Implement and cleanup System.Windows.Forms.Design event args

src/System.Windows.Forms.Design/src/System/ComponentModel/Design/LoadedEventArgs.cs

@@ -0,0 +1,33 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections;
+
+namespace System.ComponentModel.Design
+{
+    /// <summary>
+    /// Provides additional information for the Loaded event.
+    /// </summary>
+    public sealed class LoadedEventArgs : EventArgs
+    {
+        /// <summary>
+        /// Creates a new LoadedEventArgs object.
+        /// </summary>
+        public LoadedEventArgs(bool succeeded, ICollection errors)
+        {
+            HasSucceeded = succeeded;
+            Errors = errors ?? Array.Empty<object>();
+        }
+
+        /// <summary>
+        /// True to indicate the designer load was successful. Even successful loads can have errors, if the errors were not too servere to prevent the designer from loading.
+        /// </summary>
+        public bool HasSucceeded { get; }
+
+        /// <summary>
+        /// A collection of errors that occurred while the designer was loading.
+        /// </summary>
+        public ICollection Errors { get; }
+    }
+}

src/System.Windows.Forms.Design/src/System/ComponentModel/Design/LoadedEventHandler.cs

@@ -2,49 +2,10 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Collections;
-
 namespace System.ComponentModel.Design
 {
     /// <summary>
     /// Represents the method that will handle a Loaded event.
     /// </summary>
     public delegate void LoadedEventHandler(object sender, LoadedEventArgs e);
-
-    /// <summary>
-    /// Provides additional information for the Loaded event.
-    /// </summary>
-    public sealed class LoadedEventArgs : EventArgs
-    {
-        private readonly bool _succeeded;
-        private readonly ICollection _errors;
-        /// <summary>
-        /// Creates a new LoadedEventArgs object.
-        /// </summary>
-        public LoadedEventArgs(bool succeeded, ICollection errors)
-        {
-            _succeeded = succeeded;
-            _errors = errors;
-            if (_errors == null)
-            {
-                _errors = new object[0];
-            }
-        }
-
-        /// <summary>
-        /// A collection of errors that occurred while the designer was loading.
-        /// </summary>
-        public ICollection Errors
-        {
-            get => _errors;
-        }
-
-        /// <summary>
-        /// True to indicate the designer load was successful. Even successful loads can have errors, if the errors were not too servere to prevent the designer from loading.
-        /// </summary>
-        public bool HasSucceeded
-        {
-            get => _succeeded;
-        }
-    }
 }

src/System.Windows.Forms.Design/src/System/Drawing/Design/IToolboxService.cs

@@ -11,7 +11,9 @@ namespace System.Drawing.Design
     /// <summary>
     /// Provides access to the toolbox in the development environment.
     /// </summary>
-    [ComImport(), Guid("4BACD258-DE64-4048-BC4E-FEDBEF9ACB76"), InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
+    [ComImport]
+    [Guid("4BACD258-DE64-4048-BC4E-FEDBEF9ACB76")]
+    [InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
     public interface IToolboxService
     {
         /// <summary>
@@ -167,4 +169,3 @@ public interface IToolboxService
         void SetSelectedToolboxItem(ToolboxItem toolboxItem);
     }
 }
-

src/System.Windows.Forms.Design/src/System/Drawing/Design/IToolboxUser.cs

@@ -21,4 +21,3 @@ public interface IToolboxUser
         void ToolPicked(ToolboxItem tool);
     }
 }
-

src/System.Windows.Forms.Design/src/System/Drawing/Design/ToolboxComponentsCreatedEventArgs.cs

@@ -12,14 +12,19 @@ namespace System.Drawing.Design
     /// </summary>
     public class ToolboxComponentsCreatedEventArgs : EventArgs
     {
+        private IComponent[] _components;
+
         /// <summary>
         /// Initializes a new instance of the <see cref='System.Drawing.Design.ToolboxComponentsCreatedEventArgs'
         /// </summary>
-        public ToolboxComponentsCreatedEventArgs(IComponent[] components) => throw new NotImplementedException(SR.NotImplementedByDesign);
+        public ToolboxComponentsCreatedEventArgs(IComponent[] components)
+        {
+            _components = components;
+        }
 
         /// <summary>
         /// An array storing the toolbox components.
         /// </summary>
-        public IComponent[] Components => throw new NotImplementedException(SR.NotImplementedByDesign);
+        public IComponent[] Components => (IComponent[])_components?.Clone();
     }
 }

src/System.Windows.Forms.Design/src/System/Drawing/Design/ToolboxComponentsCreatingEventArgs.cs

