feature<DiffViewer>: add combined diff view mode; optimize line number using virtualizing ItemsControl instead of TextBox

src/Git/Preference.cs

@@ -110,6 +110,10 @@ namespace SourceGit.Git {
         ///     Use list instead of tree in change view.
         /// </summary>
         public bool UIUseListInChanges { get; set; }
+        /// <summary>
+        ///     Use one side diff instead of two sides.
+        /// </summary>
+        public bool UIUseOneSideDiff { get; set; }
         #endregion
 
         #region SETTING_REPOS

src/Resources/Icons.xaml

@@ -22,12 +22,14 @@
     
     <Geometry x:Key="Icon.MoveUp">M868 545.5L536.1 163c-12.7-14.7-35.5-14.7-48.3 0L156 545.5c-4.5 5.2-0.8 13.2 6 13.2h81c4.6 0 9-2 12.1-5.5L474 300.9V864c0 4.4 3.6 8 8 8h60c4.4 0 8-3.6 8-8V300.9l218.9 252.3c3 3.5 7.4 5.5 12.1 5.5h81c6.8 0 10.5-8 6-13.2z</Geometry>
     <Geometry x:Key="Icon.MoveDown">M862 465.3h-81c-4.6 0-9 2-12.1 5.5L550 723.1V160c0-4.4-3.6-8-8-8h-60c-4.4 0-8 3.6-8 8v563.1L255.1 470.8c-3-3.5-7.4-5.5-12.1-5.5h-81c-6.8 0-10.5 8.1-6 13.2L487.9 861c12.7 14.7 35.5 14.7 48.3 0L868 478.5c4.5-5.2 0.8-13.2-6-13.2z</Geometry>
-
     <Geometry x:Key="Icon.Down">M509.44 546.304l270.848-270.912 90.56 90.56-347.52 349.056-0.832-0.768-13.056 13.056-362.624-361.28 91.136-91.264z</Geometry>
     <Geometry x:Key="Icon.DoubleDown">M256 224l1e-8 115.2L512 544l255.99999999-204.8 1e-8-115.2-256 204.80000001L256 224zM512 684.8l-256-204.8L256 595.2 512 800 768 595.2l0-115.2L512 684.8z</Geometry>
     <Geometry x:Key="Icon.Up">M169.5 831l342.8-341.9L855.1 831l105.3-105.3-448.1-448.1L64.2 725.7 169.5 831z</Geometry>
     <Geometry x:Key="Icon.DoubleUp">M768 800V684.8L512 480 256 684.8V800l256-204.8L768 800zM512 339.2L768 544V428.8L512 224 256 428.8V544l256-204.8z</Geometry>
 
+    <Geometry x:Key="Icon.SplitHorizontal">M73.152 1024H1024V658.282667h-73.152v292.565333H73.173333V658.282667H0V1024h73.152zM0 0v365.717333h73.152V73.152H950.826667V0H0z m950.848 365.717333V0H1024v365.717333h-73.152zM0 548.565333v-73.130666h1024v73.130666H0z</Geometry>
+    <Geometry x:Key="Icon.SplitVertical">M0 73.152V1024h365.717333v-73.152H73.152V73.173333h292.565333V0H0v73.152zM1024 0H658.282667v73.152h292.565333V950.826667H1024V0zM658.282667 950.848H1024V1024H658.282667v-73.152zM475.434667 0h73.130666v1024h-73.130666V0z</Geometry>
+    
     <Geometry x:Key="Icon.Preference">M64.2 180.3h418.2v120.6H64.2zM64.2 461.7h358.5v120.6H64.2zM64.2 723.1h418.2v120.6H64.2zM601.9 180.3h358.5v120.6H601.9zM482.4 119.9h179.2v241.3H482.4zM303.2 401.4h179.2v241.3H303.2zM482.4 662.8h179.2v241.3H482.4zM540.3 461.7h420.1v120.6H540.3zM601.9 723.1h358.5v120.6H601.9z</Geometry>
     <Geometry x:Key="Icon.Setting">M887 576.8v-129.4L796.6 418c-4.6-14-10.2-27.4-16.8-40.4l43.2-84.8-91.6-91.6-84.8 43.2c-13-6.6-26.6-12.2-40.4-16.8l-29.4-90.4h-129.4L418 227.6c-13.8 4.6-27.4 10.2-40.4 16.8l-84.8-43.2-91.6 91.6 43.2 84.8c-6.6 13-12.2 26.6-16.8 40.4l-90.4 29.4v129.4l90.4 29.4c4.6 13.8 10.2 27.4 16.8 40.4l-43.2 84.8 91.6 91.6 84.8-43.2c13 6.6 26.6 12.2 40.4 16.8l29.4 90.4h129.4l29.4-90.4c14-4.6 27.4-10.2 40.4-16.8l84.8 43.2 91.6-91.6-43.2-84.8c6.6-13 12.2-26.6 16.8-40.4l90.4-29.4zM512 662c-82.8 0-150-67.2-150-150s67.2-150 150-150 150 67.2 150 150-67.2 150-150 150z</Geometry>
     <Geometry x:Key="Icon.Info">M 38,19C 48.4934,19 57,27.5066 57,38C 57,48.4934 48.4934,57 38,57C 27.5066,57 19,48.4934 19,38C 19,27.5066 27.5066,19 38,19 Z M 33.25,33.25L 33.25,36.4167L 36.4166,36.4167L 36.4166,47.5L 33.25,47.5L 33.25,50.6667L 44.3333,50.6667L 44.3333,47.5L 41.1666,47.5L 41.1666,36.4167L 41.1666,33.25L 33.25,33.25 Z M 38.7917,25.3333C 37.48,25.3333 36.4167,26.3967 36.4167,27.7083C 36.4167,29.02 37.48,30.0833 38.7917,30.0833C 40.1033,30.0833 41.1667,29.02 41.1667,27.7083C 41.1667,26.3967 40.1033,25.3333 38.7917,25.3333 Z</Geometry>

