Tobii.Research.IEyeTracker Interface Reference

Provides methods and properties to manage and get data from an eye tracker. More...

Inheritance diagram for Tobii.Research.IEyeTracker:

Public Member Functions
GazeOutputFrequencyCollection	GetAllGazeOutputFrequencies ()
	Gets a list of gaze output frequencies supported by the eye tracker.
float	GetGazeOutputFrequency ()
	Gets the gaze output frequency of the eye tracker.
void	SetGazeOutputFrequency (float gazeOutputFrequency)
	Sets the gaze output frequency of the eye tracker.
EyeTrackingModeCollection	GetAllEyeTrackingModes ()
	Gets a list of eye tracking modes supported by the eye tracker.
string	GetEyeTrackingMode ()
	Gets the eye tracking mode of the eye tracker.
void	SetEyeTrackingMode (string eyeTrackingMode)
	Sets the eye tracking mode of the eye tracker.
CalibrationData	RetrieveCalibrationData ()
	Gets the calibration data used currently by the eye tracker. This data can be saved to a file for later use.
void	ApplyCalibrationData (CalibrationData calibrationData)
	Sets the provided calibration data to the eye tracker, which means it will be active calibration.
bool	TryApplyLicenses (LicenseCollection licenses, out FailedLicenseCollection failedLicenses)
	Apply one or more licenses to unlock features of the eye tracker. A return value indicates whether all licenses where applied or not.
void	ClearAppliedLicenses ()
	Clears any previously applied licenses.
DisplayArea	GetDisplayArea ()
	Gets the size and corners of the display area.
void	SetDisplayArea (DisplayArea displayArea)
	Sets the display area of the eye tracker. It is strongly recommended to use Eye Tracker Manager to calculate the display area coordinates as the origin of the User Coordinate System differs between eye tracker models.".
void	SetDeviceName (string deviceName)
	Changes the device name. This is not supported by all eye trackers.

Properties
Uri	Address [get]
	Gets the address (URI) of the eye tracker device.
string	DeviceName [get]
	Gets the name of the eye tracker.
string	SerialNumber [get]
	Gets the serial number of the eye tracker. All physical eye trackers have a unique serial number.
string	Model [get]
	Gets the model of the eye tracker.
string	FirmwareVersion [get]
	Gets the firmware version of the eye tracker.
string	RuntimeVersion [get]
	Gets the runtime version of the eye tracker.
Capabilities	DeviceCapabilities [get]
	Gets the capabilities of the device.

Events
EventHandler< GazeDataEventArgs >	GazeDataReceived
	Event fired when gaze data is received.
EventHandler< EyeOpennessDataEventArgs >	EyeOpennessDataReceived
	Event fired when eye openness data is received.
EventHandler< UserPositionGuideEventArgs >	UserPositionGuideReceived
	Event fired when user position guide is received.
EventHandler< TimeSynchronizationReferenceEventArgs >	TimeSynchronizationReferenceReceived
	Occurs when the computer and the eye trackers clocks gets synchronized. To handle normal drifts between clocks the clocks are checked on regular basis, and this results in that the time stamps are adjusted for the drifts in the data streams. This drift handling is done in real time. The data received from this event could be used for an even more accurate drift adjustment in the post processing.
EventHandler< ExternalSignalValueEventArgs >	ExternalSignalReceived
	Occurs when the value of the external signal port (TTL input) on the eye tracker device changes. Not all eye trackers have a sampling trigger port. The sampling feature could be used to synchronize the eye tracker data with data from other devices. The sampling data contains a time reference that matches the time reference on the time synchronized gaze data.
EventHandler< EventErrorEventArgs >	EventErrorOccurred
	Fired when an error occurs on any of the other events for the eye tracker.
EventHandler< EyeImageEventArgs >	EyeImageReceived
	Occurs when a new eye image is received, and the occurrence depends on the eye tracker model. Not all eye tracker models support this feature. If no one is listening to gaze data, the eye tracker will only deliver full images, otherwise either cropped or full images will be delivered depending on whether or not the eye tracker has detected eyes.
EventHandler< EyeImageRawEventArgs >	EyeImageRawReceived
	Occurs when a new eye image raw is received, and the occurrence depends on the eye tracker model. Not all eye tracker models support this feature. If no one is listening to gaze data, the eye tracker will only deliver full images, otherwise either cropped or full images will be delivered depending on whether or not the eye tracker has detected eyes.
EventHandler< GazeOutputFrequencyEventArgs >	GazeOutputFrequencyChanged
	Occurs when the gaze output frequency has changed.
EventHandler< CalibrationModeEnteredEventArgs >	CalibrationModeEntered
	Occurs when the eye tracker enters calibration mode.
EventHandler< CalibrationModeLeftEventArgs >	CalibrationModeLeft
	Occurs when the eye tracker leaves calibration mode.
EventHandler< CalibrationChangedEventArgs >	CalibrationChanged
	Occurs when the calibration is changed for the eye tracker.
EventHandler< DisplayAreaEventArgs >	DisplayAreaChanged
	Occurs when the display area has changed.
EventHandler< ConnectionLostEventArgs >	ConnectionLost
	Occurs when the client loses connection to the eye tracker.
EventHandler< ConnectionRestoredEventArgs >	ConnectionRestored
	Occurs when connection to the eye tracker is restored.
EventHandler< EyeTrackingModeChangedEventArgs >	EyeTrackingModeChanged
	Occurs when the eye tracking mode has changed.
EventHandler< DeviceFaultsEventArgs >	DeviceFaults
	Occurs when the device reports new faults.
EventHandler< DeviceWarningsEventArgs >	DeviceWarnings
	Occurs when the device reports new warnings.
EventHandler< StreamBufferOverflowEventArgs >	StreamBufferOverflow
	Occurs when there is a stream buffer overflow, usually caused by a user-provided callback being unable to process its stream's data quickly enough.