@@ -15,12 +15,15 @@ public class ToolboxComponentsCreatingEventArgs : EventArgs
         /// <summary>
         /// Initializes a new instance of the <see cref='System.Drawing.Design.ToolboxComponentsCreatingEventArgs'/> object.
         /// </summary>
-        public ToolboxComponentsCreatingEventArgs(IDesignerHost host) => throw new NotImplementedException(SR.NotImplementedByDesign);
+        public ToolboxComponentsCreatingEventArgs(IDesignerHost host)
+        {
+            DesignerHost = host;
+        }
 
         /// <summary>
-        /// An instance of IDesignerHost that has made the creat request.  This can be null if no designer host
-        /// was provided to the toolbox item.
+        /// An instance of IDesignerHost that has made the creat request.
+        /// This can be null if no designer host was provided to the toolbox item.
         /// </summary>
-        public IDesignerHost DesignerHost => throw new NotImplementedException(SR.NotImplementedByDesign);
+        public IDesignerHost DesignerHost { get; }
     }
 }

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/Behavior/BehaviorDragDropEventArgs.cs

@@ -7,23 +7,19 @@
 namespace System.Windows.Forms.Design.Behavior
 {
     /// <summary>
-    ///     This class represents the arguments describing a BehaviorDragDrop event
-    ///     fired by the BehaviorService.
+    /// This class represents the arguments describing a BehaviorDragDrop event
+    /// fired by the BehaviorService.
     /// </summary>
     public class BehaviorDragDropEventArgs : EventArgs
     {
-        /// <summary>
-        ///     Constructor.  This class is created by the BehaviorService directly
-        ///     before a drag operation begins.
-        /// </summary>
         public BehaviorDragDropEventArgs(ICollection dragComponents)
         {
-            throw new NotImplementedException(SR.NotImplementedByDesign);
+            DragComponents = dragComponents;
         }
 
         /// <summary>
-        ///     Returns the list of IComponents currently being dragged.
+        /// Returns the list of IComponents currently being dragged.
         /// </summary>
-        public ICollection DragComponents => throw new NotImplementedException(SR.NotImplementedByDesign);
+        public ICollection DragComponents { get; }
     }
 }

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/DesignerActionListsChangedEventArgs.cs

@@ -9,34 +9,29 @@ namespace System.ComponentModel.Design
     /// </summary>
     public class DesignerActionListsChangedEventArgs : EventArgs
     {
-
-        private readonly object _relatedObject;
-        private readonly DesignerActionListCollection _actionLists;
-        private readonly DesignerActionListsChangedType _changeType;
-
         /// <summary>
         /// Constructor that requires the object in question, the type of change and the remaining actionlists left for the object. on the related object.
-        /// </summary> 
+        /// </summary>
         public DesignerActionListsChangedEventArgs(object relatedObject, DesignerActionListsChangedType changeType, DesignerActionListCollection actionLists)
         {
-            _relatedObject = relatedObject;
-            _changeType = changeType;
-            _actionLists = actionLists;
+            RelatedObject = relatedObject;
+            ChangeType = changeType;
+            ActionLists = actionLists;
         }
 
         /// <summary>
-        /// The type of changed that caused the related event to be thrown.
-        /// </summary> 
-        public DesignerActionListsChangedType ChangeType => _changeType;
+        /// The object this change is related to.
+        /// </summary>
+        public object RelatedObject { get; }
 
         /// <summary>
-        /// The object this change is related to.
-        /// </summary> 
-        public object RelatedObject => _relatedObject;
+        /// The type of changed that caused the related event to be thrown.
+        /// </summary>
+        public DesignerActionListsChangedType ChangeType { get; }
 
         /// <summary>
         /// The remaining actionlists left for the related object.
-        /// </summary> 
-        public DesignerActionListCollection ActionLists => _actionLists;
+        /// </summary>
+        public DesignerActionListCollection ActionLists { get; }
     }
 }

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/DesignerActionListsChangedEventHandler.cs

@@ -2,11 +2,10 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Runtime.InteropServices;
+
 namespace System.ComponentModel.Design
 {
-    /// <summary>
-    /// This event is thown by the DesignerActionListservice when a shortcut is either added or removed to/from the related object.
-    /// </summary>
-    [System.Runtime.InteropServices.ComVisible(true)]
+    [ComVisible(true)]
     public delegate void DesignerActionListsChangedEventHandler(object sender, DesignerActionListsChangedEventArgs e);
 }

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/DesignerActionListsChangedType.cs

