Show no-notification message in the bottom label of message center

ui/message_center/views/message_center_view.cc

 // Copyright (c) 2013 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 "ui/message_center/views/message_center_view.h"
 
 #include <list>
 #include <map>
 
 #include "base/macros.h"
@@ skipping 93 matching lines @@
   int margin = (height() - text_height) / 2;
   label_->SetBounds(0, margin, width(), text_height);
 }
 
 // MessageCenterView ///////////////////////////////////////////////////////////
 
 MessageCenterView::MessageCenterView(MessageCenter* message_center,
                                      MessageCenterTray* tray,
                                      int max_height,
                                      bool initially_settings_visible,
-                                     bool top_down,
-                                     const base::string16& title)
+                                     bool top_down)
     : message_center_(message_center),
       tray_(tray),
       scroller_(NULL),
       settings_view_(NULL),
       button_bar_(NULL),
       top_down_(top_down),
       settings_visible_(initially_settings_visible),
       source_view_(NULL),
       source_height_(0),
       target_view_(NULL),
       target_height_(0),
       is_closing_(false),
       context_menu_controller_(new MessageViewContextMenuController(this)) {
   message_center_->AddObserver(this);
   set_notify_enter_exit_on_child(true);
   set_background(views::Background::CreateSolidBackground(
       kMessageCenterBackgroundColor));
 
   NotifierSettingsProvider* notifier_settings_provider =
       message_center_->GetNotifierSettingsProvider();
-  button_bar_ = new MessageCenterButtonBar(this,
-                                           message_center,
-                                           notifier_settings_provider,
-                                           initially_settings_visible,
-                                           title);
+  button_bar_ = new MessageCenterButtonBar(
+      this, message_center, notifier_settings_provider,
+      initially_settings_visible, GetButtonBarTitle());
 
   const int button_height = button_bar_->GetPreferredSize().height();
 
   scroller_ = new views::ScrollView();
   scroller_->ClipHeightTo(kMinScrollViewHeight, max_height - button_height);
   scroller_->SetVerticalScrollBar(new views::OverlayScrollBar(false));
   scroller_->set_background(
       views::Background::CreateSolidBackground(kMessageCenterBackgroundColor));
 
   scroller_->SetPaintToLayer(true);
@@ skipping 95 matching lines @@
   } else {
     parts.push_back(gfx::MultiAnimation::Part());
   }
   settings_transition_animation_.reset(new gfx::MultiAnimation(
       parts, base::TimeDelta::FromMicroseconds(1000000 / kDefaultFrameRateHz)));
   settings_transition_animation_->set_delegate(this);
   settings_transition_animation_->set_continuous(false);
   settings_transition_animation_->Start();
 
   button_bar_->SetBackArrowVisible(visible);
+  button_bar_->SetTitle(GetButtonBarTitle());
 }
 
 void MessageCenterView::ClearAllClosableNotifications() {
   if (is_closing_)
     return;
 
   SetViewHierarchyEnabled(scroller_, false);
   button_bar_->SetAllButtonsEnabled(false);
   message_list_view_->ClearAllClosableNotifications(
       scroller_->GetVisibleRect());
@@ skipping 328 matching lines @@
       no_message_views ? empty_list_view_.get() : message_list_view_.get());
 
   bool no_closable_views = true;
   for (const auto& view : notification_views_) {
     if (!view.second->IsPinned()) {
       no_closable_views = false;
       break;
     }
   }
   button_bar_->SetCloseAllButtonEnabled(!no_closable_views);
+  button_bar_->SetTitle(GetButtonBarTitle());
 
   if (no_message_views) {
     scroller_->SetFocusBehavior(FocusBehavior::NEVER);
   } else {
 #if defined(OS_MACOSX)
     scroller_->SetFocusBehavior(FocusBehavior::ACCESSIBLE_ONLY);
 #else
     scroller_->SetFocusBehavior(FocusBehavior::ALWAYS);
 #endif
   }
 
   if (focus_manager && focused_view)
     focus_manager->SetFocusedView(focused_view);
 
   scroller_->InvalidateLayout();
   PreferredSizeChanged();
   Layout();
 }
 
+base::string16 MessageCenterView::GetButtonBarTitle() const {
+  bool no_message_views = notification_views_.empty();
+  if (no_message_views && !settings_visible_)
+    return l10n_util::GetStringUTF16(IDS_MESSAGE_CENTER_NO_MESSAGES);
+
+  return l10n_util::GetStringUTF16(IDS_MESSAGE_CENTER_FOOTER_TITLE);
+}
+
 void MessageCenterView::SetNotificationViewForTest(MessageView* view) {
   message_list_view_->AddNotificationAt(view, 0);
 }
 
 }  // namespace message_center