Let's begin by familiarizing ourselves with the use of ArrayList objects. Examine the class called ArrayListTestProgram. It does not compile. The compiler will complain, stating that Variable 'numbers' might not have been initialized. Fix this by adding the following line of code before the println statements:

numbers = new ArrayList();

Run the code. You will notice that the code generates an IndexOutOfBoundsException when we attempt to ask for the 5th element. Do you understand why ? It is simple. The list has been created, but it is empty, with a size of zero.

Now let us add some objects to the list. Insert the following code (copy/paste it) just after the line that creates the ArrayList:

numbers.add(1);

numbers.add(45);

numbers.add(23);

numbers.add(87);

numbers.add(89);

numbers.add(213);

Now recompile and run the code. You will notice that element 5 is now 89 (notice that it is not 213 because array indexing always starts at 0 instead of 1). Notice as well that the size() of the list is now 6.

Replace the 3 System.out.println lines of code by some code that will compute and display the total sum of the integers in the numbers list. Make use of the total variable that has already been declared for you and use a FOR EACH loop to loop through the elements of the list. The total should be 458.

At the bottom of the program, add more code that loops through the list using a regular FOR loop (i.e., for (int i=0; i<...) etc..) to re-compute the total of the numbers in the list. Don't forget to reset the total to 0 before the loop. You should get the same answer. Look at the two FOR loops. Which one do you prefer to use ? Which one uses the least amount of code ?

Now Also provided in the tutorial code, is the solutions to Tutorial #3 in which we had used Customer, Store and Mall classes. All of the code made use of array objects. We will now convert the code to use ArrayLists instead. When we are done, you will notice that the code is simpler. The Customer class does not need to have anything changed. In the Store class, change the type of the customers attribute from Customer[] to ArrayList. Also, remove the customerCount attribute, since ArrayLists already keep this information. Lastly, remove the MAX_CUSTOMERS static constant, since our list will no longer have a bound to it. Now, go through the code to fix all methods properly. When possible, change the FOR loops to FOR EACH loops. Take note of these changes:

The add() method becomes much simpler since we no longer need to check the bounds.

The getCustomersWithGender() and friendsFor() methods should now return an ArrayList<Customer> which can grow ... so we no longer need to compute the size of it first. The code is greatly reduced.

Update the StoreTestProgram too so that the result variable holds an ArrayList object. You will also need to use the get(i) method at the bottom in order to access a particular element from the ArrayList. Update the Mall and MallTestProgram classes accordingly as well so that it uses ArrayLists instead of arrays. Test the StoreTestProgram and MallTestProgram to make sure that it still works.

A modified version of the DVDCollectionApp class is available in the tutorial code that was given to you. It makes use of a DVDCollection that uses ArrayLists instead of arrays and it has the two Dialog boxes that we created in the previous tutorial as well as the Menubar. If you run the code, you will notice that it allows you to sort the DVDs by title. Sort the DVDs and then add a DVD via the Add button. You will notice that the new DVD appears at the bottom of the list ... unsorted.

Go into the DVDCollection class and change the code in the sortByTitle() method to use the sort() method in the Collections class (i.e., see section 8.8 of the course notes) instead of performing the manual insertion sort that we were doing previously. The method should be one line long now. Run the code and make sure that it still works to sort by the DVD title. This code only works because we already have the DVD class implementing the Comparable interface. That is, the DVD class has a compareTo() method that is used by the sort() method to determine which DVDs come before others in the sort order. We would like this to work with any sort strategy (e.g., by year or by length). To do this, define the following 3 constants and single attribute in the DVD class:

public static final int SORT_BY_TITLE = 0;

public static final int SORT_BY_YEAR = 1;

public static final int SORT_BY_LENGTH= 2;

public static int sortStrategy = SORT_BY_TITLE;

