Hover buttons for notification.

 * Chagned WidgetGtk so that any GtkFixed can be parent of WidgetGtk.
 * Close button and Options menu is moved to separate TYPE_CHILD WidgetGtk
   which is shown/hidden as mouse moves.

TODO: host Widget is not transparent right now. I'll address this in separate CL.

BUG=41011
TEST=none

Review URL: http://codereview.chromium.org/1654006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@44861 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 326 insertions, 156 deletions

diff --git a/chrome/browser/chromeos/notifications/balloon_collection_impl.h b/chrome/browser/chromeos/notifications/balloon_collection_impl.h
index a7c2051..013cfcd 100644
--- a/chrome/browser/chromeos/notifications/balloon_collection_impl.h
+++ b/chrome/browser/chromeos/notifications/balloon_collection_impl.h
@@ -20,6 +20,8 @@ class Size;
 
 namespace chromeos {
 
+class BalloonViewImpl;
+
 // A balloon collection represents a set of notification balloons being
 // shown in the chromeos notification panel. Unlike other platforms,
 // chromeos shows the all notifications in the notification panel, and
@@ -38,8 +40,13 @@ class BalloonCollectionImpl : public BalloonCollection,
     virtual void Add(Balloon* balloon) = 0;
     virtual bool Update(Balloon* balloon) = 0;
     virtual void Remove(Balloon* balloon) = 0;
+
+    // Resize notification from webkit.
     virtual void ResizeNotification(Balloon* balloon,
                                     const gfx::Size& size) = 0;
+
+    // Sets the active view.
+    virtual void SetActiveView(BalloonViewImpl* view) = 0;
    private:
     DISALLOW_COPY_AND_ASSIGN(NotificationUI);
   };
diff --git a/chrome/browser/chromeos/notifications/balloon_view.cc b/chrome/browser/chromeos/notifications/balloon_view.cc
index af03ad3..a59219f 100644
--- a/chrome/browser/chromeos/notifications/balloon_view.cc
+++ b/chrome/browser/chromeos/notifications/balloon_view.cc
@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "app/l10n_util.h"
+#include "app/menus/simple_menu_model.h"
 #include "app/resource_bundle.h"
 #include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
@@ -22,36 +23,171 @@
 #include "chrome/common/notification_type.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
+#include "views/background.h"
+#include "views/controls/button/button.h"
+#include "views/controls/button/image_button.h"
 #include "views/controls/button/menu_button.h"
-#include "views/controls/button/text_button.h"
+#include "views/controls/label.h"
 #include "views/controls/menu/menu_2.h"
+#include "views/controls/menu/view_menu_delegate.h"
 #include "views/widget/root_view.h"
+#include "views/widget/widget_gtk.h"
 
 namespace {
 // Menu commands
 const int kRevokePermissionCommand = 0;
 
+// Vertical margin between close button and menu button.
+const int kControlButtonsMargin = 4;
 }  // namespace
 