Detailed Description

Provides methods and properties to manage and get data from an eye tracker.

Examples

ScreenBasedCalibration_CalibrateDuringGazeRecording.cs.

Member Function Documentation

ApplyCalibrationData()

void Tobii.Research.IEyeTracker.ApplyCalibrationData

(

CalibrationData

calibrationData

)

Sets the provided calibration data to the eye tracker, which means it will be active calibration.

Parameters

calibrationData

The calibration data to apply.

private static void CalibrationData(IEyeTracker eyeTracker)
{
    // Create a file in the current directory and store the calibration data in it.
    string path = "calibrationData.xml";
    using (System.IO.FileStream fileStream = System.IO.File.Create(path))
    {
        var dataContractSerializer = new System.Runtime.Serialization.DataContractSerializer(typeof(CalibrationData));
 
        // Retrieve the calibration data from the eye tracker.
        CalibrationData calibrationData = eyeTracker.RetrieveCalibrationData();
 
        // Save the calibration data to the file;
        dataContractSerializer.WriteObject(fileStream, calibrationData);
    }
 
    // Reopen the file and read the calibration data back.
    using (System.IO.FileStream fileStream = System.IO.File.OpenRead(path))
    {
        var dataContractSerializer = new System.Runtime.Serialization.DataContractSerializer(typeof(CalibrationData));
 
        // Read the calibration data from file.
        CalibrationData calibrationData = dataContractSerializer.ReadObject(fileStream) as CalibrationData;
 
        // Don't apply empty calibration.
        if (calibrationData.Data.Length != 0)
        {
            // Apply the calibration data to the eye tracker.
            eyeTracker.ApplyCalibrationData(calibrationData);
        }
    }
}

ClearAppliedLicenses()

void Tobii.Research.IEyeTracker.ClearAppliedLicenses

(

)

Clears any previously applied licenses.

private static void ApplyLicense(IEyeTracker eyeTracker, string licensePath)
{
    // Create a collection with the license.
    var licenseCollection = new LicenseCollection(
        new System.Collections.Generic.List<LicenseKey>
        {
           new LicenseKey(System.IO.File.ReadAllBytes(licensePath))
        });
 
    // See if we can apply the license.
    FailedLicenseCollection failedLicenses;
    if (eyeTracker.TryApplyLicenses(licenseCollection, out failedLicenses))
    {
        Console.WriteLine(
            "Successfully applied license from {0} on eye tracker with serial number {1}.",
            licensePath, eyeTracker.SerialNumber);
    }
    else
    {
        Console.WriteLine(
            "Failed to apply license from {0} on eye tracker with serial number {1}.\n" +
            "The validation result is {2}.",
            licensePath, eyeTracker.SerialNumber, failedLicenses[0].ValidationResult);
    }
}

GetAllEyeTrackingModes()

EyeTrackingModeCollection Tobii.Research.IEyeTracker.GetAllEyeTrackingModes

(

)

Gets a list of eye tracking modes supported by the eye tracker.

Returns

A list of valid and available eye tracking modes.

internal static void EyeTrackingModes(IEyeTracker eyeTracker)
{
    Console.WriteLine("\nEye tracking modes.");
 
    // Get and store current eye tracking mode so it can be restored.
    var initialEyeTrackingMode = eyeTracker.GetEyeTrackingMode();
    Console.WriteLine("New eye tracking mode is: {0}.", initialEyeTrackingMode);
 
    try
    {
        // Get all eye tracking modes.
        var allEyeTrackingModes = eyeTracker.GetAllEyeTrackingModes();
        foreach (var eyeTrackingMode in allEyeTrackingModes)
        {
            eyeTracker.SetEyeTrackingMode(eyeTrackingMode);
            Console.WriteLine("New eye tracking mode is: {0}.", eyeTrackingMode.ToString());
        }
    }
    finally
    {
        eyeTracker.SetEyeTrackingMode(initialEyeTrackingMode);
        Console.WriteLine("Eye tracking mode reset to: {0}.", eyeTracker.GetEyeTrackingMode());
    }
}

GetAllGazeOutputFrequencies()

GazeOutputFrequencyCollection Tobii.Research.IEyeTracker.GetAllGazeOutputFrequencies

(

)

Gets a list of gaze output frequencies supported by the eye tracker.

