/**
 * Class for creating a graphic display
 *
 * @author T. K. Rogers
 * @version 1-22-05
 */
import java.awt.* ;
import javax.swing.* ;
import java.util.* ;
class GraphicsDisplay extends JPanel {
    private static int    y_velocity ,     // Dot's y component of velocity
                                x_velocity ,     // Dot's x component of velocity
                                x_coordinate , // Dot's x coordinate
                                y_coordinate , // Dot's y coordinate
                                y_velocity1 ,
                                x_velocity1 ,
                                x_coordinate1 ,
                                y_coordinate1 ;                           
                       
    public static boolean stop = true ;          // A value of true stops the dot's motion
    private static long      delay = 3000000 ; // Slows down the dot's motion 
    //Constructer///////////////////////////////////////////////////////////////
    public GraphicsDisplay ( ) {
        y_velocity =  2 ;
        x_velocity =  3 ;
        x_coordinate = 80 ;
        y_coordinate = 30 ;
        y_velocity1 = 5 ;
        x_velocity1 = 6 ;
        x_coordinate1 = 120 ;
        y_coordinate1 = 120 ;
    }
    //////////////////////////////////////////////////////////////////////////////
    public void paint ( Graphics g2 ) {
         int a ; // Loop counter
       
         // Sets and fills background color in applet, Color ( red, green, blue ).
         // Values range from 0 to 255
         g2.setColor(new Color ( 240, 240, 230 ) ) ;
         g2.fillRect (0, 0, getSize ( ).width, getSize ( ).height ) ;
       
         // Draws a retangular boundary
         g2.setColor ( new Color ( 0, 0, 0 ) ) ;
         g2.drawRect ( 30, 30, getSize ( ).width-60, getSize ( ).height-60 ) ;
      
         // Sets color for the dot and draws it.  
         g2.setColor(new Color ( 240, 0, 0 ) ) ;
         g2.fillOval ( x_coordinate1, y_coordinate, 6, 6 ) ;
        
         g2.setColor ( new Color ( 1,5,155 ) ) ;
         g2.fillOval ( x_coordinate1 + 1, y_coordinate1 - 1,6, 6 ) ;
             
         if ( GuiMenu.option.isSelected ( ) )  {
                 setDelay ( "slow" ) ;
           } else {
                    GraphicsDisplay.setDelay ( "fast" ) ;
                }
        
         // code for making the dot bounce back and forth.
         if ( !stop ) {
            for ( a=0; a<delay; a++ ) ; //This code slows down the loop
            moveDot ( ) ;
         }    
           
         // Sets up Legend.
         g2.setColor ( new Color ( 0, 0, 0 ) ) ;
         g2.drawString ( "Bouncing Dot", getSize ( ).width/2-36, 25 ) ;
        
         repaint ( ) ;
    }
   
    ///////////////////////////////////////////////////////////////////////////
    /**
     * Moves the dot.
     *
     * @param  y none
     * @return     none
     */
    // The following moveDot ( ) code works but is inefficient. Why?
    public void moveDot ( ) {
        // Code for advancing the dot in each time increment.
        x_coordinate += x_velocity ;
        y_coordinate += y_velocity ;
        x_coordinate1 += x_velocity1 ;
        y_coordinate1 += y_velocity1 ;
           
        // Code for making the dot bounce when it hits the wall. The dot
        // has an elastic collision, hence kinetic energy is conserved.
        if ( x_coordinate >= ( getSize ( ).width-30 ) ) {
            x_coordinate -= x_coordinate - ( getSize ( ).width - 30 ) ;
            x_velocity *= -1; // When hitting a vertical wall the x-velocity reverses
        }
       
        if ( x_coordinate <= 30 ) {
            x_coordinate -= x_coordinate - 30 ;
            x_velocity *= -1;
        }
       
        if ( x_coordinate1 >= ( getSize ( ).width - 30 ) ) {
            x_coordinate1 -= x_coordinate1 - ( getSize ( ).width - 30 ) ;
            x_velocity1 *= -1;
        }
       
        if ( x_coordinate1 <= 30 ) {
            x_coordinate1 -= x_coordinate1 - 30 ;
            x_velocity1 *= -1;
        }
       
        if ( y_coordinate >= ( getSize ( ).height - 30 ) ) {
             y_coordinate -= y_coordinate - ( getSize ( ).height - 30 ) ;
             y_velocity *= -1;
        }
       
        if ( y_coordinate <= 30 ) {
             y_coordinate -= y_coordinate - 30 ;
             y_velocity *= -1 ;
        }
       
        if ( y_coordinate1 >= ( getSize ( ).height - 30 ) ) {
             y_coordinate1 -= y_coordinate1 - (getSize().height-30);
             y_velocity1 *= -1 ;
        }
       
        if ( y_coordinate1 <= 30 ) {
             y_coordinate1 -= y_coordinate1 - 30 ;
             y_velocity1 *= -1;
        }
    }
    ////////////////////////////////////////////////////////////////////////
    public static void stopDot ( ) {
        // Stops the dot
        stop = true ;
    }
    ////////////////////////////////////////////////////////////////////////
    public static void startDot ( ) {
        // Starts the dot
        stop = false ;
    }
   ////////////////////////////////////////////////////////////////////////
    public static void resetDot ( ) {
        // Resets the dot
        stopDot ( ) ;
        y_velocity = 2 ;
        x_velocity = 3 ;
        x_coordinate = 80 ;
        y_coordinate = 30 ;
        y_velocity1 = 5 ;
        x_velocity1 = 6 ;
        x_coordinate1 = 90 ;
        y_coordinate1 = 50 ;
    }  
    ////////////////////////////////////////////////////////////////////////
    public static void setDelay ( String setting ) {
        if ( setting == "slow" ) {
            delay = 90000000 ;
        } else {
                delay = 3000000 ;
        }
    }
}