 namespace chromeos {
 
+// NotificationControlView has close and menu buttons and
+// overlays on top of renderer view.
+class NotificationControlView : public views::View,
+                                public views::ViewMenuDelegate,
+                                public menus::SimpleMenuModel::Delegate,
+                                public views::ButtonListener {
+ public:
+  explicit NotificationControlView(BalloonViewImpl* view)
+      : balloon_view_(view),
+        close_button_(NULL),
+        options_menu_contents_(NULL),
+        options_menu_menu_(NULL),
+        options_menu_button_(NULL) {
+    // TODO(oshima): make background transparent.
+    set_background(views::Background::CreateSolidBackground(SK_ColorWHITE));
+
+    ResourceBundle& rb = ResourceBundle::GetSharedInstance();
+
+    SkBitmap* close_button_n = rb.GetBitmapNamed(IDR_TAB_CLOSE);
+    SkBitmap* close_button_m = rb.GetBitmapNamed(IDR_TAB_CLOSE_MASK);
+    SkBitmap* close_button_h = rb.GetBitmapNamed(IDR_TAB_CLOSE_H);
+    SkBitmap* close_button_p = rb.GetBitmapNamed(IDR_TAB_CLOSE_P);
+
+    close_button_ = new views::ImageButton(this);
+    close_button_->SetImage(views::CustomButton::BS_NORMAL, close_button_n);
+    close_button_->SetImage(views::CustomButton::BS_HOT, close_button_h);
+    close_button_->SetImage(views::CustomButton::BS_PUSHED, close_button_p);
+    close_button_->SetBackground(
+        SK_ColorBLACK, close_button_n, close_button_m);
+
+    AddChildView(close_button_);
+
+    options_menu_button_
+        = new views::MenuButton(NULL, std::wstring(), this, false);
+    options_menu_button_->SetFont(rb.GetFont(ResourceBundle::SmallFont));
+    options_menu_button_->SetIcon(*rb.GetBitmapNamed(IDR_NOTIFICATION_MENU));
+    options_menu_button_->set_border(NULL);
+
+    options_menu_button_->set_icon_placement(views::TextButton::ICON_ON_RIGHT);
+    AddChildView(options_menu_button_);
+
+    // The control view will never be resized, so just layout once.
+    gfx::Size button_size = close_button_->GetPreferredSize();
+    close_button_->SetBounds(
+        0, 0, button_size.width(), button_size.height());
+    gfx::Size options_size = options_menu_button_->GetPreferredSize();
+    options_menu_button_->SetBounds(
+        0, button_size.height() + kControlButtonsMargin,
+        options_size.width(), options_size.height());
+
+    SizeToPreferredSize();
+  }
+
+  virtual gfx::Size GetPreferredSize() {
+    gfx::Rect total_bounds =
+        close_button_->bounds().Union(options_menu_button_->bounds());
+    return total_bounds.size();
+  }
+
+  // views::ViewMenuDelegate implements.
+  virtual void RunMenu(views::View* source, const gfx::Point& pt) {
+    CreateOptionsMenu();
+    options_menu_menu_->RunMenuAt(pt, views::Menu2::ALIGN_TOPRIGHT);
+  }
+
+  // views::ButtonListener implements.
+  virtual void ButtonPressed(views::Button* sender, const views::Event&) {
+    balloon_view_->Close(true);
+  }
+
+  // menus::SimpleMenuModel::Delegate impglements.
+  virtual bool IsCommandIdChecked(int /* command_id */) const {
+    // Nothing in the menu is checked.
+    return false;
+  }
+
+  virtual bool IsCommandIdEnabled(int /* command_id */) const {
+    // All the menu options are always enabled.
+    return true;
+  }
+
+  virtual bool GetAcceleratorForCommandId(
+      int /* command_id */, menus::Accelerator* /* accelerator */) {
+    // Currently no accelerators.
+    return false;
+  }
+
+  virtual void ExecuteCommand(int command_id) {
+    switch (command_id) {
+      case kRevokePermissionCommand:
+        balloon_view_->DenyPermission();
+      default:
+        NOTIMPLEMENTED();
+    }
+  }
+
+ private:
+  void CreateOptionsMenu() {
+    if (options_menu_contents_.get())
+      return;
+    const string16 source_label_text = WideToUTF16Hack(l10n_util::GetStringF(
+        IDS_NOTIFICATION_BALLOON_SOURCE_LABEL,
+        balloon_view_->balloon_->notification().display_source()));
+    const string16 label_text = WideToUTF16Hack(l10n_util::GetStringF(
+        IDS_NOTIFICATION_BALLOON_REVOKE_MESSAGE,
+        balloon_view_->balloon_->notification().display_source()));
+
+    options_menu_contents_.reset(new menus::SimpleMenuModel(this));
+    // TODO(oshima): Showing the source info in the menu for now.
+    // Figure out where to show the source info.
+    options_menu_contents_->AddItem(-1, source_label_text);
+    options_menu_contents_->AddItem(kRevokePermissionCommand, label_text);
+
+    options_menu_menu_.reset(new views::Menu2(options_menu_contents_.get()));
+  }
+
+  BalloonViewImpl* balloon_view_;
+
+  views::ImageButton* close_button_;
+
+  // The options menu.
+  scoped_ptr<menus::SimpleMenuModel> options_menu_contents_;
+  scoped_ptr<views::Menu2> options_menu_menu_;
+  views::MenuButton* options_menu_button_;
+
+  DISALLOW_COPY_AND_ASSIGN(NotificationControlView);
+};
+
 BalloonViewImpl::BalloonViewImpl(bool sticky, bool controls)
     : balloon_(NULL),
       html_contents_(NULL),
       method_factory_(this),
-      close_button_(NULL),
-      options_menu_contents_(NULL),
-      options_menu_menu_(NULL),
-      options_menu_button_(NULL),
       stale_(false),
       sticky_(sticky),
-      controls_(controls) {
+      controls_(controls),
+      closed_(false) {
   // This object is not to be deleted by the views hierarchy,
   // as it is owned by the balloon.
   set_parent_owned(false);
 }
 
