Re: FlowLayout and lightweight IDEs

From:
bH <bherbst65@hotmail.com>
Newsgroups:
comp.lang.java.help
Date:
Sat, 9 Aug 2008 20:08:30 -0700 (PDT)
Message-ID:
<fae17e23-2385-4c45-b8c4-f06dd5e0398e@m44g2000hsc.googlegroups.com>
On Aug 9, 6:28 pm, "John B. Matthews" <nos...@nospam.invalid> wrote:

In article
<b0fd658a-18f1-4264-986d-179ca9378...@w7g2000hsa.googlegroups.com>,

 bH <bherbs...@hotmail.com> wrote:

On Aug 8, 2:44 pm, "John B. Matthews" <nos...@nospam.invalid> wrote:

In article <489c6ec2$0$4045$b9f67...@news.newsdemon.com>,
 Knute Johnson <nos...@rabbitbrush.frazmtn.com> wrote:

bH wrote:

This Q is about using a FlowLayout.

[...]
I compiled it and it displayed and ran. I don't use an IDE so I =

can't

help you there. It is possible that your problem is from not cre=

ating

the GUI on the EDT. And speaking of the EDT, you block it while
retrieving your image. Any change that would occur to the displa=

yed

components will not happen until the EDT is freed. This may or m=

ay not

cause you to lose some of your GUI but the GUI will not be able to
respond until the image gathering code returns.


Knute's right about blocking. There's more here about perceived
performance when loading an image here:

<http://java.sun.com/docs/books/tutorial/uiswing/components/icon.html=

Also, I'm suspicious of overriding the JFrame's paint() method
(inherited from Container), without calling super.paint():


[...]
<http://groups.google.com/group/comp.lang.java.help/msg/bb2203c080c1b4e2?
hl=en>
[...]

Thanks for your responses. I have been unable to reconstruct the
program using panels. That rewrite of placing it on a panel makes none
of the labels and textfields appear reagrdless of which IDE I use. Yes
I did download John's sample above and it runs. but my adapting it to
my original one does not work. If I place the mouse over some of the
buttons they show up but nothing else shows up.


Yes, as documented: if I override paint in my code (above), I get the
same effect. If I call super.paint(), I don't:

  public void paint(Graphics g) { super.paint(g); ... }

Instead, just have your button set the imageLabel's icon to whatever
image you get back from the server and call repaint():

  public void actionPerformed(ActionEvent ae) {
    String cmd = ae.getActionCommand();
    if ("quit".equals(cmd)) {
      System.exit(0);
    } else if ("grab".equals(cmd)) {
      try {
        ImageIcon icon = new ImageIcon(new URL(
          "<some valid chart url>"));
        imageLabel.setIcon(icon);
        imageLabel.repaint();
      } catch (MalformedURLException e) {
        System.err.println(e.toString());
      }
    }
  }

So I went back to my design written above with these revsions below.


Did you mean to post code below?

[...] This is not a good programming example, too quirky.


Or that it's too quirky to post?

--
John B. Matthews
trashgod at gmail dot com
home dot woh dot rr dot com slash jbmatthews- Hide quoted text -

- Show quoted text -

Hi John,
Your efforts are appreciated. Thanks for the reply. I have to study
this a while longer and do an acceptable revision that fully opens
with all three IDE's not just one. Since it happens with only one,
that is my defintion of quirky. I will post the code below.
bH

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