Exports gesture manager to a separate file and adds its unittests.

BUG=403813
R=sadrul@chromium.org
TEST=athena_unittests

Review URL: https://codereview.chromium.org/502583002

Cr-Commit-Position: refs/heads/master@{#291945}

9 files changed, 401 insertions, 153 deletions

diff --git a/athena/athena.gyp b/athena/athena.gyp
index 713c1d3..99e8079 100644
--- a/athena/athena.gyp
+++ b/athena/athena.gyp
@@ -55,6 +55,10 @@
         'home/app_list_view_delegate.h',
         'home/athena_start_page_view.cc',
         'home/athena_start_page_view.h',
+        'home/home_card_constants.cc',
+        'home/home_card_constants.h',
+        'home/home_card_gesture_manager.cc',
+        'home/home_card_gesture_manager.h',
         'home/home_card_impl.cc',
         'home/minimized_home.cc',
         'home/minimized_home.h',
@@ -206,6 +210,7 @@
         'activity/activity_manager_unittest.cc',
         'common/fill_layout_manager_unittest.cc',
         'content/app_activity_unittest.cc',
+        'home/home_card_gesture_manager_unittest.cc',
         'home/home_card_unittest.cc',
         'input/accelerator_manager_unittest.cc',
         'screen/screen_manager_unittest.cc',
diff --git a/athena/home/DEPS b/athena/home/DEPS
index 768b162..e6ce933 100644
--- a/athena/home/DEPS
+++ b/athena/home/DEPS
@@ -1,4 +1,5 @@
 include_rules = [
+  "+athena/athena_export.h",
   "+athena/env/public",
   "+athena/input/public",
   "+athena/screen/public",
diff --git a/athena/home/athena_start_page_view.cc b/athena/home/athena_start_page_view.cc
index 3bbcd44..b5b8fb9 100644
--- a/athena/home/athena_start_page_view.cc
+++ b/athena/home/athena_start_page_view.cc
@@ -4,6 +4,7 @@
 
 #include "athena/home/athena_start_page_view.h"
 
+#include "athena/home/home_card_constants.h"
 #include "base/bind.h"
 #include "base/strings/string_util.h"
 #include "third_party/skia/include/core/SkPaint.h"
@@ -42,9 +43,6 @@ const int kSearchBoxCornerRadius = 2;
 const int kSearchBoxWidth = 490;
 const int kSearchBoxHeight = 40;
 
-// The preferred height for VISIBLE_BOTTOM state.
-const int kPreferredHeightBottom = 100;
-
 class PlaceHolderButton : public views::ImageButton,
                           public views::ButtonListener {
  public:
@@ -214,7 +212,7 @@ void AthenaStartPageView::LayoutSearchResults(bool should_show_search_results) {
       search_results_view_->layer()->GetTargetVisibility()) {
     return;
   }
-  if (GetContentsBounds().height() <= kPreferredHeightBottom) {
+  if (GetContentsBounds().height() <= kHomeCardHeight) {
     search_results_view_->SetVisible(false);
     Layout();
     return;
@@ -281,7 +279,7 @@ void AthenaStartPageView::Layout() {
   gfx::Rect bounds = GetContentsBounds();
   search_results_view_->SetVisible(false);
 
-  if (bounds.height() <= kPreferredHeightBottom) {
+  if (bounds.height() <= kHomeCardHeight) {
     logo_->SetVisible(false);
     gfx::Rect icon_bounds(app_icon_container_->GetPreferredSize());
     icon_bounds.set_x(bounds.x() + kIconMargin);
@@ -296,7 +294,7 @@ void AthenaStartPageView::Layout() {
 
     search_box_container_->SetBounds(
         icon_bounds.right(), bounds.y(),
-        control_bounds.x() - icon_bounds.right(), kPreferredHeightBottom);
+        control_bounds.x() - icon_bounds.right(), kHomeCardHeight);
 
