Snippets: make ${Caret} work as expected when ${Selection} isn't used.

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/Snippets/DefaultSnippetElementProvider.cs

@@ -13,8 +13,14 @@ namespace ICSharpCode.AvalonEdit.AddIn.Snippets
 		{
 			if ("Selection".Equals(snippetInfo.Tag, StringComparison.OrdinalIgnoreCase))
 				return new SnippetSelectionElement() { Indentation = GetWhitespaceBefore(snippetInfo.SnippetText, snippetInfo.Position).Length };
-			if ("Caret".Equals(snippetInfo.Tag, StringComparison.OrdinalIgnoreCase))
-				return new SnippetCaretElement();
+			if ("Caret".Equals(snippetInfo.Tag, StringComparison.OrdinalIgnoreCase)) {
+				// If a ${Selection} exists, use the ${Caret} only if there is text selected
+				// (if no text is selected, ${Selection} will set the caret
+				if (snippetInfo.SnippetText.IndexOf("${Selection}", StringComparison.OrdinalIgnoreCase) >= 0)
+					return new SnippetCaretElement(setCaretOnlyIfTextIsSelected: true);
+				else
+					return new SnippetCaretElement();
+			}
 			
 			return null;
 		}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Snippets/SnippetCaretElement.cs

@@ -2,6 +2,7 @@
 // This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
 using System;
+using System.Runtime.Serialization;
 using System.Windows.Input;
 using ICSharpCode.AvalonEdit.Document;
 
@@ -13,10 +14,32 @@ namespace ICSharpCode.AvalonEdit.Snippets
 	[Serializable]
 	public class SnippetCaretElement : SnippetElement
 	{
+		[OptionalField]
+		bool setCaretOnlyIfTextIsSelected;
+		
+		/// <summary>
+		/// Creates a new SnippetCaretElement.
+		/// </summary>
+		public SnippetCaretElement()
+		{
+		}
+		
+		/// <summary>
+		/// Creates a new SnippetCaretElement.
+		/// </summary>
+		/// <param name="setCaretOnlyIfSelectionExists">
+		/// If set to true, the caret is set only when some text was selected.
+		/// This is useful 
+		/// </param>
+		public SnippetCaretElement(bool setCaretOnlyIfTextIsSelected)
+		{
+			this.setCaretOnlyIfTextIsSelected = setCaretOnlyIfTextIsSelected;
+		}
+		
 		/// <inheritdoc/>
 		public override void Insert(InsertionContext context)
 		{
-			if (!string.IsNullOrEmpty(context.SelectedText))
+			if (!setCaretOnlyIfTextIsSelected || !string.IsNullOrEmpty(context.SelectedText))
 				SetCaret(context);
 		}