class/System.ComponentModel.Composition/src/ComponentModel/System/ComponentModel/Composition/Hosting/AtomicCompositionExtensions.cs

   1 using System;
   2 using System.Diagnostics;
   3 using System.Collections.Generic;
   4 using Microsoft.Internal;
   5
   6 namespace System.ComponentModel.Composition.Hosting
   7 {
   8     internal static class AtomicCompositionExtensions
   9     {
  10         internal static T GetValueAllowNull<T>(this AtomicComposition atomicComposition, T defaultResultAndKey) where T : class
  11         {
  12             Assumes.NotNull(defaultResultAndKey);
  13
  14             return GetValueAllowNull<T>(atomicComposition, defaultResultAndKey, defaultResultAndKey);
  15         }
  16
  17         internal static T GetValueAllowNull<T>(this AtomicComposition atomicComposition, object key, T defaultResult)
  18         {
  19             T result;
  20             if (atomicComposition != null && atomicComposition.TryGetValue(key, out result))
  21             {
  22                 return result;
  23             }
  24
  25             return defaultResult;
  26         }
  27
  28         internal static void AddRevertActionAllowNull(this AtomicComposition atomicComposition, Action action)
  29         {
  30             Assumes.NotNull(action);
  31
  32             if (atomicComposition == null)
  33             {
  34                 action();
  35             }
  36             else
  37             {
  38                 atomicComposition.AddRevertAction(action);
  39             }
  40         }
  41
  42         internal static void AddCompleteActionAllowNull(this AtomicComposition atomicComposition, Action action)
  43         {
  44             Assumes.NotNull(action);
  45
  46             if (atomicComposition == null)
  47             {
  48                 action();
  49             }
  50             else
  51             {
  52                 atomicComposition.AddCompleteAction(action);
  53             }
  54         }
  55     }
  56 }