src/Resources/Styles/ToggleButton.xaml

@@ -108,4 +108,34 @@
             </Setter.Value>
         </Setter>
     </Style>
+
+    <Style x:Key="Style.ToggleButton.SplitDirection" TargetType="{x:Type ToggleButton}">
+        <Setter Property="Background" Value="Transparent"/>
+        <Setter Property="BorderBrush" Value="Transparent"/>
+        <Setter Property="BorderThickness" Value="0"/>
+
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="{x:Type ToggleButton}">
+                    <Grid Background="Transparent">
+                        <Path 
+                            x:Name="Icon" 
+                            Height="12"
+                            Width="12"
+                            Style="{DynamicResource Style.Icon}"
+                            Fill="Transparent"
+                            Stroke="{DynamicResource Brush.FG}"
+                            StrokeThickness=".4"
+                            Data="{DynamicResource Icon.SplitHorizontal}"/>
+                    </Grid>
+
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsChecked" Value="True">
+                            <Setter TargetName="Icon" Property="Data" Value="{DynamicResource Icon.SplitVertical}"/>
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
 </ResourceDictionary>

src/UI/DiffViewer.xaml

@@ -3,6 +3,7 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
              xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:sourcegit="clr-namespace:SourceGit"
              mc:Ignorable="d"
              FontFamily="Consolas">
     <Border BorderThickness="1" BorderBrush="{StaticResource Brush.Border2}">
@@ -32,7 +33,7 @@
                         <Path x:Name="loading" Width="10" Style="{StaticResource Style.Icon}" Data="{StaticResource Icon.Loading}"/>
                     </StackPanel>
 
-                    <StackPanel Grid.Column="2" x:Name="diffNavigation" Orientation="Horizontal" HorizontalAlignment="Right">
+                    <StackPanel Grid.Column="2" x:Name="textChangeOptions" Orientation="Horizontal" HorizontalAlignment="Right">
                         <Button Width="26" Click="Go2Next" ToolTip="Next Difference" Background="Transparent">
                             <Path Width="10" Style="{StaticResource Style.Icon}" Data="{StaticResource Icon.MoveDown}"/>
                         </Button>
@@ -40,43 +41,68 @@
                         <Button Click="Go2Prev" ToolTip="Previous Difference" Background="Transparent">
                             <Path Width="10" Style="{StaticResource Style.Icon}" Data="{StaticResource Icon.MoveUp}"/>
                         </Button>
+
+                        <ToggleButton
+                            Margin="8,0,0,0"
+                            Style="{StaticResource Style.ToggleButton.SplitDirection}"
+                            ToolTip="Toggle One-Side/Two-Sides"
+                            IsChecked="{Binding Source={x:Static sourcegit:App.Preference}, Path=UIUseOneSideDiff, Mode=TwoWay}"
+                            Checked="ChangeDiffMode" Unchecked="ChangeDiffMode"/>
                     </StackPanel>
                 </Grid>
             </Border>
 