 BalloonViewImpl::~BalloonViewImpl() {
+  if (control_view_host_.get()) {
+    control_view_host_->CloseNow();
+  }
   if (html_contents_) {
     html_contents_->Shutdown();
   }
@@ -61,48 +197,10 @@ BalloonViewImpl::~BalloonViewImpl() {
 // BallonViewImpl, BalloonView implementation.
 
 void BalloonViewImpl::Show(Balloon* balloon) {
-  ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-  const std::wstring source_label_text = l10n_util::GetStringF(
-      IDS_NOTIFICATION_BALLOON_SOURCE_LABEL,
-      balloon->notification().display_source());
-  const std::wstring options_text =
-      l10n_util::GetString(IDS_NOTIFICATION_OPTIONS_MENU_LABEL);
-  const std::wstring dismiss_text =
-      l10n_util::GetString(IDS_NOTIFICATION_BALLOON_DISMISS_LABEL);
   balloon_ = balloon;
 
   html_contents_ = new BalloonViewHost(balloon);
   AddChildView(html_contents_->view());
-  if (controls_) {
-    close_button_ = new views::TextButton(this, dismiss_text);
-    close_button_->SetIcon(*rb.GetBitmapNamed(IDR_BALLOON_CLOSE));
-    close_button_->SetHoverIcon(*rb.GetBitmapNamed(IDR_BALLOON_CLOSE_HOVER));
-    close_button_->SetFont(rb.GetFont(ResourceBundle::SmallFont));
-    close_button_->SetEnabledColor(SK_ColorWHITE);
-    close_button_->SetHoverColor(SK_ColorDKGRAY);
-    close_button_->set_alignment(views::TextButton::ALIGN_CENTER);
-    close_button_->set_icon_placement(views::TextButton::ICON_ON_RIGHT);
-    AddChildView(close_button_);
-
-    options_menu_button_
-        = new views::MenuButton(NULL, options_text, this, false);
-    options_menu_button_->SetFont(rb.GetFont(ResourceBundle::SmallFont));
-    options_menu_button_->SetIcon(
-        *rb.GetBitmapNamed(IDR_BALLOON_OPTIONS_ARROW));
-    options_menu_button_->SetHoverIcon(
-        *rb.GetBitmapNamed(IDR_BALLOON_OPTIONS_ARROW_HOVER));
-    options_menu_button_->set_alignment(views::TextButton::ALIGN_CENTER);
-    options_menu_button_->set_icon_placement(views::TextButton::ICON_ON_RIGHT);
-    options_menu_button_->SetEnabledColor(SK_ColorWHITE);
-    options_menu_button_->SetHoverColor(SK_ColorDKGRAY);
-    AddChildView(options_menu_button_);
-
-    source_label_ = new views::Label(source_label_text);
-    source_label_->SetFont(rb.GetFont(ResourceBundle::SmallFont));
-    source_label_->SetColor(SK_ColorWHITE);
-    source_label_->SetHorizontalAlignment(views::Label::ALIGN_LEFT);
-    AddChildView(source_label_);
-  }
   notification_registrar_.Add(this,
     NotificationType::NOTIFY_BALLOON_DISCONNECTED, Source<Balloon>(balloon));
 }
@@ -115,6 +213,7 @@ void BalloonViewImpl::Update() {
 }
 
 void BalloonViewImpl::Close(bool by_user) {
+  closed_ = true;
   MessageLoop::current()->PostTask(
       FROM_HERE,
       method_factory_.NewRunnableMethod(
@@ -138,77 +237,30 @@ void BalloonViewImpl::RepositionToBalloon() {
 // views::View interface overrides.
 
 void BalloonViewImpl::Layout() {
-  gfx::Size button_size;
-  if (close_button_) {
-    button_size = close_button_->GetPreferredSize();
-  }
+  gfx::Size size = balloon_->content_size();
 
