Class 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

      Fields 
      Modifier and Type Field Description
      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

      Constructors 
      Constructor Description
      SensorEvent()
      Creates a new ephemeral SensorEvent.
      SensorEvent​(SensorEvent e)
      Creates a copy of the given SensorEvent.
      SensorEvent​(java.lang.Object source, int id, Sensor sensor, Transform3D sensorRead, int[] buttonState, int button, long time, long lastTime)
      Creates a new SensorEvent.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      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
    • 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.