import processing.core.*; import java.applet.*; import java.awt.*; import java.awt.image.*; import java.awt.event.*; import java.io.*; import java.net.*; import java.text.*; import java.util.*; import java.util.zip.*; import java.util.regex.*; public class Inheritance extends PApplet { /** * Inheritance * * A class can be defined using another class as a foundation. In object-oriented * programming terminology, one class can inherit fi elds and methods from another. * An object that inherits from another is called a subclass, and the object it * inherits from is called a superclass. A subclass extends the superclass. */ SpinSpots spots; SpinArm arm; public void setup() { size(200, 200); smooth(); arm = new SpinArm(width/2, height/2, 0.01f); spots = new SpinSpots(width/2, height/2, -0.02f, 33.0f); } public void draw() { background(204); arm.update(); arm.display(); spots.update(); spots.display(); } class Spin { float x, y, speed; float angle = 0.0f; Spin(float xpos, float ypos, float s) { x = xpos; y = ypos; speed = s; } public void update() { angle += speed; } } class SpinArm extends Spin { SpinArm(float x, float y, float s) { super(x, y, s); } public void display() { strokeWeight(1); stroke(0); pushMatrix(); translate(x, y); angle += speed; rotate(angle); line(0, 0, 66, 0); popMatrix(); } } class SpinSpots extends Spin { float dim; SpinSpots(float x, float y, float s, float d) { super(x, y, s); dim = d; } public void display() { noStroke(); pushMatrix(); translate(x, y); angle += speed; rotate(angle); ellipse(-dim/2, 0, dim, dim); ellipse(dim/2, 0, dim, dim); popMatrix(); } } static public void main(String args[]) { PApplet.main(new String[] { "Inheritance" }); } }