             <Grid x:Name="textChange" Grid.Row="1" ClipToBounds="True">
                 <Grid.ColumnDefinitions>
-                    <ColumnDefinition Width="*" MinWidth="100"/>
+                    <ColumnDefinition Width="4"/>
-                    <ColumnDefinition Width="2"/>
-                    <ColumnDefinition Width="*" MinWidth="100"/>
-                </Grid.ColumnDefinitions>
-
-                <Grid Grid.Column="0">
-                    <Grid.ColumnDefinitions>
                     <ColumnDefinition Width="Auto"/>
+                    <ColumnDefinition Width="4"/>
                     <ColumnDefinition Width="1"/>
-                        <ColumnDefinition Width="*"/>
+                    <ColumnDefinition x:Name="twoSideLeft"/>
+                    <ColumnDefinition x:Name="twoSideSplittter" Width="1"/>
+                    <ColumnDefinition Width="4"/>
+                    <ColumnDefinition Width="Auto"/>
+                    <ColumnDefinition Width="4"/>
+                    <ColumnDefinition Width="1"/>
+                    <ColumnDefinition Width="*" MinWidth="100"/>
                 </Grid.ColumnDefinitions>
 
-                    <TextBox
+                <ItemsControl
+                    Grid.Column="1"
                     x:Name="leftLineNumber"
-                        Grid.Column="0"
+                    Padding="0"
-                        AcceptsReturn="True"
+                    Margin="0"
-                        AcceptsTab="True"
                     BorderThickness="0"
                     Background="Transparent"
-                        IsReadOnly="True"
+                    VirtualizingPanel.ScrollUnit="Item"
-                        Padding="2,0"
+                    VirtualizingPanel.IsVirtualizing="True"
-                        Margin="0"
+                    VirtualizingPanel.VirtualizationMode="Recycling">
-                        FontSize="13"
+                    <ItemsControl.ItemsPanel>
-                        HorizontalContentAlignment="Right"
+                        <ItemsPanelTemplate>
-                        VerticalAlignment="Stretch"/>
+                            <VirtualizingStackPanel Orientation="Vertical"/>
+                        </ItemsPanelTemplate>
+                    </ItemsControl.ItemsPanel>
 
-                    <Rectangle Grid.Column="1" Width="1" Fill="{StaticResource Brush.Border2}"/>
+                    <ItemsControl.Template>
+                        <ControlTemplate TargetType="{x:Type ItemsControl}">
+                            <ScrollViewer CanContentScroll="True" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Disabled">
+                                <ItemsPresenter/>
+                            </ScrollViewer>
+                        </ControlTemplate>
+                    </ItemsControl.Template>
+
+                    <ItemsControl.ItemTemplate>
+                        <DataTemplate>
+                            <TextBlock Text="{Binding .}" Padding="0" Margin="0" FontFamily="Consolas" FontSize="13" HorizontalAlignment="Right" VerticalAlignment="Center" Foreground="{StaticResource Brush.FG}"/>
+                        </DataTemplate>
+                    </ItemsControl.ItemTemplate>
+                </ItemsControl>
+
+                <Rectangle Grid.Column="3" Width="1" Fill="{StaticResource Brush.Border2}"/>
 
                 <RichTextBox
                     x:Name="leftText"
-                        Grid.Column="2"
+                    Grid.Column="4"
                     AcceptsReturn="True"
                     AcceptsTab="True"
                     IsReadOnly="True"
@@ -90,49 +116,53 @@
                     RenderOptions.ClearTypeHint="Enabled"
                     ScrollViewer.ScrollChanged="OnViewerScroll"
                     PreviewMouseWheel="OnViewerMouseWheel"
-                        SizeChanged="LeftSizeChanged"
+                    SizeChanged="OnSizeChanged"
                     SelectionChanged="OnViewerSelectionChanged"
                     HorizontalAlignment="Stretch"
                     VerticalAlignment="Stretch">
                     <RichTextBox.Document>
                         <FlowDocument PageWidth="0"/>
                     </RichTextBox.Document>
-                        <RichTextBox.ContextMenu>
-                            <ContextMenu>
-                                <MenuItem Command="ApplicationCommands.Copy"/>
-                            </ContextMenu>
-                        </RichTextBox.ContextMenu>
                 </RichTextBox>
-                </Grid>
 
