+  EXPECT_TRUE(sequence.properties().find(LayerAnimationElement::BOUNDS) !=
+              sequence.properties().end());
+  EXPECT_EQ(delta + delta + delta, sequence.duration());
+}
+
+TEST(LayerAnimatorTest, ImplicitAnimation) {
+  scoped_ptr<LayerAnimator> animator(
+      LayerAnimator::CreateImplicitAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+  base::TimeTicks now = base::TimeTicks::Now();
+  animator->SetOpacity(0.5);
+  EXPECT_TRUE(animator->IsAnimating());
+  animator->Step(now + base::TimeDelta::FromSeconds(1));
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), 0.5);
+}
+
+TEST(LayerAnimatorTest, NoImplicitAnimation) {
+  scoped_ptr<LayerAnimator> animator(
+      LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+  base::TimeTicks now = base::TimeTicks::Now();
+  animator->SetOpacity(0.5);
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), 0.5);
+}
+
+TEST(LayerAnimatorTest, StopAnimatingProperty) {
+  scoped_ptr<LayerAnimator> animator(
+      LayerAnimator::CreateImplicitAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+  base::TimeTicks now = base::TimeTicks::Now();
+  double target_opacity(0.5);
+  gfx::Rect target_bounds(0, 0, 50, 50);
+  animator->SetOpacity(target_opacity);
+  animator->SetBounds(target_bounds);
+  animator->StopAnimatingProperty(LayerAnimationElement::OPACITY);
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), 0.5);
+  animator->StopAnimatingProperty(LayerAnimationElement::BOUNDS);
+  EXPECT_FALSE(animator->IsAnimating());
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), target_bounds);
+}
+
+TEST(LayerAnimatorTest, StopAnimating) {
+  scoped_ptr<LayerAnimator> animator(
+      LayerAnimator::CreateImplicitAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+  base::TimeTicks now = base::TimeTicks::Now();
+  double target_opacity(0.5);
+  gfx::Rect target_bounds(0, 0, 50, 50);
+  animator->SetOpacity(target_opacity);
+  animator->SetBounds(target_bounds);
+  EXPECT_TRUE(animator->IsAnimating());
+  animator->StopAnimating();
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), 0.5);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), target_bounds);
+}
+
+// schedule animation (that can run immediately)
+TEST(LayerAnimatorTest, ScheduleAnimationThatCanRunImmediately) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double middle_opacity(0.5);
+  double target_opacity(1.0);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+
+  animator->ScheduleAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(500));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+}
+
+// schedule two animations on separate properties
+TEST(LayerAnimatorTest, ScheduleTwoAnimationsThatCanRunImmediately) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double middle_opacity(0.5);
+  double target_opacity(1.0);
+
+  gfx::Rect start_bounds, target_bounds, middle_bounds;
+  start_bounds = target_bounds = middle_bounds = gfx::Rect(0, 0, 50, 50);
+  start_bounds.set_x(-90);
+  target_bounds.set_x(90);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+  delegate.SetBoundsFromAnimation(start_bounds);
+
+  animator->ScheduleAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  animator->ScheduleAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateBoundsElement(target_bounds, delta)));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), start_bounds);
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(500));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), middle_bounds);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), target_bounds);
+}
+
+// schedule two animations on the same property
+TEST(LayerAnimatorTest, ScheduleTwoAnimationsOnSameProperty) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double middle_opacity(0.5);
+  double target_opacity(1.0);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+
+  animator->ScheduleAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  animator->ScheduleAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(start_opacity, delta)));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(500));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1500));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(2000));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+}
+
+// schedule {o}, {o,b}, {b} and ensure that {b} doesn't run right away.