@@ -2,12 +2,14 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Runtime.InteropServices;
+
 namespace System.ComponentModel.Design
 {
     /// <summary>
     /// An enum that defines what time of action happend to the related object's DesignerActionLists collection.
     /// </summary>
-    [System.Runtime.InteropServices.ComVisible(true)]
+    [ComVisible(true)]
     public enum DesignerActionListsChangedType
     {
         /// <summary>
@@ -19,6 +21,5 @@ public enum DesignerActionListsChangedType
         /// Signifies that one or more DesignerActionList was removed.
         /// </summary>
         ActionListsRemoved
-
     }
 }

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/DesignerActionUIStateChangeEventArgs.cs

@@ -9,27 +9,23 @@ namespace System.ComponentModel.Design
     /// </summary>
     public class DesignerActionUIStateChangeEventArgs : EventArgs
     {
-        private readonly object _relatedObject;
-        private readonly DesignerActionUIStateChangeType _changeType;
-
         /// <summary>
         /// Constructor that requires the object in question, the type of change and the remaining actionlists left for the object on the related object.
         /// </summary> 
         public DesignerActionUIStateChangeEventArgs(object relatedObject, DesignerActionUIStateChangeType changeType)
         {
-            _relatedObject = relatedObject;
-            _changeType = changeType;
+            RelatedObject = relatedObject;
+            ChangeType = changeType;
         }
 
-        /// <summary>
-        /// The type of changed that caused the related event to be thrown.
-        /// </summary>
-        public DesignerActionUIStateChangeType ChangeType => _changeType;
-
         /// <summary>
         /// The object this change is related to.
         /// </summary> 
-        public object RelatedObject => _relatedObject;
+        public object RelatedObject { get; }
 
+        /// <summary>
+        /// The type of changed that caused the related event to be thrown.
+        /// </summary>
+        public DesignerActionUIStateChangeType ChangeType { get; }
     }
 }

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/DesignerActionUIStateChangeType.cs

@@ -6,6 +6,8 @@ namespace System.ComponentModel.Design
 {
     public enum DesignerActionUIStateChangeType
     {
-        Show, Hide, Refresh
+        Show,
+        Hide,
+        Refresh
     }
 }

src/System.Windows.Forms.Design/tests/UnitTests/System/ComponentModel/Design/DesignerActionListsChangedEventArgsTests.cs

@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections;
+using System.Collections.Generic;
+using Xunit;
+
+namespace System.ComponentModel.Design.Tests
+{
+    public class DesignerActionListsChangedEventArgsTests
+    {
+        public static IEnumerable<object[]> Ctor_Object_DesignerActionListsChangedType_DesignerActionListCollection_TestData()
+        {
+            yield return new object[] { null, DesignerActionListsChangedType.ActionListsAdded - 1, null };
+            yield return new object[] { new object(), DesignerActionListsChangedType.ActionListsAdded, new DesignerActionListCollection() };
+        }
+
+        [Theory]
+        [MemberData(nameof(Ctor_Object_DesignerActionListsChangedType_DesignerActionListCollection_TestData))]
+        public void Ctor_Object_DesignerActionListsChangedType_DesignerActionListCollection(object relatedObject, DesignerActionListsChangedType changeType, DesignerActionListCollection actionLists)
+        {
+            var e = new DesignerActionListsChangedEventArgs(relatedObject, changeType, actionLists);
+            Assert.Same(relatedObject, e.RelatedObject);
+            Assert.Equal(changeType, e.ChangeType);
+            Assert.Same(actionLists, e.ActionLists);
+        }
+    }
+}

src/System.Windows.Forms.Design/tests/UnitTests/System/ComponentModel/Design/DesignerActionUIStateChangeEventArgsTests.cs

@@ -0,0 +1,28 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections;
+using System.Collections.Generic;
+using Xunit;
+
+namespace System.ComponentModel.Design.Tests
+{
+    public class DesignerActionUIStateChangeEventArgsTests
+    {
+        public static IEnumerable<object[]> Ctor_Object_DesignerActionUIStateChangeType_TestData()
+        {
+            yield return new object[] { null, DesignerActionUIStateChangeType.Show - 1 };
+            yield return new object[] { new object(), DesignerActionUIStateChangeType.Show };
+        }
+
+        [Theory]
+        [MemberData(nameof(Ctor_Object_DesignerActionUIStateChangeType_TestData))]
+        public void Ctor_Object_DesignerActionUIStateChangeType(object relatedObject, DesignerActionUIStateChangeType changeType)
+        {
+            var e = new DesignerActionUIStateChangeEventArgs(relatedObject, changeType);
+            Assert.Same(relatedObject, e.RelatedObject);
+            Assert.Equal(changeType, e.ChangeType);
+        }
+    }
+}