The sortStrategy attribute will be used to indicate which sort strategy we would like to use when displaying the DVDs. Adjust the compareTo() method so that it first looks at the sortStrategy value and then compares either the titles, years or lengths of the DVDs accordingly. Note that you will need to determine a simple way to return a negative number if one DVD's year is before the other's and a positive number otherwise, because you cannot call compareTo() on integers. You will need to adjust the three sorting methods in the DVDCollection class so that it sets the appropriate sortStrategy and then sorts the DVDs. Now in the add() method, simply resort the DVDs after the new one has been added. Test your DVDCollectionApp to see that the list is always sorted after adding a new DVD. Hopefully you see the advantage of having this sort() method available and how easy it is to sort be various criteria.

import java.util.ArrayList; public class ArrayListTestProgram { public static void main(String args[]) { int total = 0; ArrayList numbers; System.out.println("The ArrayList looks like this: " + numbers); System.out.println("It has " + numbers.size() + " elements in it"); System.out.println("The 5th element in it is: " + numbers.get(4)); } } 

public class Customer { private int id; private String name; private int age; private char gender; private float money; // A simple constructor  public Customer(String n, int a, char g, float m) { name = n; age = a; gender = g; money = m; id = -1; } // Return a String representation of the object  public String toString() { String result; result = "Customer " + name + ": a " + age + " year old "; if (gender == 'F') result += "fe"; return result + "male with $" + money; } public boolean hasMoreMoneyThan(Customer c) { return money > c.money; } // Get methods  public String getName() { return name; } public int getAge() { return age; } public char getGender() { return gender; } public int getId() { return id; } // Set Methods  public void setId(int newID) { id = newID; } } 

public class Store { public static final int MAX_CUSTOMERS = 500; public static int LATEST_ID = 1000000; private String name; private Customer[] customers; private int customerCount; public Store(String n) { name = n; customers = new Customer[MAX_CUSTOMERS]; customerCount = 0; } public void addCustomer(Customer c) { if (customerCount < MAX_CUSTOMERS) { customers[customerCount++] = c; c.setId(LATEST_ID++); } } public Customer[] getCustomers() { return customers; } public int getCustomerCount() { return customerCount; } public void listCustomers() { for (int i=0; ipublic int averageCustomerAge() { int avg = 0; for (int i=0; ireturn avg / customerCount; } public char mostPopularGender() { int mCount = 0, fCount = 0; for (int i=0; iif (customers[i].getGender() == 'M') mCount++; else  fCount++; } if (mCount > fCount) return 'M'; return 'F'; } public Customer richestCustomer() { Customer richest = customers[0]; for (int i=1; iif (customers[i].hasMoreMoneyThan(richest)) richest = customers[i]; } return richest; } public Customer[] getCustomersWithGender(char g) { int matchCount = 0; // Count them first  for (int i=0; iif (customers[i].getGender() == g) matchCount++; } // Now make the array  Customer[] matches = new Customer[matchCount]; matchCount = 0; for (int i=0; iif (customers[i].getGender() == g) matches[matchCount++] = customers[i]; } return matches; } public Customer[] friendsFor(Customer lonelyCustomer) { int friendCount = 0; // Count them first  for (int i=0; iif ((customers[i] != lonelyCustomer) && (customers[i].getGender() == lonelyCustomer.getGender()) && (Math.abs(customers[i].getAge() - lonelyCustomer.getAge()) <= 3)) { friendCount++; } } // Now make the array  Customer[] friends = new Customer[friendCount]; friendCount = 0; for (int i=0; iif ((customers[i] != lonelyCustomer) && (customers[i].getGender() == lonelyCustomer.getGender()) && (Math.abs(customers[i].getAge() - lonelyCustomer.getAge()) <= 3)) { friends[friendCount++] = customers[i]; } } return friends; } } 

public class Mall { public static final int MAX_STORES = 100; private String name; private Store[] stores; private int storeCount; public Mall(String n) { name = n; stores = new Store[MAX_STORES]; storeCount = 0; } public void addStore(Store s) { if (storeCount < MAX_STORES) { stores[storeCount++] = s; } } public boolean shoppedAtSameStore(Customer c1, Customer c2) { // Go through each store  for (int i=0; iint numInStore = stores[i].getCustomerCount(); boolean foundC1 = false, foundC2 = false; for (int j=0; jif (customersInStore[j] == c1) foundC1 = true; if (customersInStore[j] == c2) foundC2 = true; } if (foundC1 && foundC2) return true; } return false; } // Determine the total number of unique customers that have visited the mall  public int uniqueCustomers() { // First determine how many customers are in the stores  int total = 0; for (int i=0; i// Now go through and add all the customers to an array, as long as they are not already in there  // Keep track of unique ones  int unique = 0; Customer[] uniqueCustomers = new Customer[total]; for (int i=0; iint numInStore = stores[i].getCustomerCount(); for (int j=0; jboolean found = false; for(int k=0; kif (customersInStore[j] == uniqueCustomers[k]) found = true; } if (!found) { uniqueCustomers[unique] = customersInStore[j]; unique++; } } } return unique; } } 

