athena: Add a minimized state for the home-card.

athena/home/home_card_impl.cc

Index: athena/home/home_card_impl.cc
diff --git a/athena/home/home_card_impl.cc b/athena/home/home_card_impl.cc
index 5edf5de4ff1fd7603c83474b232f6fe00fa962d0..4ed12a4c13acb4014f45857e5462481dff8303de 100644
--- a/athena/home/home_card_impl.cc
+++ b/athena/home/home_card_impl.cc
@@ -5,13 +5,18 @@
 #include "athena/home/public/home_card.h"
 
 #include "athena/home/app_list_view_delegate.h"
+#include "athena/home/minimized_home.h"
 #include "athena/home/public/app_model_builder.h"
 #include "athena/input/public/accelerator_manager.h"
 #include "athena/screen/public/screen_manager.h"
+#include "athena/wm/public/window_manager.h"
+#include "athena/wm/public/window_manager_observer.h"
+#include "base/bind.h"
 #include "ui/app_list/search_provider.h"
 #include "ui/app_list/views/app_list_view.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/window.h"
+#include "ui/views/layout/box_layout.h"
 #include "ui/wm/core/visibility_controller.h"
 #include "ui/wm/core/window_animations.h"
 
@@ -20,10 +25,27 @@ namespace {
 
 HomeCard* instance = NULL;
 
+// Makes sure the homecard is center-aligned horizontally and bottom-aligned
+// vertically.
 class HomeCardLayoutManager : public aura::LayoutManager {
  public:
-  explicit HomeCardLayoutManager(aura::Window* container)
-      : container_(container) {}
+  class Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    virtual int GetHomeCardHeight() const = 0;
+
+    virtual int GetHorizontalMargin() const = 0;
+
+    // TODO(mukai): Remove this when bubble is no longer used for
+    // VISIBLE_CENTERED or VISIBLE_BOTTOM states.
+    virtual bool HasShadow() const = 0;
+
+    virtual aura::Window* GetNativeWindow() = 0;
+  };
+
+  explicit HomeCardLayoutManager(Delegate* delegate)
+      : delegate_(delegate) {}
   virtual ~HomeCardLayoutManager() {}
 
   void UpdateVirtualKeyboardBounds(const gfx::Rect& bounds) {
@@ -49,37 +71,42 @@ class HomeCardLayoutManager : public aura::LayoutManager {
   }
 
   void Layout() {
-    const int kHomeCardHeight = 150;
-    const int kHomeCardHorizontalMargin = 50;
-    // Currently the home card is provided as a bubble and the bounds has to be
-    // increased to cancel the shadow.
-    // TODO(mukai): stops using the bubble and remove this.
-    const int kHomeCardShadowWidth = 30;
-    if (container_->children().size() < 1)
-      return;
-    aura::Window* home_card = container_->children()[0];
-    if (!home_card->IsVisible())
+    int height = delegate_->GetHomeCardHeight();
+    int horiz_margin = delegate_->GetHorizontalMargin();
+    aura::Window* home_card = delegate_->GetNativeWindow();
+    // |home_card| could be detached from the root window (e.g. when it is being
+    // destroyed).
+    if (!home_card || !home_card->GetRootWindow())
       return;
 
     gfx::Rect screen_bounds = home_card->GetRootWindow()->bounds();
     if (!virtual_keyboard_bounds_.IsEmpty())
       screen_bounds.set_height(virtual_keyboard_bounds_.y());
     gfx::Rect card_bounds = screen_bounds;
-    card_bounds.Inset(kHomeCardHorizontalMargin,
-                      screen_bounds.height() - kHomeCardHeight,
-                      kHomeCardHorizontalMargin,
-                      0);
-    card_bounds.Inset(-kHomeCardShadowWidth, -kHomeCardShadowWidth);
+    card_bounds.Inset(horiz_margin, screen_bounds.height() - height,
+                      horiz_margin, 0);
+
+    if (delegate_->HasShadow()) {
+      // Currently the home card is provided as a bubble and the bounds has to
+      // be increased to cancel the shadow.
+      // TODO(mukai): stops using the bubble and remove this.
+      const int kHomeCardShadowWidth = 30;
+      card_bounds.Inset(-kHomeCardShadowWidth, -kHomeCardShadowWidth);
+    }
     SetChildBoundsDirect(home_card, card_bounds);
   }
 
-  aura::Window* container_;
+  Delegate* delegate_;
   gfx::Rect virtual_keyboard_bounds_;
 
   DISALLOW_COPY_AND_ASSIGN(HomeCardLayoutManager);
 };
 
-class HomeCardImpl : public HomeCard, public AcceleratorHandler {
+class HomeCardImpl : public HomeCard,
+                     public AcceleratorHandler,
+                     public HomeCardLayoutManager::Delegate,
+                     public MinimizedHomeDragDelegate,
+                     public WindowManagerObserver {
  public:
   explicit HomeCardImpl(AppModelBuilder* model_builder);
   virtual ~HomeCardImpl();
@@ -111,11 +138,59 @@ class HomeCardImpl : public HomeCard, public AcceleratorHandler {
     return true;
   }
 
