Refactor the home card structure and introduce animation.

This CL includes the following refactorings:
- minimized home is simply a layer instead of views
- moves the mouse click handler of minimized home to home card impl
- home card now has the same size of the screen. Changing state is
  now simply changing its position.

Then schedule the animation between BOTTOM state and CENTERED state.

BUG=398062
R=sadrul@chromium.org, oshima@chromium.org
TEST=manually on remote desktop

Review URL: https://codereview.chromium.org/478293004

Cr-Commit-Position: refs/heads/master@{#292092}

athena/home/athena_start_page_view.cc

@@ -127,17 +127,13 @@ class SearchBoxContainer : public views::View {
         new views::RoundRectPainter(SK_ColorGRAY, kSearchBoxCornerRadius),
         gfx::Insets(kSearchBoxBorderWidth, kSearchBoxBorderWidth,
                     kSearchBoxBorderWidth, kSearchBoxBorderWidth)));
+    SetLayoutManager(new views::FillLayout());
     AddChildView(search_box_);
   }
   virtual ~SearchBoxContainer() {}
 
  private:
   // views::View:
-  virtual void Layout() OVERRIDE {
-    gfx::Rect search_box_bounds = GetContentsBounds();
-    search_box_bounds.ClampToCenteredSize(GetPreferredSize());
-    search_box_->SetBoundsRect(search_box_bounds);
-  }
   virtual gfx::Size GetPreferredSize() const OVERRIDE {
     return gfx::Size(kSearchBoxWidth, kSearchBoxHeight);
   }
@@ -152,13 +148,30 @@ class SearchBoxContainer : public views::View {
 
 namespace athena {
 
+// static
+const char AthenaStartPageView::kViewClassName[] = "AthenaStartPageView";
+
+AthenaStartPageView::LayoutData::LayoutData()
+    : logo_opacity(1.0f),
+      background_opacity(1.0f) {
+}
+
 AthenaStartPageView::AthenaStartPageView(
     app_list::AppListViewDelegate* view_delegate)
     : delegate_(view_delegate),
+      layout_state_(0.0f),
       weak_factory_(this) {
+  background_ = new views::View();
+  background_->set_background(
+      views::Background::CreateSolidBackground(SK_ColorWHITE));
+  background_->SetPaintToLayer(true);
+  background_->SetFillsBoundsOpaquely(false);
+  AddChildView(background_);
+
   logo_ = view_delegate->CreateStartPageWebView(
       gfx::Size(kWebViewWidth, kWebViewHeight));
   logo_->SetPaintToLayer(true);
+  logo_->SetSize(logo_->GetPreferredSize());
   AddChildView(logo_);
 
   search_results_view_ = new app_list::SearchResultListView(
@@ -183,13 +196,7 @@ AthenaStartPageView::AthenaStartPageView(
       view_delegate->GetModel()->top_level_item_list();
   for (size_t i = 0; i < std::min(top_level->item_count(), kMaxIconNum); ++i)
     app_icon_container_->AddChildView(new AppIconButton(top_level->item_at(i)));
-
-  search_box_view_ = new app_list::SearchBoxView(this, view_delegate);
-  search_box_view_->set_contents_view(this);
-  search_box_container_ = new SearchBoxContainer(search_box_view_);
-  search_box_container_->SetPaintToLayer(true);
-  search_box_container_->SetFillsBoundsOpaquely(false);
-  AddChildView(search_box_container_);
+  app_icon_container_->SetSize(app_icon_container_->GetPreferredSize());
 
   control_icon_container_ = new views::View();
   control_icon_container_->SetPaintToLayer(true);
@@ -199,6 +206,15 @@ AthenaStartPageView::AthenaStartPageView(
       views::BoxLayout::kHorizontal, 0, 0, kIconMargin));
   for (size_t i = 0; i < kMaxIconNum; ++i)
     control_icon_container_->AddChildView(new PlaceHolderButton());
+  control_icon_container_->SetSize(control_icon_container_->GetPreferredSize());
+
+  search_box_view_ = new app_list::SearchBoxView(this, view_delegate);
+  search_box_view_->set_contents_view(this);
+  search_box_container_ = new SearchBoxContainer(search_box_view_);
+  search_box_container_->SetPaintToLayer(true);
+  search_box_container_->SetFillsBoundsOpaquely(false);
+  search_box_container_->SetSize(search_box_container_->GetPreferredSize());
+  AddChildView(search_box_container_);
 }
 
 AthenaStartPageView::~AthenaStartPageView() {}
@@ -207,6 +223,69 @@ void AthenaStartPageView::RequestFocusOnSearchBox() {
   search_box_view_->search_box()->RequestFocus();
 }
 
