stash and restore clipboard when inserting custom snipet

OneMore/Commands/Snippets/InsertSnippetCommand.cs

@@ -8,7 +8,6 @@ namespace River.OneMoreAddIn.Commands
 	using WindowsInput;
 	using WindowsInput.Native;
 	using Resx = River.OneMoreAddIn.Properties.Resources;
-	using Win = System.Windows;
 
 
 	internal class InsertSnippetCommand : Command
@@ -40,17 +39,21 @@ public override async Task Execute(params object[] args)
 				return;
 			}
 
-			await SingleThreaded.Invoke(() =>
-			{
-				Win.Clipboard.SetText(snippet, Win.TextDataFormat.Html);
-			});
+			var clippy = new ClipboardProvider();
+			await clippy.StashState();
+
+			await clippy.SetHtml(snippet);
 
 			// both SetText and SendWait are very unpredictable so wait a little
 			await Task.Delay(200);
 
 			//SendKeys.SendWait("^(v)");
 			new InputSimulator().Keyboard
 				.ModifiedKeyStroke(VirtualKeyCode.CONTROL, VirtualKeyCode.VK_V);
+
+			await Task.Delay(200);
+
+			await clippy.RestoreState();
 		}
 	}
 }

OneMore/Helpers/ClipboardProvider.cs

@@ -0,0 +1,129 @@
+//************************************************************************************************
+// Copyright © 2022 Steven M Cohn. All rights reserved.
+//************************************************************************************************                
+
+#pragma warning disable S3267 // Loops should be simplified with "LINQ" expressions
+
+namespace River.OneMoreAddIn
+{
+	using System;
+	using System.Collections.Generic;
+	using System.Threading.Tasks;
+	using System.Windows.Media.Imaging;
+	using Win = System.Windows;
+
+
+	internal class ClipboardProvider
+	{
+		private readonly Dictionary<Win.TextDataFormat, string> stash;
+		private BitmapSource stashedImage;
+
+
+		public ClipboardProvider()
+		{
+			stash = new Dictionary<Win.TextDataFormat, string>();
+		}
+
+
+		public async Task SetHtml(string text)
+		{
+			await SingleThreaded.Invoke(() =>
+			{
+				Win.Clipboard.SetText(text, Win.TextDataFormat.Html);
+			});
+		}
+
+
+		public async Task SetText(string text)
+		{
+			await SingleThreaded.Invoke(() =>
+			{
+				Win.Clipboard.SetText(text, Win.TextDataFormat.Text);
+			});
+		}
+
+
+		public async Task StashState()
+		{
+			stash.Clear();
+			stashedImage = null;
+
+			await SingleThreaded.Invoke(() =>
+			{
+				// prioritize images
+				if (Win.Clipboard.ContainsImage())
+				{
+					stashedImage = Win.Clipboard.GetImage();
+				}
+				else
+				{
+					// collect each text format
+					foreach (Win.TextDataFormat format in Enum.GetValues(typeof(Win.TextDataFormat)))
+					{
+						if (Win.Clipboard.ContainsText(format))
+						{
+							stash.Add(format, Win.Clipboard.GetText(format));
+						}
+					}
+				}
+
+				// TODO: other formats, e.g. files?
+			});
+		}
+
+
+		public async Task RestoreState()
+		{
+			await SingleThreaded.Invoke(() =>
+			{
+				if (stashedImage != null)
+				{
+					Win.Clipboard.SetImage(stashedImage);
+				}
+				else if (stash.Count > 0)
+				{
+					// multiple texxt formats must be collated into a data object
+					var data = new Win.DataObject();
+					foreach (var key in stash.Keys)
+					{
+						data.SetData(ConvertToDataFormats(key), stash[key]);
+					}
+
+					Win.Clipboard.SetDataObject(data, true);
+				}
+			});
+
+			stash.Clear();
+		}
+
+
+		// duplicates the internal System.Windows.DataFormats.ConvertToDataFormats method
+		private static string ConvertToDataFormats(Win.TextDataFormat textDataformat)
+		{
+			var result = Win.DataFormats.UnicodeText;
+			switch (textDataformat)
+			{
+				case Win.TextDataFormat.Text:
+					result = Win.DataFormats.Text;
+					break;
+				case Win.TextDataFormat.UnicodeText:
+					result = Win.DataFormats.UnicodeText;
+					break;
+				case Win.TextDataFormat.Rtf:
+					result = Win.DataFormats.Rtf;
+					break;
+				case Win.TextDataFormat.Html:
+					result = Win.DataFormats.Html;
+					break;
+				case Win.TextDataFormat.CommaSeparatedValue:
+					result = Win.DataFormats.CommaSeparatedValue;
+					break;
+				case Win.TextDataFormat.Xaml:
+					result = Win.DataFormats.Xaml;
+					break;
+			}
+
+			return result;
+		}
+	}
+}

OneMore/OneMore.csproj

@@ -428,6 +428,7 @@
       <DependentUpon>UpdateDialog.cs</DependentUpon>
     </Compile>
     <Compile Include="Helpers\ApplicationFactory.cs" />
+    <Compile Include="Helpers\ClipboardProvider.cs" />
     <Compile Include="Helpers\ErrorCodes.cs" />
     <Compile Include="Helpers\Extensions\ByteExtensions.cs" />
     <Compile Include="Helpers\Extensions\ColorMatrixExtensions.cs" />