mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/Model/ModelItemHelper.cs

   1 //----------------------------------------------------------------
   2 // <copyright company="Microsoft Corporation">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 //----------------------------------------------------------------
   6
   7 namespace System.Activities.Presentation.Model
   8 {
   9     using System.Runtime;
  10
  11     internal static class ModelItemHelper
  12     {
  13         internal static ModelEditingScope ModelItemBeginEdit(ModelTreeManager modelTreeManager, string description, bool shouldApplyChangesImmediately)
  14         {
  15             if (shouldApplyChangesImmediately && modelTreeManager.Context.Services.GetService<UndoEngine>().IsBookmarkInPlace)
  16             {
  17                 throw FxTrace.Exception.AsError(new InvalidOperationException(SR.InvalidNestedModelItemBeginEditExceptionMessage));
  18             }
  19
  20             EditingScope editingScope = modelTreeManager.CreateEditingScope(description, shouldApplyChangesImmediately);
  21
  22             if (shouldApplyChangesImmediately && editingScope == null)
  23             {
  24                 throw FxTrace.Exception.AsError(new InvalidOperationException(SR.InvalidNestedModelItemBeginEditExceptionMessage));
  25             }
  26
  27             return editingScope;
  28         }
  29
  30         internal static bool CanCreateImmediateEditingScope(ModelItem modelItem)
  31         {
  32             Fx.Assert(modelItem is IModelTreeItem, "modelItem must implement IModelTreeItem");
  33
  34             return ((IModelTreeItem)modelItem).ModelTreeManager.CanCreateImmediateEditingScope();
  35         }
  36
  37         internal static void TryCreateImmediateEditingScopeAndExecute(EditingContext context, string editingScopeDescription, Action<EditingScope> modelEditingWork)
  38         {
  39             Fx.Assert(context != null, "context should not be null.");
  40             Fx.Assert(modelEditingWork != null, "modelEditingWork should not be null.");
  41
  42             ModelTreeManager manager = context.Services.GetRequiredService<ModelTreeManager>();
  43
  44             if (manager.CanCreateImmediateEditingScope())
  45             {
  46                 using (EditingScope editingScope = manager.CreateEditingScope(editingScopeDescription, true))
  47                 {
  48                     modelEditingWork(editingScope);
  49                 }
  50             }
  51             else
  52             {
  53                 modelEditingWork(null);
  54             }
  55         }
  56
  57         internal static EditingScope TryCreateImmediateEditingScope(ModelTreeManager manager, string editingScopeDescription)
  58         {
  59             if (manager.CanCreateImmediateEditingScope())
  60             {
  61                 return manager.CreateEditingScope(editingScopeDescription, true);
  62             }
  63
  64             return null;
  65         }
  66     }
  67 }