Create a simple java bean having bound and constrained properties
import java.awt.Graphics;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.io.Serializable;
import javax.swing.JComponent;
/**
* Bean with bound properties.
*/
public class MyBean
extends JComponent
implements Serializable
{
private String title;
private String[] lines = new String[10];
private final PropertyChangeSupport pcs = new PropertyChangeSupport( this );
public String getTitle()
{
return this.title;
}
public void setTitle( String title )
{
String old = this.title;
this.title = title;
this.pcs.firePropertyChange( "title", old, title );
}
public String[] getLines()
{
return this.lines.clone();
}
public String getLines( int index )
{
return this.lines[index];
}
public void setLines( String[] lines )
{
String[] old = this.lines;
this.lines = lines;
this.pcs.firePropertyChange( "lines", old, lines );
}
public void setLines( int index, String line )
{
String old = this.lines[index];
this.lines[index] = line;
this.pcs.fireIndexedPropertyChange( "lines", index, old, lines );
}
public void addPropertyChangeListener( PropertyChangeListener listener )
{
this.pcs.addPropertyChangeListener( listener );
}
public void removePropertyChangeListener( PropertyChangeListener listener )
{
this.pcs.removePropertyChangeListener( listener );
}
protected void paintComponent( Graphics g )
{
g.setColor( getForeground() );
int height = g.getFontMetrics().getHeight();
paintString( g, this.title, height );
if ( this.lines != null )
{
int step = height;
for ( String line : this.lines )
paintString( g, line, height += step );
}
}
private void paintString( Graphics g, String str, int height )
{
if ( str != null )
g.drawString( str, 0, height );
}
}