fix bugs in SearchPanel + add documentation comments

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Search/ISearchStrategy.cs

@@ -10,33 +10,45 @@ using ICSharpCode.AvalonEdit.Document;
 namespace ICSharpCode.AvalonEdit.Search
 {
 	/// <summary>
-	/// Description of ISearchStrategy.
+	/// Basic interface for search algorithms.
 	/// </summary>
 	public interface ISearchStrategy
 	{
+		/// <summary>
+		/// Finds all matches for a predicate in the given ITextSource.
+		/// </summary>
+		/// <remarks>This method is thread-safe.</remarks>
 		IEnumerable<ISearchResult> FindAll(ITextSource document);
 	}
 	
+	/// <summary>
+	/// Represents a search result.
+	/// </summary>
 	public interface ISearchResult : ISegment
 	{
 		
 	}
 	
+	/// <inheritdoc/>
 	public class SearchPatternException : Exception, ISerializable
 	{
+		/// <inheritdoc/>
 		public SearchPatternException()
 		{
 		}
 		
-	 	public SearchPatternException(string message) : base(message)
+		/// <inheritdoc/>
+		public SearchPatternException(string message) : base(message)
 		{
 		}
 		
+		/// <inheritdoc/>
 		public SearchPatternException(string message, Exception innerException) : base(message, innerException)
 		{
 		}
 
 		// This constructor is needed for serialization.
+		/// <inheritdoc/>
 		protected SearchPatternException(SerializationInfo info, StreamingContext context) : base(info, context)
 		{
 		}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Search/SearchCommands.cs

@@ -14,12 +14,22 @@ using ICSharpCode.AvalonEdit.Rendering;
 
 namespace ICSharpCode.AvalonEdit.Search
 {
+	/// <summary>
+	/// Search commands for AvalonEdit.
+	/// </summary>
 	public static class SearchCommands
 	{
+		/// <summary>
+		/// Finds the next occurrence in the file.
+		/// </summary>
 		public static readonly RoutedCommand FindNext = new RoutedCommand(
 			"FindNext", typeof(SearchPanel),
 			new InputGestureCollection { new KeyGesture(Key.F3) }
 		);
+		
+		/// <summary>
+		/// Finds the previous occurrence in the file.
+		/// </summary>
 		public static readonly RoutedCommand FindPrevious = new RoutedCommand(
 			"FindPrevious", typeof(SearchPanel),
 			new InputGestureCollection { new KeyGesture(Key.F3, ModifierKeys.Shift) }

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Search/SearchPanel.xaml

@@ -16,7 +16,7 @@
 					<Popup StaysOpen="False">
 						<Border Background="White" BorderBrush="DimGray" BorderThickness="1">
 							<StackPanel Orientation="Vertical">
-								<CheckBox x:FieldModifier="private" x:Name="matchCase" Content="Match case" Margin="3"  />
+								<CheckBox x:FieldModifier="private" x:Name="matchCase" Content="Match case" Margin="3" />
 								<CheckBox x:FieldModifier="private" x:Name="wholeWords" Content="Match whole words" Margin="3" />
 								<CheckBox x:FieldModifier="private" x:Name="useRegex" Content="Use Regular Expressions" Margin="3" />
 							</StackPanel>
@@ -30,10 +30,11 @@
 			<Button Margin="3" Height="24" Width="24" Command="local:SearchCommands.FindNext" ToolTip="Find Next (F3)">
 				<Image Width="16" Height="16" Stretch="Fill" Source="next.png" />
 			</Button>
-			<Button Click="CloseClick" HorizontalAlignment="Right" VerticalAlignment="Top" Height="16" Width="16">
+			<Button Click="CloseClick" Height="16" Width="16" HorizontalAlignment="Right" VerticalAlignment="Top"
+			        VerticalContentAlignment="Center" HorizontalContentAlignment="Center">
 				<Grid>
-					<Line X1="2" Y1="2" X2="8" Y2="8" Stroke="Black" StrokeThickness="1" />
-					<Line X1="8" Y1="2" X2="2" Y2="8" Stroke="Black" StrokeThickness="1" />
+					<Line X1="0" Y1="0" X2="8" Y2="8" Stroke="Black" StrokeThickness="1" />
+					<Line X1="8" Y1="0" X2="0" Y2="8" Stroke="Black" StrokeThickness="1" />
 				</Grid>
 			</Button>
 		</StackPanel>

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Search/SearchPanel.xaml.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Windows;
@@ -30,13 +31,16 @@ namespace ICSharpCode.AvalonEdit.Search
 		SearchResult currentResult;
 		FoldingManager foldingManager;
 		
-		public bool UseRegex { get { return useRegex.IsChecked == true; } }
-		public bool MatchCase { get { return matchCase.IsChecked == true; } }
-		public bool WholeWords { get { return wholeWords.IsChecked == true; } }
+		bool UseRegex { get { return useRegex.IsChecked == true; } }
+		bool MatchCase { get { return matchCase.IsChecked == true; } }
+		bool WholeWords { get { return wholeWords.IsChecked == true; } }
 		
 		string searchPattern;
 		ISearchStrategy strategy;
 		
