Package org.biojava.utils

Class ChangeForwarder

java.lang.Object
org.biojava.utils.ChangeForwarder
All Implemented Interfaces:
EventListener, ChangeListener
Direct Known Subclasses:
AbstractSymbolList.EditScreener, Annotatable.AnnotationForwarder, ChangeForwarder.Retyper, Distribution.NullModelForwarder, MergeAnnotation.PropertyForwarder, OverlayAnnotation.PropertyForwarder, PairwiseSequenceRenderer.PairwiseRendererForwarder, SequenceDBWrapper.SequencesForwarder, SequenceRenderer.RendererForwarder
public class ChangeForwarder extends Object implements ChangeListener
This is a ChangeListener that is designed to adapt events of one type from one source to events of another type emitted by another source. For example, you could adapt events made by edits in a database to being events fired by a sequence implementation.
Since:
1.1
Author:
Matthew Pocock

  • Constructor Details

    • ChangeForwarder

      public ChangeForwarder(Object source, ChangeSupport changeSupport)
      Create a new ChangeForwarder for forwarding events.
      Parameters:
      source - the new source Object
      changeSupport - the ChangeSupport managing the listeners

  • Method Details

    • getSource

      public Object getSource()
      Retrieve the 'source' object for ChangeEvents fired by this forwarder.
      Returns:
      the source Object

    • changeSupport

      public ChangeSupport changeSupport()
      Return the underlying ChangeSupport instance that can be used to fire ChangeEvents and mannage listeners.
      Returns:
      the ChangeSupport delegate

    • generateEvent

      protected ChangeEvent generateEvent(ChangeEvent ce) throws ChangeVetoException

      Return the new event to represent the originating event ce.

      The returned ChangeEvent is the event that will be fired, and should be built from information in the original event. If it is null, then no event will be fired.

      The default implementation just constructs a ChangeEvent of the same type that chains back to ce.

      Parameters:
      ce - the originating ChangeEvent
      Returns:
      a new ChangeEvent to pass on, or null if no event should be sent
      Throws:
      ChangeVetoException - if for any reason this event can't be handled

    • preChange

      public void preChange(ChangeEvent ce) 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:
      ce - An event encapsulating the change which is about to take place.
      Throws:
      ChangeVetoException - Description of Exception

    • postChange

      public void postChange(ChangeEvent ce)
      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:
      ce - An event encapsulating the change which has occured.