Merge pull request #20 from danwalmsley/fixes/fix-scrolling

Fixes/fix scrolling

src/AvaloniaEdit/Editing/TextArea.cs

@@ -616,6 +616,11 @@ private void CaretPositionChanged(object sender, EventArgs e)
             TextView.HighlightedLine = Caret.Line;
 
             ScrollToLine(Caret.Line);
+
+            Dispatcher.UIThread.InvokeAsync(() =>
+            {
+                (this as ILogicalScrollable).InvalidateScroll?.Invoke();
+            });
         }
 
         public static readonly DirectProperty<TextArea, ObservableCollection<IControl>> LeftMarginsProperty
@@ -1075,7 +1080,7 @@ Vector IScrollable.Offset
             {
                 TextView.SetScrollOffset(new Vector(value.X, value.Y * TextView.DefaultLineHeight));
 
-                SetAndRaise(OffsetProperty, ref _offset, value);
+                _offset = value;
             }
         }
 

src/AvaloniaEdit/Rendering/TextView.cs

@@ -1422,6 +1422,8 @@ internal void SetScrollOffset(Vector vector)
             {
                 _scrollOffset = vector;
                 ScrollOffsetChanged?.Invoke(this, EventArgs.Empty);
+
+                InvalidateMeasure();
             }
         }