     set_background(views::Background::CreateSolidBackground(
         255, 255, 255, 255 * 0.9));
diff --git a/athena/home/home_card_constants.cc b/athena/home/home_card_constants.cc
new file mode 100644
index 0000000..38596c4
--- /dev/null
+++ b/athena/home/home_card_constants.cc
@@ -0,0 +1,12 @@
+// Copyright 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 "athena/home/home_card_constants.h"
+
+namespace athena {
+
+const int kHomeCardHeight = 100;
+const int kHomeCardMinimizedHeight = 6;
+
+}  // namespace athena
diff --git a/athena/home/home_card_constants.h b/athena/home/home_card_constants.h
new file mode 100644
index 0000000..57520ec
--- /dev/null
+++ b/athena/home/home_card_constants.h
@@ -0,0 +1,20 @@
+// Copyright 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.
+
+#ifndef ATHENA_HOME_HOME_CARD_CONSTANTS_H_
+#define ATHENA_HOME_HOME_CARD_CONSTANTS_H_
+
+#include "athena/athena_export.h"
+
+namespace athena {
+
+// The height of the home card in BOTTOM state.
+ATHENA_EXPORT extern const int kHomeCardHeight;
+
+// The height of the home card of MINIMIZED state.
+ATHENA_EXPORT extern const int kHomeCardMinimizedHeight;
+
+}  // namespace athena
+
+#endif  // ATHENA_HOME_HOME_CARD_CONSTANTS_H_
diff --git a/athena/home/home_card_gesture_manager.cc b/athena/home/home_card_gesture_manager.cc
new file mode 100644
index 0000000..755c29c
--- /dev/null
+++ b/athena/home/home_card_gesture_manager.cc
@@ -0,0 +1,115 @@
+// Copyright 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 "athena/home/home_card_gesture_manager.h"
+
+#include "athena/home/home_card_constants.h"
+#include "ui/events/event.h"
+
+namespace athena {
+
+HomeCardGestureManager::HomeCardGestureManager(Delegate* delegate,
+                                               const gfx::Rect& screen_bounds)
+    : delegate_(delegate),
+      last_state_(HomeCard::Get()->GetState()),
+      y_offset_(0),
+      last_estimated_height_(0),
+      screen_bounds_(screen_bounds) {}
+
+HomeCardGestureManager::~HomeCardGestureManager() {}
+
+void HomeCardGestureManager::ProcessGestureEvent(ui::GestureEvent* event) {
+  switch (event->type()) {
+    case ui::ET_GESTURE_SCROLL_BEGIN:
+      y_offset_ = event->location().y();
+      event->SetHandled();
+      break;
+    case ui::ET_GESTURE_SCROLL_END:
+      event->SetHandled();
+      delegate_->OnGestureEnded(GetClosestState());
+      break;
+    case ui::ET_GESTURE_SCROLL_UPDATE:
+      UpdateScrollState(*event);
+      break;
+    case ui::ET_SCROLL_FLING_START: {
+      const ui::GestureEventDetails& details = event->details();
+      const float kFlingCompletionVelocity = 100.0f;
+      if (::fabs(details.velocity_y()) > kFlingCompletionVelocity) {
+        int step = (details.velocity_y() > 0) ? 1 : -1;
+        int new_state = static_cast<int>(last_state_) + step;
+        if (new_state >= HomeCard::VISIBLE_CENTERED &&
+            new_state <= HomeCard::VISIBLE_MINIMIZED) {
+          last_state_ = static_cast<HomeCard::State>(new_state);
+        }
+        delegate_->OnGestureEnded(last_state_);
+      }
+      break;
+    }
+    default:
+      // do nothing.
+      break;
+  }
+}
+
+HomeCard::State HomeCardGestureManager::GetClosestState() const {
+  // The top position of the bounds for one smaller state than the current
+  // one.
+
+  if (last_estimated_height_ <= kHomeCardMinimizedHeight)
+    return HomeCard::VISIBLE_MINIMIZED;
+
+  HomeCard::State smaller_state = HomeCard::VISIBLE_MINIMIZED;
+  int smaller_height = kHomeCardMinimizedHeight;
+  int bigger_height = kHomeCardHeight;
+  if (last_estimated_height_ > kHomeCardHeight) {
+    smaller_state = HomeCard::VISIBLE_BOTTOM;
+    smaller_height = kHomeCardHeight;
