test.janw.nl

Class Ball

java.lang.Object

test.janw.nl.Ball

public class Ball
extends java.lang.Object

This class was written as a part of creating a squash program for the Open.HPI.de course "Java Capstone series 1." This class is responsible for the ball; it has attributes for x- and y-position, the speed and for convenience its speeds along the x-axis and y-axis (using sin/cos of the angle and the speed) This class has methods for creating, moving and drawing of the ball It has private methods for setting the speed, and bouncing against the walls, ceiling or the bat. What I have doubts about, is the fact that the ball is aware of the canvas (subclass of PApplet of the processing framework). I would like it if the ball was loosely coupled, without a hard reference. ToDo: For now, if you miss the ball there will only be a System.out.println()-message. That should be made nicer. My current idea is to raise either an exception; or to raise an event, so I will learn something about catching events. Furthermore, I think it would be nice to refactor the whole solution to a model-view-controller. However, as the deadline of the course approaches, and the rest of the team does not seem to be very active, this will most likely be the solution to be submitted.

Field Summary

Fields

Modifier and Type	Field and Description
private int	angle
private PlayField	playField
private float	radius
private double	speed
private float	x_as
private double	x_speed
private float	y_as
private double	y_speed

Constructor Summary

Constructors

Constructor and Description
Ball(PlayField playField, float start_x, float start_y, float radius, double speed, int angle) constructor The constructor takes the canvas as input, so it knows where it lives (and can ask the size of its canvas (eg. ceiling and borders) Furthermore it gets its starting position (start_x, start_y) and its starting speed and starting angle).

Method Summary

Modifier and Type	Method and Description
private void	bounceHorizontal() Bounce on a horizontal boundary (eg. ceiling or bat/paddle)
private void	bounceVertical() Bounce on a vertical boundary (eg. one of the walls)
void	draw() Paint the ball on the canvas.
void	move() Method move: This method moves the ball.
private void	setSpeeds(double newSpeed) Set the speed; total speed and the relative speed on the axis of the canvas; using the sin and cos of the angle.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

angle

private int angle

playField

private PlayField playField

radius

private float radius

speed

private double speed

x_as

private float x_as

x_speed

private double x_speed

y_as

private float y_as

y_speed

private double y_speed

Constructor Detail

Ball

public Ball(PlayField playField,
            float start_x,
            float start_y,
            float radius,
            double speed,
            int angle)

constructor The constructor takes the canvas as input, so it knows where it lives (and can ask the size of its canvas (eg. ceiling and borders) Furthermore it gets its starting position (start_x, start_y) and its starting speed and starting angle). Finally it is being told its size in radius.

Method Detail

bounceHorizontal

private void bounceHorizontal()

Bounce on a horizontal boundary (eg. ceiling or bat/paddle)

bounceVertical

private void bounceVertical()

Bounce on a vertical boundary (eg. one of the walls)

draw

public void draw()

Paint the ball on the canvas.

move

public void move()

Method move: This method moves the ball. Furthermore, it checks if the ball hits the ceiling, one of the walls, or the bat/paddle. If it is at the same height as the bat/paddle, but doesn't hit it for now it generates a message that you lose, currently as a System.out.println()-message. Furthermore, as a temporarily solution, the ground reacts as a boundary as well, so the ball will never leave the canvas.

setSpeeds

private void setSpeeds(double newSpeed)

Set the speed; total speed and the relative speed on the axis of the canvas; using the sin and cos of the angle.