Returns

A list of valid and available gaze output frequencies in hertz.

internal static void GazeOutputFrequencies(IEyeTracker eyeTracker)
{
    Console.WriteLine("\nGaze output frequencies.");
 
    // Get and store current frequency so it can be restored.
    var initialGazeOutputFrequency = eyeTracker.GetGazeOutputFrequency();
    Console.WriteLine("Gaze output frequency is: {0} hertz.", initialGazeOutputFrequency);
 
    try
    {
        // Get all gaze output frequencies.
        var allGazeOutputFrequencies = eyeTracker.GetAllGazeOutputFrequencies();
        foreach (var gazeOutputFrequency in allGazeOutputFrequencies)
        {
            eyeTracker.SetGazeOutputFrequency(gazeOutputFrequency);
            Console.WriteLine("New gaze output frequency is: {0} hertz.", gazeOutputFrequency.ToString());
        }
    }
    finally
    {
        eyeTracker.SetGazeOutputFrequency(initialGazeOutputFrequency);
        Console.WriteLine("Gaze output frequency reset to: {0} hertz.", eyeTracker.GetGazeOutputFrequency());
    }
}

GetDisplayArea()

DisplayArea Tobii.Research.IEyeTracker.GetDisplayArea

(

)

Gets the size and corners of the display area.

Returns

The eye tracker's display area.

private static void PrintDisplayArea(IEyeTracker eyeTracker)
{
    // Get the display area.
    DisplayArea displayArea = eyeTracker.GetDisplayArea();
 
    Console.WriteLine(
        "Got display area from tracker with serial number {0} with height {1}, width {2} and coordinates:",
        eyeTracker.SerialNumber,
        displayArea.Height,
        displayArea.Width);
 
    Console.WriteLine("Bottom Left: ({0}, {1}, {2})",
        displayArea.BottomLeft.X, displayArea.BottomLeft.Y, displayArea.BottomLeft.Z);
    Console.WriteLine("Bottom Right: ({0}, {1}, {2})",
        displayArea.BottomRight.X, displayArea.BottomRight.Y, displayArea.BottomRight.Z);
    Console.WriteLine("Top Left: ({0}, {1}, {2})",
        displayArea.TopLeft.X, displayArea.TopLeft.Y, displayArea.TopLeft.Z);
    Console.WriteLine("Top Right: ({0}, {1}, {2})",
        displayArea.TopRight.X, displayArea.TopRight.Y, displayArea.TopRight.Z);
 
    // Set the display area. A new object is used to show usage.
    DisplayArea displayAreaToSet = new DisplayArea(displayArea.TopLeft, displayArea.BottomLeft, displayArea.TopRight);
    eyeTracker.SetDisplayArea(displayAreaToSet);
}

GetEyeTrackingMode()

string Tobii.Research.IEyeTracker.GetEyeTrackingMode

(

)

Gets the eye tracking mode of the eye tracker.

Returns

The eye tracking mode.

internal static void EyeTrackingModes(IEyeTracker eyeTracker)
{
    Console.WriteLine("\nEye tracking modes.");
 
    // Get and store current eye tracking mode so it can be restored.
    var initialEyeTrackingMode = eyeTracker.GetEyeTrackingMode();
    Console.WriteLine("New eye tracking mode is: {0}.", initialEyeTrackingMode);
 
    try
    {
        // Get all eye tracking modes.
        var allEyeTrackingModes = eyeTracker.GetAllEyeTrackingModes();
        foreach (var eyeTrackingMode in allEyeTrackingModes)
        {
            eyeTracker.SetEyeTrackingMode(eyeTrackingMode);
            Console.WriteLine("New eye tracking mode is: {0}.", eyeTrackingMode.ToString());
        }
    }
    finally
    {
        eyeTracker.SetEyeTrackingMode(initialEyeTrackingMode);
        Console.WriteLine("Eye tracking mode reset to: {0}.", eyeTracker.GetEyeTrackingMode());
    }
}

GetGazeOutputFrequency()

float Tobii.Research.IEyeTracker.GetGazeOutputFrequency

(

)

Gets the gaze output frequency of the eye tracker.

Returns

The gaze output frequency in hertz.

internal static void GazeOutputFrequencies(IEyeTracker eyeTracker)
{
    Console.WriteLine("\nGaze output frequencies.");
 
    // Get and store current frequency so it can be restored.
    var initialGazeOutputFrequency = eyeTracker.GetGazeOutputFrequency();
    Console.WriteLine("Gaze output frequency is: {0} hertz.", initialGazeOutputFrequency);
 
    try
    {
        // Get all gaze output frequencies.
        var allGazeOutputFrequencies = eyeTracker.GetAllGazeOutputFrequencies();
        foreach (var gazeOutputFrequency in allGazeOutputFrequencies)
        {
            eyeTracker.SetGazeOutputFrequency(gazeOutputFrequency);
            Console.WriteLine("New gaze output frequency is: {0} hertz.", gazeOutputFrequency.ToString());
        }
    }
    finally
    {
        eyeTracker.SetGazeOutputFrequency(initialGazeOutputFrequency);
        Console.WriteLine("Gaze output frequency reset to: {0} hertz.", eyeTracker.GetGazeOutputFrequency());
    }
}

RetrieveCalibrationData()

CalibrationData Tobii.Research.IEyeTracker.RetrieveCalibrationData

(

)

Gets the calibration data used currently by the eye tracker. This data can be saved to a file for later use.

