Polish it a bit, fix exception text

dotnet · h3xds1nz · May 20, 2025 · May 20, 2025 · May 21, 2025 · May 22, 2025
commit b6f4102c327878764b3907796184c72e7c3035a0
@@ -10,10 +10,9 @@
 
 using System.Windows;
 using System.Windows.Automation;
-using System.Windows.Automation.Provider;
 using System.Windows.Automation.Peers;
+using System.Windows.Automation.Provider;
 using System.Windows.Input;
-using System.Windows.Threading;
 
 namespace MS.Internal.Automation
 {
@@ -25,7 +24,7 @@ namespace MS.Internal.Automation
     //
     // Currently exposes just BoundingRectangle, ClassName, IsEnabled
     // and IsKeyboardFocused properties.
-    internal class ElementProxy: IRawElementProviderFragmentRoot, IRawElementProviderAdviseEvents
+    internal class ElementProxy : IRawElementProviderFragmentRoot, IRawElementProviderAdviseEvents
     {
         //------------------------------------------------------
         //
@@ -88,44 +87,31 @@ public object GetPropertyValue(int property)
 
         public ProviderOptions ProviderOptions
         {
-            get 
+            get
             {
                 AutomationPeer peer = Peer;
-                if (peer == null)
-                {
-                    return ProviderOptions.ServerSideProvider;
-                }
-                return ElementUtil.Invoke(peer, static (state) => state.InContextGetProviderOptions(), this);
+
+                return peer is null ? ProviderOptions.ServerSideProvider : ElementUtil.Invoke(peer, static (state) => state.InContextGetProviderOptions(), this);
             }
-        }  
+        }
 
         public IRawElementProviderSimple HostRawElementProvider
         {
             get
             {
-                IRawElementProviderSimple host  = null;
-                HostedWindowWrapper hwndWrapper = null;
                 AutomationPeer peer = Peer;
-                if (peer == null)
+
+                if (peer is null)
                 {
                     return null;
                 }
-                hwndWrapper = ElementUtil.Invoke(peer, static (state) => state.InContextGetHostRawElementProvider(), this);
 
-                if (hwndWrapper != null)
-                    host = GetHostHelper(hwndWrapper);
-
-                return host;
-            }
-        }
+                HostedWindowWrapper hwndWrapper = ElementUtil.Invoke(peer, static (state) => state.InContextGetHostRawElementProvider(), this);
 
-        private static IRawElementProviderSimple GetHostHelper(HostedWindowWrapper hwndWrapper)
-        {
-            return AutomationInteropProvider.HostProviderFromHandle(hwndWrapper.Handle);
+                return hwndWrapper is not null ? AutomationInteropProvider.HostProviderFromHandle(hwndWrapper.Handle) : null;
+            }
         }
 
-        // IRawElementProviderFragment methods...
-
         public IRawElementProviderFragment Navigate(NavigateDirection direction)
         {
             AutomationPeer peer = Peer;
@@ -149,12 +135,12 @@ public Rect BoundingRectangle
                 return ElementUtil.Invoke(peer, static (state) => state.InContextBoundingRectangle(), this);
             }
         }
-        
+
         public IRawElementProviderSimple[] GetEmbeddedFragmentRoots()
         {
             return null;
         }
-        
+
         public void SetFocus()
         {
             AutomationPeer peer = Peer ?? throw new ElementNotAvailableException();
@@ -172,7 +158,6 @@ public IRawElementProviderFragmentRoot FragmentRoot
             }
         }
 
-        // IRawElementProviderFragmentRoot methods..
         public IRawElementProviderFragment ElementProviderFromPoint(double x, double y)
         {
             AutomationPeer peer = Peer;
@@ -259,9 +244,9 @@ internal AutomationPeer Peer
         {
             get
             {
-                if (_peer is WeakReference)
+                if (_peer is WeakReference weakRef)
                 {
-                    AutomationPeer peer = (AutomationPeer)((WeakReference)_peer).Target;
+                    AutomationPeer peer = (AutomationPeer)weakRef.Target;
                     return peer;
                 }
                 else