+    bigger_height = screen_bounds_.height();
+  }
+
+  if (last_estimated_height_ - smaller_height <=
+      (bigger_height - smaller_height) / 5) {
+    return smaller_state;
+  }
+
+  return static_cast<HomeCard::State>(smaller_state - 1);
+}
+
+void HomeCardGestureManager::UpdateScrollState(const ui::GestureEvent& event) {
+  last_estimated_height_ =
+      screen_bounds_.height() - event.root_location().y() + y_offset_;
+
+  if (last_estimated_height_ <= kHomeCardMinimizedHeight) {
+    delegate_->OnGestureProgressed(
+        last_state_, HomeCard::VISIBLE_MINIMIZED, 1.0f);
+    last_state_ = HomeCard::VISIBLE_MINIMIZED;
+    return;
+  }
+
+  HomeCard::State state = HomeCard::VISIBLE_BOTTOM;
+  float smaller_height = kHomeCardMinimizedHeight;
+  float bigger_height = kHomeCardHeight;
+  if (last_estimated_height_ > kHomeCardHeight) {
+    state = HomeCard::VISIBLE_CENTERED;
+    smaller_height = kHomeCardHeight;
+    bigger_height = screen_bounds_.height();
+  }
+
+  // The finger is between two states.
+  float progress = (last_estimated_height_ - smaller_height) /
+      (bigger_height - smaller_height);
+
+  if (last_state_ == state) {
+    if (event.details().scroll_y() > 0) {
+      state = static_cast<HomeCard::State>(state + 1);
+      progress = 1.0f - progress;
+    } else {
+      last_state_ = static_cast<HomeCard::State>(last_state_ + 1);
+    }
+  }
+  delegate_->OnGestureProgressed(last_state_, state, progress);
+  last_state_ = state;
+}
+
+}  // namespace athena
diff --git a/athena/home/home_card_gesture_manager.h b/athena/home/home_card_gesture_manager.h
new file mode 100644
index 0000000..8749b91
--- /dev/null
+++ b/athena/home/home_card_gesture_manager.h
@@ -0,0 +1,71 @@
+// Copyright 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.
+
+#ifndef ATHENA_HOME_HOME_CARD_GESTURE_MANAGER_H_
+#define ATHENA_HOME_HOME_CARD_GESTURE_MANAGER_H_
+
+#include "athena/home/public/home_card.h"
+#include "athena/athena_export.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace ui {
+class GestureEvent;
+}
+
+namespace athena {
+
+// Handles the touch gestures over the home card.
+class ATHENA_EXPORT HomeCardGestureManager {
+ public:
+  class Delegate {
+   public:
+    // Called when the gesture has ended. The state of the home card will
+    // end up with |final_state|.
+    virtual void OnGestureEnded(HomeCard::State final_state) = 0;
+
+    // Called when the gesture position is updated so that |delegate| should
+    // update the visual. The arguments represent the state of the current
+    // gesture position is switching from |from_state| to |to_state|, and
+    // the level of the progress is at |progress|, which is 0 to 1.
+    // |from_state| and |to_state| could be same. For example, if the user moves
+    // the finger down to the bottom of the screen, both states are MINIMIZED.
+    // In that case |progress| is 0.
+    virtual void OnGestureProgressed(
+        HomeCard::State from_state,
+        HomeCard::State to_state,
+        float progress) = 0;
+  };
+
+  HomeCardGestureManager(Delegate* delegate,
+                         const gfx::Rect& screen_bounds);
+  ~HomeCardGestureManager();
+
+  void ProcessGestureEvent(ui::GestureEvent* event);
+
+ private:
+  // Get the closest state from the last position.
+  HomeCard::State GetClosestState() const;
+
+  // Update the current position and emits OnGestureProgressed().
+  void UpdateScrollState(const ui::GestureEvent& event);
+
+  Delegate* delegate_;  // Not owned.
+  HomeCard::State last_state_;
+
+  // The offset from the top edge of the home card and the initial position of
+  // gesture.
+  int y_offset_;
+
