[ash-md] Implements a shadow over overview items and selector

This is non-MD 9-patch shadow just to test drive the looks.
Effectively this patch preserves the regular ash window shadows
and applies them in overview.

BUG=608852

Review-Url: https://codereview.chromium.org/2150823002
Cr-Commit-Position: refs/heads/master@{#405932}

ash/common/wm/overview/window_grid.cc

@@ -40,6 +40,7 @@
 #include "ui/views/painter.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
+#include "ui/wm/core/shadow.h"
 #include "ui/wm/core/window_animations.h"
 
 namespace ash {
@@ -723,6 +724,7 @@ void WindowGrid::FilterItems(const base::string16& pattern) {
       if (selection_widget_ && SelectedWindow() == *iter) {
         SelectedWindow()->SetSelected(false);
         selection_widget_.reset();
+        selector_shadow_.reset();
       }
     }
   }
@@ -823,7 +825,6 @@ void WindowGrid::InitSelectionWidget(WindowSelector::Direction direction) {
   selection_widget_.reset(CreateBackgroundWidget(root_window_, selection_color,
                                                  border_thickness,
                                                  border_radius, border_color));
-
   WmWindow* widget_window =
       WmLookup::Get()->GetWindowForWidget(selection_widget_.get());
   const gfx::Rect target_bounds =
@@ -831,6 +832,15 @@ void WindowGrid::InitSelectionWidget(WindowSelector::Direction direction) {
   gfx::Vector2d fade_out_direction =
       GetSlideVectorForFadeIn(direction, target_bounds);
   widget_window->SetBounds(target_bounds - fade_out_direction);
+
+  if (material) {
+    selector_shadow_.reset(new ::wm::Shadow());
+    selector_shadow_->Init(::wm::Shadow::STYLE_ACTIVE);
+    selector_shadow_->layer()->SetVisible(true);
+    selection_widget_->GetLayer()->SetMasksToBounds(false);
+    selection_widget_->GetLayer()->Add(selector_shadow_->layer());
+    selector_shadow_->SetContentBounds(gfx::Rect(target_bounds.size()));
+  }
 }
 
 void WindowGrid::MoveSelectionWidget(WindowSelector::Direction direction,
@@ -894,10 +904,32 @@ void WindowGrid::MoveSelectionWidgetToTarget(bool animate) {
         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
     selection_widget_->SetBounds(bounds);
     selection_widget_->SetOpacity(1.f);
+
+    if (selector_shadow_) {
+      ui::ScopedLayerAnimationSettings animation_settings_shadow(
+          selector_shadow_->shadow_layer()->GetAnimator());
+      animation_settings_shadow.SetTransitionDuration(
+          base::TimeDelta::FromMilliseconds(
+              kOverviewSelectorTransitionMilliseconds));
+      animation_settings_shadow.SetTweenType(
+          ash::MaterialDesignController::IsOverviewMaterial()
+              ? gfx::Tween::EASE_IN_OUT
+              : gfx::Tween::LINEAR_OUT_SLOW_IN);
+      animation_settings_shadow.SetPreemptionStrategy(
+          ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
+      bounds.Inset(1, 1);
+      selector_shadow_->SetContentBounds(
+          gfx::Rect(gfx::Point(1, 1), bounds.size()));
+    }
     return;
   }
   selection_widget_->SetBounds(bounds);
   selection_widget_->SetOpacity(1.f);
+  if (selector_shadow_) {
+    bounds.Inset(1, 1);
+    selector_shadow_->SetContentBounds(
+        gfx::Rect(gfx::Point(1, 1), bounds.size()));
+  }
 }
 
 bool WindowGrid::FitWindowRectsInBounds(const gfx::Rect& bounds,

ash/common/wm/overview/window_grid.h

@@ -20,6 +20,10 @@ namespace views {
 class Widget;
 }
 
+namespace wm {
+class Shadow;
+}
+
 namespace ash {
 
 class WindowSelectorItem;
@@ -174,6 +178,9 @@ class ASH_EXPORT WindowGrid : public WmWindowObserver {
   // Widget that indicates to the user which is the selected window.
   std::unique_ptr<views::Widget> selection_widget_;
 
