import java.applet.*;
import java.awt.*;
//import java.awt.event.*;
import java.util.*;
import java.math.*;
import java.text.*;
import java.awt.event.*;

public class RollerPanel extends Panel implements MouseListener {
  private int stage = 1;
  private double s = 0.75; //scale for arrowhead
  private Font f1 = new Font("Helvetica", Font.BOLD, 18);
  private Font f2 = new Font("Arial", Font.PLAIN, 14);
  private Font f3 = new Font("Helvetica", Font.PLAIN, 11);
  private String Header = "RollerFrame Exercise";
  private String IntroText1 = "Find the force required to just start the lawn roller rolling over the step of height h.";
  private String IntroText2 = "Express your results in non-dimensional terms, using R and W, the radius and weight";
  private String IntroText3 = "of the roller, as reference quanatities.  Sketch how the force varies with h/R.";
  private String xVal[] = {" 0", "0.1", "0.2", "0.3", "0.4", "0.5",
                           "0.6", "0.7", "0.8", "0.9", " 1"};
  private String yVal[] = {"0", "1", "2", "3", "4", "5", "6",
                           "7", "8", "9", "10"};
  DecimalFormat df = new DecimalFormat("###0.000");

  Image hr, fw;

  // stage explanation -
  // stage 0 = introduction -> not anymore
  // stage 1 = click on solution
  // stage 2 = clicked on dot successfully
  // stage 3 = clicked another step height


  public RollerPanel() {

		addMouseListener(this);

    this.setBackground(Color.white);

    setSize(600,500); //50 pixels for bottom panel
    setVisible(true);
  }

  public void paint(Graphics g) {
    Dimension d = this.size();
    g.setColor(Color.black);
//    g.drawRect(0,0,d.width-1,d.height-1);
    g.setFont(f2);

    switch (stage) {
      case 0: {
       //intro and header
       g.setFont(f1);
       g.drawString(Header, d.width/2-60, d.height/6-30);
       g.setFont(f2);
       g.drawString(IntroText1, 30,100);
       g.drawString(IntroText2, 30,120);
       g.drawString(IntroText3, 30,140);

       //roller and step
       g.drawOval(200,200,100,100);
       g.fillOval(245,245,10,10);
       g.fillOval(345,245,10,10);
       g.drawRect(244,244,112,12);
       g.drawLine(355,250,455,250);
       g.fillRect(150,300,140,30);
       g.fillRect(290,280,160,50);

       //solution box
       g.drawRect(500,400,70,20);
       g.setFont(f2);
       g.drawString("Solution", 510, 415);
      }
      break;

      case 1: {
       g.setColor(Color.black);
       g.drawOval(50,50,100,100);
       g.drawLine(50,151,400,151);
       g.setColor(Color.red);
       g.fillOval(142,130,5,5);
       g.setColor(Color.black);
       g.drawString("Click to make the step height... try the dot",100,300);
      }
      break;

      case 2: {
       //code for main part
       g.setFont(f2);
       g.setColor(Color.white);
       g.drawString("Click to make the step height... try the dot", 100,300); //erase instructions

          g.drawImage(hr,325, 267,this);
          g.drawImage(fw,325, 292,this);

         g.setColor(Color.black);
         g.setFont(f2);
         g.drawString("Click to try a new step height", 210,50);

       //draw vectors
       g.setColor(Color.black);
       g.drawLine(100,100,200,100);
       VHead2 head = new VHead2(s,100,100,200,100); //use VHead2 class to get arrow head
       g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead
       g.drawLine(100,100,100,200);
       head = new VHead2(s,100,100,100,200); //use VHead2 class to get arrow head
       g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead
       g.drawLine(200,200,100,100);
       head = new VHead2(s,200,200,100,100); //use VHead2 class to get arrow head
       g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead

       g.drawLine(100,100,65,135); //for R
       head = new VHead2(s,100,100,65,135);
       g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead

       //label roller
       g.drawString("R", 60, 125);
       g.drawString("W", 95,215);
       g.drawString("F", 190, 95);
       g.drawString("N", 200, 215);


       //draw roller
       g.setColor(Color.black);
       g.drawOval(50,50,100,100);
       g.drawLine(50,151,400,151);

