Oscillator.java

import java.util.*;
import java.awt.*;

public class Oscillator extends PhysicsElement implements Simulateable, SpringAttachable {
	private static int id=0;  // Oscillator's identification number
	private double center;     // oscillator's center
	private double amplitude;     // oscillation's amplitude
	private double w;     // oscillator's frequency [rad]
	private double time;
	private double pos_t; 
	private double pos_tPlusDelta; 
	private OscillatorView view;  // Oscillator view of Model-View-Controller design pattern
	private ArrayList<Elastic> springs;
	
	private Oscillator(){   // nobody can create a block without state
		this(1.0,0.3,0.5);
	}
	public Oscillator(double c, double a, double f){
		super(id++);
		pos_t = pos_tPlusDelta = center = c;
		amplitude = a;
		w = 2*Math.PI*f;
		time=0;
		view = new OscillatorView(this);
		springs = new ArrayList<Elastic>();
	}
	public double getPosition() {
		return pos_t;
	}
	public void computeNextState(double delta_t, MyWorld world) {
		time+=delta_t;
		pos_tPlusDelta = center + amplitude*Math.sin(w*time);
	}
	public void updateState(){
		pos_t = pos_tPlusDelta;
	}
	 public void updateView (Graphics2D g) {   
		view.updateView(g);  // update this Oscillator's view in Model-View-Controller design pattern     
	}
	public boolean contains(double x, double y) {
		return view.contains(x,y);
	}
	public void setSelected(){
		view.setSelected();
	}
	public void setReleased(){
		view.setReleased();
	}
	public void dragTo(double x){  // pos_t = center +dx
		center+= (x-pos_t);         // x = new_center + dx
		pos_t=x;                    // new_center= x - dx = x - (pos_t-center) 
	}                              // new_center=center +x-pos_t 

	public String getDescription() {
		return "Oscillator_" + getId()+":x";
	}
	public String getState() {
		return getPosition()+"";
	}
	public void attachSpring(Elastic s){
		springs.add(s);
	}
	public void detachSpring(Elastic s){
		springs.remove(s);
	}

	public double getMass() {
		return 0.0;
	}
	
	public boolean collide(SpringAttachable b) {
		return false;
	}

	public double getRadius() {
		return 0.1;
	}

	public double getSpeed() {
		return 0.0;
	}
}