app_list: Add sync animation.

ui/app_list/pulsing_block_view.cc

Index: ui/app_list/pulsing_block_view.cc
diff --git a/ui/app_list/pulsing_block_view.cc b/ui/app_list/pulsing_block_view.cc
new file mode 100644
index 0000000000000000000000000000000000000000..30059d1975f6bd07b76a9a909360f6c7d897eb03
--- /dev/null
+++ b/ui/app_list/pulsing_block_view.cc
@@ -0,0 +1,106 @@
+// Copyright (c) 2012 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/app_list/pulsing_block_view.h"
+
+#include <vector>
+
+#include "base/rand_util.h"
+#include "third_party/skia/include/core/SkColor.h"
+#include "ui/compositor/layer_animation_element.h"
+#include "ui/compositor/layer_animation_sequence.h"
+#include "ui/compositor/layer_animator.h"
+#include "ui/compositor/layer.h"
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/transform_util.h"
+
+namespace {
+
+const SkColor kBlockColor = SkColorSetRGB(225, 225, 225);
+const int kBlockSize = 64;
+
+const int kAnimationDurationInMs = 600;
+const float kAnimationOpacity[] = { 0.4f, 0.8f, 0.4f };
+const float kAnimationScale[] = { 0.8f, 1.0f, 0.8f };
+
+void SchedulePulsingAnimation(ui::Layer* layer) {
+  DCHECK(layer);
+  DCHECK_EQ(arraysize(kAnimationOpacity), arraysize(kAnimationScale));
+
+  scoped_ptr<ui::LayerAnimationSequence> opacity_sequence(
+      new ui::LayerAnimationSequence());
+  scoped_ptr<ui::LayerAnimationSequence> transform_sequence(
+      new ui::LayerAnimationSequence());
+
+  // The animations loop infinitely.
+  opacity_sequence->set_is_cyclic(true);
+  transform_sequence->set_is_cyclic(true);
+
+  const gfx::Rect local_bounds(layer->bounds().size());
+  for (size_t i = 0; i < arraysize(kAnimationOpacity); ++i) {
+    opacity_sequence->AddElement(
+        ui::LayerAnimationElement::CreateOpacityElement(
+            kAnimationOpacity[i],
+            base::TimeDelta::FromMilliseconds(kAnimationDurationInMs)));
+    transform_sequence->AddElement(
+        ui::LayerAnimationElement::CreateTransformElement(
+            gfx::GetScaleTransform(local_bounds.CenterPoint(),
+                                   kAnimationScale[i]),
+            base::TimeDelta::FromMilliseconds(kAnimationDurationInMs)));
+  }
+
+  ui::LayerAnimationElement::AnimatableProperties opacity_properties;
+  opacity_properties.insert(ui::LayerAnimationElement::OPACITY);
+  opacity_sequence->AddElement(
+      ui::LayerAnimationElement::CreatePauseElement(
+          opacity_properties,
+           base::TimeDelta::FromMilliseconds(kAnimationDurationInMs)));
+
+  ui::LayerAnimationElement::AnimatableProperties transform_properties;
+  transform_properties.insert(ui::LayerAnimationElement::TRANSFORM);
+  transform_sequence->AddElement(
+      ui::LayerAnimationElement::CreatePauseElement(
+          transform_properties,
+          base::TimeDelta::FromMilliseconds(kAnimationDurationInMs)));
+
+  std::vector<ui::LayerAnimationSequence*> animations;
+  animations.push_back(opacity_sequence.release());
+  animations.push_back(transform_sequence.release());
+  layer->GetAnimator()->ScheduleTogether(animations);
+}
+
+}  // namespace
+
+namespace app_list {
+
+PulsingBlockView::PulsingBlockView(const gfx::Size& size, bool start_delay) {
+#if !defined(OS_WIN)
+  SetPaintToLayer(true);
+  SetFillsBoundsOpaquely(false);
+
+  const int max_delay = kAnimationDurationInMs * arraysize(kAnimationOpacity);
+  const int delay = start_delay ? base::RandInt(0, max_delay) : 0;
+  start_delay_timer_.Start(
+      FROM_HERE,
+      base::TimeDelta::FromMilliseconds(delay),
+      this, &PulsingBlockView::OnStartDelayTimer);
+#else
+  NOTREACHED() << "Pulsing animation is not supported on Windows";
+#endif
+}
+
+PulsingBlockView::~PulsingBlockView() {
+}
+
+void PulsingBlockView::OnStartDelayTimer() {
+  SchedulePulsingAnimation(layer());
+}
+
+void PulsingBlockView::OnPaint(gfx::Canvas* canvas) {
+  gfx::Rect rect(GetContentsBounds());
+  rect.ClampToCenteredSize(gfx::Size(kBlockSize, kBlockSize));
+  canvas->FillRect(rect, kBlockColor);
+}
+
+}  // namespace app_list