+		/// <summary>
+		/// Gets/sets the content of the search box and the search string.
+		/// </summary>
 		public string SearchPattern {
 			get { return searchPattern; }
 			set {
@@ -45,18 +49,16 @@ namespace ICSharpCode.AvalonEdit.Search
 			}
 		}
 
-		void UpdateSearch(bool throwException = true)
+		void UpdateSearch()
 		{
-			if (!string.IsNullOrEmpty(searchPattern)) {
-				try {
-					strategy = SearchStrategyFactory.Create(searchPattern, !MatchCase, UseRegex, WholeWords);
-					DoSearch(true);
-				} catch (SearchPatternException) {
-					if (throwException) throw;
-				}
-			}
+			messageView.IsOpen = false;
+			strategy = SearchStrategyFactory.Create(searchPattern ?? "", !MatchCase, UseRegex, WholeWords);
+			DoSearch(true);
 		}
 		
+		/// <summary>
+		/// Creates a new SearchPanel and attaches it to a text area.
+		/// </summary>
 		public SearchPanel(TextArea textArea)
 		{
 			if (textArea == null)
@@ -73,13 +75,25 @@ namespace ICSharpCode.AvalonEdit.Search
 			textArea.Document.TextChanged += delegate { DoSearch(false); };
 			this.Loaded += delegate { searchTextBox.Focus(); };
 			
-			useRegex.Checked += delegate { UpdateSearch(false); };
-			matchCase.Checked += delegate { UpdateSearch(false); };
-			wholeWords.Checked += delegate { UpdateSearch(false); };
+			useRegex.Checked     += ValidateSearchText;
+			matchCase.Checked    += ValidateSearchText;
+			wholeWords.Checked   += ValidateSearchText;
+			
+			useRegex.Unchecked   += ValidateSearchText;
+			matchCase.Unchecked  += ValidateSearchText;
+			wholeWords.Unchecked += ValidateSearchText;
+		}
 		
-			useRegex.Unchecked += delegate { UpdateSearch(false); };
-			matchCase.Unchecked += delegate { UpdateSearch(false); };
-			wholeWords.Unchecked += delegate { UpdateSearch(false); };
+		void ValidateSearchText(object sender, RoutedEventArgs e)
+		{
+			var be = searchTextBox.GetBindingExpression(TextBox.TextProperty);
+			try {
+				Validation.ClearInvalid(be);
+				UpdateSearch();
+			} catch (SearchPatternException ex) {
+				var ve = new ValidationError(be.ParentBinding.ValidationRules[0], be, ex.Message, ex);
+				Validation.MarkInvalid(be, ve);
+			}
 		}
 		
 		/// <summary>
@@ -91,6 +105,9 @@ namespace ICSharpCode.AvalonEdit.Search
 			searchTextBox.SelectAll();
 		}
 		
+		/// <summary>
+		/// Moves to the next occurrence in the file.
+		/// </summary>
 		public void FindNext()
 		{
 			SearchResult result = null;
@@ -104,6 +121,9 @@ namespace ICSharpCode.AvalonEdit.Search
 			}
 		}
 		
+		/// <summary>
+		/// Moves to the previous occurrence in the file.
+		/// </summary>
 		public void FindPrevious()
 		{
 			SearchResult result = null;
@@ -155,17 +175,21 @@ namespace ICSharpCode.AvalonEdit.Search
 		{
 			switch (e.Key) {
 				case Key.Enter:
-					try {
-						messageView.IsOpen = false;
-						messageView.Content = null;
-						UpdateSearch();
-					} catch (SearchPatternException ex) {
-						messageView.Content = "Error: " + ex.Message;
+					e.Handled = true;
+					messageView.IsOpen = false;
+					if ((Keyboard.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift)
+						FindPrevious();
+					else
+						FindNext();
+					var error = Validation.GetErrors(searchTextBox).FirstOrDefault();
+					if (error != null) {
+						messageView.Content = "Error: " + error.ErrorContent;
 						messageView.PlacementTarget = searchTextBox;
 						messageView.IsOpen = true;
 					}
 					break;
 				case Key.Escape:
+					e.Handled = true;
 					CloseClick(sender, e);
 					break;
 			}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Search/SearchStrategyFactory.cs

@@ -3,11 +3,18 @@
 
 using System;
 using System.Text.RegularExpressions;
+using System.Windows.Controls;
 
 namespace ICSharpCode.AvalonEdit.Search
 {
+	/// <summary>
+	/// Provides factory methods for ISearchStrategies.
+	/// </summary>
 	public class SearchStrategyFactory
 	{
+		/// <summary>
+		/// Creates a default ISearchStrategy with the given parameters.
+		/// </summary>
 		public static ISearchStrategy Create(string searchPattern, bool ignoreCase, bool useRegularExpressions, bool matchWholeWords)
 		{
 			if (searchPattern == null)