-                <GridSplitter Grid.Column="1" Width="1" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="{StaticResource Brush.Border2}"/>
+                <Rectangle Grid.Column="5" Width="1" Fill="{StaticResource Brush.Border2}"/>
 
-                <Grid Grid.Column="2">
+                <ItemsControl
-                    <Grid.ColumnDefinitions>
+                    Grid.Column="7"
-                        <ColumnDefinition Width="Auto"/>
-                        <ColumnDefinition Width="1"/>
-                        <ColumnDefinition Width="*"/>
-                    </Grid.ColumnDefinitions>
-
-                    <TextBox
                     x:Name="rightLineNumber"
-                        Grid.Column="0"
+                    Padding="0"
-                        AcceptsReturn="True"
+                    Margin="0"
-                        AcceptsTab="True"
-                        IsReadOnly="True"
                     BorderThickness="0"
                     Background="Transparent"
-                        Padding="2,0"
+                    VirtualizingPanel.ScrollUnit="Item"
-                        Margin="0"
+                    VirtualizingPanel.IsVirtualizing="True"
-                        FontSize="13"
+                    VirtualizingPanel.VirtualizationMode="Recycling">
-                        HorizontalContentAlignment="Right"
+                    <ItemsControl.ItemsPanel>
-                        VerticalAlignment="Stretch"/>
+                        <ItemsPanelTemplate>
+                            <VirtualizingStackPanel Orientation="Vertical"/>
+                        </ItemsPanelTemplate>
+                    </ItemsControl.ItemsPanel>
 
-                    <Rectangle Grid.Column="1" Width="1" Fill="{StaticResource Brush.Border2}"/>
+                    <ItemsControl.Template>
+                        <ControlTemplate TargetType="{x:Type ItemsControl}">
+                            <ScrollViewer CanContentScroll="True" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Disabled">
+                                <ItemsPresenter/>
+                            </ScrollViewer>
+                        </ControlTemplate>
+                    </ItemsControl.Template>
+
+                    <ItemsControl.ItemTemplate>
+                        <DataTemplate>
+                            <TextBlock Text="{Binding .}" Padding="0" Margin="0" FontFamily="Consolas" FontSize="13" HorizontalAlignment="Right" VerticalAlignment="Center" Foreground="{StaticResource Brush.FG}"/>
+                        </DataTemplate>
+                    </ItemsControl.ItemTemplate>
+                </ItemsControl>
+
+                <Rectangle Grid.Column="9" Width="1" Fill="{StaticResource Brush.Border2}"/>
 
                 <RichTextBox
                     x:Name="rightText"
-                        Grid.Column="2"
+                    Grid.Column="10"
                     AcceptsReturn="True"
                     AcceptsTab="True"
                     IsReadOnly="True"
@@ -146,21 +176,15 @@
                     RenderOptions.ClearTypeHint="Enabled"
                     ScrollViewer.ScrollChanged="OnViewerScroll"
                     PreviewMouseWheel="OnViewerMouseWheel"
-                        SizeChanged="RightSizeChanged"
+                    SizeChanged="OnSizeChanged"
                     SelectionChanged="OnViewerSelectionChanged"
                     HorizontalAlignment="Stretch"
                     VerticalAlignment="Stretch">
                     <RichTextBox.Document>
                         <FlowDocument PageWidth="0"/>
                     </RichTextBox.Document>
-                        <RichTextBox.ContextMenu>
-                            <ContextMenu>
-                                <MenuItem Command="ApplicationCommands.Copy"/>
-                            </ContextMenu>
-                        </RichTextBox.ContextMenu>
                 </RichTextBox>
             </Grid>
-            </Grid>
 
             <Border x:Name="sizeChange" Grid.Row="1" ClipToBounds="True" Background="{StaticResource Brush.BG3}" Visibility="Collapsed">
                 <StackPanel Orientation="Vertical" VerticalAlignment="Center">

src/UI/DiffViewer.xaml.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Globalization;
 using System.Text;
 using System.Threading.Tasks;
@@ -15,6 +16,7 @@ namespace SourceGit.UI {
     /// </summary>
     public partial class DiffViewer : UserControl {
         private double minWidth = 0;
+        private Git.Diff.TextChange textChangeData = null;
 
         /// <summary>
         ///     Diff options.
@@ -49,6 +51,8 @@ namespace SourceGit.UI {
         public void Diff(Git.Repository repo, Option opts) {
             SetTitle(opts.Path, opts.OrgPath);
 