+TEST(LayerAnimatorTest, ScheduleBlockedAnimation) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double middle_opacity(0.5);
+  double target_opacity(1.0);
+
+  gfx::Rect start_bounds, target_bounds, middle_bounds;
+  start_bounds = target_bounds = middle_bounds = gfx::Rect(0, 0, 50, 50);
+  start_bounds.set_x(-90);
+  target_bounds.set_x(90);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+  delegate.SetBoundsFromAnimation(start_bounds);
+
+  animator->ScheduleAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  scoped_ptr<LayerAnimationSequence> bounds_and_opacity(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(start_opacity, delta)));
+
+  bounds_and_opacity->AddElement(
+      LayerAnimationElement::CreateBoundsElement(target_bounds, delta));
+
+  animator->ScheduleAnimation(bounds_and_opacity.release());
+
+  animator->ScheduleAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateBoundsElement(start_bounds, delta)));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), start_bounds);
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(500));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), start_bounds);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), start_bounds);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(2000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), start_bounds);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(3000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), target_bounds);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(4000));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), start_bounds);
+}
+
+// schedule {o} and then schedule {o} and {b} together
+TEST(LayerAnimatorTest, ScheduleTogether) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double target_opacity(1.0);
+
+  gfx::Rect start_bounds, target_bounds, middle_bounds;
+  start_bounds = target_bounds = gfx::Rect(0, 0, 50, 50);
+  start_bounds.set_x(-90);
+  target_bounds.set_x(90);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+  delegate.SetBoundsFromAnimation(start_bounds);
+
+  animator->ScheduleAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  std::vector<LayerAnimationSequence*> sequences;
+  sequences.push_back(new LayerAnimationSequence(
+      LayerAnimationElement::CreateOpacityElement(start_opacity, delta)));
+  sequences.push_back(new LayerAnimationSequence(
+      LayerAnimationElement::CreateBoundsElement(target_bounds, delta)));
+
+  animator->ScheduleTogether(sequences);
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), start_bounds);
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), start_bounds);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(2000));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+  CheckApproximatelyEqual(delegate.GetBoundsForAnimation(), target_bounds);
+}
+
+// start animation (that can run immediately)
+TEST(LayerAnimatorTest, StartAnimationThatCanRunImmediately) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double middle_opacity(0.5);
+  double target_opacity(1.0);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(500));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+}
+
+// preempt by immediately setting new target
+TEST(LayerAnimatorTest, PreemptBySettingNewTarget) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double target_opacity(1.0);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+
+  animator->set_preemption_strategy(LayerAnimator::IMMEDIATELY_SET_NEW_TARGET);
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(start_opacity, delta)));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+}
+
+// preempt by animating to new target
+TEST(LayerAnimatorTest, PreemptByImmediatelyAnimatingToNewTarget) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double middle_opacity(0.5);
+  double target_opacity(1.0);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+
+  animator->set_preemption_strategy(
+      LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(500));
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(start_opacity, delta)));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(start_opacity, delta)));
+
+  EXPECT_TRUE(animator->IsAnimating());
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(),
+                  0.5 * (start_opacity + middle_opacity));
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1500));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+}
+
+// preempt by enqueuing the new animation
+TEST(LayerAnimatorTest, PreemptEnqueueNewAnimation) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double middle_opacity(0.5);
+  double target_opacity(1.0);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+
+  animator->set_preemption_strategy(LayerAnimator::ENQUEUE_NEW_ANIMATION);
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(500));
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(start_opacity, delta)));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+
+  EXPECT_TRUE(animator->IsAnimating());
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1500));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(2000));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+}
+
+// Start an animation when there are sequences waiting in the queue. In this
+// case, all pending and running animations should be finished, and the new
+// animation started.
+TEST(LayerAnimatorTest, PreemptyByReplacingQueuedAnimations) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double middle_opacity(0.5);
+  double target_opacity(1.0);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+
+  animator->set_preemption_strategy(LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(500));
+
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(middle_opacity, delta)));
+
+  // Queue should now have two animations. Starting a third should replace the
+  // second.
+  animator->StartAnimation(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(start_opacity, delta)));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1500));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), middle_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(2000));
+
+  EXPECT_FALSE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+}
+
+// cyclic sequence
+TEST(LayerAnimatorTest, CyclicSequences) {
+  scoped_ptr<LayerAnimator> animator(LayerAnimator::CreateDefaultAnimator());
+  animator->SetAnimationForTest(NULL);
+  DummyLayerAnimationDelegate delegate;
+  animator->SetDelegate(&delegate);
+
+  double start_opacity(0.0);
+  double target_opacity(1.0);
+
+  base::TimeDelta delta = base::TimeDelta::FromSeconds(1);
+
+  delegate.SetOpacityFromAnimation(start_opacity);
+
+  scoped_ptr<LayerAnimationSequence> sequence(
+      new LayerAnimationSequence(
+          LayerAnimationElement::CreateOpacityElement(target_opacity, delta)));
+
+  sequence->AddElement(
+      LayerAnimationElement::CreateOpacityElement(start_opacity, delta));
+
+  sequence->set_is_cyclic(true);
+
+  animator->StartAnimation(sequence.release());
+
+  base::TimeTicks start_time = animator->get_last_step_time_for_test();
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(1000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(2000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), start_opacity);
+
+  animator->Step(start_time + base::TimeDelta::FromMilliseconds(3000));
+
+  EXPECT_TRUE(animator->IsAnimating());
+  EXPECT_FLOAT_EQ(delegate.GetOpacityForAnimation(), target_opacity);
+
+  animator->StopAnimatingProperty(LayerAnimationElement::OPACITY);
+
+  EXPECT_FALSE(animator->IsAnimating());
+}
+
+} // namespace
+
+} // namespace ui