Unified: Fix tab focus of notification controls.

Tab focusing to notification control buttons was broken in
UnifiedSystemTray because UnifiedMessageCenterView did not implement the
same OnDidChangeFocus logic as MesageCenterView did.

TEST=manual
BUG=862506

Change-Id: Ide2d9e170ecefcc87db2d43b6d8d3b1042492374
Reviewed-on: https://chromium-review.googlesource.com/1132907Reviewed-by: Yoshiki Iguchi <yoshiki@chromium.org>
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575940}

ash/system/unified/unified_message_center_view.cc

@@ -13,6 +13,7 @@
 #include "ui/message_center/message_center_types.h"
 #include "ui/message_center/views/message_view.h"
 #include "ui/message_center/views/message_view_factory.h"
+#include "ui/message_center/views/notification_control_buttons_view.h"
 #include "ui/views/controls/scroll_view.h"
 #include "ui/views/controls/scrollbar/overlay_scroll_bar.h"
 #include "ui/views/layout/box_layout.h"
@@ -87,6 +88,14 @@ UnifiedMessageCenterView::UnifiedMessageCenterView(
 
 UnifiedMessageCenterView::~UnifiedMessageCenterView() {
   message_center_->RemoveObserver(this);
+  if (focus_manager_)
+    focus_manager_->RemoveFocusChangeListener(this);
+}
+
+void UnifiedMessageCenterView::Init() {
+  focus_manager_ = GetFocusManager();
+  if (focus_manager_)
+    focus_manager_->AddFocusChangeListener(this);
 }
 
 void UnifiedMessageCenterView::SetMaxHeight(int max_height) {
@@ -174,6 +183,29 @@ void UnifiedMessageCenterView::ButtonPressed(views::Button* sender,
   tray_controller_->HandleClearAllAction();
 }
 
+void UnifiedMessageCenterView::OnWillChangeFocus(views::View* before,
+                                                 views::View* now) {}
+
+void UnifiedMessageCenterView::OnDidChangeFocus(views::View* before,
+                                                views::View* now) {
+  // Update the button visibility when the focus state is changed.
+  size_t count = message_list_view_->GetNotificationCount();
+  for (size_t i = 0; i < count; ++i) {
+    MessageView* view = message_list_view_->GetNotificationAt(i);
+    // ControlButtonsView is not in the same view hierarchy on ARC++
+    // notifications, so check it separately.
+    if (view->Contains(before) || view->Contains(now) ||
+        (view->GetControlButtonsView() &&
+         (view->GetControlButtonsView()->Contains(before) ||
+          view->GetControlButtonsView()->Contains(now)))) {
+      view->UpdateControlButtonsVisibility();
+    }
+
+    // Ensure that a notification is not removed or added during iteration.
+    DCHECK_EQ(count, message_list_view_->GetNotificationCount());
+  }
+}
+
 void UnifiedMessageCenterView::OnAllNotificationsCleared() {
   tray_controller_->OnClearAllAnimationEnded();
 }

ash/system/unified/unified_message_center_view.h

@@ -22,6 +22,12 @@ class MessageCenter;
 
 }  // namespace message_center
 
+namespace views {
+
+class FocusManager;
+
+}  // namespace views
+
 namespace ash {
 
 class UnifiedSystemTrayController;
@@ -33,12 +39,16 @@ class ASH_EXPORT UnifiedMessageCenterView
       public message_center::MessageCenterObserver,
       public views::ViewObserver,
       public views::ButtonListener,
+      public views::FocusChangeListener,
       public MessageListView::Observer {
  public:
   UnifiedMessageCenterView(UnifiedSystemTrayController* tray_controller,
                            message_center::MessageCenter* message_center);
   ~UnifiedMessageCenterView() override;
 
+  // Initialize focus listener.
+  void Init();
+
   // Set the maximum height that the view can take.
   void SetMaxHeight(int max_height);
 
@@ -66,6 +76,10 @@ class ASH_EXPORT UnifiedMessageCenterView
   // views::ButtonListener:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
+  // views::FocusChangeListener:
+  void OnWillChangeFocus(views::View* before, views::View* now) override;
+  void OnDidChangeFocus(views::View* before, views::View* now) override;
+
   // MessageListView::Observer:
   void OnAllNotificationsCleared() override;
 
@@ -84,6 +98,8 @@ class ASH_EXPORT UnifiedMessageCenterView
   views::ScrollView* const scroller_;
   MessageListView* const message_list_view_;
 
+  views::FocusManager* focus_manager_ = nullptr;
+
   DISALLOW_COPY_AND_ASSIGN(UnifiedMessageCenterView);
 };
 

ash/system/unified/unified_system_tray_bubble.cc

@@ -105,6 +105,8 @@ UnifiedSystemTrayBubble::UnifiedSystemTrayBubble(UnifiedSystemTray* tray,
 
   TrayBackgroundView::InitializeBubbleAnimations(bubble_widget_);
   bubble_view_->InitializeAndShowBubble();
+  unified_view_->Init();
+
   if (app_list::features::IsBackgroundBlurEnabled()) {
     bubble_widget_->client_view()->layer()->SetBackgroundBlur(
         kUnifiedMenuBackgroundBlur);

ash/system/unified/unified_system_tray_view.cc

@@ -175,6 +175,10 @@ UnifiedSystemTrayView::UnifiedSystemTrayView(
 
 UnifiedSystemTrayView::~UnifiedSystemTrayView() = default;
 
+void UnifiedSystemTrayView::Init() {
+  message_center_view_->Init();
+}
+
 void UnifiedSystemTrayView::SetMaxHeight(int max_height) {
   message_center_view_->SetMaxHeight(max_height);
 }

ash/system/unified/unified_system_tray_view.h

@@ -52,6 +52,9 @@ class ASH_EXPORT UnifiedSystemTrayView : public views::View {
                         bool initially_expanded);
   ~UnifiedSystemTrayView() override;
 
+  // Initialize after the view is attached to the widget.
+  void Init();
+
   // Set the maximum height that the view can take.
   void SetMaxHeight(int max_height);