+  // Shadow around the selector.
+  std::unique_ptr<::wm::Shadow> selector_shadow_;
+
   // Current selected window position.
   size_t selected_index_;
 

ash/common/wm/overview/window_selector_item.cc

@@ -42,6 +42,7 @@
 #include "ui/views/controls/button/image_button.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/window/non_client_view.h"
+#include "ui/wm/core/shadow.h"
 #include "ui/wm/core/window_util.h"
 
 namespace ash {
@@ -372,6 +373,17 @@ void WindowSelectorItem::SetSelected(bool selected) {
   animation_settings.SetPreemptionStrategy(
       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
   window->SetOpacity(selected ? 0.0f : 1.0f);
+
+  ui::ScopedLayerAnimationSettings animation_settings_shadow(
+      shadow_->shadow_layer()->GetAnimator());
+  animation_settings_shadow.SetTransitionDuration(
+      base::TimeDelta::FromMilliseconds(kSelectorFadeInMilliseconds));
+  animation_settings_shadow.SetTweenType(selected
+                                             ? gfx::Tween::FAST_OUT_LINEAR_IN
+                                             : gfx::Tween::LINEAR_OUT_SLOW_IN);
+  animation_settings_shadow.SetPreemptionStrategy(
+      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
+  shadow_->shadow_layer()->SetOpacity(selected ? 0.0f : 1.0f);
 }
 
 void WindowSelectorItem::RecomputeWindowTransforms() {
@@ -546,6 +558,12 @@ void WindowSelectorItem::CreateWindowLabel(const base::string16& title) {
     window_label_button_view_->SetVisible(false);
     window_label_->Show();
 
+    shadow_.reset(new ::wm::Shadow());
+    shadow_->Init(::wm::Shadow::STYLE_INACTIVE);
+    shadow_->layer()->SetVisible(true);
+    window_label_->GetLayer()->Add(shadow_->layer());
+    window_label_->GetLayer()->SetMasksToBounds(false);
+
     views::View* background_view =
         new RoundedContainerView(kLabelBackgroundRadius, kLabelBackgroundColor);
     window_label_selector_.reset(new views::Widget);
@@ -594,6 +612,7 @@ void WindowSelectorItem::UpdateHeaderLayout(
     // the window including its sizing borders.
     label_rect.set_height(label_rect.height() +
                           transformed_window_bounds.height());
+    gfx::Rect shadow_bounds(label_rect.size());
     label_rect.Inset(-kWindowSelectorMargin, -kWindowSelectorMargin);
     window_label_window->SetBounds(label_rect);
     gfx::Transform label_transform;
@@ -601,6 +620,9 @@ void WindowSelectorItem::UpdateHeaderLayout(
                               transformed_window_bounds.y());
     window_label_window->SetTransform(label_transform);
     window_label_selector_window->SetTransform(label_transform);
+
+    shadow_bounds.Offset(kWindowSelectorMargin, kWindowSelectorMargin);
+    shadow_->SetContentBounds(shadow_bounds);
   } else {
     if (!close_button_->visible()) {
       close_button_->SetVisible(true);

ash/common/wm/overview/window_selector_item.h

@@ -21,6 +21,10 @@ namespace views {
 class ImageButton;
 }
 
+namespace wm {
+class Shadow;
+}
+
 namespace ash {
 
 class WindowSelector;
@@ -174,6 +178,9 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   // Otherwise it is shown under the window.
   std::unique_ptr<views::Widget> window_label_;
 
+  // Shadow around the item in overview.
+  std::unique_ptr<::wm::Shadow> shadow_;
+
   // Label background widget used to fade in opacity when moving selection.
   std::unique_ptr<views::Widget> window_label_selector_;
 

ui/wm/core/shadow.h

@@ -45,6 +45,10 @@ class WM_EXPORT Shadow : public ui::ImplicitAnimationObserver {
   // transformations to this layer).
   ui::Layer* layer() const { return layer_.get(); }
 
+  // Exposed to allow setting animation parameters for bounds and opacity
+  // animations.
+  ui::Layer* shadow_layer() const { return shadow_layer_.get(); }
+
   const gfx::Rect& content_bounds() const { return content_bounds_; }
   Style style() const { return style_; }