HandyControl/Net40/HandyControl_Net40/Themes/Styles/Base/ChatBubbleBaseStyle.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:controls="clr-namespace:HandyControl.Controls">

    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="../../Basic/Converters.xaml"/>
        <ResourceDictionary Source="../../Basic/Geometries.xaml"/>
        <ResourceDictionary Source="../../Basic/Sizes.xaml"/>
    </ResourceDictionary.MergedDictionaries>

    <ControlTemplate x:Key="ChatBubbleStringBaseTemplate" TargetType="controls:ChatBubble">
        <Grid>
            <Path Name="Tail"  Data="{StaticResource BubbleTailGeometry}" Fill="{TemplateBinding Background}" HorizontalAlignment="Right" Stretch="Uniform" VerticalAlignment="Bottom" Width="15" Height="15" RenderTransformOrigin="0.5,0.5"/>
            <Border Name="Body" Background="{TemplateBinding Background}" CornerRadius="15" Margin="0,0,3,0">
                <TextBlock TextWrapping="Wrap" Text="{TemplateBinding Content}" VerticalAlignment="Center" Margin="{TemplateBinding Padding}"/>
            </Border>
        </Grid>
        <ControlTemplate.Triggers>
            <Trigger Property="Role" Value="Receiver">
                <Setter TargetName="Tail" Property="HorizontalAlignment" Value="Left"/>
                <Setter TargetName="Tail" Property="RenderTransform">
                    <Setter.Value>
                        <TransformGroup>
                            <ScaleTransform ScaleY="1" ScaleX="-1"/>
                        </TransformGroup>
                    </Setter.Value>
                </Setter>
                <Setter TargetName="Body" Property="Margin" Value="3,0,0,0"/>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>

    <ControlTemplate x:Key="ChatBubbleImageBaseTemplate" TargetType="controls:ChatBubble">
        <Grid>
            <Path Name="Tail"  Data="{StaticResource BubbleTailGeometry}" Fill="{TemplateBinding Background}" HorizontalAlignment="Right" Stretch="Uniform" VerticalAlignment="Bottom" Width="15" Height="15" RenderTransformOrigin="0.5,0.5"/>
            <Border Name="Body" Background="{TemplateBinding Background}" CornerRadius="15" Margin="0,0,3,0">
                <Grid>
                    <Image Margin="{TemplateBinding Padding}" VerticalAlignment="Center" Source="{TemplateBinding Content}"/>
                    <Border BorderThickness="{TemplateBinding Padding}" BorderBrush="{TemplateBinding Background}" Background="{x:Null}" CornerRadius="15"/>
                </Grid>
            </Border>
        </Grid>
        <ControlTemplate.Triggers>
            <Trigger Property="Role" Value="Receiver">
                <Setter TargetName="Tail" Property="HorizontalAlignment" Value="Left"/>
                <Setter TargetName="Tail" Property="RenderTransform">
                    <Setter.Value>
                        <TransformGroup>
                            <ScaleTransform ScaleY="1" ScaleX="-1"/>
                        </TransformGroup>
                    </Setter.Value>
                </Setter>
                <Setter TargetName="Body" Property="Margin" Value="3,0,0,0"/>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>

