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Demo Pie Graph

//Display a pie graph representing the number of A's, B's, C's, D's and F's
// on the Java Programming Final Exam
//notice the new items for this style graph displayed in blue

import java.awt.*;
import BreezyGUI.*;

public class piegraph extends GBFrame
{
   //Establish the look of the drop down box
   Label LabelA = addLabel("A", 1,1,1,1);
   IntegerField FieldA = addIntegerField(0,1,2,1,1);
   Label LabelB = addLabel("B", 1,3,1,1);
   IntegerField FieldB = addIntegerField(0,1,4,1,1);
   Label LabelC = addLabel("C", 1,5,1,1);
   IntegerField FieldC = addIntegerField(0,1,6,1,1);
   Label LabelD = addLabel("D", 1,7,1,1);
   IntegerField FieldD = addIntegerField(0,1,8,1,1);
   Label LabelF = addLabel("F", 1,9,1,1);
   IntegerField FieldF = addIntegerField(0,1,10,1,1);
 
   //Establish a drop down menu for the drawing
   //Right now we only have one choice -- Pier
   MenuItem pieChoice = addMenuItem ("Graph", "Pie");
 
  //Establish variables for this program
   int numberOfScores = 5;
   int Xleft = 100;
   int Xright = 300;
   int Ytop = 100;
   int Ybottom = 250;

   int totalX , totalY;
   int[ ] scores;
   char graphChoice;
 

  //Constructor to establish the initial values in the program
   public piegraph ()
   {
        int i;
        scores = new int[numberOfScores];
        for (i=0; i<scores.length; i++)
               scores[i] = 0;
       totalX = Xright - Xleft + 1;
       totalY = Ybottom - Ytop + 1;
       graphChoice = 'P';
   }
 

   //Allow for the menu choices
   //Remember, we only have one choice right now
   public void menuItemSelected (MenuItem item)
   {
       if (item == pieChoice)
            graphChoice = 'P';
      repaint();
   }

   public void paint (Graphics g)
   {
        getInputData();
        drawPieGraph(g);

   }
  

  //Get input from the screen
   public void getInputData()
   {
         scores[0] = FieldA.getNumber();
         scores[1] = FieldB.getNumber();
         scores[2] = FieldC.getNumber();
         scores[3] = FieldD.getNumber();
         scores[4] = FieldF.getNumber();
    }

   //Draw the pie graph
   public void drawPieGraph(Graphics g)
   {
            int i, totalUnits, centerX, centerY, radius, startAngle;
           double unitAngleSize;
    //Set up center point and radius of the pie, and the unit angle size
           totalUnits = sum(scores);
          centerX = getSize().width / 2;
          centerY = getSize().height / 2;
          radius = centerX - centerX/3;
          centerX = radius;
          centerY = centerY - centerY/3;

        if (totalUnits == 0)
                unitAngleSize = 0;
        else
                unitAngleSize = 360.0 / totalUnits;

        startAngle = 0;

       //Draw the wedges of the pie
       for(i=0; i < numberOfScores; i++)
       {
          int centralAngle = (int)(unitAngleSize * scores[i]);
          g.setColor(intToColor(i));
         g.fillArc(centerX, centerY, radius, radius, startAngle, centralAngle);
         startAngle = startAngle + centralAngle;
        }
       g.setColor(Color.black);
    }
 
   //Find the sum of the array
   public int sum(int [ ] a)
   {
          int i;
          int total = 0;
          for (i=0; i<a.length; i++)
                 total = total + a[i];
          return total;
   }
  //Set the colors for the pie slices
   public Color intToColor (int i)
   {
           Color color = Color.black;
           switch (i)
           {
                 case 0: {
                                color = Color.red;
                                break;
                               }
                 case 1: {
                                color = Color.green;
                                break;
                              }
                 case 2: {
                                color = Color.blue;
                                break;
                               }
                 case 3: {
                                 color = Color.yellow;
                                 break;
                              }
                 case 4: {
                                 color = Color.magenta;
                                 break;
                               }
          }
         return color;
   }
   //Main
   public static void main(String[ ] args)
   {
           Frame frm = new piegraph();
           frm.setSize (400, 300);
           frm.setVisible (true);
   }
}

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