-  SetBounds(x(), y(),
-            balloon_->content_size().width(),
-            balloon_->content_size().height() +
-            button_size.height());
-  int x = width() - button_size.width();
-  int y = height() - button_size.height();
+  SetBounds(x(), y(), size.width(), size.height());
 
-  html_contents_->view()->SetBounds(0, 0, width(), y);
+  html_contents_->view()->SetBounds(0, 0, size.width(), size.height());
   if (html_contents_->render_view_host()) {
     RenderWidgetHostView* view = html_contents_->render_view_host()->view();
     if (view)
-      view->SetSize(gfx::Size(width(), y));
+      view->SetSize(size);
   }
-  if (controls_) {
-    close_button_->SetBounds(x, y, button_size.width(), button_size.height());
-    x -= close_button_->GetPreferredSize().width();
-    options_menu_button_->SetBounds(
-        x, y, button_size.width(), button_size.height());
-    source_label_->SetBounds(0, y, x, button_size.height());
-  }
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// views::ViewMenuDelegate implementation.
-
-void BalloonViewImpl::RunMenu(views::View* source, const gfx::Point& pt) {
-  CreateOptionsMenu();
-  options_menu_menu_->RunMenuAt(pt, views::Menu2::ALIGN_TOPRIGHT);
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// views::Button implementation.
-
-void BalloonViewImpl::ButtonPressed(views::Button* sender,
-                                    const views::Event&) {
-  Close(true);
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// menus::SimpleMenuModel::Delegate implementation.
-
-bool BalloonViewImpl::IsCommandIdChecked(int /* command_id */) const {
-  // Nothing in the menu is checked.
-  return false;
-}
-
-bool BalloonViewImpl::IsCommandIdEnabled(int /* command_id */) const {
-  // All the menu options are always enabled.
-  return true;
-}
-
-bool BalloonViewImpl::GetAcceleratorForCommandId(
-    int /* command_id */, menus::Accelerator* /* accelerator */) {
-  // Currently no accelerators.
-  return false;
 }
 
-void BalloonViewImpl::ExecuteCommand(int command_id) {
-  DesktopNotificationService* service =
-      balloon_->profile()->GetDesktopNotificationService();
-  switch (command_id) {
-    case kRevokePermissionCommand:
-      service->DenyPermission(balloon_->notification().origin_url());
-      break;
-    default:
-      NOTIMPLEMENTED();
+void BalloonViewImpl::ViewHierarchyChanged(
+    bool is_add, View* parent, View* child) {
+  if (is_add && GetWidget() && !control_view_host_.get() && controls_) {
+    control_view_host_.reset(
+        new views::WidgetGtk(views::WidgetGtk::TYPE_CHILD));
+    control_view_host_->Init(GetParentNativeView(), gfx::Rect());
+    NotificationControlView* control = new NotificationControlView(this);
+    control_view_host_->set_delete_on_destroy(false);
+    control_view_host_->SetContentsView(control);
+  }
+  if (!is_add && GetWidget() && control_view_host_.get() && controls_) {
+    control_view_host_.release()->CloseNow();
   }
 }
 
@@ -231,30 +283,47 @@ void BalloonViewImpl::Observe(NotificationType type,
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// BalloonViewImpl private.
-
-void BalloonViewImpl::CreateOptionsMenu() {
-  if (options_menu_contents_.get())
-    return;
+// BalloonViewImpl public.
 
-  const string16 label_text = WideToUTF16Hack(l10n_util::GetStringF(
-      IDS_NOTIFICATION_BALLOON_REVOKE_MESSAGE,
-      this->balloon_->notification().display_source()));
+bool BalloonViewImpl::IsFor(const Notification& notification) const {
+  return balloon_->notification().IsSame(notification);
+}
 
-  options_menu_contents_.reset(new menus::SimpleMenuModel(this));
-  options_menu_contents_->AddItem(kRevokePermissionCommand, label_text);
+void BalloonViewImpl::Activated() {
+  DCHECK(control_view_host_.get());
+  // Get the size of Control View.
+  gfx::Size size =
+      control_view_host_->GetRootView()->GetChildViewAt(0)->GetPreferredSize();
+  control_view_host_->Show();
+  control_view_host_->SetBounds(
+      gfx::Rect(width() - size.width(), 0, size.width(), size.height()));
+}
 