Returns

The retrieved calibration data.

private static void CalibrationData(IEyeTracker eyeTracker)
{
    // Create a file in the current directory and store the calibration data in it.
    string path = "calibrationData.xml";
    using (System.IO.FileStream fileStream = System.IO.File.Create(path))
    {
        var dataContractSerializer = new System.Runtime.Serialization.DataContractSerializer(typeof(CalibrationData));
 
        // Retrieve the calibration data from the eye tracker.
        CalibrationData calibrationData = eyeTracker.RetrieveCalibrationData();
 
        // Save the calibration data to the file;
        dataContractSerializer.WriteObject(fileStream, calibrationData);
    }
 
    // Reopen the file and read the calibration data back.
    using (System.IO.FileStream fileStream = System.IO.File.OpenRead(path))
    {
        var dataContractSerializer = new System.Runtime.Serialization.DataContractSerializer(typeof(CalibrationData));
 
        // Read the calibration data from file.
        CalibrationData calibrationData = dataContractSerializer.ReadObject(fileStream) as CalibrationData;
 
        // Don't apply empty calibration.
        if (calibrationData.Data.Length != 0)
        {
            // Apply the calibration data to the eye tracker.
            eyeTracker.ApplyCalibrationData(calibrationData);
        }
    }
}

SetDeviceName()

void Tobii.Research.IEyeTracker.SetDeviceName

(

string

deviceName

)

Changes the device name. This is not supported by all eye trackers.

Parameters

deviceName

The eye tracker's desired name.

SetDisplayArea()

void Tobii.Research.IEyeTracker.SetDisplayArea

(

DisplayArea

displayArea

)

Sets the display area of the eye tracker. It is strongly recommended to use Eye Tracker Manager to calculate the display area coordinates as the origin of the User Coordinate System differs between eye tracker models.".

Parameters

displayArea

The eye tracker's display area.

private static void PrintDisplayArea(IEyeTracker eyeTracker)
{
    // Get the display area.
    DisplayArea displayArea = eyeTracker.GetDisplayArea();
 
    Console.WriteLine(
        "Got display area from tracker with serial number {0} with height {1}, width {2} and coordinates:",
        eyeTracker.SerialNumber,
        displayArea.Height,
        displayArea.Width);
 
    Console.WriteLine("Bottom Left: ({0}, {1}, {2})",
        displayArea.BottomLeft.X, displayArea.BottomLeft.Y, displayArea.BottomLeft.Z);
    Console.WriteLine("Bottom Right: ({0}, {1}, {2})",
        displayArea.BottomRight.X, displayArea.BottomRight.Y, displayArea.BottomRight.Z);
    Console.WriteLine("Top Left: ({0}, {1}, {2})",
        displayArea.TopLeft.X, displayArea.TopLeft.Y, displayArea.TopLeft.Z);
    Console.WriteLine("Top Right: ({0}, {1}, {2})",
        displayArea.TopRight.X, displayArea.TopRight.Y, displayArea.TopRight.Z);
 
    // Set the display area. A new object is used to show usage.
    DisplayArea displayAreaToSet = new DisplayArea(displayArea.TopLeft, displayArea.BottomLeft, displayArea.TopRight);
    eyeTracker.SetDisplayArea(displayAreaToSet);
}

SetEyeTrackingMode()

void Tobii.Research.IEyeTracker.SetEyeTrackingMode

(

string

eyeTrackingMode

)

Sets the eye tracking mode of the eye tracker.

Parameters

eyeTrackingMode

The new eye tracking mode. The string must be from the list returned by GetAllEyeTrackingModes().

internal static void EyeTrackingModes(IEyeTracker eyeTracker)
{
    Console.WriteLine("\nEye tracking modes.");
 
    // Get and store current eye tracking mode so it can be restored.
    var initialEyeTrackingMode = eyeTracker.GetEyeTrackingMode();
    Console.WriteLine("New eye tracking mode is: {0}.", initialEyeTrackingMode);
 
    try
    {
        // Get all eye tracking modes.
        var allEyeTrackingModes = eyeTracker.GetAllEyeTrackingModes();
        foreach (var eyeTrackingMode in allEyeTrackingModes)
        {
            eyeTracker.SetEyeTrackingMode(eyeTrackingMode);
            Console.WriteLine("New eye tracking mode is: {0}.", eyeTrackingMode.ToString());
        }
    }
    finally
    {
        eyeTracker.SetEyeTrackingMode(initialEyeTrackingMode);
        Console.WriteLine("Eye tracking mode reset to: {0}.", eyeTracker.GetEyeTrackingMode());
    }
}

SetGazeOutputFrequency()

void Tobii.Research.IEyeTracker.SetGazeOutputFrequency

(

float

gazeOutputFrequency

)

Sets the gaze output frequency of the eye tracker.

Parameters

gazeOutputFrequency

The the gaze output frequency in hertz. The value must be from the list returned by GetAllGazeOutputFrequencies().

internal static void GazeOutputFrequencies(IEyeTracker eyeTracker)
{
    Console.WriteLine("\nGaze output frequencies.");
 
    // Get and store current frequency so it can be restored.
    var initialGazeOutputFrequency = eyeTracker.GetGazeOutputFrequency();
    Console.WriteLine("Gaze output frequency is: {0} hertz.", initialGazeOutputFrequency);
 
    try
    {
        // Get all gaze output frequencies.
        var allGazeOutputFrequencies = eyeTracker.GetAllGazeOutputFrequencies();
        foreach (var gazeOutputFrequency in allGazeOutputFrequencies)
        {
            eyeTracker.SetGazeOutputFrequency(gazeOutputFrequency);
            Console.WriteLine("New gaze output frequency is: {0} hertz.", gazeOutputFrequency.ToString());
        }
    }
    finally
    {
        eyeTracker.SetGazeOutputFrequency(initialGazeOutputFrequency);
        Console.WriteLine("Gaze output frequency reset to: {0} hertz.", eyeTracker.GetGazeOutputFrequency());
    }
}

TryApplyLicenses()

bool Tobii.Research.IEyeTracker.TryApplyLicenses	(	LicenseCollection	licenses,
		out FailedLicenseCollection	failedLicenses
	)

Apply one or more licenses to unlock features of the eye tracker. A return value indicates whether all licenses where applied or not.

