Computer Science 120
Introduction to Programming

Fall 2011, Siena College

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Overview

• The Birthday Grid allows you to count birthdays by month and year by clicking on a grid.
• Click on the grid to increment the birthday count for a particular year and month.
• Click on a year to calculate the sum for the year
• Click on a month to calculate the sum for the month

Implementation

Basic Setup

1. Create a new folder called lab8

2. Create a new BlueJ project called Arrays and save it your lab8 folder.

3. Create a new class called BirthdayGrid

Getting Started

Add the following to create BirthdayGrid:

import objectdraw.*;
 

public class BirthdayGrid extends WindowController {

   private static final int WIDTH = 50;
   private static final int HEIGHT = 30;

 
   private int months;
   private int years;
   
   private Text monthSum;
   private Text yearSum;
   
   private Text[] monthArray;
   private Text[] yearArray;
   
   private FramedRect[][] grid;
   private Text [][] text;
   private int [][] birthdayCount;

Creating the Grid

Add the following code to your begin method to create your headers

public void begin() {

 months = 12;
 years = 7;
 
 monthArray = new Text[months];
 yearArray = new Text[years];
 

String[] monthNames = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};

 for (int m = 0; m < months; m++) {
   monthArray[m] = new Text(monthNames[m], 20, HEIGHT*m+HEIGHT, canvas);
 }

 for (int y = 0; y < years; y++) {
   yearArray[y] = new Text(1988 + y,WIDTH*y+50, 10, canvas);
 }

Task 1: Use the code above as a model and create the nested loop to generate the grid of FramedRectangles.

Here is some starter code:

for (int m = 0....) {
   for (int y = 0...) {
      grid[m][y] = ?
   }
}

Task 2: Create the nested loop to generate the Text objects (2D text array) inside each Rectangle

Here is some starter code:

for (int m = 0....) {
   for (int y = 0...) {
      ?
   }
}

Task 3: Create the nest loop to set all the birthdayCounts to zero

Implementing onMouseClick

Remember that p is the location of your mouse click

public void onMouseClick(Location p) {



}

Task 1 - Incrementing Birthday Count: Test to see if each FramedRectangle (grid[m][y]) contains p (i.e., the clicked Location)

Here is some starter code:

for (int m = 0....) {
   for (int y = 0...) {
      if (?) {
         // increment birthdayCount
         // set the text of text[m][y] to the new value for birthdayCount
   }
}

Task 2 - Add up the counts for a month: Test to see if a month label (monthArray) was clicked. If yes, iterate over all the years for that month (birthdayCount[m][?]) and sum all the values. Then, output the sum by setting the text of monthSum and placing it on the canvas.

Here is some starter code:

for ("each month") {
            if (monthArray contains p) {
                
                // set sum to zero
                for ("each year") {
                    // increment sum by the birthdayCount
                }
                // Output the sum by creating a new Text object (monthSum) and placing it on the canvas
            }
        }

Task 3 - Add up the counts for the year: Test to see if a year label (yearArray) was clicked. If yes, iterate over all the months for that year (birthdayCount[?][y]) and sum all the values. Then, output the sum by setting the text of yearSum and placing it on the canvas.