Don't crash when InlineUIElementGenerator's anchor is deleted.

Fix focus when inline UIElement is removed from TextView.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@5261 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/AvalonEditEditorUIService.cs

@@ -13,7 +13,7 @@ using ICSharpCode.SharpDevelop.Editor;
 
 namespace ICSharpCode.AvalonEdit.AddIn
 {
-	public class AvalonEditEditorUIService : IEditorUIService
+	sealed class AvalonEditEditorUIService : IEditorUIService
 	{
 		TextView textView;
 		
@@ -24,6 +24,10 @@ namespace ICSharpCode.AvalonEdit.AddIn
 		
 		public IInlineUIElement CreateInlineUIElement(ITextAnchor position, UIElement element)
 		{
+			if (position == null)
+				throw new ArgumentNullException("position");
+			if (element == null)
+				throw new ArgumentNullException("element");
 			InlineUIElementGenerator inline = new InlineUIElementGenerator(textView, element, position);
 			this.textView.ElementGenerators.Add(inline);
 			return inline;

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/InlineUIElementGenerator.cs

@@ -13,7 +13,7 @@ using ICSharpCode.SharpDevelop.Editor;
 
 namespace ICSharpCode.AvalonEdit.AddIn
 {
-	public class InlineUIElementGenerator : VisualLineElementGenerator, IInlineUIElement
+	sealed class InlineUIElementGenerator : VisualLineElementGenerator, IInlineUIElement
 	{
 		ITextAnchor anchor;
 		UIElement element;
@@ -24,6 +24,7 @@ namespace ICSharpCode.AvalonEdit.AddIn
 			this.textView = textView;
 			this.element = element;
 			this.anchor = anchor;
+			anchor.Deleted += delegate { Remove(); };
 		}
 		
 		public override int GetFirstInterestedOffset(int startOffset)

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/TextLayer.cs

@@ -8,6 +8,7 @@
 using System;
 using System.Collections.Generic;
 using System.Windows;
+using System.Windows.Input;
 using System.Windows.Media;
 
 namespace ICSharpCode.AvalonEdit.Rendering
@@ -67,14 +68,32 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			inlineObjects.RemoveAll(
 				ior => {
 					if (visualLinesWithOutstandingInlineObjects.Contains(ior.VisualLine)) {
-						ior.VisualLine = null;
-						RemoveVisualChild(ior.Element);
+						RemoveInlineObjectRun(ior);
 						return true;
 					}
 					return false;
 				});
 			visualLinesWithOutstandingInlineObjects.Clear();
 		}
+
+		// Remove InlineObjectRun.Element from TextLayer.
+		// Caller of RemoveInlineObjectRun will remove it from inlineObjects collection.
+		void RemoveInlineObjectRun(InlineObjectRun ior)
+		{
+			if (ior.Element.IsKeyboardFocusWithin) {
+				// When the inline element that has the focus is removed, WPF will reset the
+				// focus to the main window without raising appropriate LostKeyboardFocus events.
+				// To work around this, we manually set focus to the next focusable parent.
+				UIElement element = textView;
+				while (element != null && !element.Focusable) {
+					element = VisualTreeHelper.GetParent(element) as UIElement;
+				}
+				if (element != null)
+					Keyboard.Focus(element);
+			}
+			ior.VisualLine = null;
+			RemoveVisualChild(ior.Element);
+		}
 		
 		/// <summary>
 		/// Removes the inline object that displays the specified UIElement.
@@ -84,8 +103,7 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			inlineObjects.RemoveAll(
 				ior => {
 					if (ior.Element == element) {
-						ior.VisualLine = null;
-						RemoveVisualChild(ior.Element);
+						RemoveInlineObjectRun(ior);
 						return true;
 					}
 					return false;