Parameters

licenses	A LicenseCollection containing the licenses to apply.
failedLicenses	This method always return a FailedLicensesCollection. When this method is successful the collection is empty, when at least one license failed to be applied, then the collection contains the failed licenses together with a reason for failing.

Returns

True if all licenses were successfully applied.

private static void ApplyLicense(IEyeTracker eyeTracker, string licensePath)
{
    // Create a collection with the license.
    var licenseCollection = new LicenseCollection(
        new System.Collections.Generic.List<LicenseKey>
        {
           new LicenseKey(System.IO.File.ReadAllBytes(licensePath))
        });
 
    // See if we can apply the license.
    FailedLicenseCollection failedLicenses;
    if (eyeTracker.TryApplyLicenses(licenseCollection, out failedLicenses))
    {
        Console.WriteLine(
            "Successfully applied license from {0} on eye tracker with serial number {1}.",
            licensePath, eyeTracker.SerialNumber);
    }
    else
    {
        Console.WriteLine(
            "Failed to apply license from {0} on eye tracker with serial number {1}.\n" +
            "The validation result is {2}.",
            licensePath, eyeTracker.SerialNumber, failedLicenses[0].ValidationResult);
    }
}

Property Documentation

DeviceCapabilities

Capabilities Tobii.Research.IEyeTracker.DeviceCapabilities

get

Gets the capabilities of the device.

internal static IEyeTracker GetEyeTracker(Uri address)
{
    Console.WriteLine("\nGet eye tracker from Uri: {0}.", address);
 
    var eyeTracker = EyeTrackingOperations.GetEyeTracker(address);
 
    Console.WriteLine("Got eye tracker");
    Console.WriteLine("Address: {0}", eyeTracker.Address);
    Console.WriteLine("Device name: {0}", eyeTracker.DeviceName);
    Console.WriteLine("Model: {0}", eyeTracker.Model);
    Console.WriteLine("Serial number: {0}", eyeTracker.SerialNumber);
    Console.WriteLine("Firmware version: {0}", eyeTracker.FirmwareVersion);
    Console.WriteLine("Runtime version: {0}", eyeTracker.RuntimeVersion);
 
    return eyeTracker;
}

Event Documentation

CalibrationModeEntered

EventHandler<CalibrationModeEnteredEventArgs> Tobii.Research.IEyeTracker.CalibrationModeEntered

Occurs when the eye tracker enters calibration mode.

private static void CalibrationModeEntered(IEyeTracker eyeTracker)
{
    // Start listening to calibration mode entered event.
    eyeTracker.CalibrationModeEntered += EyeTracker_CalibrationModeEntered;
 
    var calibration = new ScreenBasedCalibration(eyeTracker);
 
    // Trigger the event.
    calibration.EnterCalibrationMode();
 
    // Stop listening to calibration mode entered event.
    eyeTracker.CalibrationModeEntered -= EyeTracker_CalibrationModeEntered;
 
    // Cleanup.
    calibration.LeaveCalibrationMode();
}
 
private static void EyeTracker_CalibrationModeEntered(object sender, CalibrationModeEnteredEventArgs e)
{
    Console.WriteLine("Calibration mode was entered at time stamp {0}.", e.SystemTimeStamp);
}

CalibrationModeLeft

EventHandler<CalibrationModeLeftEventArgs> Tobii.Research.IEyeTracker.CalibrationModeLeft

Occurs when the eye tracker leaves calibration mode.

private static void CalibrationModeLeft(IEyeTracker eyeTracker)
{
    // Start listening to calibration mode left event.
    eyeTracker.CalibrationModeLeft += EyeTracker_CalibrationModeLeft;
 
    var calibration = new ScreenBasedCalibration(eyeTracker);
    calibration.EnterCalibrationMode();
 
    // Trigger the event.
    calibration.LeaveCalibrationMode();
 
    // Stop listening to calibration mode left event.
    eyeTracker.CalibrationModeLeft -= EyeTracker_CalibrationModeLeft;
}
 
private static void EyeTracker_CalibrationModeLeft(object sender, CalibrationModeLeftEventArgs e)
{
    Console.WriteLine("Calibration mode was left at time stamp {0}.", e.SystemTimeStamp);
}

ConnectionLost

EventHandler<ConnectionLostEventArgs> Tobii.Research.IEyeTracker.ConnectionLost

Occurs when the client loses connection to the eye tracker.

private static void ConnectionLost(IEyeTracker eyeTracker)
{
    // Start listening to connection lost event.
    eyeTracker.ConnectionLost += EyeTracker_ConnectionLost;
 
    // You can't trigger this event programatically.
    Console.WriteLine("Event will be triggered if connection is lost here.");
 
    // Stop listening to connection lost event.
    eyeTracker.ConnectionLost -= EyeTracker_ConnectionLost;
}
 
private static void EyeTracker_ConnectionLost(object sender, ConnectionLostEventArgs e)
{
    Console.WriteLine("Connection to the eye tracker was lost at time stamp {0}.", e.SystemTimeStamp);
}