public class StoreTestProgram { public static void main(String args[]) { Customer[] result; Store walmart; walmart = new Store("Walmart off Innes"); walmart.addCustomer(new Customer("Amie", 14, 'F', 100)); walmart.addCustomer(new Customer("Brad", 15, 'M', 0)); walmart.addCustomer(new Customer("Cory", 10, 'M', 100)); walmart.addCustomer(new Customer("Dave", 5, 'M', 48)); walmart.addCustomer(new Customer("Earl", 21, 'M', 500)); walmart.addCustomer(new Customer("Flem", 18, 'M', 1)); walmart.addCustomer(new Customer("Gary", 8, 'M', 20)); walmart.addCustomer(new Customer("Hugh", 65, 'M', 30)); walmart.addCustomer(new Customer("Iggy", 43, 'M', 74)); walmart.addCustomer(new Customer("Joan", 55, 'F', 32)); walmart.addCustomer(new Customer("Kyle", 16, 'M', 88)); walmart.addCustomer(new Customer("Lore", 12, 'F', 1000)); walmart.addCustomer(new Customer("Mary", 17, 'F', 6)); walmart.addCustomer(new Customer("Nick", 13, 'M', 2)); walmart.addCustomer(new Customer("Omar", 18, 'M', 24)); walmart.addCustomer(new Customer("Patt", 24, 'F', 45)); walmart.addCustomer(new Customer("Quin", 42, 'M', 355)); walmart.addCustomer(new Customer("Ruth", 45, 'F', 119)); walmart.addCustomer(new Customer("Snow", 74, 'F', 20)); walmart.addCustomer(new Customer("Tamy", 88, 'F', 25)); walmart.addCustomer(new Customer("Ulsa", 2, 'F', 75)); walmart.addCustomer(new Customer("Vern", 9, 'M', 90)); walmart.addCustomer(new Customer("Will", 11, 'M', 220)); walmart.addCustomer(new Customer("Xeon", 17, 'F', 453)); walmart.addCustomer(new Customer("Ying", 19, 'F', 76)); walmart.addCustomer(new Customer("Zack", 22, 'M', 35)); System.out.println("Here are the customers: "); walmart.listCustomers(); // Find average Customer age  System.out.println(" Average age of customers: " + walmart.averageCustomerAge()); // Find most popular gender  System.out.println(" Most popular gender is: " + walmart.mostPopularGender()); // Find richest customer  System.out.println(" Richest customer is: " + walmart.richestCustomer()); // Find male customers  System.out.println(" Here are all the male customers:"); result = walmart.getCustomersWithGender('M'); for (Customer c: result) System.out.println(c); // Find female customers  System.out.println(" Here are all the female customers:"); result = walmart.getCustomersWithGender('F'); for (Customer c: result) System.out.println(c); // Find friends for Amie  System.out.println(" Friends for 14 year old female Amie:"); result = walmart.friendsFor(walmart.getCustomers()[0]); for (Customer c: result) System.out.println(c); // Find friends for Brad  System.out.println(" Friends for 15 year old male Brad:"); result = walmart.friendsFor(walmart.getCustomers()[1]); for (Customer c: result) System.out.println(c); } } 

