Blazor API Review: UIEventArgs types

Fixes: #12550

Removes UIEventArgs in favor of EventArgs as the base class.

Moving Type into all of our event args types - this is important because
many of the events types are used for multiple events.

The only think about this that isn't perfect is that we have keep
special casing change because of how binding works. I renamed the type
to drop the `UI` prefix. It's not possible to define a subclass in the
Web project because of the way covariance works (or doesn't work) in
.NET.

Author: Ryan Nowak

src/Components/Blazor/Blazor/ref/Microsoft.AspNetCore.Blazor.netstandard2.0.cs

@@ -62,7 +62,7 @@ public partial class WebAssemblyRenderer : Microsoft.AspNetCore.Components.Rende
         public override Microsoft.AspNetCore.Components.Dispatcher Dispatcher { get { throw null; } }
         public System.Threading.Tasks.Task AddComponentAsync(System.Type componentType, string domElementSelector) { throw null; }
         public System.Threading.Tasks.Task AddComponentAsync<TComponent>(string domElementSelector) where TComponent : Microsoft.AspNetCore.Components.IComponent { throw null; }
-        public override System.Threading.Tasks.Task DispatchEventAsync(ulong eventHandlerId, Microsoft.AspNetCore.Components.Rendering.EventFieldInfo eventFieldInfo, Microsoft.AspNetCore.Components.UIEventArgs eventArgs) { throw null; }
+        public override System.Threading.Tasks.Task DispatchEventAsync(ulong eventHandlerId, Microsoft.AspNetCore.Components.Rendering.EventFieldInfo eventFieldInfo, System.EventArgs eventArgs) { throw null; }
         protected override void Dispose(bool disposing) { }
         protected override void HandleException(System.Exception exception) { }
         protected override System.Threading.Tasks.Task UpdateDisplayAsync(in Microsoft.AspNetCore.Components.Rendering.RenderBatch batch) { throw null; }

src/Components/Blazor/Blazor/src/Rendering/WebAssemblyRenderer.cs

@@ -120,7 +120,7 @@ protected override void HandleException(Exception exception)
         }
 
         /// <inheritdoc />
-        public override Task DispatchEventAsync(ulong eventHandlerId, EventFieldInfo eventFieldInfo, UIEventArgs eventArgs)
+        public override Task DispatchEventAsync(ulong eventHandlerId, EventFieldInfo eventFieldInfo, EventArgs eventArgs)
         {
             // Be sure we only run one event handler at once. Although they couldn't run
             // simultaneously anyway (there's only one thread), they could run nested on
@@ -185,10 +185,10 @@ readonly struct IncomingEventInfo
         {
             public readonly ulong EventHandlerId;
             public readonly EventFieldInfo EventFieldInfo;
-            public readonly UIEventArgs EventArgs;
+            public readonly EventArgs EventArgs;
             public readonly TaskCompletionSource<object> TaskCompletionSource;
 
-            public IncomingEventInfo(ulong eventHandlerId, EventFieldInfo eventFieldInfo, UIEventArgs eventArgs)
+            public IncomingEventInfo(ulong eventHandlerId, EventFieldInfo eventFieldInfo, EventArgs eventArgs)
             {
                 EventHandlerId = eventHandlerId;
                 EventFieldInfo = eventFieldInfo;

src/Components/Blazor/Build/test/ComponentRenderingRazorIntegrationTest.cs

@@ -253,7 +253,7 @@ namespace Test
     public class MyComponent : ComponentBase
     {
         [Parameter]
-        public Action<UIEventArgs> OnClick { get; set; }
+        public Action<EventArgs> OnClick { get; set; }
     }
 }
 "));
@@ -263,7 +263,7 @@ public class MyComponent : ComponentBase
 
 @code {
     private int counter;
-    private void Increment(UIEventArgs e) {
+    private void Increment(EventArgs e) {
         counter++;
     }
 }");
@@ -280,7 +280,7 @@ private void Increment(UIEventArgs e) {
                     AssertFrame.Attribute(frame, "OnClick", 1);
 
                     // The handler will have been assigned to a lambda
-                    var handler = Assert.IsType<Action<UIEventArgs>>(frame.AttributeValue);
+                    var handler = Assert.IsType<Action<EventArgs>>(frame.AttributeValue);
                     Assert.Equal("Test.TestComponent", handler.Target.GetType().FullName);
                     Assert.Equal("Increment", handler.Method.Name);
                 });

src/Components/Blazor/Build/test/RenderingRazorIntegrationTest.cs

@@ -332,7 +332,7 @@ public async Task SupportsTwoWayBindingForTextboxes()
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = "Modified value", }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = "Modified value", }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -367,7 +367,7 @@ public async Task SupportsTwoWayBindingForTextareas()
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = "Modified value", }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = "Modified value", }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -404,7 +404,7 @@ public async Task SupportsTwoWayBindingForDateValues()
             //
             // This should always complete synchronously.
             var newDateValue = new DateTime(2018, 3, 5, 4, 5, 6);
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = newDateValue.ToString(), }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = newDateValue.ToString(), }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -440,7 +440,7 @@ public async Task SupportsTwoWayBindingForDateValuesWithFormatString()
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = new DateTime(2018, 3, 5).ToString(testDateFormat), }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = new DateTime(2018, 3, 5).ToString(testDateFormat), }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -559,7 +559,7 @@ public async Task SupportsTwoWayBindingForBoolValues()
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task =  renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs() { Value = false, }));
+            var task =  renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs() { Value = false, }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;
 
@@ -595,7 +595,7 @@ public async Task SupportsTwoWayBindingForEnumValues()
             // Trigger the change event to show it updates the property
             //
             // This should always complete synchronously.
-            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new UIChangeEventArgs { Value = MyEnum.SecondValue.ToString(), }));
+            var task = renderer.Dispatcher.InvokeAsync(() => setter.InvokeAsync(new ChangeEventArgs { Value = MyEnum.SecondValue.ToString(), }));
             Assert.Equal(TaskStatus.RanToCompletion, task.Status);
             await task;