ConnectionRestored

EventHandler<ConnectionRestoredEventArgs> Tobii.Research.IEyeTracker.ConnectionRestored

Occurs when connection to the eye tracker is restored.

private static void ConnectionRestored(IEyeTracker eyeTracker)
{
    // Start listening to connection restored event.
    eyeTracker.ConnectionRestored += EyeTracker_ConnectionRestored;
 
    // You can't trigger this event programatically.
    Console.WriteLine("Event will be triggered if connection is restored here.");
 
    // Stop listening to connection restored event.
    eyeTracker.ConnectionRestored -= EyeTracker_ConnectionRestored;
}
 
private static void EyeTracker_ConnectionRestored(object sender, ConnectionRestoredEventArgs e)
{
    Console.WriteLine("Connection to the eye tracker was restored at time stamp {0}.", e.SystemTimeStamp);
}

DisplayAreaChanged

EventHandler<DisplayAreaEventArgs> Tobii.Research.IEyeTracker.DisplayAreaChanged

Occurs when the display area has changed.

private static void DisplayAreaChanged(IEyeTracker eyeTracker)
{
    // Start listening to display area changed event.
    eyeTracker.DisplayAreaChanged += EyeTracker_DisplayAreaChanged;
 
    // You can't trigger this event programatically.
    Console.WriteLine("Event will be triggered if display area is changed here.");
 
    // Stop listening to display area changed event.
    eyeTracker.DisplayAreaChanged -= EyeTracker_DisplayAreaChanged;
}
 
private static void EyeTracker_DisplayAreaChanged(object sender, DisplayAreaEventArgs e)
{
    Console.WriteLine("Display area changed at time stamp {0}.", e.SystemTimeStamp);
 
    Console.WriteLine("New height {0} and width {1}.", e.DisplayArea.Height, e.DisplayArea.Width);
 
    Console.WriteLine("Coordinates:");
    Console.WriteLine("Bottom Left: ({0}, {1}, {2})",
        e.DisplayArea.BottomLeft.X, e.DisplayArea.BottomLeft.Y, e.DisplayArea.BottomLeft.Z);
    Console.WriteLine("Bottom Right: ({0}, {1}, {2})",
        e.DisplayArea.BottomRight.X, e.DisplayArea.BottomRight.Y, e.DisplayArea.BottomRight.Z);
    Console.WriteLine("Top Left: ({0}, {1}, {2})",
        e.DisplayArea.TopLeft.X, e.DisplayArea.TopLeft.Y, e.DisplayArea.TopLeft.Z);
    Console.WriteLine("Top Right: ({0}, {1}, {2})",
        e.DisplayArea.TopRight.X, e.DisplayArea.TopRight.Y, e.DisplayArea.TopRight.Z);
}

EventErrorOccurred

EventHandler<EventErrorEventArgs> Tobii.Research.IEyeTracker.EventErrorOccurred

Fired when an error occurs on any of the other events for the eye tracker.

private static bool errorThrownInEventHandler = false;
 
private static void EventErrorOccurred(IEyeTracker eyeTracker)
{
    // Start listening to event errors.
    eyeTracker.EventErrorOccurred += EyeTracker_EventErrorOccurred;
 
    // Trigger an event by throwing an exception in an event handler.
    errorThrownInEventHandler = false;
    eyeTracker.GazeDataReceived += EyeTracker_GazeDataReceived;
    System.Threading.Thread.Sleep(1000);
    eyeTracker.GazeDataReceived -= EyeTracker_GazeDataReceived;
 
    // Stop listening to event errors
    eyeTracker.EventErrorOccurred -= EyeTracker_EventErrorOccurred;
}
 
private static void EyeTracker_EventErrorOccurred(object sender, EventErrorEventArgs e)
{
    Console.WriteLine("An error occured at time stamp {0}.", e.SystemTimeStamp);
    Console.WriteLine(e.Message);
}
 
private static void EyeTracker_GazeDataReceived(object sender, GazeDataEventArgs e)
{
    if (!errorThrownInEventHandler)
    {
        // Throw some generic error.
        errorThrownInEventHandler = true;
        throw new ArgumentNullException();
    }
}

ExternalSignalReceived

EventHandler<ExternalSignalValueEventArgs> Tobii.Research.IEyeTracker.ExternalSignalReceived

Occurs when the value of the external signal port (TTL input) on the eye tracker device changes. Not all eye trackers have a sampling trigger port. The sampling feature could be used to synchronize the eye tracker data with data from other devices. The sampling data contains a time reference that matches the time reference on the time synchronized gaze data.

private static void ExternalSignal(IEyeTracker eyeTracker)
{
    // Start listening to external signals.
    eyeTracker.ExternalSignalReceived += EyeTracker_ExternalSignalReceived;
 
    // Wait for signals to arrive.
    System.Threading.Thread.Sleep(1000);
 
    // Stop listening to external signals.
    eyeTracker.ExternalSignalReceived -= EyeTracker_ExternalSignalReceived;
}
 
private static void EyeTracker_ExternalSignalReceived(object sender, ExternalSignalValueEventArgs e)
{
    Console.WriteLine(
        "Got external signal with change type {0}, value {1} and device time stamp {2}.",
        e.ChangeType, e.Value, e.DeviceTimeStamp);
}

