ChangeListener (biojava-legacy 1.9.5 API)

All Superinterfaces:

EventListener

All Known Implementing Classes:

AbstractSymbolList.EditScreener, AbstractSymbolList.EditTranslater, Annotatable.AnnotationForwarder, ChangeAdapter, ChangeForwarder, ChangeForwarder.Retyper, ChangeListener.AlwaysVetoListener, ChangeListener.ChangeEventRecorder, ChangeListener.LoggingListener, Distribution.NullModelForwarder, MergeAnnotation.PropertyForwarder, OverlayAnnotation.PropertyForwarder, PairwiseSequenceRenderer.PairwiseRendererForwarder, SequenceDBWrapper.SequencesForwarder, SequenceRenderer.RendererForwarder, SimpleSymbolList
```
public interface ChangeListener
extends EventListener
```
Interface for objects which listen to ChangeEvents.

Since:

1.1

Author:

Thomas Down, Matthew Pocock, Keith James

Nested Class Summary

Nested Classes
Modifier and Type	Interface	Description
`static class`	`ChangeListener.AlwaysVetoListener`	An implementation that always vetoes everything.
`static class`	`ChangeListener.ChangeEventRecorder`	A listener that remembers the ChangeEvent of the last change.
`static class`	`ChangeListener.LoggingListener`	A listener that writes information about the event stream to a PrintStream.

Field Summary

Fields
Modifier and Type	Field	Description
`static ChangeListener`	`ALWAYS_VETO`	Convenience implementation which vetoes every change of which it is notified.
`static ChangeListener`	`LOG_TO_OUT`	Convenience implementation that echoes all events to out.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`postChange(ChangeEvent cev)`	Called when a change has just taken place.
`void`	`preChange(ChangeEvent cev)`	Called before a change takes place.

- Field Detail
  - ALWAYS_VETO
```
static final ChangeListener ALWAYS_VETO
```
    Convenience implementation which vetoes every change of which it is notified. You could add this to an object directly to stop it changing in any way, or alternatively you could add it for a specific ChangeType to stop that single item from altering.
  - LOG_TO_OUT
```
static final ChangeListener LOG_TO_OUT
```
    Convenience implementation that echoes all events to out.
- Method Detail
  - preChange
```
void preChange(ChangeEvent cev)
        throws ChangeVetoException
```
    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.
    
    Parameters:
    
    cev - An event encapsulating the change which is about to take place.
    
    Throws:
    
    ChangeVetoException - Description of Exception
    
    ChangeVetoException - if the receiver does not wish this change to occur at this time.
  - postChange
```
void postChange(ChangeEvent cev)
```
    Called when a change has just taken place.
    
    This method is the place to perform any behavior in response to the change event.
    
    Parameters:
    
    cev - An event encapsulating the change which has occured.