package jalview.api;

import java.util.EventListener;

/**
 * A listener class which receives state updates of {@link AlignCalcWorkerI}.
 * It can be registered with an {@link AlignCalcManagerI2}.
 * 
 * @author mmwarowny
 *
 */
public interface AlignCalcListener extends EventListener
{
  /**
   * Called when the worker is scheduler for execution with
   * {@link AlignCalcManagerI2#startWorker(AlignCalcWorkerI)}.
   */
  default void workerQueued(AlignCalcWorkerI worker) {}
  
  /**
   * Called when the worker starts calculations.
   */
  default void workerStarted(AlignCalcWorkerI worker) {}
  
  /**
   * Called when the worker finishes successfully.
   */
  default void workerCompleted(AlignCalcWorkerI worker) {}
  
  /**
   * Called when the worker is cancelled.
   */
  default void workerCancelled(AlignCalcWorkerI worker) {}
  
  /**
   * Called when the worker finishes with an exception.
   */
  default void workerExceptional(AlignCalcWorkerI worker, Throwable throwable) {}
}