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Groups > comp.lang.java.programmer > #15692
| From | bilsch <bilsch01@gmail.com> |
|---|---|
| Newsgroups | comp.lang.java.programmer |
| Subject | Re: I need a different approach - suggestions please |
| Date | 2012-06-27 18:36 -0700 |
| Organization | A noiseless patient Spider |
| Message-ID | <jsgce5$sr6$1@dont-email.me> (permalink) |
| References | <jsaos3$bht$1@dont-email.me> <jsarei$tfl$1@dont-email.me> <jsatb2$6ki$1@dont-email.me> <f5a21759-b102-4a8a-b701-c84e52855962@googlegroups.com> |
On 6/25/2012 6:36 PM, Lew wrote:
> bilsch wrote:
>> markspace wrote:
>>> bilsch wrote:
>>>> I'm trying to make a program that works like the calculator in Windows
>>>> Accessories - all input is from button clicks. ...
>>>> Everytime the method is called the string is reinitialized
>>>> with the result that my sequence of digits is only ever one digit long.
>>>> My plan would work if I could initialize the string outside the method,
>>>> however variable scope in Java doesn't allow it.
>>>
>>> First, good job on making a very reasonable SSCCE.
>>>
>>> Second, the trick to Java's scoping rules is to change the rules!
>>>
>>> Move the string strng1 from inside the actionPerformed to outside, right
>>> below the CalcGUIQ1 gui; line. Now Java's scoping rules help you rather
>>> than hinder you.
>>>
>>> BTW, this looks like a homework problem, and it looks like you've been
>>> getting help on it. Some if it is a bit sophisticated for someone who
>>> doesn't understand scoping. Please try to talk to your instructor or a
>>> TA, they need to understand when you're having problems with your lessons.
>>>
>> Thanks for the help. I could swear I tried that first but got error
>> messages about static and non-static conflict problem. i will be taking
>> Java in fall quarter. Right now I'm working from "Learn Java in 24
>> Hours" I thought up the calculator project myself. Thanks again.
>
> There are a few mistakes in your code.
>
> You don't need to call 'super()' in the constructor explicitly.
> That's what happens by default anyway.
>
> You called the constructor directly from the 'main()' routine. That means
> you called it from the primary thread of the program. You don't know this
> yet, probably, unless you've already studied concurrency in Java a little bit.
>
> The problem is that the GUI won't work right if you do that. You have to
> move GUI actions onto the "Event Dispatch Thread" (EDT), a background
> thread that the system creates to handle all GUI actions.
>
> Also, you start all the action from the constructor. That's bad. As its name
> implies, a constructor's purpose is to _construct_ an object, not run its logic.
> Run the logic after construction completes and the instance is no longer in a
> partially-built state.
>
> And make your indentation consistent with the Java coding conventions (available
> on line).
>
> So all together, you'd do something like:
>
> public static void main(String[] arguments) {
> java.awt.EventQueue.invokeAndWait( new Runnable() {
> @Override public void run() {
> CalcGUIQ1 calculator = new CalcGUIQ1();
> calculator.setVisible(true);
> }
> });
> }
Hello Lew,
With help I've gotten some errors out of the program but I have reached
a point where something just won't work how it should. Your comments
here lead me to believe the reason is the basic way I have things laid
out. But I don't know how to:
> move GUI actions onto the "Event Dispatch Thread" (EDT), further I
dont know how to write an EDT, or what specifically are 'GUI actions' as
opposed to other lines that relate to the GUI.
Also, I thought the stuff I have in the constructor belonged there.
I dont know where to call the constructor from if not from 'main'.
I did some reading about threads being unsafe.
It would be very helpful to me if you could show how to rearrange the
code like you say would be better. If you have the time, it would be
very helpful. Thanks.
Bill S.
