aistudio-wpf-diagram/AIStudio.Wpf.ADiagram/Controls/ScrollViewer.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
                    xmlns:sys="clr-namespace:System;assembly=System.Runtime"
                    xmlns:controls="clr-namespace:AIStudio.Wpf.ADiagram.Controls">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="pack://application:,,,/Util.Controls.Handy;component/Style/Themes/ScrollViewer.xaml"/>
    </ResourceDictionary.MergedDictionaries>

    <ControlTemplate x:Key="ScrollViewerBaseControlTemplate" TargetType="controls:ScrollViewer">
        <ControlTemplate.Resources>
            <Storyboard x:Key="Storyboard1">
                <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_VerticalScrollBar">
                    <EasingDoubleKeyFrame KeyTime="0:0:.1" Value=".8"/>
                </DoubleAnimationUsingKeyFrames>
                <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_HorizontalScrollBar">
                    <EasingDoubleKeyFrame KeyTime="0:0:.1" Value=".8"/>
                </DoubleAnimationUsingKeyFrames>
            </Storyboard>
            <Storyboard x:Key="Storyboard2">
                <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_VerticalScrollBar">
                    <EasingDoubleKeyFrame KeyTime="0:0:.2" Value="0"/>
                </DoubleAnimationUsingKeyFrames>
                <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_HorizontalScrollBar">
                    <EasingDoubleKeyFrame KeyTime="0:0:.2" Value="0"/>
                </DoubleAnimationUsingKeyFrames>
            </Storyboard>
        </ControlTemplate.Resources>
        <Grid x:Name="Grid" Background="{TemplateBinding Background}">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="Auto"/>
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="*"/>
                <RowDefinition Height="Auto"/>
            </Grid.RowDefinitions>
            <ScrollContentPresenter x:Name="PART_ScrollContentPresenter" Grid.RowSpan="2" Grid.ColumnSpan="2" CanContentScroll="{TemplateBinding CanContentScroll}" CanHorizontallyScroll="False" CanVerticallyScroll="False" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Grid.Column="0" Margin="{TemplateBinding Padding}" Grid.Row="0"/>
            <ScrollBar x:Name="PART_VerticalScrollBar" Opacity="0" Style="{StaticResource ScrollBarBaseStyle}" AutomationProperties.AutomationId="VerticalScrollBar" Cursor="Arrow" Grid.Column="1" Maximum="{TemplateBinding ScrollableHeight}" Minimum="0" Grid.Row="0" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportHeight}"/>
            <ScrollBar x:Name="PART_HorizontalScrollBar" Opacity="0" Style="{StaticResource ScrollBarBaseStyle}" AutomationProperties.AutomationId="HorizontalScrollBar" Cursor="Arrow" Grid.Column="0" Maximum="{TemplateBinding ScrollableWidth}" Minimum="0" Orientation="Horizontal" Grid.Row="1" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" Value="{Binding HorizontalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportWidth}"/>
        </Grid>
        <ControlTemplate.Triggers>
            <DataTrigger Binding="{Binding IsMouseOver,RelativeSource={RelativeSource Self}}" Value="True">
                <DataTrigger.EnterActions>
                    <BeginStoryboard Storyboard="{StaticResource Storyboard1}"/>
                </DataTrigger.EnterActions>
                <DataTrigger.ExitActions>
                    <BeginStoryboard Storyboard="{StaticResource Storyboard2}"/>
                </DataTrigger.ExitActions>
            </DataTrigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>

    <Style x:Key="ScrollViewerBaseStyle" TargetType="controls:ScrollViewer">
        <Setter Property="VerticalScrollBarVisibility" Value="Auto"/>
        <Setter Property="Focusable" Value="False"/>
        <Setter Property="Template" Value="{StaticResource ScrollViewerBaseControlTemplate}"/>
    </Style>  
</ResourceDictionary>