    <ControlTemplate x:Key="ChatBubbleAudioBaseTemplate" TargetType="controls:ChatBubble">
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="12" Name="Definition1"/>
                <ColumnDefinition Name="Definition2"/>
            </Grid.ColumnDefinitions>
            <Ellipse Name="Dot" VerticalAlignment="Top" Fill="{DynamicResource DangerBrush}" Width="6" Height="6" Visibility="{TemplateBinding IsRead,Converter={StaticResource Boolean2VisibilityReConverter}}" Margin="0,0,6,0"/>
            <Path Name="Tail" Grid.Column="1" Data="{StaticResource BubbleTailGeometry}" Fill="{TemplateBinding Background}" HorizontalAlignment="Right" Stretch="Uniform" VerticalAlignment="Bottom" Width="15" Height="15" RenderTransformOrigin="0.5,0.5"/>
            <Border Name="Body" Grid.Column="1" Background="{TemplateBinding Background}" CornerRadius="15" Margin="0,0,3,0">
                <Grid VerticalAlignment="Center" Margin="{TemplateBinding Padding}">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto"/>
                        <ColumnDefinition Width="Auto"/>
                    </Grid.ColumnDefinitions>
                    <ContentPresenter Name="Presenter" VerticalAlignment="Center"/>
                    <Path Name="Audio" Grid.Column="1" Data="{StaticResource AudioGeometry}" Fill="{TemplateBinding Foreground}" Width="16" Height="16" Margin="6,0,0,0" RenderTransformOrigin="0.5,0.5">
                        <Path.RenderTransform>
                            <TransformGroup>
                                <ScaleTransform ScaleY="1" ScaleX="-1"/>
                            </TransformGroup>
                        </Path.RenderTransform>
                    </Path>
                </Grid>
            </Border>
        </Grid>
        <ControlTemplate.Triggers>
            <Trigger Property="Role" Value="Receiver">
                <Setter TargetName="Tail" Property="HorizontalAlignment" Value="Left"/>
                <Setter TargetName="Tail" Property="RenderTransform">
                    <Setter.Value>
                        <TransformGroup>
                            <ScaleTransform ScaleY="1" ScaleX="-1"/>
                        </TransformGroup>
                    </Setter.Value>
                </Setter>
                <Setter TargetName="Tail" Property="Grid.Column" Value="0"/>
                <Setter TargetName="Dot" Property="Grid.Column" Value="1"/>
                <Setter TargetName="Dot" Property="Margin" Value="6,0,0,0"/>
                <Setter TargetName="Body" Property="Margin" Value="3,0,0,0"/>
                <Setter TargetName="Body" Property="Grid.Column" Value="0"/>
                <Setter TargetName="Definition1" Property="Width" Value="Auto"/>
                <Setter TargetName="Definition2" Property="Width" Value="12"/>
                <Setter TargetName="Audio" Property="Grid.Column" Value="0"/>
                <Setter TargetName="Audio" Property="Margin" Value="0,0,6,0"/>
                <Setter TargetName="Audio" Property="RenderTransform">
                    <Setter.Value>
                        <TransformGroup>
                            <ScaleTransform ScaleY="1" ScaleX="1"/>
                        </TransformGroup>
                    </Setter.Value>
                </Setter>
                <Setter TargetName="Presenter" Property="Grid.Column" Value="1"/>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>

    <ControlTemplate x:Key="ChatBubbleCustomBaseTemplate" TargetType="controls:ChatBubble">
        <Grid>
            <Path Name="Tail"  Data="{StaticResource BubbleTailGeometry}" Fill="{TemplateBinding Background}" HorizontalAlignment="Right" Stretch="Uniform" VerticalAlignment="Bottom" Width="15" Height="15" RenderTransformOrigin="0.5,0.5"/>
            <Border Name="Body" Background="{TemplateBinding Background}" CornerRadius="15" Margin="0,0,3,0">
                <ContentPresenter VerticalAlignment="Center" Margin="{TemplateBinding Padding}"/>
            </Border>
        </Grid>
        <ControlTemplate.Triggers>
            <Trigger Property="Role" Value="Receiver">
                <Setter TargetName="Tail" Property="HorizontalAlignment" Value="Left"/>
                <Setter TargetName="Tail" Property="RenderTransform">
                    <Setter.Value>
                        <TransformGroup>
                            <ScaleTransform ScaleY="1" ScaleX="-1"/>
                        </TransformGroup>
                    </Setter.Value>
                </Setter>
                <Setter TargetName="Body" Property="Margin" Value="3,0,0,0"/>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>

    <Style x:Key="ChatBubbleBaseStyle" TargetType="controls:ChatBubble">
        <Setter Property="HorizontalAlignment" Value="Right"/>
        <Setter Property="Background" Value="{DynamicResource DarkPrimaryBrush}"/>
        <Setter Property="Foreground" Value="{DynamicResource TextIconBrush}"/>
        <Setter Property="Padding" Value="10"/>
        <Setter Property="Margin" Value="10"/>
        <Setter Property="MinHeight" Value="{StaticResource DefaultControlHeight}"/>
        <Setter Property="Template" Value="{StaticResource ChatBubbleStringBaseTemplate}"/>
        <Setter Property="IsRead" Value="{Binding IsSelected,RelativeSource={RelativeSource Self}}"/>
        <Setter Property="MaxWidth" Value="280"/>
        <Style.Triggers>
            <Trigger Property="Role" Value="Receiver">
                <Setter Property="Background" Value="{DynamicResource BorderBrush}"/>
                <Setter Property="Foreground" Value="{DynamicResource PrimaryTextBrush}"/>
                <Setter Property="HorizontalAlignment" Value="Left"/>
            </Trigger>
            <Trigger Property="Type" Value="Image">
                <Setter Property="Template" Value="{StaticResource ChatBubbleImageBaseTemplate}"/>
                <Setter Property="MaxHeight" Value="280"/>
            </Trigger>
            <Trigger Property="Type" Value="Audio">
                <Setter Property="Template" Value="{StaticResource ChatBubbleAudioBaseTemplate}"/>
            </Trigger>
            <Trigger Property="Type" Value="Custom">
                <Setter Property="Template" Value="{StaticResource ChatBubbleCustomBaseTemplate}"/>
            </Trigger>
        </Style.Triggers>
    </Style>

</ResourceDictionary>