Help with a Polling Program.

**HalfAZN** · 09-12-2012, 04:43 PM

I'm attempting to make a program that will count votes, and then formulate the number of votes into a pie chart. I have three parts to the program: The Control Panel, which manages the window, and vote buttons; The Display Panel, which contains my methods; and my driver, which I have named "Poll". All 3 parts of the program compile and run, however when I "Vote" for a subject, the pie chart disappears. I believe that the problem lies within my formulas in the display panel part of the program, but I haven't been able to figure it out. Any help is appreciated.

Here is the Display Panel part of the program:

Java Code:

import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;

public class PollDisplayPanel extends JPanel
{
  private String name1, name2, name3;
  // Declare the int fields count1, count2, count3:
  //int count 1, count 2, count 3
    int count1 = 0;   // optional
    int count2 = 0;   // optional
    int count3 = 0;   // optional;

  //________________________________________________________

  // Constructor
  public PollDisplayPanel(String nm1, String nm2, String nm3)
  {
    setBackground(Color.WHITE);
    name1 = nm1;
    name2 = nm2;
    name3 = nm3;
    //int count1 = 0;   // optional
  //  int count2 = 0;   // optional
  //  int count3 = 0;   // optional
  }

  // Increments count1
  public void vote1()
  {

   count1++;
  }

  // Increments count2
  public void vote2()
  {

    count2++;
  }

  // Increments count3
  public void vote3()
  {

    count3++;
  }

  // Returns a string representation of this object
  public String toString()
  {
    return "Candidate 1: "+count1+" Candidate 2: "+count2+" Candidate 3: "+count3;


  }

  // Redefines JPanel's paintComponent to draw this pie chart
  public void paintComponent(Graphics g)
  {
    super.paintComponent(g);

    int w = getWidth();
    int h = getHeight();
    int x = w/2;
    int y = h/2;
    int r = Math.min(w, h) / 4;
    drawPieChart(g, x, y, r);
    drawLegend(g, x, y, r);
  }

  // Draws the pie chart.

  private void drawPieChart(Graphics g, int x, int y, int r)
  {
    int total = count1 + count2 + count3;
    int fromDegree = 0;

    if (total > 0)
    {
      int degrees;
      g.setColor(Color.RED);
      degrees = countToDegrees;//(count1, total);
      drawSector(g, x, y, r, fromDegree, degrees);
    }
    else
    {
      g.setColor(Color.LIGHT_GRAY);
      drawSector(g, x, y, r, fromDegree, 360);
    }
  }

  // Draws the vote counts and the corresponding color squares.
  private void drawLegend(Graphics g, int x, int y, int r)
  {
    // Display the counts:
    y += (r + 20);
    g.setColor(Color.BLACK);

    g.drawString( (""+count1), x - r, y);

    g.drawString(""+count2, x, y);

    g.drawString( ""+count3, x + r, y);


    // Display the color squares:
    y += 5;
    x -= 2;
    g.setColor(Color.RED);
    g.fillRect(x - r, y, 10, 10);
    g.setColor(Color.GREEN);
    g.fillRect(x, y, 10, 10);
    g.setColor(Color.BLUE);
    g.fillRect(x + r, y, 10, 10);
  }

  // Returns the number of degrees in a pie slice that
  // corresponds to count / total, rounded to the nearest integer.
  private int countToDegrees()
  {

	int first= count/total;
	int num1= first*360;
	return num1;
  }


  // Draws a sector, centered at x, y, of radius r,
  // of angle measure degrees, starting at fromDegree.
  private void drawSector(Graphics g, int x, int y, int r, int fromDegree, int degrees)
  {
    if (degrees > 359)
      g.fillOval(x - r, y - r, 2 * r, 2 * r);
    else
      g.fillArc(x - r, y - r, 2 * r, 2 * r, fromDegree, degrees);
  }
}

Here's the ControlPanel, although I don't think this is where the program is going wrong:

Java Code:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class PollControlPanel extends JPanel
                          implements ActionListener
{
  private JButton button1, button2, button3;
  private PollDisplayPanel chartPanel;

  public PollControlPanel(PollDisplayPanel chart)
  {
    chartPanel = chart;

    button1 = new JButton("Tami");
    button1.setPreferredSize(new Dimension(80, 30));
    button1.setToolTipText("Vote for Tami");
    button1.addActionListener(this);

    button2 = new JButton("Brian");
    button2.setPreferredSize(new Dimension(80, 30));
    button2.setToolTipText("Vote for Brian");
    button2.addActionListener(this);

    button3 = new JButton("Liz");
    button3.setPreferredSize(new Dimension(80, 30));
    button3.setToolTipText("Vote for Liz");
    button3.addActionListener(this);

    add(button1);
    add(button2);
    add(button3);
  }

  // Processes button events
  public void actionPerformed(ActionEvent e)
  {
    JButton button = (JButton)e.getSource();

    if (button == button1)
      chartPanel.vote1();
    else if (button == button2)
      chartPanel.vote2();
    else if (button == button3)
      chartPanel.vote3();
    chartPanel.repaint();
  }

}

And here's the driver:

Java Code:

import java.awt.*;
import javax.swing.*;

public class Poll extends JFrame
{
  public Poll()
  {
    super("Vote for Tami, Brian, or Liz");

    Container c = getContentPane();
    c.setBackground(Color.WHITE);
    PollDisplayPanel chart = new PollDisplayPanel("Tami", "Brian", "Liz");
    PollControlPanel controls = new PollControlPanel(chart);
    c.add(chart, BorderLayout.CENTER);
    c.add(controls, BorderLayout.SOUTH);
  }

  public static void main(String[] args)
  {
    Poll w = new Poll();
    w.setBounds(300, 300, 400, 400);
    w.setDefaultCloseOperation(EXIT_ON_CLOSE);
    w.setVisible(true);
  }
}