Unified foundation for WPF

Below you can find some insight into current sample and how its easy to add some gaze based behaviors to your WPF application.

To get started we need to instantiate Host, which handles connection to the Tobii Engine, and provides access to different features of Tobii Core SDK. The best place to instantiate Host would be App.xaml.cs file. In current sample we have overridden the OnStartup method of App class:

// some usings here

public partial class App : Application
{
    private Host _host;
    private WpfInteractorAgent _agent;

    protected override void OnStartup(StartupEventArgs e)
    {
        _host = new Host();
        _agent = _host.InitializeWpfAgent();
    }
}

You have noticed that we actually made one more thing - initialized WpfInteractorAgent. InteractorAgents designed to help you work with Interactors which are basically regions in your application with some gaze based behaviors. Let's see how such behavior has been defined in the sample.

If you take a look at the MainWindow.xaml you can notice that we have added wpf:Behaviors.IsGazeAware to the Rectangle element:

<Rectangle wpf:Behaviors.IsGazeAware="True" 
	   Style="{StaticResource RectangleWithGazeAwareAnimation}" />

This will instruct Tobii Engine to treat this rectangle as an Interactor with GazeAware behavior. It means that whenever somebody will be looking at the rectangle, another attached property wpf:Behaviors.HasGaze will be set to true and when nobody is looking at it, property will be false.

Taking a look at the Style we have defined for the rectangle, you can see how we used this property in the Trigger.

<Style x:Key="RectangleWithGazeAwareAnimation" TargetType="Rectangle">
    <Setter Property="Fill" Value="White"></Setter>
    <Style.Triggers>
        <Trigger Property="wpf:Behaviors.HasGaze" Value="True">
            <Trigger.EnterActions>
			     <!-- Enter animation -->
            </Trigger.EnterActions>
            <Trigger.ExitActions>
			     <!-- Exit animation -->
            </Trigger.ExitActions>
       </Trigger>
    </Style.Triggers>
</Style>