+  // The estimated height of the home card after the last touch event.
+  int last_estimated_height_;
+
+  // The bounds of the screen to compute the home card bounds.
+  gfx::Rect screen_bounds_;
+
+  DISALLOW_COPY_AND_ASSIGN(HomeCardGestureManager);
+};
+
+}  // namespace athena
+
+#endif  // ATHENA_HOME_HOME_CARD_GESTURE_MANAGER_H_
diff --git a/athena/home/home_card_gesture_manager_unittest.cc b/athena/home/home_card_gesture_manager_unittest.cc
new file mode 100644
index 0000000..06dc792
--- /dev/null
+++ b/athena/home/home_card_gesture_manager_unittest.cc
@@ -0,0 +1,171 @@
+// Copyright 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 "athena/home/home_card_gesture_manager.h"
+
+#include "athena/home/home_card_constants.h"
+#include "athena/home/public/home_card.h"
+#include "athena/test/athena_test_base.h"
+#include "base/time/time.h"
+#include "ui/events/event.h"
+#include "ui/events/event_constants.h"
+
+namespace athena {
+
+class HomeCardGestureManagerTest : public test::AthenaTestBase,
+                                   public HomeCardGestureManager::Delegate {
+ public:
+  HomeCardGestureManagerTest()
+      : final_state_(HomeCard::HIDDEN),
+        last_from_state_(HomeCard::HIDDEN),
+        last_to_state_(HomeCard::HIDDEN),
+        last_progress_(0.0f),
+        last_y_(0),
+        progress_count_(0),
+        end_count_(0) {}
+  virtual ~HomeCardGestureManagerTest() {}
+
+  // testing::Test:
+  virtual void SetUp() OVERRIDE {
+    test::AthenaTestBase::SetUp();
+    gesture_manager_.reset(new HomeCardGestureManager(this, screen_bounds()));
+  }
+
+ protected:
+  int GetEndCountAndReset() {
+    int result = end_count_;
+    end_count_ = 0;
+    return result;
+  }
+  int GetProgressCountAndReset() {
+    int result = progress_count_;
+    progress_count_ = 0;
+    return result;
+  }
+
+  // Process a gesture event for our use case.
+  bool ProcessGestureEvent(ui::EventType type, int y) {
+    ui::GestureEvent event(0, y, ui::EF_NONE, base::TimeDelta(),
+                           ui::GestureEventDetails(type, 0, (y - last_y_)));
+    // Assumes the initial location is based on minimized height.
+    if (type == ui::ET_GESTURE_SCROLL_BEGIN) {
+      gfx::Point location = event.location();
+      location.set_y(
+          location.y() - (screen_bounds().bottom() - kHomeCardMinimizedHeight));
+      event.set_location(location);
+    }
+    gesture_manager_->ProcessGestureEvent(&event);
+    last_y_ = y;
+    return event.handled();
+  }
+  void ProcessFlingGesture(float velocity) {
+    ui::GestureEvent event(0, last_y_, ui::EF_NONE, base::TimeDelta(),
+                           ui::GestureEventDetails(
+                               ui::ET_SCROLL_FLING_START, 0, velocity));
+    gesture_manager_->ProcessGestureEvent(&event);
+  }
+
+  HomeCard::State final_state_;
+  HomeCard::State last_from_state_;
+  HomeCard::State last_to_state_;
+  float last_progress_;
+
+ private:
+  gfx::Rect screen_bounds() const {
+    return gfx::Rect(0, 0, 1280, 1024);
+  }
+
+  // HomeCardGestureManager::Delegate:
+  virtual void OnGestureEnded(HomeCard::State final_state) OVERRIDE {
+    final_state_ = final_state;
+    ++end_count_;
+  }
+
+  virtual void OnGestureProgressed(HomeCard::State from_state,
+                                   HomeCard::State to_state,
+                                   float progress) OVERRIDE {
+    last_from_state_ = from_state;
+    last_to_state_ = to_state;
+    last_progress_ = progress;
+    ++progress_count_;
+  }
+
+  int last_y_;
+  int progress_count_;
+  int end_count_;
+  scoped_ptr<HomeCardGestureManager> gesture_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(HomeCardGestureManagerTest);
+};