+            textChangeData = null;
+
             loading.Visibility = Visibility.Visible;
             mask.Visibility = Visibility.Collapsed;
             textChange.Visibility = Visibility.Collapsed;
@@ -80,7 +84,8 @@ namespace SourceGit.UI {
                 if (rs.IsBinary) {
                     SetBinaryChange(Git.Diff.GetSizeChange(repo, opts.RevisionRange, opts.Path, opts.OrgPath));
                 } else if (rs.Blocks.Count > 0) {
-                    SetTextChange(rs);
+                    textChangeData = rs;
+                    SetTextChange();
                 } else {
                     SetSame();
                 }
@@ -107,28 +112,41 @@ namespace SourceGit.UI {
         ///     Show diff content.
         /// </summary>
         /// <param name="rs"></param>
-        private void SetTextChange(Git.Diff.TextChange rs) {
+        private void SetTextChange() {
+            if (textChangeData == null) return;
+
             Dispatcher.Invoke(() => {
                 loading.Visibility = Visibility.Collapsed;
                 textChange.Visibility = Visibility.Visible;
-                diffNavigation.Visibility = Visibility.Visible;
+                textChangeOptions.Visibility = Visibility.Visible;
+
+                if (App.Preference.UIUseOneSideDiff) {
+                    twoSideLeft.Width = new GridLength(0);
+                    twoSideLeft.MinWidth = 0;
+                    twoSideSplittter.Width = new GridLength(0);
+                } else {
+                    twoSideLeft.Width = new GridLength(1, GridUnitType.Star);
+                    twoSideLeft.MinWidth = 100;
+                    twoSideSplittter.Width = new GridLength(2);
+                }
 
                 minWidth = Math.Max(leftText.ActualWidth, rightText.ActualWidth) - 16;
 
-                leftLineNumber.Text = "";
+                leftLineNumber.ItemsSource = null;
-                rightLineNumber.Text = "";
+                rightLineNumber.ItemsSource = null;
+
                 leftText.Document.Blocks.Clear();
                 rightText.Document.Blocks.Clear();
 
-                var leftLineNumberBuilder = new StringBuilder();
+                var lLineNumbers = new List<string>();
-                var rightLineNumberBuilder = new StringBuilder();
+                var rLineNumbers = new List<string>();
 
-                foreach (var b in rs.Blocks) ShowBlock(b, leftLineNumberBuilder, rightLineNumberBuilder);
+                foreach (var b in textChangeData.Blocks) ShowBlock(b, lLineNumbers, rLineNumbers);
 
-                leftText.Document.PageWidth = minWidth + 16;
+                if (!App.Preference.UIUseOneSideDiff) leftText.Document.PageWidth = minWidth + 16;
                 rightText.Document.PageWidth = minWidth + 16;
-                leftLineNumber.Text = leftLineNumberBuilder.ToString();
+                leftLineNumber.ItemsSource = lLineNumbers;
-                rightLineNumber.Text = rightLineNumberBuilder.ToString();
+                rightLineNumber.ItemsSource = rLineNumbers;
                 leftText.ScrollToHome();
             });
         }
@@ -141,7 +159,7 @@ namespace SourceGit.UI {
             Dispatcher.Invoke(() => {
                 loading.Visibility = Visibility.Collapsed;
                 sizeChange.Visibility = Visibility.Visible;
-                diffNavigation.Visibility = Visibility.Collapsed;
+                textChangeOptions.Visibility = Visibility.Collapsed;
                 txtSizeChangeTitle.Content = "BINARY DIFF";
                 txtNewSize.Content = $"{bc.Size} Bytes";
                 txtOldSize.Content = $"{bc.PreSize} Bytes";
@@ -159,7 +177,7 @@ namespace SourceGit.UI {
 
                 loading.Visibility = Visibility.Collapsed;
                 sizeChange.Visibility = Visibility.Visible;
-                diffNavigation.Visibility = Visibility.Collapsed;
+                textChangeOptions.Visibility = Visibility.Collapsed;
                 txtSizeChangeTitle.Content = "LFS OBJECT CHANGE";
                 txtNewSize.Content = $"{newSize} Bytes";
                 txtOldSize.Content = $"{oldSize} Bytes";
@@ -173,44 +191,34 @@ namespace SourceGit.UI {
             Dispatcher.Invoke(() => {
                 loading.Visibility = Visibility.Collapsed;
                 noChange.Visibility = Visibility.Visible;
-                diffNavigation.Visibility = Visibility.Collapsed;
+                textChangeOptions.Visibility = Visibility.Collapsed;
             });
         }
 
