// same as BouncingBall but with an overloaded move method to move based on parameters received of a new dx and dy value, to be controlled by keyboard

import java.awt.*;				// for Color
import java.util.*;				// for Random

public class BouncingBall2		// represents a Ball to be drawn on a Graphics object that will bounce around as it moves
{
	private int x, y, dx, dy, borderx, bordery;		// x,y coordinate of ball, dx,dy is the motion of the ball, borderx,bordery is used to rebound ball if it hits right or lower edge
	private Color c;								// Color of ball, selected randomly
	private Random generator;						// used to determine initial motion and rebound motion
	private int size;								// the size of the ball (this could be assigned randomly, passed in via a constructor or hard-coded, we will hard-code in this example)
	
	public BouncingBall2(int bx, int by, Random g)	// initialize borders and Random number generator given parameters 
	{
		size=10;
		borderx=bx;									// set borders
		bordery=by;
		generator=g;								// set Random number generator
		x=generator.nextInt(bx-10)+10;				// establish random x,y location at least 5 in from any edge
		y=generator.nextInt(by-10)+10;
		do {										// get motion but do not let this ball have an initial motion of 0 in both directions
			dx=generator.nextInt(9)-4;				// dx is how far to move x each time the Timer sends an ActionEvent
			dy=generator.nextInt(9)-4;				// dy is how far to move y each time the Timer sends an ActionEvent
		}while(dx==0&&dy==0);						// if both are 0, the ball will not move!
		int red=generator.nextInt(200);				// get a random color, but only use rgb values between 0 and 199 so that the ball does not appear to close to white or it will
		int green=generator.nextInt(200);				// not be visible
		int blue=generator.nextInt(200);
		c=new Color(red,green,blue);				// set the Color given the random r,g,b values
	}
	
	public void move(int newdx, int newdy)
	{
		x+=newdx;
		y+=newdy;
		if(x>borderx-5)								// if the movement puts the ball too close to the right border
		{											//    then move it back and change its horizontal motion to the opposite direction
			x-=dx;
			dx*=-1;
		}
		else if(x<5)								// if the movement puts the ball too close to the left border
		{											//    then move it back and change its horizontal motion to the opposite direction
			x-=dx;
			dx*=-1;
		}
		if(y>bordery-5)								// do the same for the bottom border, changing the vertical motion
		{
			y-=dy;
			dy*=-1;
		}
		else if(y<5)								// and the same for the top border
		{
			y-=dy;
			dy*=-1;
		}		
	}
	
	public void move()								// moves the ball and tests to see if in moving it, it hits (comes close to) a border
	{
		x+=dx;										// move the ball a small amount based on the values of dx and dy
		y+=dy;
		if(x>borderx-5)								// if the movement puts the ball too close to the right border
		{											//    then move it back and change its horizontal motion to the opposite direction
			x-=dx;
			dx*=-1;
		}
		else if(x<5)								// if the movement puts the ball too close to the left border
		{											//    then move it back and change its horizontal motion to the opposite direction
			x-=dx;
			dx*=-1;
		}
		if(y>bordery-5)								// do the same for the bottom border, changing the vertical motion
		{
			y-=dy;
			dy*=-1;
		}
		else if(y<5)								// and the same for the top border
		{
			y-=dy;
			dy*=-1;
		}
	}
	
	public void draw(Graphics g)					// draw the BouncingBall onto the Graphics object
	{
		g.setColor(c);
		g.fillOval(x,y,size,size);
	}
	
	// the following methods are needed to support the change from the BouncingBalls program to the BouncingBallsWithRebound program
	
	public int getX() {return x;}					// accessors needed for the collide method
	public int getY() {return y;}
	
	public boolean collide(BouncingBall b)			// compare this BouncingBall and another BouncingBall b to see if they have collided
	{
		int bx=b.getX();							// get b's x,y coordinates
		int by=b.getY();
		if(x>=bx&&x<=bx+size&&y>=by&&y<=by+size) 	// see if they touch (this BouncingBall's x,y coordinate lies somewhere within b
			return true; 							// and if so, return true
		else return false;							// otherwise return false
	}
	
	public void rebound()							// when told to rebound, this BouncingBall generates a new dx,dy value ensuring that both are not 0
	{
		do {										// we could have done a normal rebound by doing dx*=-1;dy*=-1; but this gives a more interesting result
			dx=generator.nextInt(9)-4;
			dy=generator.nextInt(9)-4;
		}while(dx==0&&dy==0);		
	}
}