move() method

You're changing the state of the object, but I see no evidence that you're redisplaying anything.

Why have a loop here? It's not going to animate anything, if that's what you're trying to do.From the point of view of an animation, you're changing the state just once, but really inefficientlly.

Are you aware that if both x and acceleration are positive or zero, then this loop will not terminate?

paulcwa at 2007-7-9 0:10:32 >

Okay, I appologize :( Here's the basic outline of what each class does:

Here's the code for the class Block.java (the superclass):

import java.awt.*;

import java.awt.geom.*;

import javax.swing.*;

/*

Block.java contains methods and constructors for the block object.

CONSTRUCTOR

Block(mass, acceleration, static, kinetic);

METHODS

doesMove(force);

doesGoForever(kineitic);

setForce(mass, acceleration);

getForce();

setDistance(mass, acceleration, kinetic);

getDistance();

*/

public class Block extends Rectangle2D.Float

{

//VARIABLES

//Constructor-dependent variables:

private double acceleration, time, kinetic;

protected double sttic;

//Other variables:

private double velocity, mass, a, distance, friction, force;

//CONSTRUCTOR

public Block (double m, double a, double sF, double kF, double t)

{

mass = m;

acceleration = a;

sttic = sF;

kinetic = kF;

time = t;

}

//METHODS

/*Calculate and return the force on the block*/

public double getForce()

{

force = mass * acceleration;

return force;

}

//Using the force exerted on the block, compare it to the force of friction. If it's less, then the block does not move.

public boolean doesMove()

{

if (this.getForce() >= (sttic * mass * 9.8 )) return true;

else return false;

}

//If the kinetic friction is zero, then the block goes forever!!!

public boolean doesGoForever()

{

if (kinetic == 0)

return true;

else

return false;

}

//Calculates and returns the distance the block travels when released

public double getDistance ()

{

distance = ((0.5 * (acceleration - (kinetic * 9.8)) * Math.pow(time, 2)));

return distance;

}

//Calculates and returns the initial velocity upon releasing the block

public double getVelocity ()

{

velocity = (acceleration / time);

return velocity;

}

public double getForceFriction()

{

friction = (9.8 * kinetic);

return friction;

}

public void setDistance (double dist)

{

dist = distance;

}

public void setVelocity (double vel)

{

velocity = vel;

}

public void setForceFriction (double ff)

{

ff = friction;

}

public void move()

{

double n = 10.0;

while (x >= 0)

{

x = (int)((x) + (x*acceleration));

super.setRect(n, 10, 10, 20);

}

}

}

Here's the code for Model.java:

import javax.swing.*;

import java.awt.geom.*;

import java.awt.*;

import TerminalIO.*;

import java.applet.*; //*Whew!*

/*

Interface Model: draws the simulation

1.Draw the rectangle.

2.Draw the line.

3.Redraw the rectangle.

*/

public class Model extends JFrame

{

public static void main (String[] args)

{

KeyboardReader reader = new KeyboardReader();

System.out.print("Mass: ");

double mass = reader.readDouble();

System.out.print("Accelleration due to pushing the block: ");

double acceleration = reader.readDouble();

System.out.print("Coefficient of Static Friction: ");

double stic = reader.readDouble();

System.out.print("Coefficient of Kinetic Friction: " );

double kinetic = reader.readDouble();

System.out.print("Time the block is accellerated: ");

double time = reader.readDouble();

Block b = new Block(mass, acceleration, stic, kinetic, time);

String str;

//Boolean expression to check if there is friction

if ((b.doesMove() == false) ||

(b.getDistance() <= 0))

{

str = "The block did not move.\n";

}

else

str = "The block moved with a velocity of " + b.getVelocity() + " m/s \n" +

"for a distance of " + b.getDistance() + " m.";

System.out.println("\nRESULTS:\n" +

"You applied a force of " + b.getForce() +

" Newtons.\n" + str);

Model m = new Model();

b.move();

}

public Model()

{

this.setSize(500, 100);

this.setTitle("THE SIMULATION");

this.setResizable(false);

this.add(new Sim(), BorderLayout.CENTER);

this.setVisible(true);

}

}

Finally, here's the code for Sim.java:

import java.awt.*;

import java.awt.geom.*;

import javax.swing.*;

public class Sim extends JComponent

{

//Parameters for rect

public float yr = 10;//y-value

public float h = 10;//height

public float w = 20;//width

//Parameters for ln

public float xln1 = 0; //x1-value

public float xln2 = 500;//x2-value

public float yln1 = 20;//y1-value

public float yln2 = 20;//y2-value

public void paint(Graphics g)

{

Graphics2D g2 = (Graphics2D)g;

g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,

RenderingHints.VALUE_ANTIALIAS_ON);

Shape rect = new Rectangle2D.Float(10, yr, w, h);

Shape ln = new Line2D.Float(xln1, yln1, xln2, yln2);

g2.setPaint(Color.BLACK);

g2.draw(rect);

g2.setPaint(Color.RED);

g2.draw(ln);

}

public int toInt(float f)

{

String f1 = String.valueOf(f);

return Integer.valueOf(f1);

}

}

The reason why I wasn't sure if I should post all this was I didn't want to do something bad like maybe bog down the server, create a really long thread etc.

In the code, you may not be familiar with KeyboardReader, but it's a little like the Scanner class. I hope this was helpful, and I can explain any reasoning questions you have. Thanks :)

t1m3ra at 2007-7-9 0:10:32 >

Oh, yeah, and I compile it as a project (on my Linux machine "javac <dir>" and on the Windows machine I just use JCreator to compile it as a project). If you're wondering how it's implemented, in Model.java, the Model adds the Sim. I tried to do it in the same class Model, originally, but it didn't work out.

t1m3ra at 2007-7-9 0:10:33 >