         /// <summary>
-        ///     Make paragraph.
+        ///     Make paragraph for two-sides diff
         /// </summary>
         /// <param name="b"></param>
-        private void ShowBlock(Git.Diff.Block b, StringBuilder leftNumber, StringBuilder rightNumber) {
+        /// <param name="leftNumber"></param>
+        /// <param name="rightNumber"></param>
+        private void ShowBlock(Git.Diff.Block b, List<string> leftNumber, List<string> rightNumber) {
+            bool useOneSide = App.Preference.UIUseOneSideDiff;
+            if (useOneSide && b.Mode == Git.Diff.LineMode.Empty) return;
+
             var content = b.Builder.ToString();
 
+            // Make paragraph element
             Paragraph p = new Paragraph(new Run(content));
             p.Margin = new Thickness(0);
-            p.Padding = new Thickness();
+            p.Padding = new Thickness(0);
             p.LineHeight = 1;
-            p.Background = Brushes.Transparent;
+            p.Background = GetBlockBackground(b);
-            p.Foreground = FindResource("Brush.FG") as SolidColorBrush;
+            p.Foreground = b.Mode == Git.Diff.LineMode.Indicator ? Brushes.Gray : FindResource("Brush.FG") as SolidColorBrush;
-            p.FontStyle = FontStyles.Normal;
+            p.FontStyle = b.Mode == Git.Diff.LineMode.Indicator ? FontStyles.Italic : FontStyles.Normal;
             p.DataContext = b;
+            p.ContextMenuOpening += OnParagraphContextMenuOpening;
 
-            switch (b.Mode) {
+            // Calculate with
-            case Git.Diff.LineMode.Normal:
-                break;
-            case Git.Diff.LineMode.Indicator:
-                p.Foreground = Brushes.Gray;
-                p.FontStyle = FontStyles.Italic;
-                break;
-            case Git.Diff.LineMode.Empty:
-                p.Background = new SolidColorBrush(Color.FromArgb(40, 0, 0, 0));
-                break;
-            case Git.Diff.LineMode.Added:
-                p.Background = new SolidColorBrush(Color.FromArgb(60, 0, 255, 0));
-                break;
-            case Git.Diff.LineMode.Deleted:
-                p.Background = new SolidColorBrush(Color.FromArgb(60, 255, 0, 0));
-                break;
-            }
-
             var formatter = new FormattedText(
                 content,
                 CultureInfo.CurrentUICulture,
@@ -220,24 +228,50 @@ namespace SourceGit.UI {
                 Brushes.Black,
                 new NumberSubstitution(),
                 TextFormattingMode.Ideal);
-
             if (minWidth < formatter.Width) minWidth = formatter.Width;
 
+            // Line numbers
             switch (b.Side) {
             case Git.Diff.Side.Left:
-                leftText.Document.Blocks.Add(p);
                 for (int i = 0; i < b.Count; i++) {
-                    if (b.CanShowNumber) leftNumber.AppendLine($"{i + b.LeftStart}");
+                    if (b.CanShowNumber) leftNumber.Add($"{i + b.LeftStart}");
-                    else leftNumber.AppendLine();
+                    else leftNumber.Add("");
+
+                    if (useOneSide) rightNumber.Add("");
                 }
                 break;
             case Git.Diff.Side.Right:
-                rightText.Document.Blocks.Add(p);
                 for (int i = 0; i < b.Count; i++) {
-                    if (b.CanShowNumber) rightNumber.AppendLine($"{i + b.RightStart}");
+                    if (b.CanShowNumber) rightNumber.Add($"{i + b.RightStart}");
-                    else rightNumber.AppendLine();
+                    else rightNumber.Add("");
+
+                    if (useOneSide) leftNumber.Add("");
                 }
                 break;
+            default:
+                for (int i = 0; i < b.Count; i++) {
+                    if (b.CanShowNumber) {
+                        leftNumber.Add($"{i + b.LeftStart}");
+                        rightNumber.Add($"{i + b.RightStart}");
+                    } else {
+                        leftNumber.Add("");
+                        rightNumber.Add("");
+                    }
+                }
+                break;
+            }
+            
+            // Add this paragraph to document.
+            if (App.Preference.UIUseOneSideDiff) {
+                rightText.Document.Blocks.Add(p);
+            } else {
+                switch (b.Side) {
+                case Git.Diff.Side.Left:
+                    leftText.Document.Blocks.Add(p);
+                    break;
+                case Git.Diff.Side.Right:
+                    rightText.Document.Blocks.Add(p);
+                    break;
                 default:
                     leftText.Document.Blocks.Add(p);
 
