Question

I want to update this JAVA program to : Exit cleanly, and change the pie chart to circle rather than an oval, and provide a separate driver please and thank you

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.util.Scanner;

import javax.swing.JComponent;
import javax.swing.JFrame;

// class to store the value and color mapping of the
// pie segment(slices)
class Segment {
double value;
Color color;

// constructor
public Segment(double value, Color color) {
this.value = value;
this.color = color;
}
}

class pieChartComponent extends JComponent {

private static final long serialVersionUID = 1L;
Segment[] Segments;

// Parameterized constructor
// create 4 segments of the pie chart
pieChartComponent(int v1, int v2, int v3, int v4) {
Segments = new Segment[] { new Segment(v1, Color.black), new Segment(v2, Color.green), new Segment(v3, Color.yellow),
new Segment(v4, Color.red) };
}

// function responsible for calling the worker method drawPie
public void paint(Graphics g) {
drawPie((Graphics2D) g, getBounds(), Segments);
}

// worker function for creating the percentage wise slices of the pie chart
  
void drawPie(Graphics2D g, Rectangle area, Segment[] Segments) {
double total = 0.0D;
// fin the total of the all the inputs provided by the user
for (int i = 0; i < Segments.length; i++) {
total += Segments[i].value;
}
  
// Initialization
double curValue = 0.0D;
int strtAngle = 0;
// iterate till all the segments are covered
for (int i = 0; i < Segments.length; i++) {
// compute start angle, with percentage
strtAngle = (int) (curValue * 360 / total);
// find the area angle of the segment
int arcAngle = (int) (Segments[i].value * 360 / total);

g.setColor(Segments[i].color);
g.fillArc(area.x, area.y, area.width, area.height, strtAngle, arcAngle);
curValue += Segments[i].value;
}
}
}

public class Graphic_Pie2D {
public static void main(String[] argv) {

System.out.println("Pleae provide 4 values, to create the pie chart");
Scanner input = new Scanner(System.in);
int v1, v2, v3, v4;
v1 = input.nextInt();
v2 = input.nextInt();
v3 = input.nextInt();
v4 = input.nextInt();
  
// create a JFrame with title
JFrame frame = new JFrame("Pie Chart");
frame.getContentPane().add(new pieChartComponent(v1,v2,v3,v4));
frame.setSize(500, 300);
frame.setVisible(true);

}
}

here's the assignment for reference :

Pie chart: prompt the user (at the command line) for 4 positive integers, then draw a pie chart in a window. Convert the numbers to percentages of the numbers’ total sum; color each segment differently; use Arc2D. No text fields (other than the window title) are required. Provide a driver in a separate source file to test your class.

Answer 1

import java.awt.*;

    import java.awt.event.*;

    import java.applet.Applet;

    public class PieChartApplet extends Applet implements ActionListener {

       PieChartCanvas chart;  // A canvas that displays the pie chart.

       TextField[] inputs;    // Input boxes where the user enters the data.

       Label message;         // Label for displaying message to the user.

       public void init() {

               // Initialize the applet. 

          setBackground(Color.darkGray);     // Color for borders and gaps.

          setLayout(new BorderLayout(2,2));  // The main layout is a BorderLayout.

          /* The South position of the main BorderLayout is occupied by

             a Panel that contains the message label and two buttons.

             This panel also uses a BorderLayout.  The message label 

             occupies the Center position and the Buttons occupy the

             East and West positions.  The applet listens for ActionEvents

             from the buttons. 

          */

          Panel bottom = new Panel();

          add(bottom, BorderLayout.SOUTH);

          bottom.setLayout(new BorderLayout(2,2));

          message = new Label("Enter your data and click here: ", Label.CENTER);

          message.setBackground(Color.lightGray);

          bottom.add(message, BorderLayout.CENTER);

          Button make = new Button("Make Chart");

          make.addActionListener(this);

          make.setBackground(Color.lightGray);

          bottom.add(make, BorderLayout.EAST);

          Button clear = new Button("Clear");

          clear.addActionListener(this);

          clear.setBackground(Color.lightGray);

          bottom.add(clear, BorderLayout.WEST);

          /* The Center position of the main BorderLayout is occupied by

             a Panel that contains the input boxes and the PieChartCanvas.