EyeImageRawReceived

EventHandler<EyeImageRawEventArgs> Tobii.Research.IEyeTracker.EyeImageRawReceived

Occurs when a new eye image raw is received, and the occurrence depends on the eye tracker model. Not all eye tracker models support this feature. If no one is listening to gaze data, the eye tracker will only deliver full images, otherwise either cropped or full images will be delivered depending on whether or not the eye tracker has detected eyes.

internal static void EyeImageRaws(IEyeTracker eyeTracker)
{
    // Start receiving eye image raws.
    eyeTracker.EyeImageRawReceived += EyeTracker_EyeImageRawReceived;
 
    // Wait for some eye image raws to come.
    System.Threading.Thread.Sleep(5000);
 
    // Stop receiving eye image raws.
    eyeTracker.EyeImageRawReceived -= EyeTracker_EyeImageRawReceived;
}
 
private static void EyeTracker_EyeImageRawReceived(object sender, EyeImageRawEventArgs e)
{
    Console.WriteLine("Received a {0} image at system time {1}.", e.ImageType, e.SystemTimeStamp);
 
    // You can use the eye image raw data to create a System.Windows.Media.Imaging.BitmapSource that can be used in a WPF application.
    const double dpi = 96;
    int bytesPerPixel = (e.BitsPerPixel + e.PaddingBitsPerPixel == 8) ? 1 : 2;
    int stride = e.Width * bytesPerPixel;
    System.Windows.Media.PixelFormat pixelFormat = bytesPerPixel == 1 ?
                                            System.Windows.Media.PixelFormats.Gray8 :
                                            System.Windows.Media.PixelFormats.Gray16;
 
    System.Windows.Media.Imaging.BitmapSource bitmapSource;
    bitmapSource = System.Windows.Media.Imaging.BitmapSource.Create(e.Width, e.Height, dpi, dpi, pixelFormat, null, e.ImageData, stride);
}

EyeImageReceived

EventHandler<EyeImageEventArgs> Tobii.Research.IEyeTracker.EyeImageReceived

Occurs when a new eye image is received, and the occurrence depends on the eye tracker model. Not all eye tracker models support this feature. If no one is listening to gaze data, the eye tracker will only deliver full images, otherwise either cropped or full images will be delivered depending on whether or not the eye tracker has detected eyes.

internal static void EyeImages(IEyeTracker eyeTracker)
{
    // Start receiving eye images.
    eyeTracker.EyeImageReceived += EyeTracker_EyeImageReceived;
 
    // Wait for some eye images to come.
    System.Threading.Thread.Sleep(5000);
 
    // Stop receiving eye images.
    eyeTracker.EyeImageReceived -= EyeTracker_EyeImageReceived;
}
 
private static void EyeTracker_EyeImageReceived(object sender, EyeImageEventArgs e)
{
    Console.WriteLine("Received a {0} image at system time {1}.", e.ImageType, e.SystemTimeStamp);
 
    // You can convert the image stream to a System.Drawing.Bitmap if you're making a Windows Form application.
    var drawingBitmap = new System.Drawing.Bitmap(e.ImageStream);
 
    // Or you can convert it to a System.Windows.Media.Imaging.BitmapImage if you're making a WPF application.
    var imagingBitmap = new System.Windows.Media.Imaging.BitmapImage();
    imagingBitmap.BeginInit();
    imagingBitmap.StreamSource = e.ImageStream;
    imagingBitmap.EndInit();
}

EyeOpennessDataReceived

EventHandler<EyeOpennessDataEventArgs> Tobii.Research.IEyeTracker.EyeOpennessDataReceived

Event fired when eye openness data is received.

private static void EyeOpennessData(IEyeTracker eyeTracker)
{
    // Start listening to eye openness data.
    eyeTracker.EyeOpennessDataReceived += EyeTracker_EyeOpennessDataReceived;
 
    // Wait for some data to be received.
    System.Threading.Thread.Sleep(2000);
 
    // Stop listening to eye openness data.
    eyeTracker.EyeOpennessDataReceived -= EyeTracker_EyeOpennessDataReceived;
}
 
private static void EyeTracker_EyeOpennessDataReceived(object sender, EyeOpennessDataEventArgs e)
{
    Console.WriteLine("Got eye openness data with:");
    Console.WriteLine("Left eye validity: {0}", e.LeftEyeValidity);
    Console.WriteLine("Right eye validity: {0}", e.RightEyeValidity);
    Console.WriteLine("Left eye value: {0}", e.LeftEyeValue);
    Console.WriteLine("Right eye value: {0}", e.RightEyeValue);
    Console.WriteLine("Device timestamp: {0}", e.DeviceTimeStamp);
    Console.WriteLine("System timestamp: {0}", e.SystemTimeStamp);
}

GazeDataReceived

EventHandler<GazeDataEventArgs> Tobii.Research.IEyeTracker.GazeDataReceived

Event fired when gaze data is received.

private static void GazeData(IEyeTracker eyeTracker)
{
    // Start listening to stream buffer overflow notifications
    // and then subscribe to gaze data. If your code takes to long too process the callback, 
    // the circular buffer will overflow and EyeTrackerStreamBufferOverflowOccured will be called.
    // For further information, we refer to our section on "streambufferoverflow".
    eyeTracker.StreamBufferOverflow += EyeTrackerStreamBufferOverflowOccured;
 