+
+TEST_F(HomeCardGestureManagerTest, Basic) {
+  EXPECT_TRUE(ProcessGestureEvent(ui::ET_GESTURE_SCROLL_BEGIN, 1020));
+  EXPECT_EQ(0, GetEndCountAndReset());
+  EXPECT_EQ(0, GetProgressCountAndReset());
+
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 1019);
+  EXPECT_EQ(1, GetProgressCountAndReset());
+  EXPECT_EQ(HomeCard::VISIBLE_MINIMIZED, last_from_state_);
+  EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, last_to_state_);
+  EXPECT_GT(1.0f, last_progress_);
+
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 1010);
+  float progress_1010 = last_progress_;
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 1008);
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 1000);
+  EXPECT_EQ(3, GetProgressCountAndReset());
+  EXPECT_EQ(HomeCard::VISIBLE_MINIMIZED, last_from_state_);
+  EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, last_to_state_);
+  EXPECT_LT(progress_1010, last_progress_);
+
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 900);
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 800);
+  EXPECT_EQ(2, GetProgressCountAndReset());
+  EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, last_from_state_);
+  EXPECT_EQ(HomeCard::VISIBLE_CENTERED, last_to_state_);
+  float progress_800 = last_progress_;
+  EXPECT_GT(1.0f, last_progress_);
+  EXPECT_LT(0.0f, last_progress_);
+
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 790);
+  EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, last_from_state_);
+  EXPECT_EQ(HomeCard::VISIBLE_CENTERED, last_to_state_);
+  EXPECT_LT(progress_800, last_progress_);
+
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 810);
+  EXPECT_EQ(HomeCard::VISIBLE_CENTERED, last_from_state_);
+  EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, last_to_state_);
+  EXPECT_GT(progress_800, (1.0f - last_progress_));
+
+  EXPECT_TRUE(ProcessGestureEvent(ui::ET_GESTURE_SCROLL_END, 810));
+  EXPECT_EQ(1, GetEndCountAndReset());
+  EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, final_state_);
+}
+
+TEST_F(HomeCardGestureManagerTest, FlingUpAtEnd) {
+  EXPECT_TRUE(ProcessGestureEvent(ui::ET_GESTURE_SCROLL_BEGIN, 1020));
+  EXPECT_EQ(0, GetEndCountAndReset());
+  EXPECT_EQ(0, GetProgressCountAndReset());
+
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 1010);
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 800);
+  ProcessFlingGesture(-150.0f);
+  EXPECT_EQ(1, GetEndCountAndReset());
+  EXPECT_EQ(HomeCard::VISIBLE_CENTERED, final_state_);
+}
+
+TEST_F(HomeCardGestureManagerTest, FlingDownAtEnd) {
+  EXPECT_TRUE(ProcessGestureEvent(ui::ET_GESTURE_SCROLL_BEGIN, 1020));
+  EXPECT_EQ(0, GetEndCountAndReset());
+  EXPECT_EQ(0, GetProgressCountAndReset());
+
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 1010);
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 800);
+  ProcessGestureEvent(ui::ET_GESTURE_SCROLL_UPDATE, 200);
+  ProcessFlingGesture(150.0f);
+  EXPECT_EQ(1, GetEndCountAndReset());
+  EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, final_state_);
+}
+
+}  // namespace athena
diff --git a/athena/home/home_card_impl.cc b/athena/home/home_card_impl.cc
index f98e4ab..2078325 100644
--- a/athena/home/home_card_impl.cc
+++ b/athena/home/home_card_impl.cc
@@ -11,6 +11,8 @@
 #include "athena/env/public/athena_env.h"
 #include "athena/home/app_list_view_delegate.h"
 #include "athena/home/athena_start_page_view.h"
+#include "athena/home/home_card_constants.h"
+#include "athena/home/home_card_gesture_manager.h"
 #include "athena/home/minimized_home.h"
 #include "athena/home/public/app_model_builder.h"
 #include "athena/input/public/accelerator_manager.h"
@@ -40,8 +42,6 @@ namespace athena {
 namespace {
 