+  // HomeCardLayoutManager::Delegate:
+  virtual int GetHomeCardHeight() const OVERRIDE {
+    const int kHomeCardHeight = 150;
+    const int kHomeCardMinimizedHeight = 8;
+    CHECK_NE(HIDDEN, state_);
+    return state_ == VISIBLE_MINIMIZED ? kHomeCardMinimizedHeight :
+                                         kHomeCardHeight;
+  }
+
+  virtual int GetHorizontalMargin() const OVERRIDE {
+    CHECK_NE(HIDDEN, state_);
+    const int kHomeCardHorizontalMargin = 50;
+    return state_ == VISIBLE_MINIMIZED ? 0 : kHomeCardHorizontalMargin;
+  }
+
+  virtual bool HasShadow() const OVERRIDE {
+    CHECK_NE(HIDDEN, state_);
+    return state_ != VISIBLE_MINIMIZED;
+  }
+
+  virtual aura::Window* GetNativeWindow() OVERRIDE {
+    switch (state_) {
+      case HIDDEN:
+        return NULL;
+      case VISIBLE_MINIMIZED:
+        return minimized_widget_ ? minimized_widget_->GetNativeWindow() : NULL;
+      case VISIBLE_CENTERED:
+      case VISIBLE_BOTTOM:
+        return home_card_widget_ ? home_card_widget_->GetNativeWindow() : NULL;
+    }
+    return NULL;
+  }
+
+  // MinimizedHomeDragDelegate:
+  virtual void OnDragUpCompleted() OVERRIDE {
+    WindowManager::GetInstance()->ToggleOverview();
+  }
+
+  // WindowManagerObserver:
+  virtual void OnOverviewModeEnter() OVERRIDE {
+    SetState(VISIBLE_BOTTOM);
+  }
+
+  virtual void OnOverviewModeExit() OVERRIDE {
+    SetState(VISIBLE_MINIMIZED);
+  }
+
   scoped_ptr<AppModelBuilder> model_builder_;
 
   HomeCard::State state_;
 
   views::Widget* home_card_widget_;
+  views::Widget* minimized_widget_;
   AppListViewDelegate* view_delegate_;
   HomeCardLayoutManager* layout_manager_;
 
@@ -128,26 +203,43 @@ class HomeCardImpl : public HomeCard, public AcceleratorHandler {
 
 HomeCardImpl::HomeCardImpl(AppModelBuilder* model_builder)
     : model_builder_(model_builder),
-      state_(HIDDEN),
+      state_(VISIBLE_MINIMIZED),
       home_card_widget_(NULL),
+      minimized_widget_(NULL),
       layout_manager_(NULL) {
   DCHECK(!instance);
   instance = this;
+  WindowManager::GetInstance()->AddObserver(this);
 }
 
 HomeCardImpl::~HomeCardImpl() {
   DCHECK(instance);
+  WindowManager::GetInstance()->RemoveObserver(this);
   home_card_widget_->CloseNow();
+  minimized_widget_->CloseNow();
   view_delegate_ = NULL;
   instance = NULL;
 }
 
 void HomeCardImpl::SetState(HomeCard::State state) {
-  if (state == HIDDEN)
-    home_card_widget_->Hide();
-  else
-    home_card_widget_->Show();
+  // Update |state_| before changing the visibility of the widgets, so that
+  // LayoutManager callbacks get the correct state.
   state_ = state;
+  switch (state_) {
+    case VISIBLE_MINIMIZED:
+      home_card_widget_->Hide();
+      minimized_widget_->Show();
+      break;
+    case HIDDEN:
+      home_card_widget_->Hide();
+      minimized_widget_->Hide();
+      break;
+    case VISIBLE_BOTTOM:
+    case VISIBLE_CENTERED:
+      home_card_widget_->Show();
+      minimized_widget_->Hide();
+      break;
+  }
 }
 
 void HomeCardImpl::RegisterSearchProvider(
@@ -159,6 +251,12 @@ void HomeCardImpl::RegisterSearchProvider(
 
 void HomeCardImpl::UpdateVirtualKeyboardBounds(
     const gfx::Rect& bounds) {
+  if (state_ == VISIBLE_MINIMIZED) {
+    if (bounds.IsEmpty())
+      minimized_widget_->Show();
+    else
+      minimized_widget_->Hide();
+  }
   layout_manager_->UpdateVirtualKeyboardBounds(bounds);
 }
 
@@ -167,7 +265,7 @@ void HomeCardImpl::Init() {
 
   aura::Window* container =
       ScreenManager::Get()->CreateContainer("HomeCardContainer");
-  layout_manager_ = new HomeCardLayoutManager(container);
+  layout_manager_ = new HomeCardLayoutManager(this);
   container->SetLayoutManager(layout_manager_);
   wm::SetChildWindowVisibilityChangesAnimated(container);
 
@@ -182,9 +280,10 @@ void HomeCardImpl::Init() {
       views::BubbleBorder::FLOAT,
       true /* border_accepts_events */);
   home_card_widget_ = view->GetWidget();
-  // TODO: the initial value might not be visible.
-  state_ = VISIBLE_CENTERED;
-  view->ShowWhenReady();
+
+  // Start off in the minimized state.
+  minimized_widget_ = CreateMinimizedHome(container, this);
+  SetState(VISIBLE_MINIMIZED);
 }
 
 void HomeCardImpl::InstallAccelerators() {