@@ -0,0 +1,69 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#nullable enable
+
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace MS.Internal.Automation;
+
+/// <summary>
+/// Utility class for working with <see cref="AutomationPeer"/>.
+/// </summary>
+internal static partial class ElementUtil
+{
+    /// <summary>
+    /// Wraps the return value and exception of an asynchronous operation.
+    /// </summary>
+    /// <typeparam name="TReturn"></typeparam>
+    [StructLayout(LayoutKind.Auto)]
+    private readonly struct ReturnInfo<TReturn>
+    {
+        /// <summary>
+        /// The exception that was thrown during the operation, if any.
+        /// </summary>
+        public Exception? StoredException { get; init; }
+
+        /// <summary>
+        /// Gets a value indicating whether the operation has been completed or timed out.
+        /// </summary>
+        public bool Completed { get; init; }
+
+        /// <summary>
+        /// The return value of the operation, if it completed successfully.
+        /// </summary>
+        public TReturn Value { get; init; }
+
+        /// <summary>
+        /// Creates a new instance of <see cref="ReturnInfo{TReturn}"/> with the specified exception.
+        /// </summary>
+        /// <param name="exception">The exception that was thrown during the operation.</param>
+        /// <returns>Returns a <see cref="ReturnInfo{TReturn}"/> object.</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static ReturnInfo<TReturn> FromException(Exception exception)
+        {
+            return new ReturnInfo<TReturn>
+            {
+                StoredException = exception,
+                Completed = true,
+                Value = default!
+            };
+        }
+
+        /// <summary>
+        /// Creates a new instance of <see cref="ReturnInfo{TReturn}"/> with the specified value.
+        /// </summary>
+        /// <param name="value">The return value of the operation.</param>
+        /// <returns>Returns a <see cref="ReturnInfo{TReturn}"/> object.</returns>
+        public static ReturnInfo<TReturn> FromResult(TReturn value)
+        {
+            return new ReturnInfo<TReturn>
+            {
+                StoredException = null,
+                Completed = true,
+                Value = value
+            };
+        }
+    }
+}
@@ -14,16 +14,8 @@ namespace MS.Internal.Automation;
 /// <summary>
 /// Utility class for working with <see cref="AutomationPeer"/>.
 /// </summary>
-internal static class ElementUtil
+internal static partial class ElementUtil
 {
-    private readonly struct ReturnInfo<TReturn>
-    {
-        public Exception? StoredException { get; init; }
-        public bool Completed { get; init; }
-
-        public TReturn Value { get; init; }
-    }
-
     ///// <summary>
     ///// Provides a helper to invoke work on the UI thread, re-throwing all exceptions on the thread that invoked this execution.
     ///// </summary>
@@ -63,11 +55,11 @@ static ReturnInfo<TReturn> ExceptionWrapper(Func<TArg, TReturn> func, TArg arg)
         {
             try
             {
-                return new ReturnInfo<TReturn>() { Value = func(arg), Completed = true };
+                return ReturnInfo<TReturn>.FromResult(func(arg));
             }
             catch (Exception e)
             {
-                return new ReturnInfo<TReturn>() { StoredException = e, Completed = true };
+                return ReturnInfo<TReturn>.FromException(e);
             }
         }
 
@@ -88,11 +80,11 @@ static ReturnInfo<TReturn> ExceptionWrapper(Func<TArg1, TArg2, TReturn> func, TA
         {
             try
             {
-                return new ReturnInfo<TReturn>() { Value = func(arg1, arg2), Completed = true };
+                return ReturnInfo<TReturn>.FromResult(func(arg1, arg2));
             }
             catch (Exception e)
             {
-                return new ReturnInfo<TReturn>() { StoredException = e, Completed = true };
+                return ReturnInfo<TReturn>.FromException(e);
             }
         }
 
@@ -120,14 +112,23 @@ private static TReturn HandleReturnValue<TReturn>(Dispatcher dispatcher, ref rea
         return retVal.Value;
     }
 
+    /// <summary>
+    /// Throws an <see cref="InvalidOperationException"/> indicating that the associated dispatcher has been shut down.
+    /// </summary>
     [DoesNotReturn]
     [MethodImpl(MethodImplOptions.NoInlining)]
     private static void ThrowInvalidOperationException() => throw new InvalidOperationException(SR.AutomationDispatcherShutdown);
 
+    /// <summary>
+    /// Throws a <see cref="TimeoutException"/> indicating that the automation operation has timed out.
+    /// </summary>
     [DoesNotReturn]
     [MethodImpl(MethodImplOptions.NoInlining)]
-    private static void ThrowTimeoutException() => throw new TimeoutException(SR.AutomationDispatcherShutdown);
+    private static void ThrowTimeoutException() => throw new TimeoutException(SR.AutomationTimeout);
 
+    /// <summary>
+    /// Unwraps the exception and throws it on the current thread.
+    /// </summary>
     [DoesNotReturn]
     [MethodImpl(MethodImplOptions.NoInlining)]
     private static void UnwrapException(Exception exception) => throw exception;
@@ -144,31 +145,23 @@ internal static object Invoke(AutomationPeer peer, DispatcherOperationCallback w
         Exception? remoteException = null;
         bool completed = false;
 
-        object retVal = dispatcher.Invoke(
-            DispatcherPriority.Send,
-            TimeSpan.FromMinutes(3),
-            (DispatcherOperationCallback)delegate (object workArg)
+        object retVal = dispatcher.Invoke(DispatcherPriority.Send, TimeSpan.FromMinutes(3), (DispatcherOperationCallback)delegate (object workArg)
+        {
+            try
             {
-                try
-                {
-                    return work(workArg);
-                }
-                catch (Exception e)
-                {
-                    remoteException = e;
-                    return null;
-                }
-                catch        //for non-CLS Compliant exceptions
-                {
-                    remoteException = null;
-                    return null;
-                }
-                finally
-                {
-                    completed = true;
-                }
-            },
-            arg);
+                return work(workArg);
+            }
+            catch (Exception e)
+            {
+                remoteException = e;
+                return null;
+            }
+            finally
+            {
+                completed = true;
+            }
+        },
+        arg);
 
         if (completed)
         {

@@ -137,6 +137,7 @@
     <Compile Include="MS\Internal\Automation\DockProviderWrapper.cs" />
     <Compile Include="MS\Internal\Automation\ElementProxy.cs" />
     <Compile Include="MS\Internal\Automation\ElementUtil.cs" />
+    <Compile Include="MS\Internal\Automation\ElementUtil.ReturnInfo.cs" />
     <Compile Include="MS\Internal\Automation\EventMap.cs" />
     <Compile Include="MS\Internal\Automation\ExpandCollapseProviderWrapper.cs" />
     <Compile Include="MS\Internal\Automation\GridItemProviderWrapper.cs" />