Re: Design Patterns

From:
Doug Mika <dougmmika@gmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Sat, 2 Feb 2013 21:11:16 -0800 (PST)
Message-ID:
<fbf41347-36f8-45c9-9699-736a48576909@googlegroups.com>
So passing MainWindow to MenuWindow is one possible solution. But what are the other three. No, this is not to be a school assignmennt, I'm looking for a clean and proper way to do this.

On Saturday, February 2, 2013 10:54:07 PM UTC-6, markspace wrote:

On 2/2/2013 7:43 PM, Doug Mika wrote:

MainWindow.java and MenuBar.java are instantiated in Program.java

How can events in MenuWindow.java cause changes in MainWindow.java

ie. what's the cleanest way to do this?


The thing is, this is called "programming." There's a very large number

of ways to do this, and they all are valid, given various design

assumptions.

Static variables, "globals" as I think you mentioned, are OK if the

program is small and not going to be maintained (i.e., a small school

assignment). More robust methods all make some assumption as to rates

of code change, presence of frameworks, team size, total costs of

ownership, etc.

Your immediate problem could be solved by using constructors, and just

hiding and showing various windows, rather than destroying them and

re-creating them.

   public static void main( String... args ) {

     // startup

     ...

     createAndShowGui();

     ...

   }

   private void createAndShowGui() {

     SwingUtilities.invokeLater( new Runnable() {

        MainWindow mw = new MainWindow();

        MenuBar mb = new MenuBar();

        MenuWindow menuw = new MenuWindow( mw );

        mw.pack();

        mw.setVisible( true );

     }; );

   }

Now MenuWindow has a reference to mw so it can manipulate mw. But I

can't think of at least three other ways to do this, and they all have

advantages and short-comings, so you have to decide what is best for

your programs.

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