Moves home card background to HomeCardView.

We'll soon remove AthenaStartPageView, so AppList independent
components like background should belong to HomeCardView.

This CL also fixes the bug of the visual effect; the spec is
saying that the gradient end should be white even in
the BOTTOM state.

BUG=425717
R=oshima@chromium.org
TEST=manually

Review URL: https://codereview.chromium.org/692643003

Cr-Commit-Position: refs/heads/master@{#302219}

athena/home/athena_start_page_view.cc

@@ -163,9 +163,7 @@ namespace athena {
 const char AthenaStartPageView::kViewClassName[] = "AthenaStartPageView";
 
 AthenaStartPageView::LayoutData::LayoutData()
-    : system_info_opacity(1.0f),
-      logo_opacity(1.0f),
-      background_opacity(1.0f) {
+    : system_info_opacity(1.0f), logo_opacity(1.0f) {
 }
 
 AthenaStartPageView::AthenaStartPageView(
@@ -173,16 +171,6 @@ AthenaStartPageView::AthenaStartPageView(
     : delegate_(view_delegate),
       layout_state_(0.0f),
       weak_factory_(this) {
-  background_ = new views::View();
-  // Vertical gradient background for the time being.
-  // TODO(mukai): replace by the actual one.
-  background_->set_background(
-      views::Background::CreateVerticalGradientBackground(SK_ColorLTGRAY,
-                                                          SK_ColorWHITE));
-  background_->SetPaintToLayer(true);
-  background_->SetFillsBoundsOpaquely(false);
-  AddChildView(background_);
-
   system_info_view_ =
       SystemUI::Get()->CreateSystemInfoView(SystemUI::COLOR_SCHEME_DARK);
   system_info_view_->SetPaintToLayer(true);
@@ -303,7 +291,6 @@ AthenaStartPageView::LayoutData AthenaStartPageView::CreateBottomBounds(
 
   state.system_info_opacity = 0.0f;
   state.logo_opacity = 0.0f;
-  state.background_opacity = 0.9f;
   return state;
 }
 
@@ -325,7 +312,6 @@ AthenaStartPageView::LayoutData AthenaStartPageView::CreateCenteredBounds(
 
   state.system_info_opacity = 1.0f;
   state.logo_opacity = 1.0f;
-  state.background_opacity = 1.0f;
   return state;
 }
 
@@ -446,12 +432,6 @@ void AthenaStartPageView::Layout() {
       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

@@ -63,7 +63,6 @@ class ATHENA_EXPORT AthenaStartPageView
     gfx::Rect controls;
     float system_info_opacity;
     float logo_opacity;
-    float background_opacity;
 
     LayoutData();
   };
@@ -110,10 +109,6 @@ class ATHENA_EXPORT AthenaStartPageView
   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_;
 

athena/home/home_card_impl.cc

@@ -127,10 +127,18 @@ class HomeCardView : public views::WidgetDelegateView,
   HomeCardView(app_list::AppListViewDelegate* view_delegate,
                aura::Window* container,
                HomeCardGestureManager::Delegate* gesture_delegate)
-      : minimized_background_(new views::View()),
-        drag_indicator_(new views::View()),
+      : background_(new views::View),
         main_view_(new AthenaStartPageView(view_delegate)),
+        minimized_background_(new views::View()),
+        drag_indicator_(new views::View()),
         gesture_delegate_(gesture_delegate) {
+    background_->set_background(
+        views::Background::CreateVerticalGradientBackground(SK_ColorLTGRAY,
+                                                            SK_ColorWHITE));
+    background_->SetPaintToLayer(true);
+    background_->SetFillsBoundsOpaquely(false);
+    AddChildView(background_);
+
     // Ideally AppListMainView should be used here and have AthenaStartPageView
     // as its child view, so that custom pages and apps grid are available in
     // the home card.
@@ -163,12 +171,28 @@ class HomeCardView : public views::WidgetDelegateView,
       main_view_->SetLayoutState(1.0f - progress);
     else if (to_state == HomeCard::VISIBLE_CENTERED)
       main_view_->SetLayoutState(progress);
+
+    float background_opacity = 1.0f;
     if (from_state == HomeCard::VISIBLE_MINIMIZED ||
         to_state == HomeCard::VISIBLE_MINIMIZED) {
-      minimized_background_->layer()->SetOpacity(
-          (to_state == HomeCard::VISIBLE_MINIMIZED) ? progress
-                                                    : (1.0f - progress));
+      background_opacity = (from_state == HomeCard::VISIBLE_MINIMIZED)
+                               ? progress
+                               : (1.0f - progress);
+    }
+    background_->layer()->SetOpacity(background_opacity);
+    minimized_background_->layer()->SetOpacity(1.0f - background_opacity);
+
+    int background_height = kHomeCardHeight;
+    if (from_state == HomeCard::VISIBLE_CENTERED ||
+        to_state == HomeCard::VISIBLE_CENTERED) {
+      gfx::Rect window_bounds = GetWidget()->GetWindowBoundsInScreen();
+      background_height = window_bounds.height() - window_bounds.y();
     }
+    gfx::Transform background_transform;
+    background_transform.Scale(
+        SK_MScalar1,
+        SkIntToMScalar(background_height) / SkIntToMScalar(height()));
+    background_->layer()->SetTransform(background_transform);
 