-  options_menu_menu_.reset(new views::Menu2(options_menu_contents_.get()));
+void BalloonViewImpl::Deactivated() {
+  if (control_view_host_.get()) {
+    control_view_host_->Hide();
+  }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// BalloonViewImpl private.
+
 void BalloonViewImpl::DelayedClose(bool by_user) {
   html_contents_->Shutdown();
   html_contents_ = NULL;
   balloon_->OnClose(by_user);
 }
 
-bool BalloonViewImpl::IsFor(const Notification& notification) const {
-  return balloon_->notification().IsSame(notification);
+void BalloonViewImpl::DenyPermission() {
+  DesktopNotificationService* service =
+      balloon_->profile()->GetDesktopNotificationService();
+  service->DenyPermission(balloon_->notification().origin_url());
+}
+
+gfx::NativeView BalloonViewImpl::GetParentNativeView() {
+  RenderWidgetHostView* view = html_contents_->render_view_host()->view();
+  DCHECK(view);
+  return view->GetNativeView();
 }
 
 }  // namespace chromeos
diff --git a/chrome/browser/chromeos/notifications/balloon_view.h b/chrome/browser/chromeos/notifications/balloon_view.h
index 0ed77a8..c6032e6 100644
--- a/chrome/browser/chromeos/notifications/balloon_view.h
+++ b/chrome/browser/chromeos/notifications/balloon_view.h
@@ -7,7 +7,6 @@
 #ifndef CHROME_BROWSER_CHROMEOS_NOTIFICATIONS_BALLOON_VIEW_H_
 #define CHROME_BROWSER_CHROMEOS_NOTIFICATIONS_BALLOON_VIEW_H_
 
-#include "app/menus/simple_menu_model.h"
 #include "base/basictypes.h"
 #include "base/scoped_ptr.h"
 #include "base/task.h"
@@ -18,15 +17,14 @@
 #include "gfx/point.h"
 #include "gfx/rect.h"
 #include "gfx/size.h"
-#include "views/controls/button/button.h"
-#include "views/controls/label.h"
-#include "views/controls/menu/view_menu_delegate.h"
 #include "views/view.h"
 
 namespace views {
 class Menu2;
 class MenuButton;
+class MouseEvent;
 class TextButton;
+class WidgetGtk;
 }  // namespace views
 
 class BalloonViewHost;
@@ -36,19 +34,19 @@ class NotificationSource;
 
 namespace chromeos {
 
+class NotificationControlView;
+
 // A balloon view is the UI component for a notification panel.
 class BalloonViewImpl : public BalloonView,
                         public views::View,
-                        public views::ViewMenuDelegate,
-                        public menus::SimpleMenuModel::Delegate,
-                        public NotificationObserver,
-                        public views::ButtonListener {
+                        public NotificationObserver {
  public:
   BalloonViewImpl(bool sticky, bool controls);
   ~BalloonViewImpl();
 
   // views::View interface.
   virtual void Layout();
+  virtual void ViewHierarchyChanged(bool is_add, View* parent, View* child);
 
   // BalloonView interface.
   virtual void Show(Balloon* balloon);
@@ -67,22 +65,25 @@ class BalloonViewImpl : public BalloonView,
   // True if the notification is sticky.
   bool sticky() const { return sticky_; }
 
+  // True if the notification is being closed.
+  bool closed() const { return closed_; }
+
   // True if the balloon is for the given |notification|.
   bool IsFor(const Notification& notification) const;
 
- private:
-  // views::ViewMenuDelegate interface.
-  virtual void RunMenu(views::View* source, const gfx::Point& pt);
+  // Called when the notification becomes active (mouse is on).
+  void Activated();
 
-  // views::ButtonListener interface.
-  virtual void ButtonPressed(views::Button* sender, const views::Event&);
+  // Called when the notification becomes inactive.
+  void Deactivated();
 
-  // menus::SimpleMenuModel::Delegate interface.
-  virtual bool IsCommandIdChecked(int command_id) const;
-  virtual bool IsCommandIdEnabled(int command_id) const;
-  virtual bool GetAcceleratorForCommandId(int command_id,
-                                          menus::Accelerator* accelerator);
-  virtual void ExecuteCommand(int command_id);
+ private:
+  friend class NotificationControlView;
+
+  // views::View interface.
+  virtual gfx::Size GetPreferredSize() {
+    return gfx::Size(1000, 1000);
+  }
 
