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From: Robert Klemme <shortcutter@googlemail.com>
Newsgroups: comp.lang.java.programmer
Subject: Re: How to extend an array
Date: Wed, 1 Jun 2016 23:07:41 +0200
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On 31.05.2016 16:52, Eric Douglas wrote:
> This looks funny but seems to work.  Does it make sense, is there
> better syntax, or anything I'm missing?

First of all: the title is totally misleading.  This is not about 
arrays, it's about ArrayLists - even about generic collections generally.


After reading the thread it seems you might want parallel inheritance 
hierarchies like this:

package listeners;

public interface BaseListener {
   void fast(final BaseClass<?> o);
}

package listeners;

import java.util.ArrayList;
import java.util.List;

public class BaseClass<L extends BaseListener> {
   private final List<L> listeners = new ArrayList<>();

   protected List<L> getListeners() {
     return listeners;
   }

   public void addListener(final L listener) {
     getListeners().add(listener);
   }

   public void notifyFast() {
     for (final L listener : getListeners()) {
       listener.fast(this);
     }
   }
}

package listeners;

public interface DerivedListener extends BaseListener {
   void superFast(final DerivedClass<?> o);
}

package listeners;

public class DerivedClass<L extends DerivedListener>
extends BaseClass<L> {

   public void notifySuperFast() {
     for (final L listener : getListeners()) {
       listener.superFast(this);
     }
   }
}

Is this what you had in mind?

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
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