package jalview.ws2.actions;

import java.util.List;

import jalview.api.AlignViewportI;
import jalview.viewmodel.AlignmentViewport;
import jalview.ws.params.ArgumentI;
import jalview.ws2.actions.api.ActionI;
import jalview.ws2.actions.api.TaskI;
import jalview.ws2.api.Credentials;

/**
 * An empty implementation of the {@link ActionI} interface that does nothing.
 * Use as a placeholder for testing purposes.
 * 
 * @author mmwarowny
 *
 */
public final class NullAction extends BaseAction<Void>
{
  public static final class Builder extends BaseAction.Builder<NullAction>
  {
    public NullAction build()
    {
      return new NullAction(this);
    }
  }
  
  public static Builder newBuilder()
  {
    return new Builder();
  }
  
  protected NullAction(Builder builder)
  {
    super(builder);
  }

  @Override
  public TaskI<Void> createTask(AlignViewportI viewport,
          List<ArgumentI> args, Credentials credentials)
  {
    return new NullTask();
  }

  @Override
  public boolean isActive(AlignmentViewport viewport)
  {
    return false;
  }
}