public class MallTestProgram { public static void main(String args[]) { // Make the mall  Mall trainyards = new Mall("Trainyards"); // Make some stores  Store walmart, dollarama, michaels, farmBoy; trainyards.addStore(walmart = new Store("Walmart")); trainyards.addStore(dollarama = new Store("Dollarama")); trainyards.addStore(michaels = new Store("Michaels")); trainyards.addStore(farmBoy = new Store("Farm Boy")); // Create the customers  Customer c1, c2, c3, c4, c5, c6, c7, c8, c9, c10, c11, c12, c13, c14; Customer c15, c16, c17, c18, c19, c20, c21, c22, c23, c24, c25, c26; c1 = new Customer("Amie", 14, 'F', 100); c2 = new Customer("Brad", 15, 'M', 0); c3 = new Customer("Cory", 10, 'M', 100); c4 = new Customer("Dave", 5, 'M', 48); c5 = new Customer("Earl", 21, 'M', 500); c6 = new Customer("Flem", 18, 'M', 1); c7 = new Customer("Gary", 8, 'M', 20); c8 = new Customer("Hugh", 65, 'M', 30); c9 = new Customer("Iggy", 43, 'M', 74); c10 = new Customer("Joan", 55, 'F', 32); c11 = new Customer("Kyle", 16, 'M', 88); c12 = new Customer("Lore", 12, 'F', 1000); c13 = new Customer("Mary", 17, 'F', 6); c14 = new Customer("Nick", 13, 'M', 2); c15 = new Customer("Omar", 18, 'M', 24); c16 = new Customer("Patt", 24, 'F', 45); c17 = new Customer("Quin", 42, 'M', 355); c18 = new Customer("Ruth", 45, 'F', 119); c19 = new Customer("Snow", 74, 'F', 20); c20 = new Customer("Tamy", 88, 'F', 25); c21 = new Customer("Ulsa", 2, 'F', 75); c22 = new Customer("Vern", 9, 'M', 90); c23 = new Customer("Will", 11, 'M', 220); c24 = new Customer("Xeon", 17, 'F', 453); c25 = new Customer("Ying", 19, 'F', 76); c26 = new Customer("Zack", 22, 'M', 35); // Add the customers to the stores  walmart.addCustomer(c1); walmart.addCustomer(c3); walmart.addCustomer(c4); walmart.addCustomer(c5); walmart.addCustomer(c8); walmart.addCustomer(c12); walmart.addCustomer(c13); walmart.addCustomer(c14); walmart.addCustomer(c17); walmart.addCustomer(c19); walmart.addCustomer(c25); dollarama.addCustomer(c2); dollarama.addCustomer(c3); dollarama.addCustomer(c5); dollarama.addCustomer(c6); dollarama.addCustomer(c13); dollarama.addCustomer(c16); dollarama.addCustomer(c18); dollarama.addCustomer(c19); dollarama.addCustomer(c20); michaels.addCustomer(c1); michaels.addCustomer(c2); michaels.addCustomer(c7); michaels.addCustomer(c9); michaels.addCustomer(c15); michaels.addCustomer(c18); michaels.addCustomer(c22); michaels.addCustomer(c23); michaels.addCustomer(c24); michaels.addCustomer(c26); farmBoy.addCustomer(c1); farmBoy.addCustomer(c2); farmBoy.addCustomer(c5); farmBoy.addCustomer(c10); farmBoy.addCustomer(c11); farmBoy.addCustomer(c19); farmBoy.addCustomer(c21); farmBoy.addCustomer(c24); farmBoy.addCustomer(c25); // Determine whether or not certain customers shopped at the same store  System.out.println("Did Amie and Xeon shop at the same store: " + trainyards.shoppedAtSameStore(c1, c24)); System.out.println("Did Brad and Nick shop at the same store: " + trainyards.shoppedAtSameStore(c2, c14)); // Determine the number of unique Customers in the mall  System.out.println("The number of unique customers in the mall is: " + trainyards.uniqueCustomers()); } } 

public class DVD implements Comparable { private String title; private int year; private int duration; public DVD () { this ("",0,0); } public DVD (String newTitle, int y, int minutes) { title = newTitle; year = y; duration = minutes; } public int compareTo(Object obj) { if (obj instanceof DVD) { DVD aDVD = (DVD)obj; return title.compareTo(aDVD.title); } return 0; } public String getTitle() { return title; } public int getDuration() { return duration; } public int getYear() { return year; } public void setTitle(String t) { title = t; } public void setDuration(int d) { duration = d; } public void setYear(int y) { year = y; } public String toString() { return ("DVD (" + year + "): \"" + title + "\" with length: " + duration + " minutes"); } } 