+void AthenaStartPageView::SetLayoutState(float layout_state) {
+  layout_state_ = layout_state;
+  Layout();
+}
+
+void AthenaStartPageView::SetLayoutStateWithAnimation(float layout_state) {
+  ui::ScopedLayerAnimationSettings logo(logo_->layer()->GetAnimator());
+  ui::ScopedLayerAnimationSettings search_box(
+      search_box_container_->layer()->GetAnimator());
+  ui::ScopedLayerAnimationSettings icons(
+      app_icon_container_->layer()->GetAnimator());
+  ui::ScopedLayerAnimationSettings controls(
+      control_icon_container_->layer()->GetAnimator());
+
+  logo.SetTweenType(gfx::Tween::EASE_IN_OUT);
+  search_box.SetTweenType(gfx::Tween::EASE_IN_OUT);
+  icons.SetTweenType(gfx::Tween::EASE_IN_OUT);
+  controls.SetTweenType(gfx::Tween::EASE_IN_OUT);
+
+  SetLayoutState(layout_state);
+}
+
+AthenaStartPageView::LayoutData AthenaStartPageView::CreateBottomBounds(
+    int width) {
+  LayoutData state;
+  state.icons.set_size(app_icon_container_->size());
+  state.icons.set_x(kIconMargin);
+  state.icons.set_y(kIconMargin);
+
+  state.controls.set_size(control_icon_container_->size());
+  state.controls.set_x(width - kIconMargin - state.controls.width());
+  state.controls.set_y(kIconMargin);
+
+  state.search_box.set_size(search_box_container_->size());
+  state.search_box.set_x((width - state.search_box.width()) / 2);
+  state.search_box.set_y((kHomeCardHeight - state.search_box.height()) / 2);
+
+  state.logo_opacity = 0.0f;
+  state.background_opacity = 0.9f;
+  return state;
+}
+
+AthenaStartPageView::LayoutData AthenaStartPageView::CreateCenteredBounds(
+    int width) {
+  LayoutData state;
+
+  state.search_box.set_size(search_box_container_->size());
+  state.search_box.set_x((width - state.search_box.width()) / 2);
+  state.search_box.set_y(logo_->bounds().bottom() + kInstantContainerSpacing);
+
+  state.icons.set_size(app_icon_container_->size());
+  state.icons.set_x(width / 2 - state.icons.width() - kIconMargin / 2);
+  state.icons.set_y(state.search_box.bottom() + kInstantContainerSpacing);
+
+  state.controls.set_size(control_icon_container_->size());
+  state.controls.set_x(width / 2 + kIconMargin / 2 + kIconMargin % 2);
+  state.controls.set_y(state.icons.y());
+
+  state.logo_opacity = 1.0f;
+  state.background_opacity = 1.0f;
+  return state;
+}
+
 void AthenaStartPageView::LayoutSearchResults(bool should_show_search_results) {
   if (should_show_search_results ==
       search_results_view_->layer()->GetTargetVisibility()) {
@@ -276,57 +355,31 @@ void AthenaStartPageView::OnSearchResultLayoutAnimationCompleted(
 }
 
