Aug 26

draws a circle wherever mouse was pressed

CircleListener.java A subclass of MouseAdapter that draws a circle wherever mouse was pressed. Illustrates first approach to event-handling with listeners: attaching a separate listener
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import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

/** The listener used by CircleDrawer1. Note call
 *  to getSource to obtain reference to the applet.
 *  


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public class CircleListener extends MouseAdapter {
  private int radius = 25;

  public void mousePressed(MouseEvent event) {
    Applet app = (Applet)event.getSource();
    Graphics g = app.getGraphics();
    g.fillOval(event.getX()-radius,
               event.getY()-radius,
               2*radius,
               2*radius);
  }
}