   // NotificationObserver interface.
   virtual void Observe(NotificationType type,
@@ -95,6 +96,12 @@ class BalloonViewImpl : public BalloonView,
   // Do the delayed close work.
   void DelayedClose(bool by_user);
 
+  // Denies the permission to show the ballooon from its source.
+  void DenyPermission();
+
+  // Returns the renderer's native view.
+  gfx::NativeView GetParentNativeView();
+
   // Non-owned pointer to the balloon which owns this object.
   Balloon* balloon_;
 
@@ -104,22 +111,17 @@ class BalloonViewImpl : public BalloonView,
   // The following factory is used to call methods at a later time.
   ScopedRunnableMethodFactory<BalloonViewImpl> method_factory_;
 
-  // Pointer to sub-view is owned by the View sub-class.
-  views::TextButton* close_button_;
-
-  // Pointer to sub-view is owned by View class.
-  views::Label* source_label_;
+  // A widget for ControlView.
+  scoped_ptr<views::WidgetGtk> control_view_host_;
 
-  // The options menu.
-  scoped_ptr<menus::SimpleMenuModel> options_menu_contents_;
-  scoped_ptr<views::Menu2> options_menu_menu_;
-  views::MenuButton* options_menu_button_;
   bool stale_;
   NotificationRegistrar notification_registrar_;
   // A sticky flag. A sticky notification cannot be dismissed by a user.
   bool sticky_;
   // True if a notification should have info/option/dismiss label/buttons.
   bool controls_;
+  // True if the notification is being closed.
+  bool closed_;
 
   DISALLOW_COPY_AND_ASSIGN(BalloonViewImpl);
 };
diff --git a/chrome/browser/chromeos/notifications/desktop_notifications_unittest.cc b/chrome/browser/chromeos/notifications/desktop_notifications_unittest.cc
index f1018ca..424ea0e 100644
--- a/chrome/browser/chromeos/notifications/desktop_notifications_unittest.cc
+++ b/chrome/browser/chromeos/notifications/desktop_notifications_unittest.cc
@@ -16,6 +16,7 @@ class MockNotificationUI : public BalloonCollectionImpl::NotificationUI {
   virtual void Remove(Balloon* balloon) {}
   virtual void ResizeNotification(Balloon* balloon,
                                   const gfx::Size& size) {}
+  virtual void SetActiveView(BalloonViewImpl* view) {}
 };
 
 MockBalloonCollection::MockBalloonCollection()
diff --git a/chrome/browser/chromeos/notifications/notification_browsertest.cc b/chrome/browser/chromeos/notifications/notification_browsertest.cc
index d90d1fd..916dabe 100644
--- a/chrome/browser/chromeos/notifications/notification_browsertest.cc
+++ b/chrome/browser/chromeos/notifications/notification_browsertest.cc
@@ -176,7 +176,7 @@ IN_PROC_BROWSER_TEST_F(NotificationTest, TestKeepSizeState) {
 
   EXPECT_EQ(NotificationPanel::STICKY_AND_NEW, tester->state());
 
-  panel->OnMouseMotion();
+  panel->OnMouseMotion(gfx::Point(10, 10));
   EXPECT_EQ(NotificationPanel::KEEP_SIZE, tester->state());
 
   collection->Remove(NewMockNotification("1"));
diff --git a/chrome/browser/chromeos/notifications/notification_panel.cc b/chrome/browser/chromeos/notifications/notification_panel.cc
index a673396..fbd56c5 100644
--- a/chrome/browser/chromeos/notifications/notification_panel.cc
+++ b/chrome/browser/chromeos/notifications/notification_panel.cc
@@ -8,6 +8,7 @@
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
+#include "chrome/browser/chromeos/notifications/balloon_collection_impl.h"
 #include "chrome/browser/chromeos/notifications/balloon_view.h"
 #include "gfx/canvas.h"
 #include "grit/generated_resources.h"
@@ -62,10 +63,24 @@ class PanelWidget : public views::WidgetGtk {
         panel_(panel) {
   }
 
