Re: FlowLayout and lightweight IDEs

From:
"John B. Matthews" <nospam@nospam.invalid>
Newsgroups:
comp.lang.java.help
Date:
Fri, 08 Aug 2008 14:44:21 -0400
Message-ID:
<nospam-5DD6C5.14440608082008@web.aioe.org>
In article <489c6ec2$0$4045$b9f67a60@news.newsdemon.com>,
 Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:

bH wrote:

Hi All,

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 creating
the GUI on the EDT. And speaking of the EDT, you block it while
retrieving your image. Any change that would occur to the displayed
components will not happen until the EDT is freed. This may or may 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://java.sun.com/javase/6/docs/api/java/awt/Component.html#paint(java
..awt.Graphics)>

Absent that, I saw nothing until I tabbed through the fields.

To focus on the FlowLayout aspect of the code, I changed to a JPanel,
which uses FlowLayout by default. I also used an ImageIcon to contain an
image. Sorry, I'm not familiar with the Chart API:

import java.awt.*;
import java.awt.event.*;
import java.net.*;
import javax.swing.*;

public class GoogleDrawImage
{
  public static void main(String[] args)
  {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setContentPane(new ImagePanel());
    frame.setTitle("Google Chart API");
    frame.setSize(600, 300);
    frame.setVisible(true);
  }
}
class ImagePanel extends JPanel implements ActionListener {
  JTextField addressField, appendFieldcht, appendFieldchs,
    appendFieldchd, appendFieldchm, appendFieldchf;
  JLabel lbleGoogleInstr, lbleFieldcht, lbleFieldchs,
    lbleFieldchd, lbleFieldchm, lbleFieldchf;
  JButton btnGetGoogleApis, btnClose;

  public ImagePanel() {
    // Use default FlowLayout.
    addressField = new JTextField(20);
    addressField.setText("http://chart.apis.google.com...");
    appendFieldcht = new JTextField(8);
    appendFieldcht.setText("r");
    appendFieldchs = new JTextField(8);
    appendFieldchs.setText("400x400");
    appendFieldchd = new JTextField(8);
    appendFieldchd.setText("t:70,70,70,70,70,70");
    appendFieldchm = new JTextField(8);
    appendFieldchm.setText("B,FF0000,0,0,5");
    appendFieldchf = new JTextField(8);
    appendFieldchf.setText("c,s,000000");
    lbleGoogleInstr = new JLabel("Complete these:");
    lbleFieldcht = new JLabel("cht is: ");
    lbleFieldchs = new JLabel("chs is: ");
    lbleFieldchd = new JLabel("chd is: ");
    lbleFieldchm = new JLabel("chm is: ");
    lbleFieldchf = new JLabel("chf is: ");
    btnGetGoogleApis = new JButton("GetGoogleApis");
    btnGetGoogleApis.setActionCommand("GrabItAll");
    btnGetGoogleApis.addActionListener(this);
    btnClose = new JButton("Close Application");
    btnClose.setActionCommand("close");
    btnClose.addActionListener(this);
    // Add Components to this container.
    this.add(lbleGoogleInstr);
    this.add(addressField);
    this.add(lbleFieldcht);
    this.add(appendFieldcht);
    this.add(lbleFieldchs);
    this.add(appendFieldchs);
    this.add(lbleFieldchd);
    this.add(appendFieldchd);
    this.add(lbleFieldchm);
    this.add(appendFieldchm);
    this.add(lbleFieldchf);
    this.add(appendFieldchf);
    this.add(btnGetGoogleApis);
    this.add(btnClose);
    try {
      ImageIcon icon = new ImageIcon(new URL(
        "http://www.google.com/logos/olympics08_opening.gif"));
      JLabel imageLabel = new JLabel(icon);
      icon.setImageObserver(imageLabel);
      this.add(imageLabel);
    } catch (MalformedURLException e) {
      System.err.println(e.toString());
    }
  }

  public void actionPerformed(ActionEvent e) {
    if (e.getActionCommand().equals("close")) {
      System.exit(0);
    }
  }
}

[I appreciate your sscce, but some might reasonably be wary of code that
reads from the network and writes to the file system.]

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

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