 void AthenaStartPageView::Layout() {
-  gfx::Rect bounds = GetContentsBounds();
   search_results_view_->SetVisible(false);
-
-  if (bounds.height() <= kHomeCardHeight) {
-    logo_->SetVisible(false);
-    gfx::Rect icon_bounds(app_icon_container_->GetPreferredSize());
-    icon_bounds.set_x(bounds.x() + kIconMargin);
-    icon_bounds.set_y(bounds.x() + kIconMargin);
-    app_icon_container_->SetBoundsRect(icon_bounds);
-
-    gfx::Rect control_bounds(control_icon_container_->GetPreferredSize());
-    control_bounds.set_x(
-        bounds.right() - kIconMargin - control_bounds.width());
-    control_bounds.set_y(bounds.y() + kIconMargin);
-    control_icon_container_->SetBoundsRect(control_bounds);
-
-    search_box_container_->SetBounds(
-        icon_bounds.right(), bounds.y(),
-        control_bounds.x() - icon_bounds.right(), kHomeCardHeight);
-
-    set_background(views::Background::CreateSolidBackground(
-        255, 255, 255, 255 * 0.9));
-  } else {
-    // TODO(mukai): set the intermediate state.
-    logo_->SetVisible(true);
-    logo_->layer()->SetOpacity(1.0f);
-    set_background(views::Background::CreateSolidBackground(SK_ColorWHITE));
-    gfx::Rect logo_bounds(bounds.x() + bounds.width() / 2 - kWebViewWidth / 2,
-                          bounds.y() + kTopMargin,
-                          kWebViewWidth,
-                          kWebViewHeight);
-    logo_->SetBoundsRect(logo_bounds);
-
-    gfx::Rect search_box_bounds(search_box_container_->GetPreferredSize());
-    search_box_bounds.set_x(
-        bounds.x() + bounds.width() / 2 - search_box_bounds.width() / 2);
-    search_box_bounds.set_y(logo_bounds.bottom() + kInstantContainerSpacing);
-    search_box_container_->SetBoundsRect(search_box_bounds);
-
-    gfx::Rect icon_bounds(app_icon_container_->GetPreferredSize());
-    icon_bounds.set_x(bounds.x() + bounds.width() / 2 -
-                      icon_bounds.width() - kIconMargin / 2);
-    icon_bounds.set_y(search_box_bounds.bottom() + kInstantContainerSpacing);
-    app_icon_container_->SetBoundsRect(icon_bounds);
-
-    gfx::Rect control_bounds(control_icon_container_->GetPreferredSize());
-    control_bounds.set_x(bounds.x() + bounds.width() / 2 +
-                         kIconMargin / 2 + kIconMargin % 2);
-    control_bounds.set_y(icon_bounds.y());
-    control_icon_container_->SetBoundsRect(control_bounds);
-  }
+  gfx::Rect logo_bounds(x() + width() / 2 - kWebViewWidth / 2, y() + kTopMargin,
+                        kWebViewWidth, kWebViewHeight);
+  logo_->SetBoundsRect(logo_bounds);
+
+  LayoutData bottom_bounds = CreateBottomBounds(width());
+  LayoutData centered_bounds = CreateCenteredBounds(width());
+
+  logo_->layer()->SetOpacity(gfx::Tween::FloatValueBetween(
+      gfx::Tween::CalculateValue(gfx::Tween::EASE_IN_2, layout_state_),
+      bottom_bounds.logo_opacity, centered_bounds.logo_opacity));
+  logo_->SetVisible(logo_->layer()->GetTargetOpacity() != 0.0f);
+
+  app_icon_container_->SetBoundsRect(gfx::Tween::RectValueBetween(
+      layout_state_, bottom_bounds.icons, centered_bounds.icons));
+  control_icon_container_->SetBoundsRect(gfx::Tween::RectValueBetween(
+      layout_state_, bottom_bounds.controls, centered_bounds.controls));
+  search_box_container_->SetBoundsRect(gfx::Tween::RectValueBetween(
+      layout_state_, bottom_bounds.search_box, centered_bounds.search_box));
+
+  background_->SetBoundsRect(bounds());
+  background_->layer()->SetOpacity(gfx::Tween::FloatValueBetween(
+      layout_state_,
+      bottom_bounds.background_opacity,
+      centered_bounds.background_opacity));
 }
 
 bool AthenaStartPageView::OnKeyPressed(const ui::KeyEvent& key_event) {

athena/home/athena_start_page_view.h

@@ -17,8 +17,6 @@ class SearchResultListView;
 
 namespace athena {
 
-// It will replace app_list::StartPageView in Athena UI in the future.
-// Right now it's simply used for VISIBLE_BOTTOM state.
 class AthenaStartPageView : public views::View,
                             public app_list::SearchBoxViewDelegate {
  public:
@@ -28,7 +26,33 @@ class AthenaStartPageView : public views::View,
   // Requests the focus on the search box in the start page view.
   void RequestFocusOnSearchBox();
 
+  // Updates the layout state. See the comment of |layout_state_| field.
+  void SetLayoutState(float layout_state);
+
+  // Updates the layout state and move the subviews to the target location with
+  // animation.
+  void SetLayoutStateWithAnimation(float layout_state);
+
  private:
+  static const char kViewClassName[];
+
+  // A struct which bundles the layout data of subviews.
+  struct LayoutData {
+    gfx::Rect search_box;
+    gfx::Rect icons;
+    gfx::Rect controls;
+    float logo_opacity;
+    float background_opacity;
+
+    LayoutData();
+  };
+
+  // Returns the bounds for |VISIBLE_BOTTOM|.
+  LayoutData CreateBottomBounds(int width);
+
+  // Returns the bounds for |VISIBLE_CENTERED|.
+  LayoutData CreateCenteredBounds(int width);
+
   // Schedules the animation for the layout the search box and the search
   // results.
   void LayoutSearchResults(bool should_show_search_results);
@@ -55,9 +79,17 @@ class AthenaStartPageView : public views::View,
   app_list::SearchBoxView* search_box_view_;
   app_list::SearchResultListView* search_results_view_;
 