import java.util.ArrayList; public class DVDCollection { private ArrayList dvds; private int selectedDVD; public DVDCollection() { dvds = new ArrayList(); selectedDVD = -1; } public void setSelectedDVD(int i) { selectedDVD = i; } public ArrayList getDvds() { return dvds; } public String toString() { return ("DVD Collection of size " + dvds.size()); } public void add(DVD aDvd) { dvds.add(aDvd); } public boolean remove(String title) { for (DVD d: dvds) { if (d.getTitle().equals(title)) { dvds.remove(d); return true; } } return false; } public void sortByTitle() { for (int p = 1; pint i = p - 1; while ((i >= 0) && (dvds.get(i).getTitle().compareTo(key.getTitle()) > 0)) { dvds.set(i+1, dvds.get(i)); i = i - 1; } dvds.set(i+1, key); } } public void sortByYear() { for (int p = 1; pint i = p - 1; while ((i >= 0) && (dvds.get(i).getYear() > key.getYear())) { dvds.set(i+1, dvds.get(i)); i = i - 1; } dvds.set(i+1, key); } } public void sortByLength() { for (int p = 1; p int i = p - 1; while ((i >= 0) && (dvds.get(i).getDuration() > key.getDuration())) { dvds.set(i+1, dvds.get(i)); i = i - 1; } dvds.set(i+1, key); } } public DVD oldestDVD() { DVD min = dvds.get(0); for (DVD d: dvds) { if (d.getYear() < min.getYear()) min = d; } return min; } public DVD newestDVD() { DVD max = dvds.get(0); for (DVD d: dvds) { if (d.getYear() > max.getYear()) max = d; } return max; } public DVD shortestDVD() { DVD min = dvds.get(0); for (DVD d: dvds) { if (d.getDuration() < min.getDuration()) min = d; } return min; } public DVD longestDVD() { DVD max = dvds.get(0); for (DVD d: dvds) { if (d.getDuration() > max.getDuration()) max = d; } return max; } public static DVDCollection example1() { DVDCollection c = new DVDCollection(); c.add(new DVD("If I Was a Student", 2007, 65)); c.add(new DVD("Don't Eat Your Pencil !", 1984, 112)); c.add(new DVD("The Exam", 2001, 180)); c.add(new DVD("Tutorial Thoughts", 2003, 128)); c.add(new DVD("Fried Monitors", 1999, 94)); return c; } public static DVDCollection example2() { DVDCollection c = new DVDCollection(); c.add(new DVD("Titanic",1997,194)); c.add(new DVD("Star Wars",1977,121)); c.add(new DVD("E.T. - The Extraterrestrial",1982,115)); c.add(new DVD("Spider Man",2002,121)); c.add(new DVD("Jurassic Park",1993,127)); c.add(new DVD("Finding Nemo",2003,100)); c.add(new DVD("The Lion King",1994,89)); c.add(new DVD("Up",2009,96)); c.add(new DVD("The Incredibles",2004,115)); c.add(new DVD("Monsters Inc.",2001,92)); c.add(new DVD("Cars",2006,117)); c.add(new DVD("Beverly Hills Cop",1984,105)); c.add(new DVD("Home Alone",1990,103)); c.add(new DVD("Jaws",1975,124)); c.add(new DVD("Men in Black",1997,98)); c.add(new DVD("Independence Day",1996,145)); c.add(new DVD("National Treasure: Book of Secrets",2007,124)); c.add(new DVD("Aladdin",1992,90)); c.add(new DVD("Twister",1996,113)); c.add(new DVD("Iron Man",2008,126)); c.add(new DVD("Alice in