Improved scrolling so that the code being jumped to end up in the middle of the text area.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@4849 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs

@@ -298,6 +298,11 @@ namespace ICSharpCode.AvalonEdit.Editing
 			                lineBottom - lineTop);
 		}
 		
+		/// <summary>
+		/// Minimum distance of the caret to the view border.
+		/// </summary>
+		internal const double MinimumDistanceToViewBorder = 30;
+		
 		/// <summary>
 		/// Scrolls the text view so that the caret is visible.
 		/// </summary>
@@ -306,7 +311,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 			if (textView != null) {
 				VisualLine visualLine = textView.GetOrConstructVisualLine(textView.Document.GetLineByNumber(position.Line));
 				Rect caretRectangle = CalcCaretRectangle(visualLine);
-				caretRectangle.Inflate(30, 30); // leave at least 30 pixels distance to the view border
+				caretRectangle.Inflate(MinimumDistanceToViewBorder, MinimumDistanceToViewBorder);
 				textView.MakeVisible(caretRectangle);
 			}
 		}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/TextEditor.cs

@@ -20,6 +20,7 @@ using ICSharpCode.AvalonEdit.Editing;
 using ICSharpCode.AvalonEdit.Highlighting;
 using ICSharpCode.AvalonEdit.Rendering;
 using ICSharpCode.AvalonEdit.Utils;
+using System.Windows.Threading;
 
 namespace ICSharpCode.AvalonEdit
 {
@@ -880,5 +881,30 @@ namespace ICSharpCode.AvalonEdit
 		{
 			return textArea.GetService(serviceType);
 		}
+		
+		/// <summary>
+		/// Scrolls to the specified line/column.
+		/// This method requires that the TextEditor was already assigned a size (WPF layout must have run prior).
+		/// </summary>
+		public void ScrollTo(int line, int column)
+		{
+			const double MinimumScrollPercentage = 0.3;
+			
+			if (scrollViewer != null) {
+				Point p = textArea.TextView.GetVisualPosition(new TextViewPosition(line, column), VisualYPosition.LineMiddle);
+				double verticalPos = p.Y - scrollViewer.ViewportHeight / 2;
+				if (Math.Abs(verticalPos - scrollViewer.VerticalOffset) > MinimumScrollPercentage * scrollViewer.ViewportHeight) {
+					scrollViewer.ScrollToVerticalOffset(Math.Max(0, verticalPos));
+				}
+				if (p.X > scrollViewer.ViewportWidth - Caret.MinimumDistanceToViewBorder * 2) {
+					double horizontalPos = Math.Max(0, p.X - scrollViewer.ViewportWidth / 2);
+					if (Math.Abs(horizontalPos - scrollViewer.HorizontalOffset) > MinimumScrollPercentage * scrollViewer.ViewportWidth) {
+						scrollViewer.ScrollToHorizontalOffset(horizontalPos);
+					}
+				} else {
+					scrollViewer.ScrollToHorizontalOffset(0);
+				}
+			}
+		}
 	}
 }

src/Main/Base/Project/Src/Editor/AvalonEdit/AvalonEditTextEditorAdapter.cs

@@ -13,6 +13,7 @@ using System.Windows.Input;
 
 using ICSharpCode.AvalonEdit.Editing;
 using ICSharpCode.SharpDevelop.Editor.CodeCompletion;
+using System.Windows.Threading;
 
 namespace ICSharpCode.SharpDevelop.Editor.AvalonEdit
 {
@@ -194,7 +195,15 @@ namespace ICSharpCode.SharpDevelop.Editor.AvalonEdit
 		{
 			textEditor.TextArea.Selection = Selection.Empty;
 			textEditor.TextArea.Caret.Position = new TextViewPosition(line, column);
-			textEditor.TextArea.Caret.BringCaretToView();
+			if (textEditor.ActualHeight > 0) {
+				textEditor.ScrollTo(line, column);
+			} else {
+				// we have to delay the scrolling if the text editor is not yet loaded
+				textEditor.Dispatcher.BeginInvoke(DispatcherPriority.Loaded, new Action(
+					delegate {
+						textEditor.ScrollTo(line, column);
+					}));
+			}
 		}
 		
 		public virtual IInsightWindow ActiveInsightWindow {