import java.applet.*;
import java.awt.*;
import java.lang.Integer;

public class DoArray extends Applet
{
//for ease in finding, set the constants for this specific program

	final int FONTSIZE = 12; //size of font to indicate spacing
	final String FONTTYPE = "TimesRoman";
	final int ALIGN = 20;    //aligning values in from edge	
	final int OFFSET = FONTSIZE + 6;  //sets offset of lines
	final int END = 20;
	final int YMAX = 400;
	final int BASE = 100;

//set nonconstant values of program

	int BASE1 = 110;    //number indicating top of example
	String part1[] =
        {"       DO 10 I = 1, 5",
	 "           ARRAY[I] = I+1",
	 " 10    CONTINUE"};

	int BASE2 = BASE1 + OFFSET*3;    
	String part2[] =
	{"       ARRAY[1] = 10",
	 "       ARRAY[4] = 3"};

	int BASE3 = BASE1 + OFFSET*5;
	String part3[] =
	{"       DO 20 I = 1, 5",
	 "           IF (MOD(ARRAY[I],2).EQ.0)",
	 "              ARRAY[I] = ARRAY[I] / 2",
	 "           ENDIF",
	 " 20    CONTINUE"};

	String msg, mod, i = "undefined";
	String a[] = 
	{"undefined",
	 "undefined",
	 "undefined",
	 "undefined",
	 "undefined"};

	Font theFont = new Font(FONTTYPE, Font.BOLD, FONTSIZE);

	int count;                //what step we're on
	int firstclick;           //tells if mouse has been clicked
	int move;		  //how far has image moved?

	int pointat;             //current position of pointer
	Image pointer;           //the image used as a pointer

/* methods:
	init()
	mousedown()
	restart()
	paint()
	moveout()
	movein()

*/ 

//**************************************************

    public void init()
    {

	pointer = getImage(getCodeBase(), "images/arrow.gif");

	msg = "";
	mod = "";
	count=0;
	firstclick=0;
	pointat = BASE1;
	move=0;

	setBackground(Color.white);
	nextstep();	//this takes care of step 0!
   }

//*********************************************************

    public boolean mouseDown(Event e, int x, int y)
    {
	count++;
	nextstep();	//change variables for each click
	repaint();	//see all new in
	if (firstclick == 0)
	  firstclick=1;

	return true;       //has to be boolean
    }

//**********************************************************


    public void moveout() 
    {
	for (move = 0; move < END; move++)  //go through loop END times
	{
	    BASE1 = BASE1 - 1;
	    BASE3 = BASE3 + 1;
	    repaint();               //repaint each time for animation
	}
    }

//**********************************************************

    public void movein()
    {
	for (move = END; move>0; move--)
	{
	    BASE1 = BASE1 + 1;
	    BASE3 = BASE3 - 1;
	    repaint();
	}
    }
//*********************************************************
    public void restart()
    {
	count = 0;
	firstclick = 0;	
	pointat = BASE1;      //move pointer back to start
	move = 0;
	msg="";
	mod="";
	i="undefined";
	for (int l=0; l<5; l++)
	    a[l] = "undefined";
	repaint();
    }

//*************************************************************    
    public void next()
    {
	pointat +=OFFSET;
    }

//*************************************************************

    public void nextstep()
    {
	switch(count)
	{
	    case 0:
		msg="Click anywhere in the applet to begin";
		break;
	    case 1:                       //animation occurs
		msg="This program can be separated into 3 distinct parts";
		break;
	    case 2:                      //array statement
		moveout();
		pointat = pointat - END;
		next();
		msg = "The first spot in ARRAY is set to I+1";
		i = "1";
		break;
	    case 3:                      // continue
		next();
		msg = "";
		a[0] = "2";
		break;
	    case 4: case 7: case 10: case 13:    //for statement
		pointat = BASE1;
		msg = "";
		break;
	    case 5: 
		next();				//array
		msg = "The second spot in ARRAY is filled with I+1";
		i = "2";
		break;
	    case 6:				//for
		next();
		msg = "";
		a[1] = "3";
		break;
	    case 8: 
		next();
		msg = "The third spot in ARRAY is filled";
		i = "3";
		break;
	    case 9:
		next();
		msg = "";
		a[2] = "4";
		break;
	    case 11: 
		next();
		msg = "The fourth spot is filled";
		i = "4";
		break;
	    case 12:
		next();
		msg = "";
		a[3] = "5";
		break;
	    case 14: 
		next();
		msg = "The fifth spot is filled";
		i = "5";
		break;
	    case 15:
		next();
		msg = "";
		a[4] = "6";
		break;
	    case 16:
		pointat = BASE1;
		msg = "Can't go into loop";
		break;

