AWT repaint issues - checkbox

Question

I am trying to make some small additions to some old java code that does not support swing. I need to add a small dialog that contains a panel which has a checkbox and a couple text fields. When the user clicks on the checkbox I want to disable or enable the checkboxes. This part seems to work well but the text fields are not properly getting redrawn. When I click the checkbox the fields do not appear to become enabled but if I then click on the panel or the text field you see that they are enabled (the opposite is also true, when I un-check the checkbox the fields still look enabled until you try and click on them and they become ghosted and do not become selected). I use the setEnabled(boolean) to set the status of the fields. I have tried calling repaint and validate on both the fields and the panel after changing the status and this does not seem to work. I have also tried to have the fields request focus and this did not work. Anyone have any other ideas?
//The class that contains all of this is of type Window
//Declaration of the components
private Panel _inputPanel;
private TextField min , max;
//This method adds to two text fields
public void addMinMaxtextFields(String min, String max) {
TextField minField = new TextField(min);
TextField maxField = new TextField(max);
this.min = minField;
this.max = maxField;
this.min.setEnabled(false);
this.max.setEnabled(false);
_inputPanel.add(minField);
_inputPanel.add(maxField);
}
//listener for the checkbox
public void itemStateChanged(ItemEvent e) {
Component[] components = _inputPanel.getComponents();
min.setEnabled(!min.isEnabled());
min.setVisible(true);
min.validate();
min.repaint();
_inputPanel.validate();
_inputPanel.repaint();
this.pack();
this.setSize(this.getWidth(), this.getHeight());
this.validate();
this.repaint();
/* do nothing */
}

Answer 1

You will need to call update(Graphics g) on Panel after setEnabled(boolean) is called.
check :
http://download-llnw.oracle.com/javase/1.4.2/docs/api/java/awt/Container.html#update(java.awt.Graphics)
I tried following code (built from code you provided), Its working fine.
import java.awt.Checkbox;
import java.awt.Component;
import java.awt.Dialog;
import java.awt.Frame;
import java.awt.Panel;
import java.awt.TextField;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
public class CheckUI extends Dialog implements ItemListener {
// The class that contains all of this is of type Window
// Declaration of the components
private Panel _inputPanel;
private TextField min, max;
private Checkbox cb;
public CheckUI(Frame owner, boolean modal) {
super(owner, modal);
_inputPanel = new Panel();
this.add(_inputPanel);
addMinMaxtextFields("min", "max");
}
// This method adds to two text fields
public void addMinMaxtextFields(String min, String max) {
cb = new Checkbox();
cb.addItemListener(this);
TextField minField = new TextField(min);
TextField maxField = new TextField(max);
this.min = minField;
this.max = maxField;
this.min.setEnabled(false);
this.max.setEnabled(false);
_inputPanel.add(minField);
_inputPanel.add(maxField);
_inputPanel.add(cb);
}
// listener for the checkbox
public void itemStateChanged(ItemEvent e) {
Component[] components = _inputPanel.getComponents();
min.setEnabled(!min.isEnabled());
min.setVisible(true);
min.validate();
min.repaint();
_inputPanel.validate();
_inputPanel.repaint();
this.pack();
this.setSize(this.getWidth(), this.getHeight());
this.validate();
this.repaint();
/* do nothing */
}
/**
* #param args
*/
public static void main(String[] args) {
Frame parent = new Frame();
parent.setVisible(true);
parent.setExtendedState(Frame.MAXIMIZED_BOTH);
parent.pack();
CheckUI ui = new CheckUI(parent, true);
ui.pack();
ui.setVisible(true);
}
}