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I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-25 15:31 -0700
Re: I need a different approach - suggestions please markspace <-@.> - 2012-06-25 16:15 -0700
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-25 16:47 -0700
Re: I need a different approach - suggestions please markspace <-@.> - 2012-06-25 18:10 -0700
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-26 13:04 -0700
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-26 14:01 -0700
Re: I need a different approach - suggestions please Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-26 17:21 -0400
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-27 14:44 -0700
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-27 14:56 -0700
Re: I need a different approach - suggestions please Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-27 18:13 -0400
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-27 18:48 -0700
Re: I need a different approach - suggestions please Patricia Shanahan <pats@acm.org> - 2012-06-27 15:21 -0700
Re: I need a different approach - suggestions please Jail Bush Cronies <do.not@ask.me> - 2012-06-27 18:46 -0400
Re: I need a different approach - suggestions please markspace <-@.> - 2012-06-26 14:25 -0700
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-26 14:32 -0700
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-26 17:49 -0400
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-26 15:20 -0700
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-27 17:30 -0700
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-27 18:09 -0700
Re: I need a different approach - suggestions please Wanja Gayk <brixomatic@yahoo.com> - 2012-07-02 11:21 +0200
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-25 18:36 -0700
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-26 13:24 -0700
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-26 13:49 -0700
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-26 14:04 -0700
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-26 14:34 -0700
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-26 16:26 -0700
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-26 16:47 -0700
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-26 20:04 -0700
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-26 22:18 -0400
Re: I need a different approach - suggestions please Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-06-26 22:59 -0400
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-27 21:30 -0400
Re: I need a different approach - suggestions please Wanja Gayk <brixomatic@yahoo.com> - 2012-07-02 11:32 +0200
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-07-02 09:47 -0700
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-26 20:06 -0700
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-27 11:42 -0700
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-27 14:09 -0700
Re: I need a different approach - suggestions please Patricia Shanahan <pats@acm.org> - 2012-06-27 15:11 -0700
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-27 21:59 -0400
Re: I need a different approach - suggestions please Devil's Advocate <legal@hell.org> - 2012-06-27 22:17 -0400
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-27 21:40 -0400
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-27 19:12 -0700
Re: I need a different approach - suggestions please Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-06-27 20:47 -0500
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-27 19:12 -0700
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-27 21:28 -0400
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-27 19:14 -0700
Re: I need a different approach - suggestions please Hydrangea <hydrangea393@foo.mail.quuzzle.edu> - 2012-06-27 22:28 -0400
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-27 21:05 -0700
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-27 22:32 -0400
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-27 21:08 -0700
Re: I need a different approach - suggestions please markspace <-@.> - 2012-06-26 14:10 -0700
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-26 14:35 -0700
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-26 17:51 -0400
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-26 15:20 -0700
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-26 19:35 -0400
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-26 16:44 -0700
Re: I need a different approach - suggestions please Arne Vajhøj <arne@vajhoej.dk> - 2012-06-26 22:06 -0400
Re: I need a different approach - suggestions please Patricia Shanahan <pats@acm.org> - 2012-06-27 08:15 -0700
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-27 18:36 -0700
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-27 18:54 -0700
Re: I need a different approach - suggestions please B1ll G4tes <wm.gat3s@micro5oft.quux> - 2012-06-27 22:23 -0400
Re: I need a different approach - suggestions please Lew <lewbloch@gmail.com> - 2012-06-28 09:55 -0700
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-28 04:02 -0700
Re: I need a different approach - suggestions please Mike Winter <mlwinter@gmail.com> - 2012-06-28 04:55 -0700
Re: I need a different approach - suggestions please markspace <-@.> - 2012-06-28 07:33 -0700
[OT] Message IDs (Re: I need a different approach - suggestions please) Mike Winter <mlwinter@gmail.com> - 2012-06-28 08:45 -0700
Re: [OT] Message IDs (Re: I need a different approach - suggestions please) markspace <-@.> - 2012-06-28 09:39 -0700
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-28 09:44 -0700
Re: I need a different approach - suggestions please Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-06-28 12:51 -0400
Re: I need a different approach - suggestions please markspace <-@.> - 2012-06-28 09:58 -0700
Re: I need a different approach - suggestions please markspace <-@.> - 2012-06-28 07:32 -0700
Re: I need a different approach - suggestions please Roedy Green <see_website@mindprod.com.invalid> - 2012-06-26 03:49 -0700
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-26 13:59 -0700
Re: I need a different approach - suggestions please Patricia Shanahan <pats@acm.org> - 2012-06-29 08:12 -0700
Re: I need a different approach - suggestions please Gene Wirchenko <genew@ocis.net> - 2012-06-29 10:02 -0700
Re: I need a different approach - suggestions please bilsch <bilsch01@gmail.com> - 2012-06-29 13:07 -0700
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