final/src/GenericSprite.java

/* PlayerBall class defines behaviours for the player-controlled ball  

child of Rectangle because that makes it easy to draw and check for collision

In 2D GUI, basically everything is a rectangle even if it doesn't look like it!
*/ 
import java.awt.*;
import java.awt.event.*;

public class GenericSprite extends Rectangle{

  public double yVelocity;
  public double xVelocity;
  public final double SPEED = 20; //movement speed of ball
  public final double speedCap = 7; //Speed cap of ball
  public static final int BALL_DIAMETER = 20; //size of ball

  public boolean rightPressed = false;
  public boolean leftPressed = false;
  public boolean upPressed= false;
  public boolean downPressed = false;
  public boolean isGrounded = false;
  //constructor creates ball at given location with given dimensions
  public GenericSprite(int x, int y, int height, int width){
    super(x, y, height, width);
  }

  //called from GamePanel when any keyboard input is detected
  //updates the direction of the ball based on user input
  //if the keyboard input isn't any of the options (d, a, w, s), then nothing happens
  public void keyPressed(KeyEvent e){
    if(e.getKeyChar() == 'd'){
      rightPressed = true;
      move();
    }
    if(e.getKeyChar() == 'a'){
      leftPressed = true;
      move();
    }
    if(e.getKeyChar() == 'w'){
      upPressed = true;
      move();
    }
    if(e.getKeyChar() == 's'){
      downPressed = true;
      move();
    }
  }

  //called from GamePanel when any key is released (no longer being pressed down)
  //Makes the ball stop moving in that direction
  public void keyReleased(KeyEvent e){
    if(e.getKeyChar() == 'd'){
      rightPressed = false;
      move();
    }
    if(e.getKeyChar() == 'a'){
      leftPressed = false;
      move();
    }
    if(e.getKeyChar() == 'w'){
      upPressed = false;
      move();
    }
    if(e.getKeyChar() == 's'){
      downPressed = false;
      move();
    }
  }

  //called from GamePanel whenever a mouse click is detected
  //changes the current location of the ball to be wherever the mouse is located on the screen
  public void mousePressed(MouseEvent e){
    //x = e.getX();
	//	y = e.getY();
  }


  public void move(){
    y = y + (int)yVelocity;
    x = x + (int)xVelocity;
    if(rightPressed==true){
      xVelocity+=1;
    }
    if(leftPressed==true){
      xVelocity-=1;
    }
    if(upPressed&isGrounded){
        yVelocity = -10;
    }
    xVelocity*=0.9;
    yVelocity+=0.3;
    capSpeed();
  }

  public void capSpeed(){
    if(xVelocity>speedCap){
      xVelocity = speedCap;
    } else if(xVelocity<-1*speedCap) {
      xVelocity = -1*speedCap;
    }
  }


  //called frequently from the GamePanel class
  //draws the current location of the ball to the screen
  public void draw(Graphics g){
    g.setColor(Color.black);
    g.fillOval(x, y, BALL_DIAMETER, BALL_DIAMETER);
  }
  
}