 HomeCard* instance = NULL;
-const int kHomeCardHeight = 100;
-const int kHomeCardMinimizedHeight = 6;
 
 gfx::Rect GetBoundsForState(const gfx::Rect& screen_bounds,
                             HomeCard::State state) {
@@ -122,151 +122,6 @@ class HomeCardLayoutManager : public aura::LayoutManager {
   DISALLOW_COPY_AND_ASSIGN(HomeCardLayoutManager);
 };
 
-class HomeCardGestureManager {
- public:
-  class Delegate {
-   public:
-    // Called when the gesture has ended. The state of the home card will
-    // end up with |final_state|.
-    virtual void OnGestureEnded(HomeCard::State final_state) = 0;
-
-    // Called when the gesture position is updated so that |delegate| should
-    // update the visual. The arguments represent the state of the current
-    // gesture position is switching from |from_state| to |to_state|, and
-    // the level of the progress is at |progress|, which is 0 to 1.
-    // |from_state| and |to_state| could be same. For example, if the user moves
-    // the finger down to the bottom of the screen, both states are MINIMIZED.
-    // In that case |progress| is 0.
-    virtual void OnGestureProgressed(
-        HomeCard::State from_state,
-        HomeCard::State to_state,
-        float progress) = 0;
-  };
-
-  HomeCardGestureManager(Delegate* delegate,
-                         const gfx::Rect& screen_bounds)
-      : delegate_(delegate),
-        last_state_(HomeCard::Get()->GetState()),
-        y_offset_(0),
-        last_estimated_top_(0),
-        screen_bounds_(screen_bounds) {}
-
-  void ProcessGestureEvent(ui::GestureEvent* event) {
-    switch (event->type()) {
-      case ui::ET_GESTURE_SCROLL_BEGIN:
-        y_offset_ = event->location().y();
-        event->SetHandled();
-        break;
-      case ui::ET_GESTURE_SCROLL_END:
-        event->SetHandled();
-        delegate_->OnGestureEnded(GetClosestState());
-        break;
-      case ui::ET_GESTURE_SCROLL_UPDATE:
-        UpdateScrollState(*event);
-        break;
-      case ui::ET_SCROLL_FLING_START: {
-        const ui::GestureEventDetails& details = event->details();
-        const float kFlingCompletionVelocity = 100.0f;
-        if (::fabs(details.velocity_y()) > kFlingCompletionVelocity) {
-          int step = (details.velocity_y() > 0) ? 1 : -1;
-          int new_state = static_cast<int>(last_state_) + step;
-          if (new_state >= HomeCard::VISIBLE_CENTERED &&
-              new_state <= HomeCard::VISIBLE_MINIMIZED) {
-            last_state_ = static_cast<HomeCard::State>(new_state);
-          }
-          delegate_->OnGestureEnded(last_state_);
-        }
-        break;
-      }
-      default:
-        // do nothing.
-        break;
-    }
-  }
-
- private:
-  HomeCard::State GetClosestState() {
-    // The top position of the bounds for one smaller state than the current
-    // one.
-    int smaller_top = -1;
-    for (int i = HomeCard::VISIBLE_MINIMIZED;
-         i >= HomeCard::VISIBLE_CENTERED; --i) {
-      HomeCard::State state = static_cast<HomeCard::State>(i);
-      int top = GetBoundsForState(screen_bounds_, state).y();
-      if (last_estimated_top_ == top) {
-        return state;
-      } else if (last_estimated_top_ > top) {
-        if (smaller_top < 0)
-          return state;
-
-        if (smaller_top - last_estimated_top_ > (smaller_top - top) / 5) {
-          return state;
-        } else {
-          return static_cast<HomeCard::State>(i + 1);
-        }
-      }
-      smaller_top = top;
-    }
-
-    return last_state_;
-  }
-
-  void UpdateScrollState(const ui::GestureEvent& event) {
-    last_estimated_top_ = event.root_location().y() - y_offset_;
-
-    // The bounds which is at one smaller state than the current one.
-    gfx::Rect smaller_bounds;
-
-    for (int i = HomeCard::VISIBLE_MINIMIZED;
-         i >= HomeCard::VISIBLE_CENTERED; --i) {
-      HomeCard::State state = static_cast<HomeCard::State>(i);
-      const gfx::Rect bounds = GetBoundsForState(screen_bounds_, state);
-      if (last_estimated_top_ == bounds.y()) {
-        delegate_->OnGestureProgressed(last_state_, state, 1.0f);
-        last_state_ = state;
-        return;
-      } else if (last_estimated_top_ > bounds.y()) {
-        if (smaller_bounds.IsEmpty()) {
-          // Smaller than minimized -- returning the minimized bounds.
-          delegate_->OnGestureProgressed(last_state_, state, 1.0f);
-        } else {
-          // The finger is between two states.
-          float progress =
-              static_cast<float>((smaller_bounds.y() - last_estimated_top_)) /
-              (smaller_bounds.y() - bounds.y());
-          if (last_state_ == state) {
-            if (event.details().scroll_y() > 0) {
-              state = static_cast<HomeCard::State>(state + 1);
-              progress = 1.0f - progress;
-            } else {
-              last_state_ = static_cast<HomeCard::State>(last_state_ + 1);
-            }
-          }
-          delegate_->OnGestureProgressed(last_state_, state, progress);
-        }
-        last_state_ = state;
-        return;
-      }
-      smaller_bounds = bounds;
-    }
-  }
-
-  Delegate* delegate_;
-  HomeCard::State last_state_;
-
-  // The offset from the top edge of the home card and the initial position of
-  // gesture.
-  int y_offset_;
-
-  // The estimated top edge of the home card after the last touch event.
-  int last_estimated_top_;
-
-  // The bounds of the screen to compute the home card bounds.
-  gfx::Rect screen_bounds_;
-
-  DISALLOW_COPY_AND_ASSIGN(HomeCardGestureManager);
-};
-
 // The container view of home card contents of each state.
 class HomeCardView : public views::WidgetDelegateView {
  public: