aura: Implement app list M19 mock.

- Make AppListModel flat, i.e. remove AppListItemGroupModel and its view;
- Move BuildAppListModel from ShellDelegate into AppListViewDelegate;
- Make AppListModelBuilder ready to support simple query;
- Make AppListItemView based on CustomButton and get rid of its listener
  interface since we can use ButtonListener for that now;
- Update UI based on M19 mock:
  - AppListItemView show label on its right instead of bottom;
  - AppListItemView has a mouse hover effect now;
  - AppListModelView show AppListItemView tiles alphabetically from top to
    bottom instead of from left to right;
  - AppListView to occupy full screen include area behind the launcher;
  - AppListView to have a 0.4 black shade;

BUG=98308
TEST=Verify applist should look like M19 mock.

Review URL: https://chromiumcodereview.appspot.com/9559005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124661 0039d316-1c4b-4281-b951-d872f2087c98

24 files changed, 388 insertions, 835 deletions

diff --git a/ash/app_list/app_list.cc b/ash/app_list/app_list.cc
index d9e30d1..da9384a 100644
--- a/ash/app_list/app_list.cc
+++ b/ash/app_list/app_list.cc
@@ -4,15 +4,12 @@
 
 #include "ash/app_list/app_list.h"
 
-#include "ash/app_list/app_list_model.h"
 #include "ash/app_list/app_list_view.h"
-#include "ash/ash_switches.h"
 #include "ash/shell_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
-#include "base/bind.h"
-#include "base/command_line.h"
 #include "ui/aura/event.h"
+#include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/gfx/compositor/scoped_layer_animation_settings.h"
 #include "ui/gfx/screen.h"
@@ -22,19 +19,11 @@ namespace internal {
 
 namespace {
 
-// Gets preferred bounds of app list window in show/hide state.
-gfx::Rect GetPreferredBounds(bool show) {
-  // The y-axis offset used at the beginning of showing animation.
-  static const int kMoveUpAnimationOffset = 50;
-
+// Gets preferred bounds of app list window.
+gfx::Rect GetPreferredBounds() {
   gfx::Point cursor = gfx::Screen::GetCursorScreenPoint();
-  gfx::Rect work_area = gfx::Screen::GetMonitorWorkAreaNearestPoint(cursor);
-  gfx::Rect widget_bounds(work_area);
-  widget_bounds.Inset(100, 100);
-  if (!show)
-    widget_bounds.Offset(0, kMoveUpAnimationOffset);
-
-  return widget_bounds;
+  // Use full monitor rect so that the app list shade goes behind the launcher.
+  return gfx::Screen::GetMonitorAreaNearestPoint(cursor);
 }
 
 ui::Layer* GetLayer(views::Widget* widget) {
@@ -62,15 +51,11 @@ void AppList::SetVisible(bool visible) {
   if (widget_) {
     ScheduleAnimation();
   } else if (is_visible_) {
-    scoped_ptr<AppListModel> model(new AppListModel);
-    Shell::GetInstance()->delegate()->BuildAppListModel(model.get());
-
     // AppListModel and AppListViewDelegate are owned by AppListView. They
     // will be released with AppListView on close.
     AppListView* app_list_view = new AppListView(
-        model.release(),
         Shell::GetInstance()->delegate()->CreateAppListViewDelegate(),
-        GetPreferredBounds(false));
+        GetPreferredBounds());
     SetWidget(app_list_view->GetWidget());
   }
 }
@@ -89,12 +74,13 @@ void AppList::SetWidget(views::Widget* widget) {
     widget_ = widget;
     widget_->AddObserver(this);
     Shell::GetInstance()->AddRootWindowEventFilter(this);
+    Shell::GetRootWindow()->AddRootWindowObserver(this);
 
-    widget_->SetBounds(GetPreferredBounds(false));
     widget_->SetOpacity(0);
     ScheduleAnimation();
 
     widget_->Show();
+    widget_->Activate();
   } else {
     widget->Close();
   }
@@ -107,6 +93,7 @@ void AppList::ResetWidget() {
   widget_->RemoveObserver(this);
   GetLayer(widget_)->GetAnimator()->RemoveObserver(this);
   Shell::GetInstance()->RemoveRootWindowEventFilter(this);
+  Shell::GetRootWindow()->RemoveRootWindowObserver(this);
   widget_ = NULL;
 }
 
@@ -124,7 +111,6 @@ void AppList::ScheduleAnimation() {
 
   ui::ScopedLayerAnimationSettings app_list_animation(layer->GetAnimator());
   app_list_animation.AddObserver(this);
-  layer->SetBounds(GetPreferredBounds(is_visible_));
   layer->SetOpacity(is_visible_ ? 1.0 : 0.0);
 
   ui::Layer* default_container_layer = default_container->layer();
@@ -143,7 +129,7 @@ bool AppList::PreHandleKeyEvent(aura::Window* target,
 }
 
 bool AppList::PreHandleMouseEvent(aura::Window* target,
-                                 aura::MouseEvent* event) {
+                                  aura::MouseEvent* event) {
   if (widget_ && is_visible_ && event->type() == ui::ET_MOUSE_PRESSED) {
     aura::MouseEvent translated(*event, target, widget_->GetNativeView());
     if (!widget_->GetNativeView()->ContainsPoint(translated.location()))
@@ -164,6 +150,13 @@ ui::GestureStatus AppList::PreHandleGestureEvent(
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// AppList,  ura::RootWindowObserver implementation:
+void AppList::OnRootWindowResized(const gfx::Size& new_size) {
+  if (widget_ && is_visible_)
+    widget_->SetBounds(gfx::Rect(new_size));
+}
+
+////////////////////////////////////////////////////////////////////////////////
 // AppList, ui::ImplicitAnimationObserver implementation:
 
 void AppList::OnImplicitAnimationsCompleted() {
diff --git a/ash/app_list/app_list.h b/ash/app_list/app_list.h
index b499498..a786c35 100644
--- a/ash/app_list/app_list.h
+++ b/ash/app_list/app_list.h
@@ -9,6 +9,7 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ui/aura/event_filter.h"
+#include "ui/aura/root_window_observer.h"
 #include "ui/gfx/compositor/layer_animation_observer.h"
 #include "ui/views/widget/widget.h"
 
@@ -20,6 +21,7 @@ namespace internal {
 // While the UI is visible, it monitors things such as app list widget's
 // activation state and desktop mouse click to auto dismiss the UI.
 class AppList : public aura::EventFilter,
+                public aura::RootWindowObserver,
                 public ui::ImplicitAnimationObserver,
                 public views::Widget::Observer {
  public:
@@ -54,6 +56,9 @@ class AppList : public aura::EventFilter,
       aura::Window* target,
       aura::GestureEvent* event) OVERRIDE;
 
+  // aura::RootWindowObserver overrides:
+  virtual void OnRootWindowResized(const gfx::Size& new_size) OVERRIDE;
+
   // ui::ImplicitAnimationObserver overrides:
   virtual void OnImplicitAnimationsCompleted() OVERRIDE;
 
diff --git a/ash/app_list/app_list_groups_view.cc b/ash/app_list/app_list_groups_view.cc
deleted file mode 100644
index 01571f1..0000000
--- a/ash/app_list/app_list_groups_view.cc
+++ /dev/null
@@ -1,243 +0,0 @@
-// Copyright (c) 2011 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 "ash/app_list/app_list_groups_view.h"
-
-#include "ash/app_list/app_list_item_group_model.h"
-#include "ash/app_list/app_list_item_group_view.h"
-#include "ash/app_list/app_list_item_view.h"
-#include "ash/app_list/app_list_model.h"
-#include "base/utf_string_conversions.h"
-#include "third_party/skia/include/core/SkColor.h"
-#include "ui/base/resource/resource_bundle.h"
-#include "ui/views/animation/bounds_animator.h"
-#include "ui/views/controls/button/text_button.h"
-#include "ui/views/layout/box_layout.h"
-
-namespace ash {
-
-namespace {
-
-const SkColor kPageHeaderColor = SkColorSetARGB(0xFF, 0xB2, 0xB2, 0xB2);
-const SkColor kSelectedPageHeaderColor = SK_ColorWHITE;
-
-// Creates page headers view that hosts page title buttons.
-views::View* CreatePageHeader() {
-  views::View* header = new views::View;
-  header->SetLayoutManager(
-      new views::BoxLayout(views::BoxLayout::kHorizontal, 0, 0, 0));
-  return header;
-}
-
-// Creates page header button view that shows page title.
-views::View* CreatePageHeaderButton(views::ButtonListener* listener,
-                                    const std::string& title ) {
-  views::TextButton* button = new views::TextButton(listener,
-        UTF8ToUTF16(title));
-
-  ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-  button->SetFont(rb.GetFont(ResourceBundle::BaseFont).DeriveFont(
-      2, gfx::Font::BOLD));
-  button->SetEnabledColor(kPageHeaderColor);
-  return button;
-}
-
-// Gets preferred bounds of buttons and page.
-void GetPageAndHeaderBounds(views::View* parent,
-                            views::View* buttons,
-                            views::View* page,
-                            gfx::Rect* buttons_bounds,
-                            gfx::Rect* page_bounds) {
-  gfx::Rect content_bounds = parent->GetContentsBounds();
-
-  if (buttons) {
-    gfx::Size buttons_size = buttons->GetPreferredSize();
-    if (buttons_bounds) {
-      buttons_bounds->SetRect(
-          (content_bounds.width() - buttons_size.width()) / 2,
-          content_bounds.bottom() - buttons_size.height(),
-          buttons_size.width(), buttons_size.height());
-    }
-
-    content_bounds.set_height(
-        std::max(0, content_bounds.height() - buttons_size.height()));
-  }
-
-  if (page_bounds) {
-    gfx::Size page_size = page->GetPreferredSize();
-    *page_bounds = content_bounds.Center(page_size);
-  }
-}
-
-}  // namespace
-
-AppListGroupsView::AppListGroupsView(AppListModel* model,
-                                     AppListItemViewListener* listener)
-    : model_(model),
-      listener_(listener),
-      page_buttons_(NULL),
-      current_page_(0) {
-  animator_.reset(new views::BoundsAnimator(this));
-  model_->AddObserver(this);
-  Update();
-}
-
-AppListGroupsView::~AppListGroupsView() {
-  model_->RemoveObserver(this);
-}
-
-views::View* AppListGroupsView::GetFocusedTile() const {
-  AppListItemGroupView* page = GetCurrentPageView();
-  return page ? page->GetFocusedTile() : NULL;
-}
-
-void AppListGroupsView::Update() {
-  current_page_ = 0;
-  page_buttons_ = NULL;
-  RemoveAllChildViews(true);
-
-  int page_count = model_->group_count();
-  if (!page_count)
-    return;
-
-  if (page_count > 1)
-    AddChildView(page_buttons_ = CreatePageHeader());
-
-  for (int i = 0; i < page_count; ++i) {
-    AppListItemGroupModel* group = model_->GetGroup(i);
-    AddPage(group->title(), new AppListItemGroupView(group, listener_));
-  }
-
-  if (!size().IsEmpty())
-    Layout();
-  SetCurrentPage(0);
-}
-
-void AppListGroupsView::AddPage(const std::string& title,
-                                AppListItemGroupView* page) {
-  pages_.push_back(page);
-  AddChildView(page);
-
-  if (page_buttons_)
-    page_buttons_->AddChildView(CreatePageHeaderButton(this, title));
-}
-
-int AppListGroupsView::GetPreferredTilesPerRow() const {
-  return std::max(1, width() / AppListItemView::kTileSize);
-}
-
-AppListItemGroupView* AppListGroupsView::GetCurrentPageView() const {
-  return static_cast<size_t>(current_page_) < pages_.size() ?
-      pages_[current_page_] : NULL;
-}
-
-void AppListGroupsView::SetCurrentPage(int page) {
-  int previous_page = current_page_;
-  current_page_ = page;
-
- // Updates page buttons.
-  if (page_buttons_) {
-    for (int i = 0; i < page_buttons_->child_count(); ++i) {
-      views::TextButton* button = static_cast<views::TextButton*>(
-          page_buttons_->child_at(i));
-
-      button->SetEnabledColor(i == current_page_ ?
-          kSelectedPageHeaderColor : kPageHeaderColor);
-    }
-    page_buttons_->SchedulePaint();
-  }
-
-  // Gets sliding animation direction.
-  int dir = previous_page < current_page_ ? -1 :
-      previous_page > current_page_ ? 1 : 0;
-
-  // Skips animation if no sliding needed or no valid size.
-  if (dir == 0 || size().IsEmpty())
-    return;
-
-  animator_->Cancel();
-
-  // Makes sure new page has correct layout and focus to its focused tile.
-  AppListItemGroupView* current_view = GetCurrentPageView();
-  current_view->SetTilesPerRow(GetPreferredTilesPerRow());
-  views::View* tile = current_view->GetFocusedTile();
-  if (tile)
-    tile->RequestFocus();
-
-  // Prepares current page before animation.
-  gfx::Rect current_page_bounds;
-  GetPageAndHeaderBounds(this, page_buttons_, current_view,
-      NULL, &current_page_bounds);
-  current_page_bounds.Offset(- dir * width(), 0);
-  current_view->SetBoundsRect(current_page_bounds);
-
-  // Schedules animations to slide out previous page and slide in current page.
-  AppListItemGroupView* previous_view = pages_[previous_page];
-  gfx::Rect previous_page_bounds = previous_view->bounds();
-  previous_page_bounds.Offset(dir * width(), 0);
-  animator_->AnimateViewTo(previous_view, previous_page_bounds);
-
-  current_page_bounds.Offset(dir * width(), 0);
-  animator_->AnimateViewTo(current_view, current_page_bounds);
-}
-
-void AppListGroupsView::Layout() {
-  AppListItemGroupView* page = GetCurrentPageView();
-  if (!page)
-    return;
-
-  page->SetTilesPerRow(GetPreferredTilesPerRow());
-
-  gfx::Rect buttons_bounds;
-  gfx::Rect page_bounds;
-  GetPageAndHeaderBounds(this, page_buttons_, page,
-      &buttons_bounds, &page_bounds);
-
-  if (page_buttons_)
-    page_buttons_->SetBoundsRect(buttons_bounds);
-
-  page->SetBoundsRect(page_bounds);
-}
-
-bool AppListGroupsView::OnKeyPressed(const views::KeyEvent& event) {
-  if (event.IsControlDown()) {
-    switch (event.key_code()) {
-      case ui::VKEY_LEFT:
-        if (current_page_ > 0)
-          SetCurrentPage(current_page_ - 1);
-        return true;
-      case ui::VKEY_RIGHT:
-        if (static_cast<size_t>(current_page_ + 1) < pages_.size())
-          SetCurrentPage(current_page_ + 1);
-        return true;
-      default:
-        break;
-    }
-  }
-
-  return false;
-}
-
-void AppListGroupsView::ButtonPressed(views::Button* sender,
-                                      const views::Event& event) {
-  DCHECK(page_buttons_);
-  for (int i = 0; i < page_buttons_->child_count(); ++i) {
-    if (page_buttons_->child_at(i) == sender)
-      SetCurrentPage(i);
-  }
-}
-
-void AppListGroupsView::ListItemsAdded(int start, int count) {
-  Update();
-}
-
-void AppListGroupsView::ListItemsRemoved(int start, int count) {
-  Update();
-}
-
-void AppListGroupsView::ListItemsChanged(int start, int count) {
-  NOTREACHED();
-}
-
-}  // namespace ash
diff --git a/ash/app_list/app_list_groups_view.h b/ash/app_list/app_list_groups_view.h
deleted file mode 100644
index e08660c..0000000
--- a/ash/app_list/app_list_groups_view.h
+++ /dev/null
@@ -1,84 +0,0 @@
-// Copyright (c) 2011 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 ASH_APP_LIST_APP_LIST_GROUPS_VIEW_H_
-#define ASH_APP_LIST_APP_LIST_GROUPS_VIEW_H_
-#pragma once
-
-#include <string>
-#include <vector>
-
-#include "ash/ash_export.h"
-#include "ui/base/models/list_model_observer.h"
-#include "ui/views/controls/button/button.h"
-#include "ui/views/view.h"
-
-namespace views {
-class BoundsAnimator;
-}
-
-namespace ash {
-
-class AppListItemGroupView;
-class AppListItemViewListener;
-class AppListModel;
-
-// AppListGroupsView displays the UI for an AppListModel. If there are more than
-// one group in the model , a button strip is displayed to allow user to switch
-// between pages.
-class ASH_EXPORT AppListGroupsView : public views::View,
-                                            public views::ButtonListener,
-                                            public ui::ListModelObserver {
- public:
-  AppListGroupsView(AppListModel* model,
-                    AppListItemViewListener* listener);
-  virtual ~AppListGroupsView();
-
-  // Gets current focused tile.
-  views::View* GetFocusedTile() const;
-
- private:
-  // Updates from model.
-  void Update();
-
-  // Adds a result group page.
-  void AddPage(const std::string& title, AppListItemGroupView* page);
-
-  // Gets preferred number of tiles per row.
-  int GetPreferredTilesPerRow() const;
-
-  // Gets current result page.
-  AppListItemGroupView* GetCurrentPageView() const;
-
-  // Sets current result page.
-  void SetCurrentPage(int page);
-
-  // Overridden from views::View:
-  virtual void Layout() OVERRIDE;
-  virtual bool OnKeyPressed(const views::KeyEvent& event) OVERRIDE;
-
-  // Overridden from views::ButtonListener:
-  virtual void ButtonPressed(views::Button* sender,
-                             const views::Event& event) OVERRIDE;
-
-  // Overridden from ListModelObserver:
-  virtual void ListItemsAdded(int start, int count) OVERRIDE;
-  virtual void ListItemsRemoved(int start, int count) OVERRIDE;
-  virtual void ListItemsChanged(int start, int count) OVERRIDE;
-
-  AppListModel* model_;  // Owned by parent AppListView.
-  AppListItemViewListener* listener_;
-
-  std::vector<AppListItemGroupView*> pages_;
-  views::View* page_buttons_;
-  int current_page_;
-
-  scoped_ptr<views::BoundsAnimator> animator_;
-
-  DISALLOW_COPY_AND_ASSIGN(AppListGroupsView);
-};
-
-}  // namespace ash
-
-#endif  // ASH_APP_LIST_APP_LIST_GROUPS_VIEW_H_
diff --git a/ash/app_list/app_list_item_group_model.cc b/ash/app_list/app_list_item_group_model.cc
deleted file mode 100644
index c2fce3a..0000000
--- a/ash/app_list/app_list_item_group_model.cc
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright (c) 2011 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 "ash/app_list/app_list_item_group_model.h"
-
-namespace ash {
-
-AppListItemGroupModel::AppListItemGroupModel(const std::string& title)
-    : title_(title) {
-}
-
-AppListItemGroupModel::~AppListItemGroupModel() {
-}
-
-void AppListItemGroupModel::AddItem(AppListItemModel* item) {
-  items_.Add(item);
-}
-
-AppListItemModel* AppListItemGroupModel::GetItem(int index) {
-  DCHECK(index >= 0 && index < item_count());
-  return items_.item_at(index);
-}
-
-}  // namespace ash
diff --git a/ash/app_list/app_list_item_group_model.h b/ash/app_list/app_list_item_group_model.h
deleted file mode 100644
index 665f4a1..0000000
--- a/ash/app_list/app_list_item_group_model.h
+++ /dev/null
@@ -1,46 +0,0 @@
-// Copyright (c) 2011 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 ASH_APP_LIST_APP_LIST_ITEM_GROUP_MODEL_H_
-#define ASH_APP_LIST_APP_LIST_ITEM_GROUP_MODEL_H_
-#pragma once
-
-#include <string>
-
-#include "ash/app_list/app_list_item_model.h"
-#include "base/basictypes.h"
-#include "ash/ash_export.h"
-#include "ui/base/models/list_model.h"
-
-namespace ash {
-
-// AppListItemGroupModel holds a list of AppListItemModels.
-class ASH_EXPORT AppListItemGroupModel {
- public:
-  typedef ui::ListModel<AppListItemModel> Items;
-
-  explicit AppListItemGroupModel(const std::string& title);
-  virtual ~AppListItemGroupModel();
-
-  void AddItem(AppListItemModel* item);
-  AppListItemModel* GetItem(int index);
-
-  const std::string& title() const {
-    return title_;
-  }
-
-  int item_count() const {
-    return items_.item_count();
-  }
-
- private:
-  const std::string title_;
-  Items items_;
-
-  DISALLOW_COPY_AND_ASSIGN(AppListItemGroupModel);
-};
-
-}  // namespace ash
-
-#endif  // ASH_APP_LIST_APP_LIST_ITEM_GROUP_MODEL_H_
diff --git a/ash/app_list/app_list_item_group_view.cc b/ash/app_list/app_list_item_group_view.cc
deleted file mode 100644
index ed34983..0000000
--- a/ash/app_list/app_list_item_group_view.cc
+++ /dev/null
@@ -1,115 +0,0 @@
-// Copyright (c) 2011 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 "ash/app_list/app_list_item_group_view.h"
-
-#include "ash/app_list/app_list_item_group_model.h"
-#include "ash/app_list/app_list_item_view.h"
-#include "ui/views/layout/grid_layout.h"
-
-namespace ash {
-
-AppListItemGroupView::AppListItemGroupView(AppListItemGroupModel* model,
-                                           AppListItemViewListener* listener)
-    : model_(model),
-      listener_(listener),
-      tiles_per_row_(0),
-      focused_index_(0) {
-  Update();
-}
-
-AppListItemGroupView::~AppListItemGroupView() {
-}
-
-void AppListItemGroupView::SetTilesPerRow(int tiles_per_row) {
-  if (tiles_per_row_ == tiles_per_row)
-    return;
-
-  tiles_per_row_ = tiles_per_row;
-  Update();
-}
-
-void AppListItemGroupView::Update() {
-  RemoveAllChildViews(true);
-  if (model_->item_count() == 0 || tiles_per_row_ == 0)
-    return;
-
-  views::GridLayout* layout = new views::GridLayout(this);
-  SetLayoutManager(layout);
-
-  const int kTileColumnSetId = 0;
-  views::ColumnSet* column_set = layout->AddColumnSet(kTileColumnSetId);
-  for (int i = 0; i < tiles_per_row_; ++i) {
-    column_set->AddColumn(views::GridLayout::FILL, views::GridLayout::FILL, 1,
-                          views::GridLayout::USE_PREF, 0, 0);
-  }
-
-  for (int i = 0; i < model_->item_count(); ++i) {
-    if (i % tiles_per_row_ == 0)
-      layout->StartRow(0, kTileColumnSetId);
-
-    layout->AddView(new AppListItemView(model_->GetItem(i), listener_));
-  }
-}
-
-views::View* AppListItemGroupView::GetFocusedTile() {
-  return focused_index_ < child_count() ? child_at(focused_index_) : NULL;
-}
-
-void AppListItemGroupView::UpdateFocusedTile(views::View* tile) {
-  for (int i = 0; i < child_count(); ++i) {
-    if (child_at(i) == tile) {
-      focused_index_ = i;
-      break;
-    }
-  }
-}
-
-void AppListItemGroupView::SetFocusedTileByIndex(int index) {
-  index = std::max(0, std::min(child_count() - 1, index));
-  if (index != focused_index_)
-    child_at(index)->RequestFocus();
-}
-
-bool AppListItemGroupView::OnKeyPressed(const views::KeyEvent& event) {
-  if (!event.IsControlDown() && !event.IsShiftDown() && !event.IsAltDown()) {
-    // Arrow keys navigates in tile grid.
-    switch (event.key_code()) {
-      case ui::VKEY_LEFT:
-        if (focused_index_ > 0)
-          SetFocusedTileByIndex(focused_index_ - 1);
-        return true;
-      case ui::VKEY_RIGHT:
-        if (focused_index_ + 1 < child_count())
-          SetFocusedTileByIndex(focused_index_ + 1);
-        return true;
-      case ui::VKEY_UP:
-        if (focused_index_ - tiles_per_row_ >= 0)
-          SetFocusedTileByIndex(focused_index_ - tiles_per_row_);
-        return true;
-      case ui::VKEY_DOWN:
-        if (focused_index_ + tiles_per_row_ < child_count())
-          SetFocusedTileByIndex(focused_index_ + tiles_per_row_);
-        return true;
-      default:
-        break;
-    }
-  }
-
-  return false;
-}
-
-void AppListItemGroupView::ListItemsAdded(int start, int count) {
-  Update();
-}
-
-void AppListItemGroupView::ListItemsRemoved(int start, int count) {
-  Update();
-}
-
-void AppListItemGroupView::ListItemsChanged(int start, int count) {
-  NOTREACHED();
-}
-
-}  // namespace ash
diff --git a/ash/app_list/app_list_item_group_view.h b/ash/app_list/app_list_item_group_view.h
deleted file mode 100644
index 834fb59..0000000
--- a/ash/app_list/app_list_item_group_view.h
+++ /dev/null
@@ -1,65 +0,0 @@
-// Copyright (c) 2011 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 ASH_APP_LIST_APP_LIST_ITEM_GROUP_VIEW_H_
-#define ASH_APP_LIST_APP_LIST_ITEM_GROUP_VIEW_H_
-#pragma once
-
-#include "ash/ash_export.h"
-#include "ui/base/models/list_model_observer.h"
-#include "ui/views/view.h"
-
-namespace ash {
-
-class AppListItemGroupModel;
-class AppListItemViewListener;
-
-// AppListItemGroupView displays its children tiles in a grid.
-class ASH_EXPORT AppListItemGroupView
-    : public views::View,
-      public ui::ListModelObserver {
- public:
-  AppListItemGroupView(AppListItemGroupModel* model,
-                       AppListItemViewListener* listener);
-  virtual ~AppListItemGroupView();
-
-  // Sets tiles per row.
-  void SetTilesPerRow(int tiles_per_row);
-
-  // Gets currently focused tile.
-  views::View* GetFocusedTile();
-
-  // Updates tiles page when a tile gets focus.
-  void UpdateFocusedTile(views::View* tile);
-
- private:
-  // Updates from model.
-  void Update();
-
-  // Sets focused tile by index.
-  void SetFocusedTileByIndex(int index);
-
-  // Overridden from views::View:
-  virtual bool OnKeyPressed(const views::KeyEvent& event) OVERRIDE;
-
-  // Overridden from ListModelObserver:
-  virtual void ListItemsAdded(int start, int count) OVERRIDE;
-  virtual void ListItemsRemoved(int start, int count) OVERRIDE;
-  virtual void ListItemsChanged(int start, int count) OVERRIDE;
-
-  AppListItemGroupModel* model_;
-  AppListItemViewListener* listener_;
-
-  // Tiles per row.
-  int tiles_per_row_;
-
-  // Index of focused tile view.
-  int focused_index_;
-
-  DISALLOW_COPY_AND_ASSIGN(AppListItemGroupView);
-};
-
-}  // namespace ash
-
-#endif  // ASH_APP_LIST_APP_LIST_ITEM_GROUP_VIEW_H_
diff --git a/ash/app_list/app_list_item_view.cc b/ash/app_list/app_list_item_view.cc
index 41c1f89..ed50a86 100644
--- a/ash/app_list/app_list_item_view.cc
+++ b/ash/app_list/app_list_item_view.cc
@@ -1,53 +1,68 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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 "ash/app_list/app_list_item_view.h"
 
-#include "ash/app_list/app_list_item_group_view.h"
 #include "ash/app_list/app_list_item_model.h"
-#include "ash/app_list/app_list_item_view_listener.h"
 #include "ash/app_list/drop_shadow_label.h"
 #include "base/utf_string_conversions.h"
 #include "third_party/skia/include/core/SkColor.h"
+#include "ui/base/animation/throb_animation.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/font.h"
 #include "ui/views/controls/image_view.h"
-#include "ui/views/controls/label.h"
-#include "ui/views/widget/widget.h"
 
 namespace ash {
 
 namespace {
 
-const double kFocusedScale = 1.1;
+const int kIconTitleSpacing = 5;
 
 const SkColor kTitleColor = SK_ColorWHITE;
+const SkColor kHoverColor = SkColorSetARGB(0x33, 0xFF, 0xFF, 0xFF); // 0.2 white
 
 gfx::Font GetTitleFont() {
   static gfx::Font* font = NULL;
   if (!font) {
     ResourceBundle& rb = ResourceBundle::GetSharedInstance();
     font = new gfx::Font(rb.GetFont(ResourceBundle::BaseFont).DeriveFont(
-        2, gfx::Font::BOLD));
+        1, gfx::Font::BOLD));
   }
   return *font;
 }
 
+// An image view that is not interactive.
+class StaticImageView : public views::ImageView {
+ public:
+  StaticImageView() : ImageView() {
+  }
+
+ private:
+  // views::View overrides:
+  virtual bool HitTest(const gfx::Point& l) const OVERRIDE {
+    return false;
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(StaticImageView);
+};
+
 }  // namespace
 
+// static
+const char AppListItemView::kViewClassName[] = "ash/app_list/AppListItemView";
+
 AppListItemView::AppListItemView(AppListItemModel* model,
-                                 AppListItemViewListener* listener)
-    : model_(model),
-      listener_(listener),
-      icon_(new views::ImageView),
+                                 views::ButtonListener* listener)
+    : CustomButton(listener),
+      model_(model),
+      icon_(new StaticImageView),
       title_(new DropShadowLabel) {
-  set_focusable(true);
-
   title_->SetFont(GetTitleFont());
   title_->SetBackgroundColor(0);
   title_->SetEnabledColor(kTitleColor);
+  title_->SetHorizontalAlignment(views::Label::ALIGN_LEFT);
 
   AddChildView(icon_);
   AddChildView(title_);
@@ -61,11 +76,6 @@ AppListItemView::~AppListItemView() {
   model_->RemoveObserver(this);
 }
 
-void AppListItemView::NotifyActivated(int event_flags) {
-  if (listener_)
-    listener_->AppListItemActivated(this, event_flags);
-}
-
 void AppListItemView::ItemIconChanged() {
   icon_->SetImage(model_->icon());
 }
@@ -74,89 +84,42 @@ void AppListItemView::ItemTitleChanged() {
   title_->SetText(UTF8ToUTF16(model_->title()));
 }
 
-gfx::Size AppListItemView::GetPreferredSize() {
-  return gfx::Size(kTileSize, kTileSize);
+std::string AppListItemView::GetClassName() const {
+  return kViewClassName;
 }
 
-void AppListItemView::Layout() {
-  gfx::Rect rect(GetContentsBounds());
+gfx::Size AppListItemView::GetPreferredSize() {
+  gfx::Size icon_size = icon_->GetPreferredSize();
   gfx::Size title_size = title_->GetPreferredSize();
 
-  if (!HasFocus()) {
-    const int horiz_padding = (kTileSize - kIconSize) / 2;
-    const int vert_padding = (kTileSize - title_size.height() - kIconSize) / 2;
-    rect.Inset(horiz_padding, vert_padding);
-  }
-
-  icon_->SetBounds(rect.x(), rect.y(),
-      rect.width(), rect.height() - title_size.height());
-
-  title_->SetBounds(rect.x(), rect.bottom() - title_size.height(),
-      rect.width(), title_size.height());
+  return gfx::Size(icon_size.width() + kIconTitleSpacing + title_size.width(),
+                   std::max(icon_size.height(), title_size.height()));
 }
 
-void AppListItemView::OnFocus() {
-  View::OnFocus();
-
-  gfx::Size icon_size = icon_->GetPreferredSize();
-  icon_size.set_width(icon_size.width() * kFocusedScale);
-  icon_size.set_height(icon_size.height() * kFocusedScale);
-
-  gfx::Size max_size = GetPreferredSize();
-  if (icon_size.width() > max_size.width() ||
-      icon_size.height() > max_size.height()) {
-    double aspect =
-        static_cast<double>(icon_size.width()) / icon_size.height();
-
-    if (aspect > 1) {
-      icon_size.set_width(max_size.width());
-      icon_size.set_height(icon_size.width() / aspect);
-    } else {
-      icon_size.set_height(max_size.height());
-      icon_size.set_width(icon_size.height() * aspect);
-    }
-  }
+void AppListItemView::Layout() {
+  gfx::Rect rect(GetContentsBounds());
 
+  int preferred_icon_size = rect.height() - 2 * kPadding;
+  gfx::Size icon_size(preferred_icon_size, preferred_icon_size);
   icon_->SetImageSize(icon_size);
-  Layout();
-
-  AppListItemGroupView* group_view =
-      static_cast<AppListItemGroupView*>(parent());
-  group_view->UpdateFocusedTile(this);
-}
-
-void AppListItemView::OnBlur() {
-  icon_->ResetImageSize();
-  Layout();
-  SchedulePaint();
+  icon_->SetBounds(rect.x() + kPadding, rect.y(),
+                   icon_size.width(), rect.height());
+
+  title_->SetBounds(
+      icon_->bounds().right() + kIconTitleSpacing,
+      rect.y(),
+      rect.right() - kPadding - icon_->bounds().right() - kIconTitleSpacing,
+      rect.height());
 }
 
-bool AppListItemView::OnKeyPressed(const views::KeyEvent& event) {
-  if (event.key_code() == ui::VKEY_RETURN) {
-    NotifyActivated(event.flags());
-    return true;
+void AppListItemView::OnPaint(gfx::Canvas* canvas) {
+  gfx::Rect rect(GetContentsBounds());
+  if (hover_animation_->is_animating()) {
+    int alpha = SkColorGetA(kHoverColor) * hover_animation_->GetCurrentValue();
+    canvas->FillRect(rect, SkColorSetA(kHoverColor, alpha));
+  } else if (state() == BS_HOT) {
+    canvas->FillRect(rect, kHoverColor);
   }
-
-  return false;
-}
-
-bool AppListItemView::OnMousePressed(const views::MouseEvent& event) {
-  views::View* hit_view = GetEventHandlerForPoint(event.location());
-  bool hit = hit_view != this;
-  if (hit)
-    RequestFocus();
-
-  return hit;
-}
-
-void AppListItemView::OnMouseReleased(const views::MouseEvent& event) {
-  views::View* hit_view = GetEventHandlerForPoint(event.location());
-  if (hit_view != this)
-    NotifyActivated(event.flags());
-}
-
-void AppListItemView::OnPaintFocusBorder(gfx::Canvas* canvas) {
-  // No focus border for AppListItemView.
 }
 
 }  // namespace ash
diff --git a/ash/app_list/app_list_item_view.h b/ash/app_list/app_list_item_view.h
index 120d97c..c4ef19d 100644
--- a/ash/app_list/app_list_item_view.h
+++ b/ash/app_list/app_list_item_view.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -8,7 +8,7 @@
 
 #include "ash/app_list/app_list_item_model_observer.h"
 #include "ash/ash_export.h"
-#include "ui/views/view.h"
+#include "ui/views/controls/button/custom_button.h"
 
 class SkBitmap;
 
@@ -20,46 +20,37 @@ class Label;
 namespace ash {
 
 class AppListItemModel;
-class AppListItemViewListener;
 
-class ASH_EXPORT AppListItemView : public views::View,
-                                          public AppListItemModelObserver {
+class ASH_EXPORT AppListItemView : public views::CustomButton,
+                                   public AppListItemModelObserver {
  public:
   AppListItemView(AppListItemModel* model,
-                  AppListItemViewListener* listener);
+                  views::ButtonListener* listener);
   virtual ~AppListItemView();
 
   AppListItemModel* model() const {
     return model_;
   }
 
-  // Tile size
-  static const int kTileSize = 180;
+  // Icon padding
+  static const int kPadding = 5;
 
-  // Preferred icon size.
-  static const int kIconSize = 128;
+  // Internal class name.
+  static const char kViewClassName[];
 
  protected:
-  // Notifies listener when activated.
-  void NotifyActivated(int event_flags);
-
   // AppListItemModelObserver overrides:
   virtual void ItemIconChanged() OVERRIDE;
   virtual void ItemTitleChanged() OVERRIDE;
 
   // views::View overrides:
+  virtual std::string GetClassName() const OVERRIDE;
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   virtual void Layout() OVERRIDE;
-  virtual void OnFocus() OVERRIDE;
-  virtual void OnBlur() OVERRIDE;
-  virtual bool OnKeyPressed(const views::KeyEvent& event) OVERRIDE;
-  virtual bool OnMousePressed(const views::MouseEvent& event) OVERRIDE;
-  virtual void OnMouseReleased(const views::MouseEvent& event) OVERRIDE;
-  virtual void OnPaintFocusBorder(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
 
  private:
   AppListItemModel* model_;
-  AppListItemViewListener* listener_;
 
   views::ImageView* icon_;
   views::Label* title_;
diff --git a/ash/app_list/app_list_item_view_listener.h b/ash/app_list/app_list_item_view_listener.h
deleted file mode 100644
index a008f72..0000000
--- a/ash/app_list/app_list_item_view_listener.h
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright (c) 2011 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 ASH_APP_LIST_APP_LIST_ITEM_VIEW_LISTENER_H_
-#define ASH_APP_LIST_APP_LIST_ITEM_VIEW_LISTENER_H_
-#pragma once
-
-#include "ash/ash_export.h"
-
-namespace ash {
-
-class AppListItemView;
-
-class ASH_EXPORT AppListItemViewListener {
- public:
-  // Invoked when an AppListeItemModelView is activated by click or enter key.
-  virtual void AppListItemActivated(AppListItemView* sender,
-                                    int event_flags) = 0;
-
- protected:
-  virtual ~AppListItemViewListener() {}
-};
-
-}  // namespace ash
-
-#endif  // ASH_APP_LIST_APP_LIST_ITEM_VIEW_LISTENER_H_
diff --git a/ash/app_list/app_list_model.cc b/ash/app_list/app_list_model.cc
index 8362dd6..2d93fbe 100644
--- a/ash/app_list/app_list_model.cc
+++ b/ash/app_list/app_list_model.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -12,21 +12,20 @@ AppListModel::AppListModel() {
 AppListModel::~AppListModel() {
 }
 
-void AppListModel::AddGroup(AppListItemGroupModel* group) {
-  groups_.Add(group);
+void AppListModel::AddItem(AppListItemModel* item) {
+  items_.Add(item);
 }
 
-AppListItemGroupModel* AppListModel::GetGroup(int index) {
-  DCHECK(index >= 0 && index < group_count());
-  return groups_.item_at(index);
+AppListItemModel* AppListModel::GetItem(int index) {
+  return items_.item_at(index);
 }
 
 void AppListModel::AddObserver(ui::ListModelObserver* observer) {
-  groups_.AddObserver(observer);
+  items_.AddObserver(observer);
 }
 
 void AppListModel::RemoveObserver(ui::ListModelObserver* observer) {
-  groups_.RemoveObserver(observer);
+  items_.RemoveObserver(observer);
 }
 
 }  // namespace ash
diff --git a/ash/app_list/app_list_model.h b/ash/app_list/app_list_model.h
index bb797a1..fbced97a 100644
--- a/ash/app_list/app_list_model.h
+++ b/ash/app_list/app_list_model.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -6,32 +6,36 @@
 #define ASH_APP_LIST_APP_LIST_MODEL_H_
 #pragma once
 
-#include "ash/app_list/app_list_item_group_model.h"
 #include "base/basictypes.h"
+#include "ash/app_list/app_list_item_model.h"
 #include "ash/ash_export.h"
 #include "ui/base/models/list_model.h"
 
 namespace ash {
 
-// Model for AppListView. It is consisted of a list of AppListItemGroupModels,
-// which in turn owns a list of AppListItemModels.
+class AppListItemModel;
+
+// Model for AppListModelView that owns a list of AppListItemModels.
 class ASH_EXPORT AppListModel {
  public:
   AppListModel();
   virtual ~AppListModel();
 
-  void AddGroup(AppListItemGroupModel* group);
-  AppListItemGroupModel* GetGroup(int index);
+  // Adds an item to the model. The model takes ownership of |item|.
+  void AddItem(AppListItemModel* item);
+
+  AppListItemModel* GetItem(int index);
 
   void AddObserver(ui::ListModelObserver* observer);
   void RemoveObserver(ui::ListModelObserver* observer);
 
-  int group_count() const {
-    return groups_.item_count();
+  int item_count() const {
+    return items_.item_count();
   }
 
  private:
-  ui::ListModel<AppListItemGroupModel> groups_;
+  typedef ui::ListModel<AppListItemModel> Items;
+  Items items_;
 
   DISALLOW_COPY_AND_ASSIGN(AppListModel);
 };
diff --git a/ash/app_list/app_list_model_view.cc b/ash/app_list/app_list_model_view.cc
new file mode 100644
index 0000000..8667c66
--- /dev/null
+++ b/ash/app_list/app_list_model_view.cc
@@ -0,0 +1,120 @@
+// Copyright (c) 2012 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 "ash/app_list/app_list_model_view.h"
+
+#include "ash/app_list/app_list_item_view.h"
+#include "ash/app_list/app_list_model.h"
+#include "base/utf_string_conversions.h"
+
+namespace ash {
+
+namespace {
+
+// Minimum label width.
+const int kMinLabelWidth = 150;
+
+// Calculate preferred tile size for given |content_size| and |num_of_tiles|.
+gfx::Size CalculateTileSize(const gfx::Size& content_size, int num_of_tiles) {
+  // Icon sizes to try.
+  const int kIconSizes[] = { 64, 48, 32, 16 };
+
+  int tile_height = 0;
+  int tile_width = 0;
+  int rows = 0;
+  int cols = 0;
+
+  // Chooses the biggest icon size that could fit all tiles.
+  for (size_t i = 0; i < arraysize(kIconSizes); ++i) {
+    int icon_size = kIconSizes[i];
+    tile_height = icon_size + 2 * AppListItemView::kPadding;
+    tile_width = icon_size + std::min(kMinLabelWidth, icon_size * 2) +
+        2 * AppListItemView::kPadding;
+
+    rows = content_size.height() / tile_height;
+    cols = std::min(content_size.width() / tile_width,
+                    (num_of_tiles - 1) / rows + 1);
+    if (rows * cols >= num_of_tiles)
+      break;
+  }
+
+  if (rows && cols) {
+    // Adjusts tile width to fit |content_size| as much as possible.
+    tile_width = std::max(tile_width, content_size.width() / cols);
+    return gfx::Size(tile_width, tile_height);
+  }
+
+  return gfx::Size();
+}
+
+}  // namespace
+
+AppListModelView::AppListModelView(views::ButtonListener* listener)
+    : model_(NULL),
+      listener_(listener) {
+}
+
+AppListModelView::~AppListModelView() {
+  if (model_)
+    model_->RemoveObserver(this);
+}
+
+void AppListModelView::SetModel(AppListModel* model) {
+  DCHECK(model);
+
+  if (model_)
+    model_->RemoveObserver(this);
+
+  model_ = model;
+  model_->AddObserver(this);
+  Update();
+}
+
+void AppListModelView::Update() {
+  RemoveAllChildViews(true);
+  if (!model_ || model_->item_count() == 0)
+    return;
+
+  for (int i = 0; i < model_->item_count(); ++i)
+    AddChildView(new AppListItemView(model_->GetItem(i), listener_));
+
+  Layout();
+  SchedulePaint();
+}
+
+void AppListModelView::Layout() {
+  gfx::Rect rect(GetContentsBounds());
+  if (rect.IsEmpty())
+    return;
+
+  gfx::Size tile_size = CalculateTileSize(rect.size(), child_count());
+
+  int col_bottom = rect.bottom();
+  gfx::Rect current_tile(rect.origin(), tile_size);
+
+  for (int i = 0; i < child_count(); ++i) {
+    views::View* view = child_at(i);
+    view->SetBoundsRect(current_tile);
+
+    current_tile.Offset(0, tile_size.height());
+    if (current_tile.bottom() >= col_bottom) {
+      current_tile.set_x(current_tile.x() + tile_size.width());
+      current_tile.set_y(rect.y());
+    }
+  }
+}
+
+void AppListModelView::ListItemsAdded(int start, int count) {
+  Update();
+}
+
+void AppListModelView::ListItemsRemoved(int start, int count) {
+  Update();
+}
+
+void AppListModelView::ListItemsChanged(int start, int count) {
+  NOTREACHED();
+}
+
+}  // namespace ash
diff --git a/ash/app_list/app_list_model_view.h b/ash/app_list/app_list_model_view.h
new file mode 100644
index 0000000..55d69f7
--- /dev/null
+++ b/ash/app_list/app_list_model_view.h
@@ -0,0 +1,50 @@
+// Copyright (c) 2012 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 ASH_APP_LIST_APP_LIST_MODEL_VIEW_H_
+#define ASH_APP_LIST_APP_LIST_MODEL_VIEW_H_
+#pragma once
+
+#include "ui/base/models/list_model_observer.h"
+#include "ui/views/view.h"
+
+namespace views {
+class ButtonListener;
+}
+
+namespace ash {
+
+class AppListModel;
+
+// AppListModelView displays the UI for an AppListModel.
+class AppListModelView : public views::View,
+                         public ui::ListModelObserver {
+ public:
+  explicit AppListModelView(views::ButtonListener* listener);
+  virtual ~AppListModelView();
+
+  // Sets |model| to use. Note this does not take ownership of |model|.
+  void SetModel(AppListModel* model);
+
+ private:
+  // Updates from model.
+  void Update();
+
+  // Overridden from views::View:
+  virtual void Layout() OVERRIDE;
+
+  // Overridden from ListModelObserver:
+  virtual void ListItemsAdded(int start, int count) OVERRIDE;
+  virtual void ListItemsRemoved(int start, int count) OVERRIDE;
+  virtual void ListItemsChanged(int start, int count) OVERRIDE;
+
+  AppListModel* model_;  // Owned by parent AppListView.
+  views::ButtonListener* listener_;
+
+  DISALLOW_COPY_AND_ASSIGN(AppListModelView);
+};
+
+}  // namespace ash
+
+#endif  // ASH_APP_LIST_APP_LIST_MODEL_VIEW_H_
diff --git a/ash/app_list/app_list_view.cc b/ash/app_list/app_list_view.cc
index 9aa34108..c68312e 100644
--- a/ash/app_list/app_list_view.cc
+++ b/ash/app_list/app_list_view.cc
@@ -4,22 +4,33 @@
 
 #include "ash/app_list/app_list_view.h"
 
-#include "ash/app_list/app_list_groups_view.h"
 #include "ash/app_list/app_list_item_view.h"
 #include "ash/app_list/app_list_model.h"
+#include "ash/app_list/app_list_model_view.h"
 #include "ash/app_list/app_list_view_delegate.h"
 #include "ash/shell.h"
-#include "ui/views/layout/fill_layout.h"
+#include "ui/gfx/screen.h"
+#include "ui/views/background.h"
 #include "ui/views/widget/widget.h"
 
 namespace ash {
 
+namespace {
+
+// Margins in pixels from work area edges.
+const int kMargin = 50;
+
+// 0.4 black
+const SkColor kBackgroundColor = SkColorSetARGB(0x66, 0, 0, 0);
+
+}  // namespace
+
 AppListView::AppListView(
-    AppListModel* model,
     AppListViewDelegate* delegate,
     const gfx::Rect& bounds)
-    : model_(model),
-      delegate_(delegate) {
+    : delegate_(delegate),
+      model_view_(NULL) {
+  set_background(views::Background::CreateSolidBackground(kBackgroundColor));
   Init(bounds);
 }
 
@@ -32,13 +43,11 @@ void AppListView::Close() {
 }
 
 void AppListView::Init(const gfx::Rect& bounds) {
-  SetLayoutManager(new views::FillLayout);
-  AppListGroupsView* groups_view = new AppListGroupsView(model_.get(), this);
-  AddChildView(groups_view);
+  model_view_ = new AppListModelView(this);
+  AddChildView(model_view_);
 
   views::Widget::InitParams widget_params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
-  widget_params.bounds = bounds;
   widget_params.delegate = this;
   widget_params.keep_on_top = true;
   widget_params.transparent = true;
@@ -46,9 +55,41 @@ void AppListView::Init(const gfx::Rect& bounds) {
   views::Widget* widget = new views::Widget;
   widget->Init(widget_params);
   widget->SetContentsView(this);
+  widget->SetBounds(bounds);
+
+  UpdateModel();
+}
+
+void AppListView::UpdateModel() {
+  if (delegate_.get()) {
+    scoped_ptr<AppListModel> new_model(new AppListModel);
+    delegate_->BuildAppListModel(std::string(), new_model.get());
+    model_view_->SetModel(new_model.get());
+    model_.reset(new_model.release());
+  }
+}
+
+views::View* AppListView::GetInitiallyFocusedView() {
+  return model_view_;
+}
+
+void AppListView::Layout() {
+  gfx::Rect rect(GetContentsBounds());
+  if (rect.IsEmpty())
+    return;
 
-  if (groups_view->GetFocusedTile())
-    groups_view->GetFocusedTile()->RequestFocus();
+  // Gets work area rect, which is in screen coordinates.
+  gfx::Rect workarea = gfx::Screen::GetMonitorWorkAreaNearestWindow(
+      GetWidget()->GetNativeView());
+
+  // Converts |workarea| into view's coordinates.
+  gfx::Point origin(workarea.origin());
+  views::View::ConvertPointFromScreen(this, &origin);
+  workarea.Offset(-origin.x(), -origin.y());
+
+  rect = rect.Intersect(workarea);
+  rect.Inset(kMargin, kMargin);
+  model_view_->SetBoundsRect(rect);
 }
 
 bool AppListView::OnKeyPressed(const views::KeyEvent& event) {
@@ -67,10 +108,16 @@ bool AppListView::OnMousePressed(const views::MouseEvent& event) {
   return true;
 }
 
-void AppListView::AppListItemActivated(AppListItemView* sender,
-                                       int event_flags) {
-  if (delegate_.get())
-    delegate_->OnAppListItemActivated(sender->model(), event_flags);
+void AppListView::ButtonPressed(views::Button* sender,
+                                const views::Event& event) {
+  if (sender->GetClassName() != AppListItemView::kViewClassName)
+    return;
+
+  if (delegate_.get()) {
+    delegate_->OnAppListItemActivated(
+        static_cast<AppListItemView*>(sender)->model(),
+        event.flags());
+  }
   Close();
 }
 
diff --git a/ash/app_list/app_list_view.h b/ash/app_list/app_list_view.h
index 17bfcec..528f26c 100644
--- a/ash/app_list/app_list_view.h
+++ b/ash/app_list/app_list_view.h
@@ -6,9 +6,8 @@
 #define ASH_APP_LIST_APP_LIST_VIEW_H_
 #pragma once
 
-#include "ash/app_list/app_list_item_view_listener.h"
-#include "ash/ash_export.h"
 #include "base/memory/scoped_ptr.h"
+#include "ui/views/controls/button/button.h"
 #include "ui/views/widget/widget_delegate.h"
 
 namespace views {
@@ -18,16 +17,16 @@ class View;
 namespace ash {
 
 class AppListModel;
+class AppListModelView;
 class AppListViewDelegate;
 
 // AppListView is the top-level view and controller of app list UI. It creates
 // and hosts a AppListModelView and passes AppListModel to it for display.
-class ASH_EXPORT AppListView : public views::WidgetDelegateView,
-                                      public AppListItemViewListener {
+class AppListView : public views::WidgetDelegateView,
+                    public views::ButtonListener {
  public:
-  // Takes ownership of |model| and |delegate|.
-  AppListView(AppListModel* model,
-              AppListViewDelegate* delegate,
+  // Takes ownership of |delegate|.
+  AppListView(AppListViewDelegate* delegate,
               const gfx::Rect& bounds);
   virtual ~AppListView();
 
@@ -38,18 +37,27 @@ class ASH_EXPORT AppListView : public views::WidgetDelegateView,
   // Initializes the window.
   void Init(const gfx::Rect& bounds);
 
+  // Updates model using query text in search box.
+  void UpdateModel();
+
+  // Overridden from views::WidgetDelegateView:
+  virtual views::View* GetInitiallyFocusedView() OVERRIDE;
+
   // Overridden from views::View:
+  virtual void Layout() OVERRIDE;
   virtual bool OnKeyPressed(const views::KeyEvent& event) OVERRIDE;
   virtual bool OnMousePressed(const views::MouseEvent& event) OVERRIDE;
 
-  // Overridden from AppListItemModelViewListener:
-  virtual void AppListItemActivated(AppListItemView* sender,
-                                    int event_flags) OVERRIDE;
+  // Overridden from views::ButtonListener:
+  virtual void ButtonPressed(views::Button* sender,
+                             const views::Event& event) OVERRIDE;
 
   scoped_ptr<AppListModel> model_;
 
   scoped_ptr<AppListViewDelegate> delegate_;
 
+  AppListModelView* model_view_;
+
   DISALLOW_COPY_AND_ASSIGN(AppListView);
 };
 
diff --git a/ash/app_list/app_list_view_delegate.h b/ash/app_list/app_list_view_delegate.h
index 875fa6b..112bfcf 100644
--- a/ash/app_list/app_list_view_delegate.h
+++ b/ash/app_list/app_list_view_delegate.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -6,17 +6,24 @@
 #define ASH_APP_LIST_APP_LIST_VIEW_DELEGATE_H_
 #pragma once
 
+#include <string>
+
 #include "ash/ash_export.h"
 
 namespace ash {
 
 class AppListItemModel;
+class AppListModel;
 
 class ASH_EXPORT AppListViewDelegate {
  public:
   // AppListView owns the delegate.
   virtual ~AppListViewDelegate() {}
 
+  // Invoked to ask the delegate to populate the |model| for given |query|.
+  virtual void BuildAppListModel(const std::string& query,
+                                 AppListModel* model) = 0;
+
   // Invoked an AppListeItemModelView is  activated by click or enter key.
   virtual void OnAppListItemActivated(AppListItemModel* item,
                                       int event_flags) = 0;
diff --git a/ash/ash.gyp b/ash/ash.gyp
index db04b49..a0116b6 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -47,20 +47,15 @@
         'accelerators/nested_dispatcher_controller.h',
         'app_list/app_list.cc',
         'app_list/app_list.h',
-        'app_list/app_list_groups_view.cc',
-        'app_list/app_list_groups_view.h',
-        'app_list/app_list_item_group_model.cc',
-        'app_list/app_list_item_group_model.h',
-        'app_list/app_list_item_group_view.cc',
-        'app_list/app_list_item_group_view.h',
         'app_list/app_list_item_model.cc',
         'app_list/app_list_item_model.h',
         'app_list/app_list_item_model_observer.h',
         'app_list/app_list_item_view.cc',
         'app_list/app_list_item_view.h',
-        'app_list/app_list_item_view_listener.h',
         'app_list/app_list_model.cc',
         'app_list/app_list_model.h',
+        'app_list/app_list_model_view.cc',
+        'app_list/app_list_model_view.h',
         'app_list/app_list_view.cc',
         'app_list/app_list_view.h',
         'app_list/app_list_view_delegate.h',
diff --git a/ash/shell/app_list.cc b/ash/shell/app_list.cc
index eaa4ffa..f4f8bd6 100644
--- a/ash/shell/app_list.cc
+++ b/ash/shell/app_list.cc
@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ash/app_list/app_list_item_group_model.h"
 #include "ash/app_list/app_list_item_model.h"
 #include "ash/app_list/app_list_item_view.h"
 #include "ash/app_list/app_list_model.h"
@@ -36,17 +35,16 @@ class WindowTypeLauncherItem : public ash::AppListItemModel {
 
   static SkBitmap GetIcon(Type type) {
     static const SkColor kColors[] = {
-        SkColorSetA(SK_ColorRED, 0x4F),
-        SkColorSetA(SK_ColorGREEN, 0x4F),
-        SkColorSetA(SK_ColorBLUE, 0x4F),
-        SkColorSetA(SK_ColorYELLOW, 0x4F),
-        SkColorSetA(SK_ColorCYAN, 0x4F),
+        SK_ColorRED,
+        SK_ColorGREEN,
+        SK_ColorBLUE,
+        SK_ColorYELLOW,
+        SK_ColorCYAN,
     };
 
+    const int kIconSize = 128;
     SkBitmap icon;
-    icon.setConfig(SkBitmap::kARGB_8888_Config,
-                   ash::AppListItemView::kIconSize,
-                   ash::AppListItemView::kIconSize);
+    icon.setConfig(SkBitmap::kARGB_8888_Config, kIconSize, kIconSize);
     icon.allocPixels();
     icon.eraseColor(kColors[static_cast<int>(type) % arraysize(kColors)]);
     return icon;
@@ -111,6 +109,21 @@ class ExampleAppListViewDelegate : public ash::AppListViewDelegate {
   ExampleAppListViewDelegate() {}
 
  private:
+  // Overridden from ash::AppListViewDelegate:
+  virtual void BuildAppListModel(const std::string& query,
+                                 AppListModel* model) OVERRIDE {
+    for (int i = 0;
+         i < static_cast<int>(WindowTypeLauncherItem::LAST_TYPE);
+         ++i) {
+      WindowTypeLauncherItem::Type type =
+          static_cast<WindowTypeLauncherItem::Type>(i);
+
+      std::string title = WindowTypeLauncherItem::GetTitle(type);
+      if (title.find(query) != std::string::npos)
+        model->AddItem(new WindowTypeLauncherItem(type));
+    }
+  }
+
   virtual void OnAppListItemActivated(ash::AppListItemModel* item,
                                       int event_flags) OVERRIDE {
     static_cast<WindowTypeLauncherItem*>(item)->Activate(event_flags);
@@ -119,33 +132,8 @@ class ExampleAppListViewDelegate : public ash::AppListViewDelegate {
   DISALLOW_COPY_AND_ASSIGN(ExampleAppListViewDelegate);
 };
 
-ash::AppListItemGroupModel* CreateGroup(
-    const std::string& title,
-    WindowTypeLauncherItem::Type start_type,
-    WindowTypeLauncherItem::Type end_type) {
-  ash::AppListItemGroupModel* group =
-      new ash::AppListItemGroupModel(title);
-  for (int i = static_cast<int>(start_type);
-       i < static_cast<int>(end_type);
-       ++i) {
-    WindowTypeLauncherItem::Type type =
-      static_cast<WindowTypeLauncherItem::Type>(i);
-    group->AddItem(new WindowTypeLauncherItem(type));
-  }
-  return group;
-}
-
 }  // namespace
 
-void BuildAppListModel(ash::AppListModel* model) {
-  model->AddGroup(CreateGroup("Windows",
-      WindowTypeLauncherItem::TOPLEVEL_WINDOW,
-      WindowTypeLauncherItem::WIDGETS_WINDOW));
-  model->AddGroup(CreateGroup("Samples",
-      WindowTypeLauncherItem::WIDGETS_WINDOW,
-      WindowTypeLauncherItem::LAST_TYPE));
-}
-
 ash::AppListViewDelegate* CreateAppListViewDelegate() {
   return new ExampleAppListViewDelegate;
 }
diff --git a/ash/shell/shell_main.cc b/ash/shell/shell_main.cc
index a5dbccf..7cf509fa 100644
--- a/ash/shell/shell_main.cc
+++ b/ash/shell/shell_main.cc
@@ -178,10 +178,6 @@ class ShellDelegateImpl : public ash::ShellDelegate {
     MessageLoopForUI::current()->Quit();
   }
 
-  virtual void BuildAppListModel(ash::AppListModel* model) OVERRIDE {
-    ash::shell::BuildAppListModel(model);
-  }
-
   virtual ash::AppListViewDelegate* CreateAppListViewDelegate() OVERRIDE {
     return ash::shell::CreateAppListViewDelegate();
   }
diff --git a/ash/shell_delegate.h b/ash/shell_delegate.h
index 08caa35..c5ec41b 100644
--- a/ash/shell_delegate.h
+++ b/ash/shell_delegate.h
@@ -23,7 +23,6 @@ class Widget;
 
 namespace ash {
 
-class AppListModel;
 class AppListViewDelegate;
 class LauncherDelegate;
 class LauncherModel;
@@ -63,9 +62,6 @@ class ASH_EXPORT ShellDelegate {
   // Invoked when a user uses Ctrl-Shift-Q to close chrome.
   virtual void Exit() = 0;
 
-  // Invoked to ask the delegate to populate the |model|.
-  virtual void BuildAppListModel(AppListModel* model) = 0;
-
   // Invoked to create an AppListViewDelegate. Shell takes the ownership of
   // the created delegate.
   virtual AppListViewDelegate* CreateAppListViewDelegate() = 0;
diff --git a/ash/test/test_shell_delegate.cc b/ash/test/test_shell_delegate.cc
index 883f073..0379e5e 100644
--- a/ash/test/test_shell_delegate.cc
+++ b/ash/test/test_shell_delegate.cc
@@ -40,9 +40,6 @@ void TestShellDelegate::LockScreen() {
 void TestShellDelegate::Exit() {
 }
 
-void TestShellDelegate::BuildAppListModel(AppListModel* model) {
-}
-
 AppListViewDelegate* TestShellDelegate::CreateAppListViewDelegate() {
   return NULL;
 }
diff --git a/ash/test/test_shell_delegate.h b/ash/test/test_shell_delegate.h
index 9455da0..30f6f44 100644
--- a/ash/test/test_shell_delegate.h
+++ b/ash/test/test_shell_delegate.h
@@ -25,7 +25,6 @@ class TestShellDelegate : public ShellDelegate {
   virtual void LockScreen() OVERRIDE;
 #endif
   virtual void Exit() OVERRIDE;
-  virtual void BuildAppListModel(AppListModel* model) OVERRIDE;
   virtual AppListViewDelegate* CreateAppListViewDelegate() OVERRIDE;
   virtual std::vector<aura::Window*> GetCycleWindowList(
       CycleSource source,