     gfx::Rect from_bounds = GetDragIndicatorBounds(from_state);
     gfx::Rect to_bounds = GetDragIndicatorBounds(to_state);
@@ -181,16 +205,32 @@ class HomeCardView : public views::WidgetDelegateView,
 
   void SetStateWithAnimation(HomeCard::State state,
                              gfx::Tween::Type tween_type) {
-    float minimized_target_opacity_for_state =
+    float minimized_opacity =
         (state == HomeCard::VISIBLE_MINIMIZED) ? 1.0f : 0.0f;
-    if (minimized_target_opacity_for_state !=
+    if (minimized_opacity !=
         minimized_background_->layer()->GetTargetOpacity()) {
       ui::ScopedLayerAnimationSettings settings(
           minimized_background_->layer()->GetAnimator());
       settings.SetTweenType(gfx::Tween::EASE_IN);
-      minimized_background_->layer()->SetOpacity(
-          minimized_target_opacity_for_state);
+      minimized_background_->layer()->SetOpacity(minimized_opacity);
+    }
+
+    gfx::Transform background_transform;
+    if (state != HomeCard::VISIBLE_CENTERED) {
+      background_transform.Scale(
+          SK_MScalar1,
+          SkIntToMScalar(kHomeCardHeight) / SkIntToMScalar(height()));
+    }
+    float background_opacity = 1.0f - minimized_opacity;
+    if (background_->layer()->GetTargetTransform() != background_transform ||
+        background_->layer()->GetTargetOpacity() != background_opacity) {
+      ui::ScopedLayerAnimationSettings settings(
+          background_->layer()->GetAnimator());
+      settings.SetTweenType(tween_type);
+      background_->layer()->SetTransform(background_transform);
+      background_->layer()->SetOpacity(background_opacity);
     }
+
     if (state == HomeCard::VISIBLE_CENTERED)
       main_view_->RequestFocusOnSearchBox();
     else
@@ -245,6 +285,7 @@ class HomeCardView : public views::WidgetDelegateView,
 
   void Layout() override {
     gfx::Rect contents_bounds = GetContentsBounds();
+    background_->SetBoundsRect(contents_bounds);
     main_view_->SetBoundsRect(contents_bounds);
     minimized_background_->SetBoundsRect(contents_bounds);
     drag_indicator_->SetBoundsRect(
@@ -261,9 +302,10 @@ class HomeCardView : public views::WidgetDelegateView,
       HomeCard::Get()->SetState(HomeCard::VISIBLE_CENTERED);
   }
 
+  views::View* background_;
+  AthenaStartPageView* main_view_;
   views::View* minimized_background_;
   views::View* drag_indicator_;
-  AthenaStartPageView* main_view_;
   HomeCard::State state_;
   scoped_ptr<HomeCardGestureManager> gesture_manager_;
   HomeCardGestureManager::Delegate* gesture_delegate_;