Writing Classes - Java Software Solutions: Foundations of Program Design - page 188

The paintComponent method in the SplatPanel class draws the panel by call-
ing the draw method of each circle. Essentially, the SplatPanel class asks each
circle to draw itself.
The Circle class is shown in Listing 4.9. It defines instance data to store the
size of the circle, its ( x , y ) location, and its color. These values are set using the
constructor, and the class contains all the appropriate accessor and mutator meth-
ods. The draw method of the Circle class simply draws the circle based on the
values of its instance data (its current state).
LISTING 4.9
//********************************************************************
// Circle.java Author: Lewis/Loftus
//
// Represents a circle with a particular position, size, and color.
//********************************************************************
import java.awt.*;
public class Circle
{
private int diameter, x, y;
private Color color;
//-----------------------------------------------------------------
// Constructor: Sets up this circle with the specified values.
//-----------------------------------------------------------------
public Circle ( int size, Color shade, int upperX, int upperY)
{
diameter = size;
color = shade;
x = upperX;
y = upperY;
}
//-----------------------------------------------------------------
// Draws this circle in the specified graphics context.
//-----------------------------------------------------------------
public void draw (Graphics page)
{
page.setColor (color);
page.fillOval (x, y, diameter, diameter);
}