             This Panel uses a GridLayout that divides it horizontally into

             two pieces.  The left half is occupied by another Panel that

             holds the input boxes.  The right half is occupied by the chart.

          */

          Panel top = new Panel();

          add(top, BorderLayout.CENTER);

          top.setLayout(new GridLayout(1,2,2,2));

          Panel left = new Panel();   // Panel to hold 12 input boxes in a grid.

          top.add(left);

          left.setLayout(new GridLayout(6,2,2,2));

          inputs = new TextField[12];  // Make an array to hold the input boxes.

          for (int i = 0; i < 12; i++) {

             inputs[i] = new TextField();  // Create the i-th input box.

             inputs[i].setBackground(Color.white);

             left.add(inputs[i]);

          }

          chart = new PieChartCanvas();

          top.add(chart);

       }  // add init();

       public Insets getInsets() {

             // Specify a 2-pixel border around the edges of the applet.

          return new Insets(2,2,2,2);

       }

       public void actionPerformed(ActionEvent evt) {

              // This is called when the user clicks on one of the two buttons.

              // Call another subroutine to handle the action.

          String cmd = evt.getActionCommand();

          if (cmd.equals("Clear"))

             doClear();

          else if (cmd.equals("Make Chart"))

             doChart();

       }

       void doClear() {

              // Called by actionPerformed() when the user clicks the "Clear" 

              // button.  Empty all the TextFields, and clear the pie chart.

              // Reset the message label, in case it was showing an error message.

          chart.clearData();

          message.setText("Enter your data and click here: ");

          for (int i = 0; i < 12; i++)

             inputs[i].setText("");

          inputs[0].requestFocus();

       }

       void doChart() {

             // Called by actionPerformedI() when the user clicks the "Make Chart"

             // button.  Get up to 12 data values form the 12 input boxes.  Ignore

             // any empty boxes and zeros.  If illegal data is found, show a message

             // and exit.  Otherwise, tell the PieChartCanvas to draw a pie chart

             // for the data.  (If an error is found, clear the current pie chart

             // so the user will notice that something is wrong.)

         double[] data = new double[12];  // An array to hold the data.

         int dataCt = 0;  // Number of data items found (ignoring empty boxes).

         for (int i = 0; i < 12; i++) {

                 // Try to get data from the i-th input box.

            String numStr;  // The contents of the i-th box, as a string.

            double num;     // The contents of the i-th box, as a number.

            numStr = inputs[i].getText().trim();

            if (numStr.length() > 0) {

               try {

                      // Try to convert the string to a numerical value.

                  Double d = new Double(numStr); 

                  num = d.doubleValue();

               } 

               catch (NumberFormatException e) {

                      // The data in box i is not a legal number.

                  message.setText("Invalid number input " + i);

                  inputs[i].selectAll();

                  inputs[i].requestFocus();

                  chart.clearData();

                  return;

               }

               if (num < 0) {

                      // The data in box i is a negative number.

                  message.setText("Negative numbers not allowed.");

                  inputs[i].selectAll();

                  inputs[i].requestFocus();

                  chart.clearData();

                  return;

               }

               if (num > 0) {

                      // Put the number in the data array, but only if it

                      // is positive.  Zero values are ignored.

                  data[dataCt] = num;

                  dataCt++;

               }

            }  // end if

         }  // end for

         if (dataCt == 0) {

                // No positive numbers were found.

            message.setText("Please enter some data!");

            inputs[0].requestFocus();

            chart.clearData();

            return;

