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Groups > comp.lang.java.gui > #5454

Re: setText() is not always updating Jtextfield and Jlabel items

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On 02/26/2015 03:23 PM, Kevin Nathan wrote:
>
> I could use some direction about where to look for this. I am still
> pretty new to Java. I have a user input screen with multiple
> JTextFields for user input and matching JLabels for informational
> output for users.
>
> This is for a livestock auction system. While the animals are moving
> around on the scale, the scale instrument (a serial port device)
> returns an indication of "motion" that we want to show to the user.
> When the motion goes away, the actual weight gets written to the Weight
> JTextField. However, during the motion (which can be anywhere from
> non-existent to many seconds) we want to write "Motion" in the
> textfield and the actual, changing, weights in the label field. This is
> what is not happening. After the motion stops, the true weight does get
> written correctly, using setText().
>
> The serial port routine returns an error code of -2 if there is motion
> (and several other error codes that are handled correctly) and that is
> what I am using. Here are some code snippets to show what is being
> attempted, I hope it's enough to make sense:
>

Often in Swing, when the complaint involves
"does not work in this instance, but works everywhere else"
you've run into a thread concurrency issue.

You might have a look at "Concurrency in Swing"
<http://docs.oracle.com/javase/tutorial/uiswing/concurrency/index.html>
if you haven't already.

The section "Bound Properties and Status Methods"
refers to another section in the Java Tutorials
"Lesson: Writing Event Listeners"
<http://docs.oracle.com/javase/tutorial/uiswing/events/index.html>
which may be helpful as there was no indication in the snippets
you provided that you are using the Swing event model.

>
> I am completely puzzled why "setText" does not work in this instance,
> but works everywhere else I am using it. Thanks for any help, or
> pointers to pages that may help me to understand this
>
>

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Thread

setText() is not always updating Jtextfield and Jlabel items Kevin Nathan <knathan@project54.com> - 2015-02-26 13:23 -0700
  Re: setText() is not always updating Jtextfield and Jlabel items Jeff Higgins <jeff@invalid.invalid> - 2015-02-26 19:43 -0500
    Re: setText() is not always updating Jtextfield and Jlabel items Kevin Nathan <knathan@project54.com> - 2015-02-27 08:21 -0700
  Re: setText() is not always updating Jtextfield and Jlabel items Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2015-02-26 20:05 -0800
    Re: setText() is not always updating Jtextfield and Jlabel items Kevin Nathan <knathan@project54.com> - 2015-02-27 08:24 -0700
  Re: setText() is not always updating Jtextfield and Jlabel items Nigel Wade <nmw@ion.le.ac.uk> - 2015-02-27 15:45 +0000
    Re: setText() is not always updating Jtextfield and Jlabel items Kevin Nathan <knathan@project54.com> - 2015-03-02 09:33 -0700

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