@@ -249,23 +283,140 @@ namespace SourceGit.UI {
                     cp.Foreground = p.Foreground;
                     cp.FontStyle = p.FontStyle;
                     cp.DataContext = b;
-                rightText.Document.Blocks.Add(cp);
+                    cp.ContextMenuOpening += OnParagraphContextMenuOpening;
 
-                for (int i = 0; i < b.Count; i++) {
+                    rightText.Document.Blocks.Add(cp);
-                    if (b.Mode != Git.Diff.LineMode.Indicator) {
-                        leftNumber.AppendLine($"{i + b.LeftStart}");
-                        rightNumber.AppendLine($"{i + b.RightStart}");
-                    } else {
-                        leftNumber.AppendLine();
-                        rightNumber.AppendLine();
-                    }
-                }
                     break;
                 }
             }
+        }
+
+        /// <summary>
+        ///     Get background color of block.
+        /// </summary>
+        /// <param name="b"></param>
+        /// <returns></returns>
+        private Brush GetBlockBackground(Git.Diff.Block b) {
+            Border border = new Border();
+            border.BorderThickness = new Thickness(0);
+            border.BorderBrush = Brushes.LightBlue;
+            border.Height = b.Count * 16 - 1;
+            border.Width = minWidth - 1;
+
+            switch (b.Mode) {
+            case Git.Diff.LineMode.Empty:
+                border.Background = new SolidColorBrush(Color.FromArgb(40, 0, 0, 0));
+                break;
+            case Git.Diff.LineMode.Added:
+                border.Background = new SolidColorBrush(Color.FromArgb(60, 0, 255, 0));
+                break;
+            case Git.Diff.LineMode.Deleted:
+                border.Background = new SolidColorBrush(Color.FromArgb(60, 255, 0, 0));
+                break;
+            default:
+                border.Background = Brushes.Transparent;
+                break;
+            }
+
+            VisualBrush highlight = new VisualBrush();
+            highlight.TileMode = TileMode.None;
+            highlight.Stretch = Stretch.Fill;
+            highlight.Visual = border;
+            return highlight;
+        }
         #endregion
 
         #region EVENTS
+        /// <summary>
+        ///     Context menu for text-change paragraph
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void OnParagraphContextMenuOpening(object sender, ContextMenuEventArgs ev) {
+            var paragraph = sender as Paragraph;
+
+            var doc = (paragraph.Parent as FlowDocument);
+            if (doc != null) {
+                var textBox = doc.Parent as RichTextBox;
+                if (textBox != null && !textBox.Selection.IsEmpty) {
+                    var copyItem = new MenuItem();
+                    copyItem.Header = "Copy";
+                    copyItem.Click += (o, e) => {
+                        Clipboard.SetText(textBox.Selection.Text);
+                        e.Handled = true;
+                    };
+
+                    var copyMenu = new ContextMenu();
+                    copyMenu.Items.Add(copyItem);
+                    copyMenu.IsOpen = true;
+                    ev.Handled = true;
+                    return;
+                }
+            }
+
+            var block = paragraph.DataContext as Git.Diff.Block;
+            if (block.Mode == Git.Diff.LineMode.Empty || block.Mode == Git.Diff.LineMode.Indicator) {
+                ev.Handled = true;
+                return;
+            }
+
+            var highlight = paragraph.Background as VisualBrush;
+            if (highlight != null) {
+                (highlight.Visual as Border).BorderThickness = new Thickness(.5);
+            }
+            
+            paragraph.ContextMenu = new ContextMenu();
+            paragraph.ContextMenu.Closed += (o, e) => {
+                if (paragraph.ContextMenu == (o as ContextMenu)) {
+                    if (highlight != null) {
+                        (highlight.Visual as Border).BorderThickness = new Thickness(0);
+                    }
+                    paragraph.ContextMenu = null;
+                }
+            };
+
+            var copy = new MenuItem();
+            copy.Header = "Copy";
+            copy.Click += (o, e) => {
+                Clipboard.SetText(block.Builder.ToString());
+                e.Handled = true;
+            };
+            paragraph.ContextMenu.Items.Add(copy);
+
+            paragraph.ContextMenu.IsOpen = true;
+            ev.Handled = true;
+        }
+
+        /// <summary>
+        ///     Fix document size.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void OnSizeChanged(object sender, SizeChangedEventArgs e) {
+            var text = sender as RichTextBox;
+            if (text.Document.PageWidth < text.ActualWidth) {
+                text.Document.PageWidth = text.ActualWidth;
+            }
+        }
+
+        /// <summary>
+        ///     Scroll using mouse wheel.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void OnViewerMouseWheel(object sender, MouseWheelEventArgs e) {
+            var text = sender as RichTextBox;
+            if (text == null) return;
+
+            if (e.Delta > 0) {
+                text.LineUp();
+            } else {
+                text.LineDown();
+            }
+
+            e.Handled = true;
+        }
+
         /// <summary>
         ///     Sync scroll both sides.
         /// </summary>
@@ -294,46 +445,6 @@ namespace SourceGit.UI {
             }
         }
 