+  void UpdateControl() {
+    if (last_point_.get())
+      panel_->OnMouseMotion(*last_point_.get());
+  }
+
   // views::WidgetGtk overrides.
   virtual gboolean OnMotionNotify(GtkWidget* widget, GdkEventMotion* event) {
     gboolean result = WidgetGtk::OnMotionNotify(widget, event);
-    panel_->OnMouseMotion();
+
+    int x = 0, y = 0;
+    GetContainedWidgetEventCoordinates(event, &x, &y);
+    if (!last_point_.get()) {
+      last_point_.reset(new gfx::Point(x, y));
+    } else {
+      last_point_->set_x(x);
+      last_point_->set_y(y);
+    }
+    panel_->OnMouseMotion(*last_point_.get());
     return result;
   }
 
@@ -78,12 +93,14 @@ class PanelWidget : public views::WidgetGtk {
     GetBounds(&bounds, true);
     if (!bounds.Contains(p)) {
       panel_->OnMouseLeave();
+      last_point_.reset();
     }
     return result;
   }
 
  private:
   chromeos::NotificationPanel* panel_;
+  scoped_ptr<gfx::Point> last_point_;
   DISALLOW_COPY_AND_ASSIGN(PanelWidget);
 };
 
@@ -176,6 +193,18 @@ class BalloonSubContainer : public views::View {
     return NULL;
   }
 
+  BalloonViewImpl* FindBalloonView(const gfx::Point point) {
+    gfx::Point copy(point);
+    ConvertPointToView(GetRootView(), this, &copy);
+    for (int i = GetChildViewCount() - 1; i >= 0; --i) {
+      views::View* view = GetChildViewAt(i);
+      if (view->bounds().Contains(copy)) {
+        return static_cast<BalloonViewImpl*>(view);
+      }
+    }
+    return NULL;
+  }
+
  private:
   gfx::Size preferred_size_;
   int margin_;
@@ -252,10 +281,11 @@ class BalloonContainer : public views::View {
   }
 
   // Removes a ballon from the panel.
-  void Remove(Balloon* balloon) {
+  BalloonViewImpl* Remove(Balloon* balloon) {
     BalloonViewImpl* view =
         static_cast<BalloonViewImpl*>(balloon->view());
     GetContainerFor(balloon)->RemoveChildView(view);
+    return view;
   }
 
   // Returns the number of notifications added to the panel.
@@ -313,6 +343,11 @@ class BalloonContainer : public views::View {
     return view ? view : non_sticky_container_->FindBalloonView(notification);
   }
 
+  BalloonViewImpl* FindBalloonView(const gfx::Point& point) {
+    BalloonViewImpl* view = sticky_container_->FindBalloonView(point);
+    return view ? view : non_sticky_container_->FindBalloonView(point);
+  }
+
  private:
   BalloonSubContainer* GetContainerFor(Balloon* balloon) const {
     BalloonViewImpl* view =
@@ -336,7 +371,8 @@ NotificationPanel::NotificationPanel()
       state_(CLOSED),
       task_factory_(this),
       min_bounds_(0, 0, kBalloonMinWidth, kBalloonMinHeight),
-      stale_timeout_(1000 * kStaleTimeoutInSeconds) {
+      stale_timeout_(1000 * kStaleTimeoutInSeconds),
+      active_(NULL) {
   Init();
 }
 
@@ -394,6 +430,7 @@ void NotificationPanel::Add(Balloon* balloon) {
   // Don't resize the panel yet. The panel will be resized when WebKit tells
   // the size in ResizeNotification.
   UpdatePanel(false);
+  UpdateControl();
   StartStaleTimer(balloon);
 }
 
@@ -411,7 +448,11 @@ bool NotificationPanel::Update(Balloon* balloon) {
 }
 
 void NotificationPanel::Remove(Balloon* balloon) {
-  balloon_container_->Remove(balloon);
+  BalloonViewImpl* view = balloon_container_->Remove(balloon);
+  if (view == active_) {
+    active_ = NULL;
+  }
+
   // TODO(oshima): May be we shouldn't close
   // if the mouse pointer is still on the panel.
   if (balloon_container_->GetNotificationCount() == 0)
@@ -427,6 +468,7 @@ void NotificationPanel::Remove(Balloon* balloon) {
       SET_STATE(MINIMIZED);
     UpdatePanel(true);
   }
+  UpdateControl();
 }
 
 void NotificationPanel::ResizeNotification(
@@ -442,6 +484,19 @@ void NotificationPanel::ResizeNotification(
   UpdatePanel(true);
 }
 
+void NotificationPanel::SetActiveView(BalloonViewImpl* view) {
+  // Don't change the active view if it's same notification,
+  // or the notification is being closed.
+  if (active_ == view || (view && view->closed())) {
+    return;
+  }
+  if (active_)
+    active_->Deactivated();
+  active_ = view;
+  if (active_)
+    active_->Activated();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // PanelController overrides.
 
