samples/winrt/ImageManipulations/common/suspensionmanager.h

   1 //*********************************************************
   2 //
   3 // Copyright (c) Microsoft. All rights reserved.
   4 // THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF
   5 // ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY
   6 // IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR
   7 // PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.
   8 //
   9 //*********************************************************
  10
  11 //
  12 // SuspensionManager.h
  13 // Declaration of the SuspensionManager class
  14 //
  15
  16 #pragma once
  17
  18 #include <ppltasks.h>
  19
  20 namespace SDKSample
  21 {
  22     namespace Common
  23     {
  24         /// <summary>
  25         /// SuspensionManager captures global session state to simplify process lifetime management
  26         /// for an application.  Note that session state will be automatically cleared under a variety
  27         /// of conditions and should only be used to store information that would be convenient to
  28         /// carry across sessions, but that should be disacarded when an application crashes or is
  29         /// upgraded.
  30         /// </summary>
  31         ref class SuspensionManager sealed
  32         {
  33         internal:
  34             static void RegisterFrame(Windows::UI::Xaml::Controls::Frame^ frame, Platform::String^ sessionStateKey);
  35             static void UnregisterFrame(Windows::UI::Xaml::Controls::Frame^ frame);
  36             static Concurrency::task<void> SaveAsync(void);
  37             static Concurrency::task<void> RestoreAsync(void);
  38             static property Windows::Foundation::Collections::IMap<Platform::String^, Platform::Object^>^ SessionState
  39             {
  40                 Windows::Foundation::Collections::IMap<Platform::String^, Platform::Object^>^ get(void);
  41             };
  42             static Windows::Foundation::Collections::IMap<Platform::String^, Platform::Object^>^ SessionStateForFrame(
  43                 Windows::UI::Xaml::Controls::Frame^ frame);
  44
  45         private:
  46             static void RestoreFrameNavigationState(Windows::UI::Xaml::Controls::Frame^ frame);
  47             static void SaveFrameNavigationState(Windows::UI::Xaml::Controls::Frame^ frame);
  48         };
  49     }
  50 }