Computer Science 252
Problem Solving with Java

Fall 2013, The College of Saint Rose

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SalesGraph Demo

A working demo of SalesGraph will appear below. Click inside the applet to interact with it.

SalesGraph BlueJ Project

Click here to download a BlueJ project for SalesGraph.

SalesGraph Source Code

The Java source code for SalesGraph is below. Click on a file name to download it.

SalesGraph.java

import objectdraw.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

/*
 * Example SalesGraph: read in a series of "sales" values
 * and keep track of the values by day of the week, graphing
 * the results by daily average and maximum.
 *
 * Jim Teresco, The College of Saint Rose, CSC 252, Fall 2013
 *
 * $Id: SalesGraph.java 2276 2013-12-03 19:23:46Z terescoj $
 */

public class SalesGraph extends WindowController implements ActionListener {

    private static final int MAX_SALES_PER_DAY = 300;
    
    // graphical layout constants
    private static final int BAR_BOTTOM = MAX_SALES_PER_DAY;
    private static final int MARGIN = 5;
    private static final int BAR_WIDTH = 20;
    private static final int DAY_WIDTH = 2 * (MARGIN + BAR_WIDTH);
    
    // bars for bar graph
    private FilledRect [] maxGraphs = new FilledRect[7];
    private FilledRect [] avgGraphs = new FilledRect[7];
    
    // some GUI components we'll need to remember
    private JLabel label;
    private JTextField salesField;
    private JButton enter;
    
    // next day of week to enter
    private int dayOfWeek = 0;
    
    private static final String [] daysOfWeek = {
        "Sunday", "Monday", "Tuesday", "Wednesday",
        "Thursday", "Friday", "Saturday" };
    
    // next day overall to ask for
    private int dayNumber = 1;
    
    // store max values per day
    private int [] maxPerDay = new int[7];
    
    // array of lists of daily sales by day of week
    private ArrayList<Integer> [] salesByDay;
    
    public void begin() {
        
        // set up some GUI components
        Container contentPane = getContentPane();
        JPanel southPanel = new JPanel();
        
        label = new JLabel("Enter Day 1 Value (Sunday)");
        southPanel.add(label);
        
        salesField = new JTextField(10);
        southPanel.add(salesField);
        
        enter = new JButton("Add");
        southPanel.add(enter);
        
        contentPane.add(southPanel, BorderLayout.SOUTH);
        
        salesField.addActionListener(this);
        enter.addActionListener(this);
        contentPane.validate();
    
        // set up graphs
        for (int i = 0; i < 7; i++) {
            avgGraphs[i] = new FilledRect(i * DAY_WIDTH + MARGIN,
                BAR_BOTTOM, BAR_WIDTH, 1, canvas);
            avgGraphs[i].setColor(Color.green);
            maxGraphs[i] = new FilledRect(i * DAY_WIDTH + MARGIN + BAR_WIDTH,
                BAR_BOTTOM, BAR_WIDTH, 1, canvas);
            maxGraphs[i].setColor(Color.red);
        }
        
        // array of ArrayList references
        salesByDay = (ArrayList<Integer>[])new ArrayList[7];
        // construct individual ArrayLists
        for (int i = 0; i < 7; i++) {
            salesByDay[i] = new ArrayList<Integer>();
        }
        
    }
    
    public void actionPerformed(ActionEvent e) {
        
        // make sure we have a valid value to work with
        int value = 0;
        try {
            value = Integer.parseInt(salesField.getText());
        }
        catch (NumberFormatException ex) {
            JOptionPane.showMessageDialog(null, 
                "Please enter an integer value in the range 0-" + MAX_SALES_PER_DAY,
                "Input error", JOptionPane.ERROR_MESSAGE);
            salesField.setText("");
            return;
        }
        
        // make sure we are in the proper range
        if (value < 0 || value > MAX_SALES_PER_DAY) {
            JOptionPane.showMessageDialog(null, 
                "Please enter an integer value in the range 0-" + MAX_SALES_PER_DAY,
                "Input error", JOptionPane.ERROR_MESSAGE);
            salesField.setText("");
            return;
        }
        
        // now do something with the valid value
        System.out.println("Hey!  You entered " + value);
        salesField.setText("");
        
        // see if we have a new max sales number for this day of week
        if (value > maxPerDay[dayOfWeek]) {
            maxPerDay[dayOfWeek] = value;
            maxGraphs[dayOfWeek].setHeight(value);
            maxGraphs[dayOfWeek].moveTo(dayOfWeek * DAY_WIDTH + MARGIN + BAR_WIDTH, BAR_BOTTOM - value);
        }
        
        // add today's sales to the appropriate ArrayList of sales history
        salesByDay[dayOfWeek].add(value);
        
        // compute new average for this day of week
        int total = 0;
        for (int val : salesByDay[dayOfWeek]) {
            total += val;
        }
        double average = 1.0*total / salesByDay[dayOfWeek].size();
        
        // update graph
        avgGraphs[dayOfWeek].setHeight(average);
        avgGraphs[dayOfWeek].moveTo(dayOfWeek * DAY_WIDTH + MARGIN, BAR_BOTTOM - average);
        
        // update day of week and day number
        dayOfWeek = (dayOfWeek + 1) % 7;
        dayNumber++;
        label.setText("Enter Day " + dayNumber + " value (" + daysOfWeek[dayOfWeek] + ")");
    }
}