mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/UndoUnit.cs

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4
   5 namespace System.Activities.Presentation
   6 {
   7     using System;
   8     using System.Collections.Generic;
   9     using System.Text;
  10     using System.Activities.Presentation.View;
  11     using System.Activities.Presentation.Model;
  12
  13     public abstract class UndoUnit
  14     {
  15         EditingContext context;
  16         ModelItem designerRoot;
  17
  18         public string Description { get; set; }
  19         public abstract void Redo();
  20         public abstract void Undo();
  21
  22         protected UndoUnit(EditingContext context)
  23         {
  24             if (context == null)
  25             {
  26                 throw FxTrace.Exception.AsError(new ArgumentNullException("context"));
  27             }
  28             this.context = context;
  29         }
  30         protected void SaveGlobalState()
  31         {
  32             DesignerView designerView = context.Services.GetService<DesignerView>();
  33             if (designerView != null && designerView.RootDesigner != null)
  34             {
  35                 designerRoot = ((WorkflowViewElement)designerView.RootDesigner).ModelItem;
  36             }
  37         }
  38
  39         protected void ApplyGlobalState()
  40         {
  41             DesignerView designerView = context.Services.GetService<DesignerView>();
  42             if (designerView != null && designerView.RootDesigner != null)
  43             {
  44                 ModelItem currentDesignerRoot = ((WorkflowViewElement)designerView.RootDesigner).ModelItem;
  45                 if (currentDesignerRoot != designerRoot)
  46                 {
  47                     designerView.MakeRootDesigner(designerRoot);
  48                 }
  49             }
  50         }
  51     }
  52 }