-        /// <summary>
-        ///     Scroll using mouse wheel.
-        /// </summary>
-        /// <param name="sender"></param>
-        /// <param name="e"></param>
-        private void OnViewerMouseWheel(object sender, MouseWheelEventArgs e) {
-            var text = sender as RichTextBox;
-            if (text == null) return;
-
-            if (e.Delta > 0) {
-                text.LineUp();
-            } else {
-                text.LineDown();
-            }
-
-            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>
@@ -366,9 +477,20 @@ namespace SourceGit.UI {
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private void Go2Next(object sender, RoutedEventArgs e) {
-            Paragraph next = null;
             double minTop = 0;
 
+            if (App.Preference.UIUseOneSideDiff) {
+                foreach (var p in rightText.Document.Blocks) {
+                    var rect = p.ContentStart.GetCharacterRect(LogicalDirection.Forward);
+                    var block = p.DataContext as Git.Diff.Block;
+                    if (rect.Top > 17 && (block.IsLeftDelete || block.IsRightAdded)) {
+                        minTop = rect.Top;
+                        break;
+                    }
+                }
+            } else {
+                Paragraph next = null;
+
                 foreach (var p in leftText.Document.Blocks) {
                     var rect = p.ContentStart.GetCharacterRect(LogicalDirection.Forward);
                     var block = p.DataContext as Git.Diff.Block;
@@ -391,8 +513,9 @@ namespace SourceGit.UI {
                         break;
                     }
                 }
+            }
 
-            if (next != null) {
+            if (minTop > 0) {
                 rightText.ScrollToVerticalOffset(rightText.VerticalOffset + minTop - 16);
             }
         }
@@ -403,8 +526,22 @@ namespace SourceGit.UI {
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private void Go2Prev(object sender, RoutedEventArgs e) {
+            double maxTop = double.MaxValue;
+
+            if (App.Preference.UIUseOneSideDiff) {
+                var p = rightText.Document.Blocks.LastBlock as Paragraph;
+                do {
+                    var rect = p.ContentStart.GetCharacterRect(LogicalDirection.Forward);
+                    var block = p.DataContext as Git.Diff.Block;
+                    if (rect.Top < 15 && (block.IsLeftDelete || block.IsRightAdded)) {
+                        maxTop = rect.Top;
+                        break;
+                    }
+
+                    p = p.PreviousBlock as Paragraph;
+                } while (p != null);
+            } else {
                 Paragraph next = null;
-            double maxTop = 0;
 
                 var p = leftText.Document.Blocks.LastBlock as Paragraph;
                 do {
@@ -424,21 +561,27 @@ namespace SourceGit.UI {
                     var rect = p.ContentStart.GetCharacterRect(LogicalDirection.Forward);
                     var block = p.DataContext as Git.Diff.Block;
                     if (rect.Top < 15 && block.IsRightAdded) {
-                    if (next == null || maxTop < rect.Top) {
+                        if (next == null || maxTop < rect.Top) maxTop = rect.Top;
-                        next = p;
-                        maxTop = rect.Top;
-                    }
-
                         break;
                     }
 
                     p = p.PreviousBlock as Paragraph;
                 } while (p != null);
+            }
 
-            if (next != null) {
+            if (maxTop != double.MaxValue) {
                 rightText.ScrollToVerticalOffset(rightText.VerticalOffset + maxTop - 16);
             }
         }
+
+        /// <summary>
+        ///     Chang diff mode.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void ChangeDiffMode(object sender, RoutedEventArgs e) {
+            SetTextChange();
+        }
         #endregion
     }
 }