Re: I need a different approach - suggestions please

From:
Eric Sosman <esosman@ieee-dot-org.invalid>
Newsgroups:
comp.lang.java.programmer
Date:
Wed, 27 Jun 2012 18:13:00 -0400
Message-ID:
<jsg0he$rab$1@dont-email.me>
On 6/27/2012 5:44 PM, bilsch wrote:

On 6/26/2012 2:21 PM, Eric Sosman wrote:

[...]
You needn't use the same listener for the 7 key as for
the Backspace key ...


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.

Could you explain please?


     In your code there's a class called CrunchQ1, and because it
implements the ActionListener interface you can (and do) tell
your buttons to use an instance of that class as their action
listeners:

    CrunchQ1 crunchNu = new CrunchQ1(this);
    ...
    dot.addActionListener(crunchNu);
    zro.addActionListener(crunchNu);
    one.addActionListener(crunchNu);
    ...

     What I'm suggesting is that you could perfectly have another
class, maybe CrunchQ2, that also implements ActionListener but does
something different in its ActionPerformed method. Then you could
make yourself an instance of the CrunchQ2 class, and use it instead
of the CrunchQ1 instance for some of your buttons:

    CrunchQ1 crunchNu = new CrunchQ1(this);
    CrunchQ2 dotty = new CrunchQ2(...whatever...);
    ...
    dot.addActionListener(dotty);
    zro.addActionListener(crunchNu);
    one.addActionListener(crunchNu);
    ...

     If you have other buttons with idiosyncratic behaviors, you
could give them their own ActionListener implementations, too.
There is no reason in the world why every button in your program
should share the same listener!

--
Eric Sosman
esosman@ieee-dot-org.invalid

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