    // Start listening to gaze data.
    eyeTracker.GazeDataReceived += EyeTrackerGazeDataReceived;
 
    // Wait for some data to be received.
    System.Threading.Thread.Sleep(2000);
 
    // Stop listening to gaze data.
    eyeTracker.GazeDataReceived -= EyeTrackerGazeDataReceived;
 
    // Stop listening to stream buffer overflow notifications
    eyeTracker.StreamBufferOverflow -= EyeTrackerStreamBufferOverflowOccured;
 
}
 
private static void EyeTrackerGazeDataReceived(object sender, GazeDataEventArgs e)
{
    Console.WriteLine(
        "Got gaze data with {0} left eye origin at point ({1}, {2}, {3}) in the user coordinate system.",
        e.LeftEye.GazeOrigin.Validity,
        e.LeftEye.GazeOrigin.PositionInUserCoordinates.X,
        e.LeftEye.GazeOrigin.PositionInUserCoordinates.Y,
        e.LeftEye.GazeOrigin.PositionInUserCoordinates.Z);
}
 
private static void EyeTrackerStreamBufferOverflowOccured(object sender, StreamBufferOverflowEventArgs e)
{
    Console.WriteLine($"Stream buffer overflow at: {e.SystemTimeStamp}");
}

GazeOutputFrequencyChanged

EventHandler<GazeOutputFrequencyEventArgs> Tobii.Research.IEyeTracker.GazeOutputFrequencyChanged

Occurs when the gaze output frequency has changed.

private static void GazeOutputFrequencyChanged(IEyeTracker eyeTracker)
{
    // Start listening to gaze output frequency changed event.
    eyeTracker.GazeOutputFrequencyChanged += EyeTracker_GazeOutputFrequencyChanged;
 
    var originalGazeOutputFrequency = eyeTracker.GetGazeOutputFrequency();
 
    // Find a frequency (using System.Linq).
    var newGazeOutputFrequency = eyeTracker.GetAllGazeOutputFrequencies().Where(f => f != originalGazeOutputFrequency).FirstOrDefault();
    if (newGazeOutputFrequency == default(float))
    {
        // This eye tracker only had one frequency.
        return;
    }
 
    // Trigger the event.
    eyeTracker.SetGazeOutputFrequency(newGazeOutputFrequency);
 
    // Set back original frequency.
    eyeTracker.SetGazeOutputFrequency(originalGazeOutputFrequency);
 
    // Stop listening to gaze output frequency changed event.
    eyeTracker.GazeOutputFrequencyChanged -= EyeTracker_GazeOutputFrequencyChanged;
}
 
private static void EyeTracker_GazeOutputFrequencyChanged(object sender, GazeOutputFrequencyEventArgs e)
{
    Console.WriteLine("Gaze output frequency changed to {0} at time stamp {1}.", e.GazeOutputFrequency, e.SystemTimeStamp);
}

TimeSynchronizationReferenceReceived

EventHandler<TimeSynchronizationReferenceEventArgs> Tobii.Research.IEyeTracker.TimeSynchronizationReferenceReceived

Occurs when the computer and the eye trackers clocks gets synchronized. To handle normal drifts between clocks the clocks are checked on regular basis, and this results in that the time stamps are adjusted for the drifts in the data streams. This drift handling is done in real time. The data received from this event could be used for an even more accurate drift adjustment in the post processing.

private static void TimeSynchronizationData(IEyeTracker eyeTracker)
{
    // Start listening to time synchronization events.
    eyeTracker.TimeSynchronizationReferenceReceived += EyeTracker_TimeSynchronizationReferenceReceived;
 
    // Wait for some events to arrive.
    System.Threading.Thread.Sleep(2000);
 
    // Stop listening to time synchronization events.
    eyeTracker.TimeSynchronizationReferenceReceived -= EyeTracker_TimeSynchronizationReferenceReceived;
}
 
private static void EyeTracker_TimeSynchronizationReferenceReceived(object sender, TimeSynchronizationReferenceEventArgs e)
{
    Console.WriteLine("Received a time synchronization package with latency {0} microseconds. The eye tracker time stamp was {1}.",
        e.SystemResponseTimeStamp - e.SystemRequestTimeStamp, e.DeviceTimeStamp);
}

UserPositionGuideReceived

EventHandler<UserPositionGuideEventArgs> Tobii.Research.IEyeTracker.UserPositionGuideReceived

Event fired when user position guide is received.

private static void UserPositionGuide(IEyeTracker eyeTracker)
{
    // Start listening to user position guide.
    eyeTracker.UserPositionGuideReceived += EyeTracker_UserPositionGuideReceived;
 
    // Wait for some data to be received.
    System.Threading.Thread.Sleep(2000);
 
    // Stop listening to user position guide.
    eyeTracker.UserPositionGuideReceived -= EyeTracker_UserPositionGuideReceived;
}
 
private static void EyeTracker_UserPositionGuideReceived(object sender, UserPositionGuideEventArgs e)
{
    Console.WriteLine(
        "Got user position guide with validity: {0} left normalized coordinates: ({1}, {2}, {3}).",
        e.LeftEye.Validity,
        e.LeftEye.UserPosition.X,
        e.LeftEye.UserPosition.Y,
        e.LeftEye.UserPosition.Z);
}