com.singularsys.jep.misc
Class VariableTableObserver

java.lang.Object
  com.singularsys.jep.misc.VariableTableObserver

All Implemented Interfaces:

java.util.Observer

public class VariableTableObserver
extends java.lang.Object
implements java.util.Observer

Base class for observing Variables and the VariableTable. The methods variableValueChanged(), variableAdded(), variableRemoved(), tableCleared() will be called when these events occur. These methods can be overridden to provide appropriate behaviour, the default action is just to print the a message.

Results are unpredictable if two variable tables are observed using the same object.

Constructor Summary

VariableTableObserver(Jep jep)

VariableTableObserver(VariableTable vt)

Method Summary

void	addObserver(java.util.Observable obs)
void	addObservers(VariableTable vt)
void	deleteObserver(java.util.Observable obs)
void	deleteObservers() Stop observing all variables.
java.util.Iterator<java.util.Observable>	iterator() Returns a list of items this class is observing.
protected void	tableCleared(VariableTable table) Called when the variable table has been cleared.
void	update(java.util.Observable o, java.lang.Object arg) Called when the Observable.notifyObservers() method is called.
protected void	variableAdded(Variable var) Called when a variable is added to the table.
protected void	variableChanged(Variable var) Called when a variable value has changed.
protected void	variableRemoved(Variable var) Called when a variable is removed from the table.

Methods inherited from class java.lang.Object

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

Constructor Detail

VariableTableObserver

public VariableTableObserver(VariableTable vt)

VariableTableObserver

public VariableTableObserver(Jep jep)

Method Detail

addObserver

public void addObserver(java.util.Observable obs)

addObservers

public void addObservers(VariableTable vt)

deleteObserver

public void deleteObserver(java.util.Observable obs)

deleteObservers

public void deleteObservers()

Stop observing all variables.

update

public void update(java.util.Observable o,
                   java.lang.Object arg)

Called when the Observable.notifyObservers() method is called. This methods calls the variableAdded(), variableValueChanged() etc. methods and maintains the list of variables it is observing.

Specified by:

update in interface java.util.Observer

variableChanged

protected void variableChanged(Variable var)

Called when a variable value has changed. Intended to be overridden by subclasses.

Parameters:

var - the variable which has changed.

variableAdded

protected void variableAdded(Variable var)

Called when a variable is added to the table. Intended to be overridden by subclasses.

Parameters:

var - the variable which has been added.

variableRemoved

protected void variableRemoved(Variable var)

Called when a variable is removed from the table. Intended to be overridden by subclasses.

Parameters:

var - the variable which has been removed.

tableCleared

protected void tableCleared(VariableTable table)

Called when the variable table has been cleared. Intended to be overridden by subclasses.

Parameters:

table - table which has been cleared

iterator

public java.util.Iterator<java.util.Observable> iterator()

Returns a list of items this class is observing.

Returns:

an iterator for the list.