       //draw graph
       g.drawLine(100,230,100,430);
       g.drawLine(100,430,300,430);
       g.setColor(Color.orange);
       //draw x grid
       for (int i=120; i<=300; i=i+20) g.drawLine(i,230,i,435);
       //draw y grid
       for (int i=230; i<=410; i=i+20) g.drawLine(95,i,300,i);
       //label the graph
       g.setColor(Color.black);
       g.setFont(f3);
       g.drawString("F/W", 50 ,310);
       g.drawString("h/R", 310,435);
       g.setFont(f3);
       int j = 0;
       for (int i=100; i<=300; i=i+20) {
          g.drawString(xVal[j], i-5, 445);
          j++;
       }  j = 10;
       for (int i=240; i<=440; i=i+20) {
          g.drawString(yVal[j], 85,i-3);
          j--;
       }

      }
    }
  }


		//MouseListener functions
		public void mouseReleased(MouseEvent e) {}
		public void mouseClicked(MouseEvent e)  {}
		public void mouseEntered(MouseEvent e)  {}
		public void mouseExited(MouseEvent e)   {}
		public void mousePressed(MouseEvent e) {

		int x = e.getX();
		int y = e.getY();

     switch (stage) {
      case 0: {
       if ( (x>=500) & (x<=570) & (y>400) & (y<420) )  {
         stage = 1;
         Graphics g = getGraphics();
         g.setColor(Color.red);
         g.drawRect(500,400,70,20);
         g.setFont(f2);
         g.drawString("Solution", 510, 415);

       //erase screen
       g.setColor(Color.white);
       g.fillRect(0,0,1000,1000);

       g.setColor(Color.black);
       g.drawOval(50,50,100,100);
       g.drawLine(50,151,400,151);
       g.setColor(Color.red);
       g.fillOval(142,130,5,5);
       g.setColor(Color.black);
       g.drawString("Click to make the step height... try the dot",100,300);

         //included next four lines to prevent screen from repainting
          g.drawImage(hr,325, 267,this);
          g.drawImage(fw,325, 292,this);

       }
      }
      break;

      case 1: {
       Graphics g = getGraphics();
       g.setColor(Color.black);
       g.drawOval(50,50,100,100);
       g.drawLine(50,151,400,151);
       g.setColor(Color.red);
       g.fillOval(142,130,5,5);
       g.setColor(Color.black);
       g.setFont(f2);
       g.drawString("Click to make the step height... try the dot", 100,300);
       if ((Math.sqrt( (x-144)*(x-144)+(y-132)*(y-132))<6 )) { //see if dot clicked with tolerance of 2 pixels
         g.setColor(Color.white);
         g.drawString("Click to make the step height... try the dot", 100,300);
         g.fillOval(142,130,5,5);
         g.setColor(Color.black);
         g.setFont(f2);
         g.drawString("Click to try a new step height", 210,50);


         //draw vectors
         g.setColor(Color.black);
         g.drawLine(100,100,200,100);
         VHead2 head = new VHead2(s,100,100,200,100); //use VHead2 class to get arrow head coordinates
         g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead
         g.drawLine(100,100,100,200);
         head = new VHead2(s,100,100,100,200); //use VHead2 class to get arrow head coordinates
         g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead
         g.drawLine(200,200,100,100);
         head = new VHead2(s,200,200,100,100); //use VHead2 class to get arrow head coordinates
         g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead

         g.drawLine(100,100,65,135); //for R
   head = new VHead2(s,100,100,65,135);
         g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead

   //label roller
   g.drawString("R", 60, 125);
   g.drawString("W", 95,215);
   g.drawString("F", 190, 95);
   g.drawString("N", 200, 215);

         PlotRoller PlotPt = new PlotRoller(x,y);
         g.drawLine(PlotPt.xcircle(), y, 300, y);
         g.drawLine(PlotPt.xcircle(), y, PlotPt.xcircle(), 150);
         g.fillOval(PlotPt.xpoint(), PlotPt.ypoint(), 4,4);
         g.setFont(f3);
         g.drawString("" +df.format(PlotPt.xval())+ "      ", 445, 280);
         g.drawString("" +df.format(PlotPt.yval())+ "      ", 430, 305);
          g.drawImage(hr,325, 267,this);
          g.drawImage(fw,325, 292,this);