         }

         /* Reset the message label, in case it was showing an error message. */

         message.setText("Enter your data and click here: ");

         /* Tell the PieChartCanvas to draw a pie chart with the new data. */

         chart.setData(data,dataCt);

       }  // end doChart()

    } // end PieChartApplet

    class PieChartCanvas extends Canvas {

           // A PieChartCanvas can display a pie chart, based on an array 

           // of data passed to it in its setData() method.  There can be

           // up to 12 wedges in the pie.

       private int dataCt;     // The number of data values for the chart.

       private int[] angles;   // An array to hold the angles that divide

                               // the wedges.  For convenience, this array 

                               // is of size dataCt + 1, and it starts with 

                               // 0 and ends with 360.

       private final static Color[] palette = {  // Colors for the chart.

            Color.red,                        

            Color.blue,                        

            Color.green,                     

            Color.magenta,

            Color.yellow,

            Color.cyan,

            new Color(180,0,0),

            new Color(200,200,255),

            new Color(0,180,0),

            new Color(0,180,180),

            new Color(180,180,0),

            new Color(180,0,180),

          };

       PieChartCanvas() {

             // Constructor.  Set the background to be white.

          setBackground(Color.white);

       }

       void clearData() {

             // Delete any data and redraw the canvas.  The canvas will

             // be blank except for the message "No data available".

          dataCt = 0;

          angles = null;

          repaint();

       }

       void setData(double[] data, int count) {

             // Use data and count for the pie chart.  If data is null or

             // count is <= 0, the current pie chart will be cleared.

             // The count must be in the range 0 to data.length.  If not, it

             // is set to data.length.  All the entries in the array should

             // be positive numbers.  If not, the results will be nonsense.

             // The data needed to draw the pie chart is computed and stored

             // in the angles array.  Note that the number of degrees

             // in the i-th wedge is 360*data[i]/dataSum, where dataSum

             // is the total of all the data values.  The cumulative angles

             // are computed, converted to ints, and stored in angles.

          if (count <= 0 || data == null) {

             clearData();

          }

          else {

             if (count <= data.length)

                dataCt = count;

             else

                dataCt = data.length;

             angles = new int[dataCt + 1];

             angles[0] = 0;

             angles[dataCt] = 360;

             double dataSum = 0;

             for (int i = 0; i < dataCt; i++)

                dataSum += data[i];

             double sum = 0;

             for (int i = 1; i < dataCt; i++) {

                sum += data[i-1];

                angles[i] = (int)(360*sum/dataSum + 0.5);

             }

             repaint();

          }

       }  // end setData()

       public void paint(Graphics g) {

               // Draw the pie chart, if there is data available.  

               // If not, just show the message "No data available". 

          if (dataCt == 0) {

             g.drawString("No data available.", 10,15);

             return;

          }

          /* The pie chart occupies a circle centered on the canvas.

             Compute some parameters for drawing it.

          */

          int centerX = getSize().width / 2;   // Center point of circle.

          int centerY = getSize().height / 2; 

          int radius;   // Radius of the circle.  This is 20 pixels less 

                        // than the smaller of half the width and 

                        // half the height.

          if (centerX < centerY)

             radius = centerX - 20;

          else

             radius = centerY - 20;

          int top = centerY - radius;    // Top edge of square 

                                         //    that contains the circle.

          int left = centerX - radius;   // Left edge of square 

                                         //    that contains the circle.

          int diameter = 2*radius;       // Length of a side of the square.

          for (int i = 0; i < dataCt; i++) {

                // Draw the next wedge.  The start angle for the wedge 

                // is angles[i].  The ending angle is angles[i+1}, so 

                // the number of degrees in the wedge is 

                // angles[i+1] - angles[i].

             g.setColor( palette[i] );

             g.fillArc( left, top, diameter, diameter, 

                                        angles[i], angles[i+1] - angles[i] ) ;

          }

       }  // end paint()

    }  // end PieChartCanvas