// Fig. 12.16: Metrics.java
// Displaying font metrics.
import javax.swing.JFrame;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import javax.swing.JPanel;

public class Metrics 
{
   // execute application
   public static void main( String[] args )
   {
      // create frame for MetricsJPanel
      JFrame frame = new JFrame( "Demonstrating FontMetrics" );
      frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );

      MetricsJPanel metricsJPanel = new MetricsJPanel(); 
      frame.add( metricsJPanel ); // add metricsJPanel to frame
      frame.setSize( 510, 240 ); // set frame size
      frame.setVisible( true ); // display frame
   } // end main
} // end class Metrics


class MetricsJPanel extends JPanel 
{
   // display font metrics
   public void paintComponent( Graphics g )
   {
      super.paintComponent( g ); // call superclass's paintComponent

      g.setFont( new Font( "SansSerif", Font.BOLD, 12 ) );
      FontMetrics metrics = g.getFontMetrics();
      g.drawString( "Current font: " + g.getFont(), 10, 30 );
      g.drawString( "Ascent: " + metrics.getAscent(), 10, 45 );
      g.drawString( "Descent: " + metrics.getDescent(), 10, 60 );
      g.drawString( "Height: " + metrics.getHeight(), 10, 75 );
      g.drawString( "Leading: " + metrics.getLeading(), 10, 90 );

      Font font = new Font( "Serif", Font.ITALIC, 14 );
      metrics = g.getFontMetrics( font );
      g.setFont( font );
      g.drawString( "Current font: " + font, 10, 120 );
      g.drawString( "Ascent: " + metrics.getAscent(), 10, 135 );
      g.drawString( "Descent: " + metrics.getDescent(), 10, 150 );
      g.drawString( "Height: " + metrics.getHeight(), 10, 165 );
      g.drawString( "Leading: " + metrics.getLeading(), 10, 180 );
   } // end method paintComponent
} // end class MetricsJPanel

Results