@@ -492,12 +547,15 @@ void NotificationPanel::Observe(NotificationType type,
 // PanelController public.
 
 void NotificationPanel::OnMouseLeave() {
+  SetActiveView(NULL);
   if (balloon_container_->GetNotificationCount() == 0)
     SET_STATE(CLOSED);
   UpdatePanel(true);
 }
 
-void NotificationPanel::OnMouseMotion() {
+void NotificationPanel::OnMouseMotion(const gfx::Point& point) {
+  SetActiveView(balloon_container_->FindBalloonView(point));
+
   SET_STATE(KEEP_SIZE);
 }
 
@@ -568,6 +626,11 @@ void NotificationPanel::UpdatePanel(bool contents_changed) {
   }
 }
 
+void NotificationPanel::UpdateControl() {
+  if (panel_widget_.get())
+    static_cast<PanelWidget*>(panel_widget_.get())->UpdateControl();
+}
+
 gfx::Rect NotificationPanel::GetPreferredBounds() {
   gfx::Size pref_size = balloon_container_->GetPreferredSize();
   int new_height = std::min(pref_size.height(), kMaxPanelHeight);
diff --git a/chrome/browser/chromeos/notifications/notification_panel.h b/chrome/browser/chromeos/notifications/notification_panel.h
index c739880..dfc76a5 100644
--- a/chrome/browser/chromeos/notifications/notification_panel.h
+++ b/chrome/browser/chromeos/notifications/notification_panel.h
@@ -93,6 +93,7 @@ class NotificationPanel : public PanelController::Delegate,
   virtual void Remove(Balloon* balloon);
   virtual void ResizeNotification(Balloon* balloon,
                                   const gfx::Size& size);
+  virtual void SetActiveView(BalloonViewImpl* view);
 
   // PanelController overrides.
   virtual string16 GetPanelTitle();
@@ -106,7 +107,7 @@ class NotificationPanel : public PanelController::Delegate,
 
   // Called when a mouse left the panel window.
   void OnMouseLeave();
-  void OnMouseMotion();
+  void OnMouseMotion(const gfx::Point& point);
 
   NotificationPanelTester* GetTester();
 
@@ -121,6 +122,9 @@ class NotificationPanel : public PanelController::Delegate,
   // Update the Panel Size according to its state.
   void UpdatePanel(bool contents_changed);
 
+  // Update the notification's control view state.
+  void UpdateControl();
+
   // Returns the panel's preferred bounds in the screen's coordinates.
   // The position will be controlled by window manager so
   // the origin is always (0, 0).
@@ -141,17 +145,41 @@ class NotificationPanel : public PanelController::Delegate,
   // Mark the given notification as stale.
   void MarkStale(const Notification& notification);
 
+  // Contains all notifications.
   BalloonContainer* balloon_container_;
+
+  // The notification panel's widget.
   scoped_ptr<views::Widget> panel_widget_;
+
+  // Panel controller for the notification panel.
   scoped_ptr<PanelController> panel_controller_;
+
+  // A scrollable parent of the BalloonContainer.
+  // This is owned by the panel so that we can re-attache to the widget
+  // when closing and opening the panel.
   scoped_ptr<views::ScrollView> scroll_view_;
+
+  // Panel's state.
   State state_;
+
   ScopedRunnableMethodFactory<NotificationPanel> task_factory_;
+
+  // The minimum size of a notification.
   gfx::Rect min_bounds_;
-  scoped_ptr<NotificationPanelTester> tester_;
+
+  // Stale timeout.
   int stale_timeout_;
+
+  // A registrar to subscribe PANEL_STATE_CHANGED event.
   NotificationRegistrar registrar_;
 
+  // The notification a mouse pointer is currently on. NULL if the mouse
+  // is out of the panel.
+  BalloonViewImpl* active_;
+
+  // An object that provides interfacce for tests.
+  scoped_ptr<NotificationPanelTester> tester_;
+
   DISALLOW_COPY_AND_ASSIGN(NotificationPanel);
 };