Enable auto scroll when selection changed in RichTextBox

SourceGit/UI/Blame.xaml

@@ -147,6 +147,7 @@
                             ScrollViewer.ScrollChanged="SyncScrollChanged"
                             PreviewMouseWheel="MouseWheelOnContent"
                             SizeChanged="ContentSizeChanged"
+                            SelectionChanged="ContentSelectionChanged"
                             HorizontalAlignment="Stretch"
                             VerticalAlignment="Stretch"
                             FontFamily="Consolas">

SourceGit/UI/Blame.xaml.cs

@@ -210,5 +210,31 @@ namespace SourceGit.UI {
                 content.Document.PageWidth = content.ActualWidth;
             }
         }
+
+        /// <summary>
+        ///     Auto scroll when selection changed.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void ContentSelectionChanged(object sender, RoutedEventArgs e) {
+            var doc = sender as RichTextBox;
+            if (doc == null || doc.IsFocused == false) return;
+
+            if (Mouse.LeftButton == MouseButtonState.Pressed && !doc.Selection.IsEmpty) {
+                var p = Mouse.GetPosition(doc);
+
+                if (p.X <= 8) {
+                    doc.LineLeft();
+                } else if (p.X >= doc.ActualWidth - 8) {
+                    doc.LineRight();
+                }
+
+                if (p.Y <= 8) {
+                    doc.LineUp();
+                } else if (p.Y >= doc.ActualHeight - 8) {
+                    doc.LineDown();
+                }
+            }
+        }
     }
 }

SourceGit/UI/DiffViewer.xaml

@@ -48,7 +48,7 @@
                             BorderThickness="0"
                             Background="Transparent"
                             IsReadOnly="True"
-                            Margin="4,0,4,0"                   
+                            Margin="4,0,4,0"
                             FontSize="13"
                             HorizontalContentAlignment="Right"
                             VerticalAlignment="Stretch"/>
@@ -72,6 +72,7 @@
                             ScrollViewer.ScrollChanged="OnViewerScroll"
                             PreviewMouseWheel="OnViewerMouseWheel"
                             SizeChanged="LeftSizeChanged"
+                            SelectionChanged="OnViewerSelectionChanged"
                             HorizontalAlignment="Stretch"
                             VerticalAlignment="Stretch">
                         <RichTextBox.Document>
@@ -126,6 +127,7 @@
                             ScrollViewer.ScrollChanged="OnViewerScroll"
                             PreviewMouseWheel="OnViewerMouseWheel"
                             SizeChanged="RightSizeChanged"
+                            SelectionChanged="OnViewerSelectionChanged"
                             HorizontalAlignment="Stretch"
                             VerticalAlignment="Stretch">
                         <RichTextBox.Document>

SourceGit/UI/DiffViewer.xaml.cs

@@ -268,17 +268,53 @@ namespace SourceGit.UI {
             e.Handled = true;
         }
 
+        /// <summary>
+        ///     Fix document size for left side.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
         private void LeftSizeChanged(object sender, SizeChangedEventArgs e) {
             if (leftText.Document.PageWidth < leftText.ActualWidth) {
                 leftText.Document.PageWidth = leftText.ActualWidth;
             }
         }
 
+        /// <summary>
+        ///     Fix document size for right side.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
         private void RightSizeChanged(object sender, SizeChangedEventArgs e) {
             if (rightText.Document.PageWidth < rightText.ActualWidth) {
                 rightText.Document.PageWidth = rightText.ActualWidth;
             }
         }
+
+        /// <summary>
+        ///     Auto scroll when selection changed.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void OnViewerSelectionChanged(object sender, RoutedEventArgs e) {
+            var doc = sender as RichTextBox;
+            if (doc == null || doc.IsFocused == false) return;
+
+            if (Mouse.LeftButton == MouseButtonState.Pressed && !doc.Selection.IsEmpty) {
+                var p = Mouse.GetPosition(doc);
+
+                if (p.X <= 8) {
+                    doc.LineLeft();
+                } else if (p.X >= doc.ActualWidth - 8) {
+                    doc.LineRight();
+                }
+
+                if (p.Y <= 8) {
+                    doc.LineUp();
+                } else if (p.Y >= doc.ActualHeight - 8) {
+                    doc.LineDown();
+                }
+            }
+        }
         #endregion
     }
 }