[Athena] Make a quick power button tap suspend the device

athena/system/system_ui_impl.cc

 // Copyright 2014 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 "athena/system/public/system_ui.h"
 
 #include "athena/screen/public/screen_manager.h"
 #include "athena/system/background_controller.h"
 #include "athena/system/orientation_controller.h"
 #include "athena/system/power_button_controller.h"
@@ skipping 58 matching lines @@
   views::View* time_view_;
   views::View* status_icon_view_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemInfoView);
 };
 
 class SystemUIImpl : public SystemUI {
  public:
   SystemUIImpl(scoped_refptr<base::TaskRunner> blocking_task_runner)
       : orientation_controller_(new OrientationController()),
-        power_button_controller_(new PowerButtonController),
         background_container_(NULL),
         system_modal_container_(NULL) {
     orientation_controller_->InitWith(blocking_task_runner);
   }
 
   virtual ~SystemUIImpl() {
     // Stops file watching now if exists. Waiting until message loop shutdon
     // leads to FilePathWatcher crash.
     orientation_controller_->Shutdown();
   }
 
   void Init() {
-    background_container_ = ScreenManager::Get()->CreateContainer(
+    ScreenManager* screen_manager = ScreenManager::Get();
+    background_container_ = screen_manager->CreateContainer(
         ScreenManager::ContainerParams("AthenaBackground", CP_BACKGROUND));
     background_container_->SetLayoutManager(
         new FillLayoutManager(background_container_));
     ScreenManager::ContainerParams system_modal_params(
         "AthenaSystemModalContainer", CP_SYSTEM_MODAL);
     system_modal_params.can_activate_children = true;
     system_modal_container_ =
-        ScreenManager::Get()->CreateContainer(system_modal_params);
+        screen_manager->CreateContainer(system_modal_params);
+    login_screen_system_modal_container_ = screen_manager->CreateContainer(
+        ScreenManager::ContainerParams("AthenaLoginScreenSystemModalContainer",
+                                       CP_LOGIN_SCREEN_SYSTEM_MODAL));
 
+    // Use |login_screen_system_modal_container_| for the power button's dialog
+    // because it needs to show over the login screen.
+    // TODO(pkotwicz): Pick the most appropriate container based on whether the
+    // user has logged in.
+    power_button_controller_.reset(
+        new PowerButtonController(login_screen_system_modal_container_));
     background_controller_.reset(
         new BackgroundController(background_container_));
   }
 
   virtual void SetBackgroundImage(const gfx::ImageSkia& image) OVERRIDE {
     background_controller_->SetImage(image);
   }
 
   virtual views::View* CreateSystemInfoView(ColorScheme color_scheme) OVERRIDE {
     return new SystemInfoView(color_scheme, system_modal_container_);
   }
 
  private:
   scoped_ptr<OrientationController> orientation_controller_;
   scoped_ptr<PowerButtonController> power_button_controller_;
   scoped_ptr<BackgroundController> background_controller_;
 
   // The parent container for the background.
   aura::Window* background_container_;
 
-  // The parent container used by the "select network" dialog.
+  // The parent container used by system modal dialogs.
   aura::Window* system_modal_container_;
 
+  // The parent container used by system modal dialogs when the login screen is
+  // visible.
+  aura::Window* login_screen_system_modal_container_;
+
   DISALLOW_COPY_AND_ASSIGN(SystemUIImpl);
 };
 
 }  // namespace
 
 // static
 SystemUI* SystemUI::Create(
     scoped_refptr<base::TaskRunner> blocking_task_runner) {
   SystemUIImpl* system_ui = new SystemUIImpl(blocking_task_runner);
   instance = system_ui;
   system_ui->Init();
   return instance;
 }
 
 // static
 SystemUI* SystemUI::Get() {
   DCHECK(instance);
   return instance;
 }
 
 // static
 void SystemUI::Shutdown() {
   CHECK(instance);
   delete instance;
   instance = NULL;
 }
 
 }  // namespace athena