Show the bell icon when no unread-notification state

ash/system/web_notification/web_notification_tray.cc

 // 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/system/web_notification/web_notification_tray.h"
 
 #include "ash/ash_switches.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_layout_manager_observer.h"
 #include "ash/shelf/shelf_util.h"
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/tray_background_view.h"
 #include "ash/system/tray/tray_bubble_wrapper.h"
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/tray_utils.h"
 #include "ash/system/web_notification/ash_popup_alignment_delegate.h"
 #include "ash/wm/common/shelf/wm_shelf_util.h"
 #include "base/auto_reset.h"
 #include "base/i18n/number_formatting.h"
 #include "base/i18n/rtl.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/thread_task_runner_handle.h"
+#include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/base/l10n/l10n_util.h"
+#include "ui/base/resource/resource_bundle.h"
 #include "ui/display/screen.h"
 #include "ui/message_center/message_center_style.h"
 #include "ui/message_center/message_center_tray_delegate.h"
 #include "ui/message_center/views/message_bubble_base.h"
 #include "ui/message_center/views/message_center_bubble.h"
 #include "ui/message_center/views/message_popup_collection.h"
 #include "ui/strings/grit/ui_strings.h"
 #include "ui/views/bubble/tray_bubble_view.h"
 #include "ui/views/controls/button/custom_button.h"
 #include "ui/views/controls/image_view.h"
@@ skipping 69 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(WebNotificationBubbleWrapper);
 };
 
 class WebNotificationButton : public views::CustomButton {
  public:
   WebNotificationButton(views::ButtonListener* listener)
       : views::CustomButton(listener),
         is_bubble_visible_(false),
         unread_count_(0) {
     SetLayoutManager(new views::FillLayout);
-    unread_label_ = new views::Label();
-    SetupLabelForTray(unread_label_);
-    AddChildView(unread_label_);
+
+    ResourceBundle& rb = ResourceBundle::GetSharedInstance();
+    no_unread_icon_.reset(new views::ImageView());
+    no_unread_icon_->SetImage(
+        rb.GetImageNamed(IDR_ASH_SHELF_NOTIFICATION_TRAY_EMPTY).ToImageSkia());

[oshima, 2016/05/11 02:46:30]

do you really need an image view here? Doesn't empty view work?

[yoshiki, 2016/05/11 05:42:51]

Yes, the initial state is unread_count == 0, so we want to show a bell icon at
first.

[oshima, 2016/05/11 14:35:10]

which one is bell icon? Or empty.png is just a place holder?

+    no_unread_icon_->SetImageSize(gfx::Size(18, 18));
+    no_unread_icon_->set_owned_by_client();
+
+    unread_label_.reset(new views::Label());

[oshima, 2016/05/11 02:46:30]

you can just use view::Label unread_label_;

[yoshiki, 2016/05/11 05:42:51]

Done.

+    unread_label_->set_owned_by_client();
+    SetupLabelForTray(unread_label_.get());
+
+    AddChildView(unread_label_.get());
   }
 
   void SetBubbleVisible(bool visible) {
     if (visible == is_bubble_visible_)
       return;
 
     is_bubble_visible_ = visible;
     UpdateIconVisibility();
   }
 
   void SetUnreadCount(int unread_count) {
     // base::FormatNumber doesn't convert to arabic numeric characters.
     // TODO(mukai): use ICU to support conversion for such locales.
     unread_count_ = unread_count;
-    // TODO(mukai): move NINE_PLUS message to ui_strings, it doesn't need to be
-    // in ash_strings.
-    unread_label_->SetText((unread_count > 9) ?
-        l10n_util::GetStringUTF16(IDS_ASH_NOTIFICATION_UNREAD_COUNT_NINE_PLUS) :
-        base::FormatNumber(unread_count));
     UpdateIconVisibility();
   }
 
  protected:
   // Overridden from views::ImageButton:
   gfx::Size GetPreferredSize() const override {
     return gfx::Size(kShelfItemHeight, kShelfItemHeight);
   }
 
   int GetHeightForWidth(int width) const override {
     return GetPreferredSize().height();
   }
 
  private:
   void UpdateIconVisibility() {
-    unread_label_->SetEnabledColor(
-        (!is_bubble_visible_ && unread_count_ > 0) ?
-        kWebNotificationColorWithUnread : kWebNotificationColorNoUnread);
+    if (unread_count_ == 0) {
+      if (!Contains(no_unread_icon_.get())) {
+        RemoveAllChildViews(false /* delete_children */);
+        AddChildView(no_unread_icon_.get());
+      }
+    } else {
+      if (!Contains(unread_label_.get())) {
+        RemoveAllChildViews(false /* delete_children */);
+        AddChildView(unread_label_.get());
+      }
+
+      // TODO(mukai): move NINE_PLUS message to ui_strings, it doesn't need to
+      // be in ash_strings.
+      unread_label_->SetText(
+          (unread_count_ > 9) ? l10n_util::GetStringUTF16(
+                                    IDS_ASH_NOTIFICATION_UNREAD_COUNT_NINE_PLUS)
+                              : base::FormatNumber(unread_count_));
+      unread_label_->SetEnabledColor((!is_bubble_visible_)
+                                         ? kWebNotificationColorWithUnread
+                                         : kWebNotificationColorNoUnread);
+    }
+
     SchedulePaint();
   }
 
   bool is_bubble_visible_;
   int unread_count_;
 
-  views::Label* unread_label_;
+  std::unique_ptr<views::ImageView> no_unread_icon_;
+  std::unique_ptr<views::Label> unread_label_;
 
   DISALLOW_COPY_AND_ASSIGN(WebNotificationButton);
 };
 
 WebNotificationTray::WebNotificationTray(StatusAreaWidget* status_area_widget)
     : TrayBackgroundView(status_area_widget),
       button_(NULL),
       show_message_center_on_unlock_(false),
       should_update_tray_content_(false),
       should_block_shelf_auto_hide_(false) {
@@ skipping 301 matching lines @@
 
 message_center::MessageCenterBubble*
 WebNotificationTray::GetMessageCenterBubbleForTest() {
   if (!message_center_bubble())
     return NULL;
   return static_cast<message_center::MessageCenterBubble*>(
       message_center_bubble()->bubble());
 }
 
 }  // namespace ash