В классе Ball должен быть реализован метод draw(Canvas canvas) в соответствии с условием задачи.
вроде и код элементарный
//Ball.java
@Override
public void draw(Canvas canvas){
canvas.setPoint(x,y,'0');
}package com.javarush.task.task24.task2413;
public class Ball extends BaseObject {
private double speed;
private double direction;
private double dx;
private double dy;
private boolean isFrozen;
public Ball(double x,double y,double speed,double direction) {
super(x,y,1.0);
isFrozen = true;
this.speed = speed;
this.direction = direction;
}
public double getSpeed() {
return speed;
}
public double getDirection() {
return direction;
}
public double getDx() {
return dx;
}
public double getDy() {
return dy;
}
@Override
public void draw(Canvas canvas){
canvas.setPoint(x,y,'0');
}
public void start(){
isFrozen = false;
}
public void move(){
if(isFrozen)
return;
x+=dx;
y+=dy;
}
}