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

   1 // -----------------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 // -----------------------------------------------------------------------
   4 using System;
   5 using System.Collections.Generic;
   6 using System.ComponentModel.Composition.Primitives;
   7 using Microsoft.Internal;
   8 using Microsoft.Internal.Collections;
   9
  10 namespace System.ComponentModel.Composition.Hosting
  11 {
  12     /// <summary>
  13     ///     Provides data for the <see cref="INotifyComposablePartCatalogChanged.Changed"/> and
  14     ///     <see cref="INotifyComposablePartCatalogChanged.Changing"/> events.
  15     /// </summary>
  16     public class ComposablePartCatalogChangeEventArgs : EventArgs
  17     {
  18         /// <summary>
  19         ///     Initializes a new instance of the <see cref="ComposablePartCatalogChangeEventArgs"/>.
  20         /// </summary>
  21         /// <param name="addedDefinitions">
  22         ///     An <see cref="IEnumerable{T}"/> of <see cref="ComposablePartDefinition"/> objects that
  23         ///     are being added to the <see cref="ComposablePartCatalog"/>.
  24         /// </param>
  25         /// <param name="removedDefinitions">
  26         ///     An <see cref="IEnumerable{T}"/> of <see cref="ComposablePartDefinition"/> objects that
  27         ///     are being removed from the <see cref="ComposablePartCatalog"/>.
  28         /// </param>
  29         /// <param name="atomicComposition">
  30         ///     A <see cref="AtomicComposition"/> representing all tentative changes that will
  31         ///     be completed if the change is successful, or discarded if it is not.
  32         ///     <see langword="null"/> if being applied outside a <see cref="AtomicComposition"/>
  33         ///     or during a <see cref="INotifyComposablePartCatalogChanged.Changed"/> event.
  34         /// </param>
  35         /// <exception cref="ArgumentNullException">
  36         ///     <paramref name="addedDefinitions"/> or <paramref name="removedDefinitions"/> is <see langword="null"/>.
  37         /// </exception>
  38         public ComposablePartCatalogChangeEventArgs(IEnumerable<ComposablePartDefinition> addedDefinitions,
  39             IEnumerable<ComposablePartDefinition> removedDefinitions, AtomicComposition atomicComposition)
  40         {
  41             Requires.NotNull(addedDefinitions, "addedDefinitions");
  42             Requires.NotNull(removedDefinitions, "removedDefinitions");
  43
  44             this.AddedDefinitions = addedDefinitions.AsArray();
  45             this.RemovedDefinitions = removedDefinitions.AsArray();
  46             this.AtomicComposition = atomicComposition;
  47         }
  48
  49         /// <summary>
  50         ///     Gets the identifiers of the parts that have been added.
  51         /// </summary>
  52         /// <value>
  53         ///     An <see cref="IEnumerable{T}"/> of <see cref="ComposablePartDefinition"/> objects that
  54         ///     have been added to the <see cref="ComposablePartCatalog"/>.
  55         /// </value>
  56         public IEnumerable<ComposablePartDefinition> AddedDefinitions { get; private set; }
  57
  58         /// <summary>
  59         ///     Gets the identifiers of the parts that have been removed.
  60         /// </summary>
  61         /// <value>
  62         ///     An <see cref="IEnumerable{T}"/> of <see cref="ComposablePartDefinition"/> objects that
  63         ///     have been removed from from the <see cref="ComposablePartCatalog"/>.
  64         /// </value>
  65         public IEnumerable<ComposablePartDefinition> RemovedDefinitions { get; private set; }
  66
  67         /// <summary>
  68         ///     Gets the atomicComposition, if any, that this change applies to.
  69         /// </summary>
  70         /// <value>
  71         ///     A <see cref="AtomicComposition"/> that this set of changes applies too.
  72         ///     It can be <see langword="null"/> if the changes are being applied outside a
  73         ///     <see cref="AtomicComposition"/> or during a
  74         ///     <see cref="INotifyComposablePartCatalogChanged.Changed"/> event.
  75         ///
  76         ///     When the value is non-null it should be used to record temporary changed state
  77         ///     and actions that will be executed when the atomicComposition is completeed.
  78         /// </value>
  79         public AtomicComposition AtomicComposition { get; private set; }
  80     }
  81 }