Wonderland",2010,108)); c.add(new DVD("Transformers",2007,144)); return c; } public static DVDCollection example3() { DVDCollection c = new DVDCollection(); c.add(new DVD("Avatar",2009,162)); c.add(new DVD("The Avengers",2012,143)); c.add(new DVD("Titanic",1997,194)); c.add(new DVD("The Dark Knight",2008,152)); c.add(new DVD("Star Wars",1977,121)); c.add(new DVD("Shrek 2",2004,93)); c.add(new DVD("E.T. - The Extraterrestrial",1982,115)); c.add(new DVD("Star Wars - Episode I",1999,136)); c.add(new DVD("Pirates of the Caribbean: Dead Man's Chest",2006,151)); c.add(new DVD("Toy Story 3",2010,103)); c.add(new DVD("Spider Man",2002,121)); c.add(new DVD("Transformers: Revenge of the Fallen",2009,150)); c.add(new DVD("Star Wars - Episode III",2005,140)); c.add(new DVD("Spider Man 2",2004,127)); c.add(new DVD("Jurassic Park",1993,127)); c.add(new DVD("Transformers: Dark of the Moon",2011,154)); c.add(new DVD("Finding Nemo",2003,100)); c.add(new DVD("Spider Man 3",2007,139)); c.add(new DVD("Forrest Gump",1994,142)); c.add(new DVD("The Lion King",1994,89)); c.add(new DVD("Shrek the Third",2007,93)); c.add(new DVD("The Sixth Sense",1999,107)); c.add(new DVD("Up",2009,96)); c.add(new DVD("I am Legend",2007,101)); c.add(new DVD("Shrek",2001,90)); c.add(new DVD("The Incredibles",2004,115)); c.add(new DVD("Monsters Inc.",2001,92)); c.add(new DVD("Brave",2012,100)); c.add(new DVD("Toy Story 2",1999,92)); c.add(new DVD("Cars",2006,117)); c.add(new DVD("Signs",2002,106)); c.add(new DVD("Hancock",2008,92)); c.add(new DVD("Rush Hour 2",2001,90)); c.add(new DVD("Meet the Fockers",2004,115)); c.add(new DVD("The Hangover",2009,100)); c.add(new DVD("My Big Fat Greek Wedding",2002,95)); c.add(new DVD("Beverly Hills Cop",1984,105)); c.add(new DVD("Mrs. Doubtfire",1993,125)); c.add(new DVD("The Hangover Part II",2011,102)); c.add(new DVD("The Matrix Reloaded",2003,138)); c.add(new DVD("Home Alone",1990,103)); c.add(new DVD("Jaws",1975,124)); c.add(new DVD("The Blind Side",2009,129)); c.add(new DVD("Men in Black",1997,98)); c.add(new DVD("X-Men: The Last Stand",2006,104)); c.add(new DVD("The Bourne Ultimatum",2007,115)); c.add(new DVD("WALL-E",2008,98)); c.add(new DVD("Inception",2010,148)); c.add(new DVD("Independence Day",1996,145)); c.add(new DVD("Pirates of the Caribbean: The Curse of the Black Pearl",2003,143)); c.add(new DVD("The Chronicles of Narnia",2005,143)); c.add(new DVD("War of the Worlds",2005,116)); c.add(new DVD("National Treasure: Book of Secrets",2007,124)); c.add(new DVD("Aladdin",1992,90)); c.add(new DVD("How to Train Your Dragon",2010,98)); c.add(new DVD("Shrek Forever After",2010,93)); c.add(new DVD("Twister",1996,113)); c.add(new DVD("Star Wars - Episode VI",1983,134)); c.add(new DVD("Iron Man",2008,126)); c.add(new DVD("Alice in Wonderland",2010,108)); c.add(new DVD("Transformers",2007,144)); c.add(new DVD("Star Wars - Episode II",2002,142)); return c; } } 