+  // Do not use views::Background but a views::View with ui::Layer for gradient
+  // background opacity update and animation.
+  views::View* background_;
+
   // The expected height of |search_results_view_|
   int search_results_height_;
 
+  // The state to specify how each of the subviews should be laid out, in the
+  // range of [0, 1]. 0 means fully BOTTOM state, and 1 is fully CENTERED state.
+  float layout_state_;
+
   base::WeakPtrFactory<AthenaStartPageView> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AthenaStartPageView);

athena/home/home_card_gesture_manager.cc

@@ -99,6 +99,7 @@ void HomeCardGestureManager::UpdateScrollState(const ui::GestureEvent& event) {
   // The finger is between two states.
   float progress = (last_estimated_height_ - smaller_height) /
       (bigger_height - smaller_height);
+  progress = std::min(1.0f, std::max(0.0f, progress));
 
   if (last_state_ == state) {
     if (event.details().scroll_y() > 0) {

athena/home/minimized_home.cc

@@ -4,24 +4,30 @@
 
 #include "athena/home/minimized_home.h"
 
-#include "athena/wm/public/window_manager.h"
+#include "ui/compositor/layer.h"
+#include "ui/compositor/layer_owner.h"
 #include "ui/gfx/canvas.h"
-#include "ui/views/background.h"
-#include "ui/views/view.h"
 
 namespace {
 
 const int kDragHandleWidth = 112;
 const int kDragHandleHeight = 2;
+const char kMinimizedHomeLayerName[] = "MinimizedHome";
 
-class MinimizedHomeBackground : public views::Background {
+class MinimizedHomePainter : public ui::LayerDelegate,
+                             public ui::LayerOwner {
  public:
-  MinimizedHomeBackground() {}
-  virtual ~MinimizedHomeBackground() {}
+  explicit MinimizedHomePainter(ui::Layer* layer) {
+    layer->set_name(kMinimizedHomeLayerName);
+    layer->set_delegate(this);
+    SetLayer(layer);
+  }
+  virtual ~MinimizedHomePainter() {}
 
  private:
-  virtual void Paint(gfx::Canvas* canvas, views::View* view) const OVERRIDE {
-    gfx::Rect bounds = view->GetLocalBounds();
+  // ui::LayerDelegate:
+  virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE {
+    gfx::Rect bounds(layer()->GetTargetBounds().size());
     canvas->FillRect(bounds, SK_ColorBLACK);
     canvas->FillRect(gfx::Rect((bounds.width() - kDragHandleWidth) / 2,
                                bounds.bottom() - kDragHandleHeight,
@@ -30,37 +36,27 @@ class MinimizedHomeBackground : public views::Background {
                      SK_ColorWHITE);
   }
 
-  DISALLOW_COPY_AND_ASSIGN(MinimizedHomeBackground);
-};
+  virtual void OnDelegatedFrameDamage(
+      const gfx::Rect& damage_rect_in_dip) OVERRIDE {
+  }
 
-// This View shows an instance of SmallBarView in the middle, and reacts to
-// mouse and touch-gesture events.
-class MinimizedHomeView : public views::View {
- public:
-  MinimizedHomeView() {
-    set_background(new MinimizedHomeBackground());
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {
   }
-  virtual ~MinimizedHomeView() {}
 
- private:
-  // views::View:
-  virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE {
-    if (event.IsLeftMouseButton() && event.GetClickCount() == 1) {
-      athena::WindowManager::GetInstance()->ToggleOverview();
-      return true;
-    }
-    return false;
+  virtual base::Closure PrepareForLayerBoundsChange() OVERRIDE {
+    return base::Closure();
   }
 
-  DISALLOW_COPY_AND_ASSIGN(MinimizedHomeView);
+  DISALLOW_COPY_AND_ASSIGN(MinimizedHomePainter);
 };
 
 }  // namespace
 
 namespace athena {
 
-views::View* CreateMinimizedHome() {
-  return new MinimizedHomeView();
+scoped_ptr<ui::LayerOwner> CreateMinimizedHome() {
+  return scoped_ptr<ui::LayerOwner>(
+      new MinimizedHomePainter(new ui::Layer(ui::LAYER_TEXTURED)));
 }
 
 }  // namespace athena

athena/home/minimized_home.h

@@ -5,13 +5,15 @@
 #ifndef ATHENA_HOME_MINIMIZED_HOME_H_
 #define ATHENA_HOME_MINIMIZED_HOME_H_
 
-namespace views {
-class View;
+#include "base/memory/scoped_ptr.h"
+
+namespace ui {
+class LayerOwner;
 }
 
 namespace athena {
 
-views::View* CreateMinimizedHome();
+scoped_ptr<ui::LayerOwner> CreateMinimizedHome();
 
 }  // namespace athena