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why my applet can't display components like JButton or JTextField, but
JLabel is well

wrote in news:1135317413.624665.16940
@g44g2000cwa.googlegroups.com:

> why my applet can't display components like JButton or JTextField, but
> JLabel is well
>
>

Because your computer has a pixie inside the cd-rom drive which eats
JButtons. The JTextFields are just afraid of being eaten too, even though
the pixie doesn't like them.

Without code, we can't help you.

--
Beware the False Authority Syndrome

sorry, my code is:

// FileChooserPanel.java
package test.applets;


import java.io.File;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JTextField;
import javax.swing.JFileChooser;
import javax.swing.filechooser.*;


//import javax.swing.JLabel;


public class FileChooserPanel extends JPanel
implements ActionListener {
JTextField uploadpath;
JButton opendirButton;
JFileChooser fc;


public FileChooserPanel() {
fc = new JFileChooser();
uploadpath = new JTextField(20);
JPanel uploadpathPanel = new JPanel();
uploadpathPanel.add(uploadpath);


opendirButton = new JButton("Open File...");
opendirButton.addActionListener(this);
JPanel buttonPanel = new JPanel();
buttonPanel.add(opendirButton);


add(uploadpathPanel);
add(buttonPanel);


// this will be ok
//JLabel lab = new JLabel("Hello, World!");
//add(lab);


}


public void actionPerformed(ActionEvent e) {
if (e.getSource() == opendirButton) {
fc.setFileSelectionMode(JFileChooser.DIRECTORIES_O NLY);
int returnVal = fc.showOpenDialog(FileChooserPanel.this);


if (returnVal == JFileChooser.APPROVE_OPTION) {
File file = fc.getSelectedFile();
uploadpath.setText(file.toString());
}
else {
uploadpath.setText("");
}
}
}



}


// FileChooserApplet.java
package test.applets;

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JApplet;
import javax.swing.JLabel;
import javax.swing.UIManager;


import test.applets.FileChooserPanel;


public class FileChooserApplet extends JApplet {
private void createGUI() {
FileChooserPanel fcp = new FileChooserPanel();
fcp.setOpaque(true);
fcp.setBackground(Color.white);
setContentPane(fcp);
}


public void init() {
try {

UIManager.setLookAndFeel(UIManager.getSystemLookAn dFeelClassName());
javax.swing.SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
createGUI();
}
});
}
catch (Exception e) {
System.err.println("createGUI didn't successfully
complete");
}
}



}

Well, it ran fine, when I tried it under 1.4.2_10, but some comments:
you don't need javax.swing.SwingUtilities.invokeAndWait in init.
There's no painting until well after init has finished, so doing GUI
stuff in init is safe. You only need that in some special cases, as I
explain here (if your browser supports the use of applets) :
http://javalessons.com/cgi-bin/ui/ja...=ths&sid=ao789
Another thing, why not add the components to FileChooserPanel straight
away, instead of putting them in other panels first ?
Hope this helps,

---
Paul Hamaker, SEMM
http://javalessons.com

Paulus de Boska wrote:
> Well, it ran fine, when I tried it under 1.4.2_10, but some comments:
> you don't need javax.swing.SwingUtilities.invokeAndWait in init.
> There's no painting until well after init has finished, so doing GUI
> stuff in init is safe. You only need that in some special cases, as I

Sun's information on this is contradictory. In fact, you do need the
invokeAndWait to be safe, as Swing (particularly text) is booby-trapped
with invokeLaters.

> explain here (if your browser supports the use of applets) :
> http://javalessons.com/cgi-bin/ui/ja...=ths&sid=ao789

Or use appletviewer from the JDK.

Tom Hawtin
--
Unemployed English Java programmer
http://jroller.com/page/tackline/

wrote:
> why my applet can't display components like JButton or JTextField, but
> JLabel is well

What Java is your browser running?
<http://www.physci.org/pc/property.jsp?prop=java.version+java.vendor>

What is the exception showing in the Java Console?

--
Andrew Thompson
physci, javasaver, 1point1c, lensescapes - athompson.info/andrew