Java Developer's Journal

"JavaBeans Customized"
Volume: 4 Issue: 12, p.80

Listing 1: The Clock Bean

package mybeans;

import java.awt.*;
import java.util.*;
import java.text.*;
import javax.swing.*;
import java.io.*;

public class Clock extends JLabel
implements Runnable, Serializable{
DateFormat formatter12;
DateFormat formatter24;
private boolean running;
private boolean isTwentyFourHourTime;

public Clock() {
    formatter12 =
     new SimpleDateFormat("h:mm:ss a");
    formatter24 =
         new SimpleDateFormat("H:mm:ss");
    setRunning(true);
}

public void run() {
while(running)
{
   if (isTwentyFourHourTime())
    this.setText(
     formatter24.format(new Date()));
    else
     this.setText(
      formatter12.format(new Date()));
     try {
       Thread.sleep(1000);
     }
     catch (InterruptedException e) {}
   }
}

// The running property should be hidden
public void setRunning(boolean newRunning) {
boolean oldRunning = running;
running = newRunning;
Thread t = new Thread(this);
t.start();
firePropertyChange("running",
new Boolean(oldRunning),
new Boolean(newRunning));
}

public boolean isRunning() {
return running;
}

// The twentyFourHourTime property
// should be exposed
public void setTwentyFourHourTime(
       boolean newTwentyFourHourTime) {
boolean oldTwentyFourHourTime =
       isTwentyFourHourTime;
isTwentyFourHourTime = newTwenty-
FourHourTime;
firePropertyChange("twentyFourHourTime",
    new Boolean(oldTwentyFourHourTime),
    new Boolean(newTwentyFourHourTime));
}

public boolean isTwentyFourHourTime() {
return isTwentyFourHourTime;
}
}
Listing 2: The Property Editor

package mybeans;

import java.beans.*;

public class ClockPropertyEditor
extends PropertyEditorSupport {

private boolean is_24 = false;

public ClockPropertyEditor() {
}

public String getAsText() {
return (is_24 ? "24 hour" : "12
hour");
}

public Object getValue() {
return new Boolean(is_24);
}

public void setAsText(String value)
         throws IllegalArgumentException {
    if (value.equals("24 hour"))
      setValue(new Boolean(true));
    else if (value.equals("12 hour"))
      setValue(new Boolean(false));
    else
      throw new IllegalArgumentException(
                "Unrecognized value: " + value);
}

public void setValue(Object value) {
    Boolean b = (Boolean)value;
    is_24 = b.booleanValue();
    firePropertyChange();
}

public String[] getTags() {
String [] tags = {"24 hour", "12 hour"};
return tags;
}
}
Listing 3: The ClockBeanInfo Class

package mybeans;

import java.beans.*;

public class ClockBeanInfo
extends SimpleBeanInfo {
public ClockBeanInfo() {
}

public
PropertyDescriptor[] getPropertyDescriptors() {
    try {
      // PropertyDescriptor for the
      // "twentyFourHourTime" property
      PropertyDescriptor pd1 =
        new PropertyDescriptor(
            "twentyFourHourTime",
             Clock.class,
            "isTwentyFourHourTime",
            "setTwentyFourHourTime");
      pd1.setDisplayName("Time Format");
      pd1.setShortDescription(
        "Controls whether the time is "+
        "displayed in 12 or 24 hour mode");
      pd1.setBound(true);
      pd1.setPropertyEditorClass(
        ClockPropertyEditor.class);

      // PropertyDescriptor to hide the
      // "running" property
      PropertyDescriptor pd2 =
        new PropertyDescriptor(
            "running",
            Clock.class,
            "isRunning",
            "setRunning");
      pd2.setHidden(true);

      PropertyDescriptor[] pds = new PropertyDescriptor[] {pd1, pd2};
      return pds;
    }
    catch(IntrospectionException ex) {
      return null;
    }
}

public BeanDescriptor getBeanDescriptor() {
    return new BeanDescriptor(
      Clock.class,
      ClockCustomizer.class);
}

public java.awt.Image getIcon(int iconKind) {
    switch (iconKind) {
      case BeanInfo.ICON_COLOR_16x16:
        return loadImage("Clock16x16Color.gif");
      case BeanInfo.ICON_COLOR_32x32:
        return loadImage("Clock32x32Color.gif");
      case BeanInfo.ICON_MONO_16x16:
        return loadImage("Clock16x16Mono.gif");
      case BeanInfo.ICON_MONO_32x32:
        return loadImage("Clock32x32Mono.gif");
    }
    return null;
}

public BeanInfo[] getAdditionalBeanInfo() {
    Class superclass = Clock.class.getSuperclass();
    try {
      BeanInfo superBeanInfo = Introspector.getBeanInfo(superclass);
      return new BeanInfo[] { superBeanInfo };
    }
    catch(IntrospectionException ex) {
      return null;
    }
}
}
Listing 4: The Clock Customizer

package mybeans;

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

public class ClockCustomizer extends JPanel
                      implements Customizer{
protected Clock theClockBean = null;
private JRadioButton button24 =
      new JRadioButton("24 Hour Mode");
private JRadioButton button12 =
      new JRadioButton("12 Hour Mode");

public ClockCustomizer() {
    JLabel topLabel = new JLabel();
    topLabel.setFont(
      new java.awt.Font("Dialog", 1, 20));
    topLabel.setHorizontalAlignment(
      SwingConstants.CENTER);
    topLabel.setText(
      "This controls the mode of the clock");
    this.setLayout(new BorderLayout());
    button24.addChangeListener(
      new ChangeListener() {
        public void stateChanged(ChangeEvent e) {
          button24Changed(e);}});
    this.add(topLabel, BorderLayout.NORTH);
    JPanel radioPanel = new JPanel();
    this.add(radioPanel, BorderLayout.CENTER);
    radioPanel.add(button24, null);
    radioPanel.add(button12, null);
    ButtonGroup grp = new ButtonGroup();
    grp.add(button12);
    grp.add(button24);
    button12.setSelected(true);
}

public void setObject(Object bean) {
    theClockBean = (Clock)bean;
    button24.setSelected(
      theClockBean.isTwentyFourHourTime());
}

void button24Changed(ChangeEvent e) {
theClockBean.setTwentyFourHourTime(
button24.isSelected());
}
}

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