This is a subclass of Display_T35 that allows a LongTouch gesture

GestureEnabledDisplay_T35

public class GestureEnabledDisplay_T35 : Gadgeteer.Modules.GHIElectronics.Display_T35
{
    private long _touchdownTicks;
    private const long NanosecondsInMilliseconds = 10000;

    public delegate void LongTouchEventHandler(object sender, EventArgs args);
    public event LongTouchEventHandler LongTouch;

    /// <summary>
    /// The number of milliseconds a touch needs before it raises a longtouch event
    /// </summary>
    public long LongTouchRegisterInterval { get; private set; }

    public GestureEnabledDisplay_T35(int socket1, int socket2, int socket3, long longTouchRegisterInterval = 5000)
        : base(socket1, socket2, socket3)
    {
        Initialise(longTouchRegisterInterval);
    }

    public GestureEnabledDisplay_T35(int socket1, int socket2, int socket3, int socket4, long longTouchRegisterInterval = 5000)
        : base(socket1, socket2, socket3, socket4)
    {
        Initialise(longTouchRegisterInterval);
    }

    private void Initialise(long longTouchRegisterInterval)
    {
        base.WPFWindow.TouchDown += new Microsoft.SPOT.Input.TouchEventHandler(WPFWindow_TouchDown);
        base.WPFWindow.TouchUp += new Microsoft.SPOT.Input.TouchEventHandler(WPFWindow_TouchUp);
        LongTouchRegisterInterval = longTouchRegisterInterval;
    }

    void WPFWindow_TouchDown(object sender, Microsoft.SPOT.Input.TouchEventArgs e)
    {
        _touchdownTicks = DateTime.Now.Ticks;
    }

    void WPFWindow_TouchUp(object sender, Microsoft.SPOT.Input.TouchEventArgs e)
    {
        var touchupTicks = DateTime.Now.Ticks;
        if (touchupTicks - _touchdownTicks > (NanosecondsInMilliseconds * LongTouchRegisterInterval))
        {
            OnLongTouch();
        }
    }

    private void OnLongTouch()
    {
        if (LongTouch != null)
        {
            LongTouch(this, EventArgs.Empty);
        }
    }
}