	    case 17:				//second part
		pointat = BASE2;
		i = "6";
		msg = "set the first value directly to 10";
		break;
	    case 18:
		next();
		a[0] = "10";
		msg = "set the fourth value to 3";
		break;

	    case 19:				//third part, for
		pointat = BASE3;
		a[3] = "3";
		msg = "another loop!!";
		break;
	    case 20:				//if
		next();
		msg = "ARRAY[I] = ARRAY[1] = 10";
		mod = "MOD(10, 2) equals 0";
		i = "1";
		break;
	    case 21: case 30: case 39:			//in mod, set
		next();
		msg = "IF statement was true, so proceed inside.";
		mod = "";
		break;		
	    case 22:					//endif
		next();
		msg = "";
		a[0] = "5";
		break;
	    case 23: case 27: case 32: case 36: case 41://continue
		next();	
		msg = "";
		break;
	    case 24: case 28: case 33:	case 37:	//for
		pointat = BASE3;
		msg = "procede to the next loop";
		break;
	    case 25:					//if
		next();
		msg = "ARRAY[I] = ARRAY[2] = 3";
		mod = "MOD(3,2) equals 1";
		i = "2";
		break;
	    case 26: case 35:				//endif, no set
		next(); next();
		msg = "IF statement was NOT true, skip the inside of the IF statement";
		mod = "";
		break;
	    case 29:					//if statement
		next();
		msg = "ARRAY[3] = 4";
		mod = "MOD(4,2) = 0";
		i = "3";
		break;
	    case 31:					//endif after set
		next();
		msg = "";
		a[2] = "2";
		break;
	    case 34:					//if statement
		next();
		msg = "ARRAY[I] = 3";
		mod = "MOD(3,2) = 1";
		i = "4";
		break;
	    case 38:
		next();
		msg = "ARRAY[I] = 6";
		mod = "MOD(6, 2) = 0";
		i = "5";
		break;
	    case 40:					//endif after set
		next();
		msg = "";
		a[4] = "3";
		break;
	    case 42:
		pointat = BASE3;
		msg = "adding 1 to I puts it over max.  Skip loop";
		break;
	    case 43:
		movein();
		pointat=pointat-END;
		next(); next(); next(); next();
		msg = "DONE! Click again to restart.";
		i = "6";
		break;
	    case 44:
		restart();
		break;
	}
    }

//*************************************************************
    public void paint(Graphics g)
    {
	g.setFont (theFont);                    //set 3 parts of program
	for (int l=0; l<3; l++)
		g.drawString (part1[l], ALIGN/2, BASE1+l*OFFSET);
	for (int l=0; l<2; l++) 
		g.drawString (part2[l], ALIGN/2, BASE2+l*OFFSET);
	for (int l=0; l<5; l++)
		g.drawString (part3[l], ALIGN/2, BASE3+l*OFFSET);

	g.drawImage(pointer, 230, pointat-OFFSET-6, this);
	g.drawString("I = ", 300, BASE+OFFSET);
	g.drawString("ARRAY[1] = ", 300, BASE+2*OFFSET);
	g.drawString("ARRAY[2] = ", 300, BASE+3*OFFSET);
	g.drawString("ARRAY[3] = ", 300, BASE+4*OFFSET);
	g.drawString("ARRAY[4] = ", 300, BASE+5*OFFSET);
	g.drawString("ARRAY[5] = ", 300, BASE+6*OFFSET);
	if (msg != "")
		g.drawString(msg, ALIGN/2, YMAX-50);

	g.setColor(Color.blue);
	g.drawString(i, 320, BASE+OFFSET);
	g.drawString(a[0], 375, BASE+2*OFFSET);
	g.drawString(a[1], 375, BASE+3*OFFSET);
	g.drawString(a[2], 375, BASE+4*OFFSET);
	g.drawString(a[3], 375, BASE+5*OFFSET);
	g.drawString(a[4], 375, BASE+6*OFFSET);

	if (mod != "")
		g.drawString(mod, 290, BASE+7*OFFSET+5);

	g.setColor(Color.black);
    }
}