package org.apidesign.stateful.api;

 /** API for notifying progress that cannot call

  * {@link #start(int)} and {@link InProgress#progress(int)} in wrong

  * order. In contract to {@link ProgressStateful} class which allows that.

  *

  * @author Jaroslav Tulach <jtulach@netbeans.org>

  */

 public abstract class ProgressStateless {

 // BEGIN: progress.phases

     public static ProgressStateless create(String name) {

         return createImpl(name);

     }

     public abstract InProgress start(int totalAmount);

     public abstract class InProgress {

         public abstract void progress(int howMuch);

         public abstract void finish();

         // FINISH: progress.phases

         InProgress() {

         }

     }

     ProgressStateless() {

     }

     private static ProgressStateless createImpl(String name) {

         return new Impl(name);

     }

     private static final class Impl extends ProgressStateless {

         private final String name;

         public Impl(String name) {

             this.name = name;

         }

         @Override

         public InProgress start(int totalAmount) {

             return new InImpl(totalAmount);

         }

         private class InImpl extends InProgress {

             private final int total;

             private int current;

             public InImpl(int total) {

                 this.total = total;

             }

             @Override

             public void progress(int howMuch) {

                 current = howMuch;

             }

             @Override

             public void finish() {

                 current = total;

             }

         }

     }

 }