org.jscience.util
Class ChangeListener.LoggingListener

java.lang.Object
  extended by org.jscience.util.ChangeListener.LoggingListener
All Implemented Interfaces:
java.util.EventListener, ChangeListener
Enclosing interface:
ChangeListener

public static class ChangeListener.LoggingListener
extends java.lang.Object
implements ChangeListener

A listener that writes information about the event stream to a PrintStream.

Since:
1.1

Nested Class Summary
 
Nested classes/interfaces inherited from interface org.jscience.util.ChangeListener
ChangeListener.AlwaysVetoListener, ChangeListener.LoggingListener
 
Field Summary
 
Fields inherited from interface org.jscience.util.ChangeListener
ALWAYS_VETO, LOG_TO_OUT
 
Constructor Summary
ChangeListener.LoggingListener(java.io.PrintStream out)
          Create a LoggingListener that will log all events to 'out'.
ChangeListener.LoggingListener(java.io.PrintStream out, java.lang.String prefix)
          Create a LoggingListener that will log all events to 'out' with a prefix.
 
Method Summary
 void postChange(ChangeEvent cev)
          

Called when a change has just taken place.

 void preChange(ChangeEvent cev)
          

Called before a change takes place.

 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ChangeListener.LoggingListener

public ChangeListener.LoggingListener(java.io.PrintStream out)
Create a LoggingListener that will log all events to 'out'.

Parameters:
out - the PrintStream to log events to

ChangeListener.LoggingListener

public ChangeListener.LoggingListener(java.io.PrintStream out,
                                      java.lang.String prefix)
Create a LoggingListener that will log all events to 'out' with a prefix.

Parameters:
out - the PrintStream to log events to
prefix - the prefix to attach to each line of the log
Method Detail

preChange

public void preChange(ChangeEvent cev)
               throws ChangeVetoException
Description copied from interface: ChangeListener

Called before a change takes place.

This is your chance to stop the change by throwing a ChangeVetoException. This method does not indicate that the change will definitely take place, so it is not recomended that you take any positive action within this handler.

Specified by:
preChange in interface ChangeListener
Parameters:
cev - An event encapsulating the change which is about to take place.
Throws:
ChangeVetoException - Description of Exception

postChange

public void postChange(ChangeEvent cev)
Description copied from interface: ChangeListener

Called when a change has just taken place.

This method is the place to perform any behavior in response to the change event.

Specified by:
postChange in interface ChangeListener
Parameters:
cev - An event encapsulating the change which has occured.