com.sun.j3d.utils.behaviors.sensor
Class SensorEvent

java.lang.Object
  extended by com.sun.j3d.utils.behaviors.sensor.SensorEvent

public class SensorEvent
extends java.lang.Object

This class defines the event object that is created by a SensorEventAgent and passed to registered SensorReadListener and SensorButtonListener implementations.

The events passed to the listeners are ephemeral; they are only valid until the listener has returned. This is done to avoid allocating large numbers of mostly temporary objects, especially for behaviors that wake up every frame. If a listener needs to retain the event it must be copied using the SensorEvent(SensorEvent) constructor.

Since:
Java 3D 1.3
See Also:
SensorEventAgent, SensorButtonListener, SensorReadListener

Field Summary
static int DRAGGED
          A button dragged event.
static int NOBUTTON
          The value that is returned by getButton when no buttons have changed state.
static int PRESSED
          A button pressed event.
static int READ
          A sensor read event.
static int RELEASED
          A button released event.
 
Constructor Summary
SensorEvent()
          Creates a new ephemeral SensorEvent.
SensorEvent(java.lang.Object source, int id, Sensor sensor, Transform3D sensorRead, int[] buttonState, int button, long time, long lastTime)
          Creates a new SensorEvent.
SensorEvent(SensorEvent e)
          Creates a copy of the given SensorEvent.
 
Method Summary
 int getButton()
          Gets the index of the button that changed state when passed to a pressed or released callback.
 void getButtonState(int[] buttonState)
          Copies the state of the sensor's buttons at the time of the event into the given array.
 int getID()
          Gets the event type.
 long getLastTime()
          Gets the time in nanoseconds at which the dispatchEvents method of SensorEventAgent was last called to generate events, usually from the processStimulus method of a Behavior; may be used to measure frame time in behaviors that wake up every frame.
 Sensor getSensor()
          Gets a reference to the provoking sensor.
 void getSensorRead(Transform3D t)
          Copies the sensor's read value at the time of the event into the given Transform3D.
 java.lang.Object getSource()
          Gets a reference to the originating object which instantiated the SensorEventAgent, usually a Behavior; may be null.
 long getTime()
          Gets the time in nanoseconds at which the dispatchEvents method of SensorEventAgent was called to generate this event, usually from the processStimulus method of a Behavior.
 boolean isEphemeral()
          Returns true if this event is ephemeral and is valid only until the listener returns.
 void set(java.lang.Object source, int id, Sensor sensor, Transform3D sensorRead, int[] buttonState, int button, long time, long lastTime)
          Sets the fields of an ephemeral event.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

PRESSED

public static final int PRESSED
A button pressed event.

See Also:
Constant Field Values

RELEASED

public static final int RELEASED
A button released event.

See Also:
Constant Field Values

DRAGGED

public static final int DRAGGED
A button dragged event.

See Also:
Constant Field Values

READ

public static final int READ
A sensor read event.

See Also:
Constant Field Values

NOBUTTON

public static final int NOBUTTON
The value that is returned by getButton when no buttons have changed state.

See Also:
Constant Field Values
Constructor Detail

SensorEvent

public SensorEvent(java.lang.Object source,
                   int id,
                   Sensor sensor,
                   Transform3D sensorRead,
                   int[] buttonState,
                   int button,
                   long time,
                   long lastTime)
Creates a new SensorEvent.

Parameters:
source - a reference to the originating object which instantiated the SensorEventAgent, usually a Behavior; may be null
id - event type
sensor - a reference to the provoking sensor
sensorRead - the sensor's read value at the time of the event
buttonState - the state of the sensor's buttons at the time of the event, where a 1 in the array indicates that the button at that index is down, and a 0 indicates that button is up; may be null
button - index of the button that changed state, from 0 to (buttonCount - 1), or the value NOBUTTON
time - the time in nanoseconds at which the dispatchEvents method of SensorEventAgent was called to generate this event, usually from the processStimulus method of a Behavior
lastTime - the time in nanoseconds at which the dispatchEvents method of SensorEventAgent was last called to generate events, usually from the processStimulus method of a Behavior; may be used to measure frame time in behaviors that wake up every frame

SensorEvent

public SensorEvent()
Creates a new ephemeral SensorEvent. In order to avoid creating large numbers of sensor event objects, the events passed to the button and read listeners by the dispatchEvents method of SensorEventAgent are valid only until the listener returns. If the event needs to be retained then they must be copied with the SensorEvent(SensorEvent) constructor.


SensorEvent

public SensorEvent(SensorEvent e)
Creates a copy of the given SensorEvent. Listeners must use this constructor to copy events that need to be retained. NOTE: The Sensor and Object references returned by getSensor and getSource remain references to the original objects.

Parameters:
e - the event to be copied
Method Detail

set

public void set(java.lang.Object source,
                int id,
                Sensor sensor,
                Transform3D sensorRead,
                int[] buttonState,
                int button,
                long time,
                long lastTime)
Sets the fields of an ephemeral event. No objects are copied. An IllegalStateException will be thrown if this event is not ephemeral.

Parameters:
source - a reference to the originating object which instantiated the SensorEventAgent, usually a Behavior; may be null
id - event type
sensor - a reference to the provoking sensor
sensorRead - the sensor's read value at the time of the event
buttonState - the state of the sensor's buttons at the time of the event; a 1 in the array indicates that the button at that index is down, while a 0 indicates that button is up
button - index of the button that changed state, from 0 to (buttonCount - 1), or the value NOBUTTON
time - the time in nanoseconds at which the dispatchEvents method of SensorEventAgent was called to generate this event, usually from the processStimulus method of a Behavior
lastTime - the time in nanoseconds at which the dispatchEvents method of SensorEventAgent was last called to generate events, usually from the processStimulus method of a Behavior; may be used to measure frame time in behaviors that wake up every frame

getSource

public java.lang.Object getSource()
Gets a reference to the originating object which instantiated the SensorEventAgent, usually a Behavior; may be null.

Returns:
the originating object

getID

public int getID()
Gets the event type.

Returns:
the event id

getSensor

public Sensor getSensor()
Gets a reference to the provoking sensor.

Returns:
the provoking sensor

getTime

public long getTime()
Gets the time in nanoseconds at which the dispatchEvents method of SensorEventAgent was called to generate this event, usually from the processStimulus method of a Behavior.

Returns:
time in nanoseconds

getLastTime

public long getLastTime()
Gets the time in nanoseconds at which the dispatchEvents method of SensorEventAgent was last called to generate events, usually from the processStimulus method of a Behavior; may be used to measure frame time in behaviors that wake up every frame.

Returns:
last time in nanoseconds

getSensorRead

public void getSensorRead(Transform3D t)
Copies the sensor's read value at the time of the event into the given Transform3D.

Parameters:
t - the transform to receive the sensor read

getButton

public int getButton()
Gets the index of the button that changed state when passed to a pressed or released callback. The index may range from 0 to (sensor.getSensorButtonCount() - 1). The value returned is NOBUTTON for events passed to a read or dragged callback.

Returns:
the button index

getButtonState

public void getButtonState(int[] buttonState)
Copies the state of the sensor's buttons at the time of the event into the given array. A 1 in the array indicates that the button at that index is down, while a 0 indicates that button is up.

Parameters:
buttonState - the state of the sensor buttons

isEphemeral

public boolean isEphemeral()
Returns true if this event is ephemeral and is valid only until the listener returns. A copy of the event can be created by passing it to the SensorEvent(SensorEvent) constructor.



Copyright (c) 2007 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.