Triggers on a DataTemplate when data is updated - wpf

Question

I've got a data template for a list box item similar to the one on this page...
link
I would like to take it a step further and do something to highlight the items when they change. For example, using the code in the link above, I would like to put a trigger to do something when Widget.Quantity changes. Maybe make the quiantity item (nothing else) flash or something. How can I do that? I include the relevant code below...
<Window.Resources>
<Style x:Key="RoundedItem" TargetType="ListBoxItem">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListBoxItem">
<Border CornerRadius="10" BorderBrush="Black" BorderThickness="1" Margin="1">
<ContentPresenter />
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<DataTemplate DataType="{x:Type local:Widget}">
<StackPanel Orientation="Horizontal">
<Label Content="{Binding Name}" />
<Label Content="{Binding Quantity}" />
</StackPanel>
</DataTemplate>
</Window.Resources>
<ListBox ItemsSource="{Binding Widgets}" ItemContainerStyle="{StaticResource RoundedItem}" HorizontalContentAlignment="Stretch" />

Answer 1

Just add triggers to the DataTemplate.Triggers collection.
<DataTemplate DataType="{x:Type local:Widget}">
<StackPanel x:Name="panel" Orientation="Horizontal">
<Label Content="{Binding Name}" />
<Label Content="{Binding Quantity}" />
</StackPanel>
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding SomeProperty}" Value="True">
<Setter Property="Background" Value="Yellow" TargetName="panel" />
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>

Answer 2

You'll probably want to add a property in your Widget class to do that. Or if Widget is a Model, you may want to wrap it in a WidgetViewModel class with an "IsFlashing" property on it. Then set the trigger to fire whenever this "IsFlashing" property is True.

Answer 3

I've managed to get it working with EventTriggers. Complete code below. In summary, the event trigger detects when the bound value changes, then turns the text orange briefly.
<UserControl.Resources>
<!-- instantiate an instance of the TimeSettingsCollection class -->
<c:TimeSettingsCollection x:Key="TimeSettingsCollection"/>
<Style x:Key="ListBoxItemStyle" TargetType="ListBoxItem">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListBoxItem">
<Border Name="ItemBorder" BorderBrush="Gray" BorderThickness="1" Margin="3" Padding="7" Background="Transparent">
<ContentPresenter />
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter TargetName="ItemBorder" Property="Background" Value="LightBlue" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<DataTemplate DataType="{x:Type c:TimeSettingsItem}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="80"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Row="0" Grid.Column="0" Margin="0,0,8,0"
Style="{StaticResource smallTitleStyle}">Pc Name:</TextBlock>
<TextBlock Grid.Row="0" Grid.Column="1" Text="{Binding Path=PcName}"
Style="{StaticResource textStyleTextBlock}"/>
<TextBlock Grid.Row="1" Grid.Column="0" Margin="0,0,8,0"
Style="{StaticResource smallTitleStyle}">Time:</TextBlock>
<TextBlock Grid.Row="1" Grid.Column="1" Text="{Binding Path=TimeSettings.DateTime, NotifyOnTargetUpdated=True}"
Style="{StaticResource textStyleTextBlock}" x:Name="timeTextBlock">
<TextBlock.Background>
<SolidColorBrush Color="Transparent"/>
</TextBlock.Background>
<TextBlock.Triggers>
<EventTrigger RoutedEvent="Binding.TargetUpdated">
<BeginStoryboard>
<Storyboard>
<ColorAnimation
Storyboard.TargetName="timeTextBlock"
Storyboard.TargetProperty="(TextBlock.Foreground).(SolidColorBrush.Color)"
To="Orange"
Duration="0:0:1"
AutoReverse="True"/>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</TextBlock.Triggers>
</TextBlock>
</Grid>
</DataTemplate>
</UserControl.Resources>
<DockPanel>
<ListBox Name="timeListBox" ItemsSource="{Binding Source={StaticResource TimeSettingsCollection}}" ItemContainerStyle="{StaticResource ListBoxItemStyle}" HorizontalContentAlignment="Stretch" IsSynchronizedWithCurrentItem="True">
</ListBox>
</DockPanel>