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NNTP-Posting-Date: Wed, 27 Jun 2012 17:21:01 -0500
Date: Wed, 27 Jun 2012 15:21:02 -0700
From: Patricia Shanahan <pats@acm.org>
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Subject: Re: I need a different approach - suggestions please
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On 6/27/2012 2:44 PM, bilsch wrote:
...
> The listeners all call a statement in the second file:
>
> public void actionPerformed(ActionEvent event)
>
> so I don't understand how a button listener can be different from
> another button listener.

You can write several different implementing classes for an interface
such as ActionListener. You can then create different instances of the
same implementing class.

For example, you could have a NumberKeyListener class that implements
ActionListener, and takes a constructor parameter that tells it the
value associated with its button. On the other hand, I would have a
different class for dealing with backspace.

Code like:

one.addActionListener(new NumberKeyListener(1));
two.addActionListener(new NumberKeyListener(2));

would get rid of a lot of checking which button was pressed.

Of course, as soon as you learn about arrays this will all get simpler
and shorter.

Patricia