eu.ensam.ii.vrpn
Class VrpnClient

java.lang.Object
  eu.ensam.ii.vrpn.VrpnClient

public class VrpnClient
extends Object

Send updates button, analog and tracker updates to the JsonNet Vrpn server.

A application that uses the Vrpn widgets must initialize the unique instance of this class by calling setUri before the widgets are used.

This class is not thread-safe. The methods sendButton and sendAnalog must be called from the main UI thread

Currently the messages neither include a timestamp nor a sequence number

TODO Add timestamps and sequence numbers Add a method to allow sending TODO tracker updates from the widgets

Method Summary

void	enableTiltTracker(boolean enable) Enables or disable the tilt tracker.
static VrpnClient	getInstance() Returns the unique VrpnClient instance
void	onAccuracyChanged(Sensor sensor, int accuracy) Called by the system when the sensor accuracy changes This method is empty and should not be called by widgets
void	onSensorChanged(SensorEvent event) Called by the system when a sensor data changes.
void	sendAnalog(int channelId, double channelValue) Send an update to a Vrpn Analog channel.
void	sendButton(int buttonId, boolean buttonState) Send an update to a Vrpn Button.
void	setupVrpnServer(InetAddress hostAddress, int port) Initializes the address and port of the VRPN server.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getInstance

public static VrpnClient getInstance()

Returns the unique VrpnClient instance

setupVrpnServer

public void setupVrpnServer(InetAddress hostAddress,
                            int port)

Initializes the address and port of the VRPN server.

This method must be called before sending any update to the server.

Note that the widgets trigger updates when they they are displayed for the first time. So this method must be called before calling setContentView in the main activity setContentView onCreate method

Parameters:

host - a string that is a valid host name or IP address

port - the port number of the VRPN server

sendButton

public void sendButton(int buttonId,
                       boolean buttonState)

Send an update to a Vrpn Button. This update will trigger a button callback on the application side

Parameters:

buttonId - the button number. Invalid button numbers are ignored on this side, but may trigger an error message on the Vrpn server

buttonState - the new status of the button

sendAnalog

public void sendAnalog(int channelId,
                       double channelValue)

Send an update to a Vrpn Analog channel. This update will trigger an analog callback on the application side

Parameters:

channelId - The channel number. Invalid channel numbers are ignored on this side but, they may trigger an error message on the Vrpn server

channelValue - the data that will be sent on the analog channel

enableTiltTracker

public void enableTiltTracker(boolean enable)

Enables or disable the tilt tracker. The tilt tracker send a tracker update with a quaternion that rotates the "earth vertical up" vector to the +Z vector in device coordinates. See SensorEvent for a description of the device coordinate system. This quaternion can be used to retrieve the roll and pitch of the device.

Parameters:

enable - true enables the tilt tracker updates and false disable the tilt tracker updates

onAccuracyChanged

public void onAccuracyChanged(Sensor sensor,
                              int accuracy)

Called by the system when the sensor accuracy changes This method is empty and should not be called by widgets

onSensorChanged

public void onSensorChanged(SensorEvent event)

Called by the system when a sensor data changes. This method retrieves the Android sensor object. If an vrpn Tracker is active that involves this sensor object this method sends a Vrpn tracker update to the appropriate tracker. packages the sensor data into a JSON object then send the JSON object onto an UDP socket. The target socket endpoint configuration is configured by calling setupVrpnServer