Implement ui for re-parenting an item from an app list folder to another position or folder in the …

ui/app_list/views/top_icon_animation_view.cc

Index: ui/app_list/views/top_icon_animation_view.cc
diff --git a/ui/app_list/views/top_icon_animation_view.cc b/ui/app_list/views/top_icon_animation_view.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f8f2f523b7ec11a620c4bc6519546a00e730c42a
--- /dev/null
+++ b/ui/app_list/views/top_icon_animation_view.cc
@@ -0,0 +1,82 @@
+// Copyright (c) 2014 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/views/top_icon_animation_view.h"
+
+#include "ui/app_list/app_list_constants.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/gfx/image/image_skia_operations.h"
+#include "ui/views/controls/image_view.h"
+
+namespace app_list {
+
+TopIconAnimationView::TopIconAnimationView(const gfx::ImageSkia& icon,
+                                           const gfx::Rect& scaled_rect,
+                                           bool open_folder)
+    : icon_size_(kPreferredIconDimension, kPreferredIconDimension),
+      icon_(new views::ImageView),
+      scaled_rect_(scaled_rect),
+      open_folder_(open_folder) {
+  DCHECK(!icon.isNull());
+  gfx::ImageSkia resized(gfx::ImageSkiaOperations::CreateResizedImage(
+      icon,
+      skia::ImageOperations::RESIZE_BEST, icon_size_));
+  icon_->SetImage(resized);
+  AddChildView(icon_);
+
+  SetPaintToLayer(true);
+  SetFillsBoundsOpaquely(false);
+ }
+
+TopIconAnimationView::~TopIconAnimationView() {
+}
+
+void TopIconAnimationView::AddObserver(TopIconAnimationObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void TopIconAnimationView::RemoveObserver(TopIconAnimationObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void TopIconAnimationView::TransformView() {
+  // Transform used for scaling down the icon and move it back inside to the
+  // original folder icon.
+  const float kIconTransformScale = 0.33333f;
+  gfx::Transform transform;
+  transform.Translate(scaled_rect_.x() - layer()->bounds().x(),
+                      scaled_rect_.y() - layer()->bounds().y());
+  transform.Scale(kIconTransformScale, kIconTransformScale);
+
+  if (open_folder_) {
+    // Transform to a scaled down icon inside the original folder icon.
+    layer()->SetTransform(transform);
+  }
+
+  // Animate the icon to its target location and scale when opening or
+  // closing a folder.
+  ui::ScopedLayerAnimationSettings settings(layer()->GetAnimator());
+  settings.AddObserver(this);
+  settings.SetTransitionDuration(
+      base::TimeDelta::FromMilliseconds(kFolderTransitionInDurationMs));
+  layer()->SetTransform(open_folder_ ? gfx::Transform() : transform);
+}
+
+gfx::Size TopIconAnimationView::GetPreferredSize() {
+  return icon_size_;
+}
+
+void TopIconAnimationView::Layout() {
+  icon_->SetBoundsRect(GetContentsBounds());
+}
+
+void TopIconAnimationView::OnImplicitAnimationsCompleted() {
+  SetVisible(false);
+  FOR_EACH_OBSERVER(TopIconAnimationObserver,
+                    observers_,
+                    OnTopIconAnimationsComplete());
+  delete this;
+}
+
+}  // namespace app_list