         //draw graph
         g.drawLine(100,230,100,430);
         g.drawLine(100,430,300,430);
         g.setColor(Color.orange);
         //draw x grid
         for (int i=120; i<=300; i=i+20) g.drawLine(i,230,i,435);
         //draw y grid
         for (int i=230; i<=410; i=i+20) g.drawLine(95,i,300,i);
         //label the graph
         g.setColor(Color.black);
   g.setFont(f3);
         g.drawString("F/W", 50 ,310);
         g.drawString("h/R", 310,435);
         g.setFont(f3);
         int j = 0;
         for (int i=100; i<=300; i=i+20) {
            g.drawString(xVal[j], i-5, 445);
            j++;
         }  j = 10;
         for (int i=240; i<=440; i=i+20) {
            g.drawString(yVal[j], 85,i-3);
            j--;
         }

         stage = 2;
       }
      }
      break;

      case 2: {
       //code for main part
       Graphics g = getGraphics();

       g.setFont(f2);
       g.setColor(Color.white);
       g.drawString("Click to make the step height... try the dot", 100,300); //erase instructio

       //draw roller
       g.setColor(Color.black);
       g.drawOval(50,50,100,100);
       g.drawLine(50,151,400,151);

       //draw graph
       g.drawLine(100,230,100,430);
       g.drawLine(100,430,300,430);
       g.setColor(Color.orange);
       //draw x grid
       for (int i=120; i<=300; i=i+20) g.drawLine(i,230,i,435);
       //draw y grid
       for (int i=230; i<=410; i=i+20) g.drawLine(95,i,300,i);
       //label the graph
       g.setColor(Color.black);
       g.setFont(f3);
       g.drawString("F/W", 50 ,310);
       g.drawString("h/R", 310,435);
       g.setFont(f3);
       int j = 0;
       for (int i=100; i<=300; i=i+20) {
          g.drawString(xVal[j], i-5, 445);
          j++;
       }  j = 10;
       for (int i=240; i<=440; i=i+20) {
          g.drawString(yVal[j], 85,i-3);
          j--;
       }


   //plots on the graph and draws when user clicks
       PlotRoller PlotPt = new PlotRoller(x,y);
       if (PlotPt.isInside()==true) {
    g.setColor(Color.white);
    g.drawString("You have clicked in an impossible position",320, 250); //erase impossible note
          g.fillRect(310, 230, 250, 150); //erase old numbers
          g.setColor(Color.black);
//          g.drawLine(x,y,100,100);
//          VHead2 head = new VHead2(s,x,y,100,100); //use VHead2 class to get arrowhead
//          g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead
          g.drawLine(100,100,PlotPt.NXVal(),200); //draws line for "N"
    g.drawLine(PlotPt.xcircle(), y, 300, y);
    g.drawLine(PlotPt.xcircle(), y, PlotPt.xcircle(), 150);
          g.fillOval(PlotPt.xpoint(), PlotPt.ypoint(), 4,4);
          g.drawString("" +df.format(PlotPt.xval())+ "      ", 445, 280);
          g.drawString("" +df.format(PlotPt.yval())+ "      ", 430, 305);
          g.drawImage(hr,325, 267,this);
          g.drawImage(fw,325, 292,this);

          g.setFont(f2);
    //draw "N" and "F" on graph
          //g.drawString("F", 190, 95);
          g.drawString("N", PlotPt.NXVal(), 215);
          g.drawLine(100,100,(int)(100.0+100.0*PlotPt.yval()),100);
          VHead2 head = new VHead2(s,100,100,(int)(100.0+100.0*PlotPt.yval()),100); //use VHead2
          g.fillPolygon(head.xpoints(), head.ypoints(), head.npoints()); //draw arrowhead
    g.drawString("F",(int)(100.0+100.0*PlotPt.yval())-10,95);

       }
       else {
          g.setColor(Color.white);
          g.fillRect(310, 230, 250, 150); //erase old numbers
    g.setColor(Color.black);
          g.drawString("You have clicked in an impossible position", 320, 250);
          g.drawString("0                                                  ", 445, 280);
          g.drawString("NAN                                                  ", 430, 305);
          g.drawImage(hr,325, 267,this);
          g.drawImage(fw,325, 292,this);
       }

       g.setColor(Color.black);
       g.setFont(f2);
       g.drawString("Click to try a new step height", 210,50);


      }
     }


		}//end public void mousePressed


	public void setImages(Image hr, Image fw) {
		this.hr = hr;
		this.fw = fw;
	}


}