import javafx.application.Application; import javafx.collections.FXCollections; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.geometry.HPos; import javafx.geometry.Insets; import javafx.scene.Scene; import javafx.scene.control.*; import javafx.scene.input.MouseEvent; import javafx.scene.layout.GridPane; import javafx.scene.layout.VBox; import javafx.stage.Stage; import java.util.ArrayList; import java.util.Optional; public class DVDCollectionApp extends Application { private DVDCollection model; private ListView tList; private TextField tField, yField, lField; public DVDCollectionApp() { model = DVDCollection.example2(); } public void start(Stage primaryStage) { VBox topPane = new VBox(); GridPane aPane = new GridPane(); aPane.setPadding(new Insets(10, 10, 10, 10)); // Create the labels  Label label1 = new Label("DVDs"); aPane.add(label1,0,0,1,1); aPane.setMargin(label1, new Insets(0, 0, 5, 0)); Label label2 = new Label("Title"); aPane.add(label2,0,2,1,1); Label label3 = new Label("Year"); aPane.add(label3,0,3,1,1); Label label4 = new Label("Length"); aPane.setMargin(label4, new Insets(0, 10, 0, 10)); aPane.add(label4,2,3,1,1); // Create the TextFields  tField = new TextField(); aPane.add(tField,1,2,6,1); aPane.setMargin(tField, new Insets(10, 0, 10, 0)); tField.setMinSize(500,30); tField.setPrefSize(2000,30); yField = new TextField(); aPane.add(yField,1,3,1,1); yField.setPrefSize(55,30); lField = new TextField(); aPane.add(lField,3,3,1,1); lField.setPrefSize(45,30); aPane.setMargin(lField, new Insets(0, 10, 0, 0)); // Create the list  tList = new ListView(); aPane.add(tList,0,1,7,1); tList.setMinSize(540,150); tList.setPrefSize(2000,2000); /// Create the buttons  Button addButton = new Button("Add"); addButton.setStyle("-fx-font: 12 arial; -fx-base: rgb(0,100,0); -fx-text-fill: rgb(255,255,255);"); aPane.add(addButton,4,3,1,1); addButton.setPrefSize(90,30); aPane.setMargin(addButton, new Insets(0, 5, 0, 5)); Button deleteButton = new Button("Delete"); deleteButton.setStyle("-fx-font: 12 arial; -fx-base: rgb(200,0,0); -fx-text-fill: rgb(255,255,255);"); aPane.add(deleteButton,5,3,1,1); deleteButton.setPrefSize(90,30); aPane.setMargin(deleteButton, new Insets(0, 5, 0, 5)); Button statsButton = new Button("Stats"); statsButton.setStyle("-fx-font: 12 arial;"); aPane.add(statsButton,6,3,1,1); statsButton.setPrefSize(90,30); aPane.setMargin(statsButton, new Insets(0, 0, 0, 5)); aPane.setHalignment(statsButton, HPos.RIGHT); // Populate the lists  ArrayList theList = model.getDvds(); tList.setItems(FXCollections.observableArrayList(theList)); // Add all the components to the Pane  aPane.setPrefSize(548, 268); Menu fileMenu = new Menu("_File"); MenuItem exampleItem = new MenuItem("Load Example List"); fileMenu.getItems().addAll(exampleItem); Menu sortMenu = new Menu("_Sort"); RadioMenuItem titleItem = new RadioMenuItem("By Title"); RadioMenuItem yearItem = new RadioMenuItem("By Year"); RadioMenuItem lengthItem = new RadioMenuItem("By Length"); ToggleGroup settingGroup = new ToggleGroup(); titleItem.setToggleGroup(settingGroup); yearItem.setToggleGroup(settingGroup); lengthItem.setToggleGroup(settingGroup); sortMenu.getItems().addAll(titleItem, yearItem, lengthItem); // Add the menus to a menubar and then add the menubar to the pane  MenuBar menuBar = new MenuBar(); menuBar.getMenus().addAll(fileMenu, sortMenu); topPane.getChildren().addAll(menuBar, aPane); exampleItem.setOnAction(new EventHandler() { public void handle(ActionEvent e) { TextInputDialog dialog = new TextInputDialog("1"); dialog.setTitle("Input Required"); dialog.setHeaderText(null); dialog.setContentText("Enter example list number to load (1, 2, or 3):"); Optional result = dialog.showAndWait(); if (result.isPresent()){ switch(Integer.parseInt(result.get())) { case 1: model = DVDCollection.example1(); break; case 2: model = DVDCollection.example2(); break; case 3: model = DVDCollection.example3(); break; } ArrayList theList = model.getDvds(); tList.setItems(FXCollections.observableArrayList(theList)); } } }); addButton.setOnAction(new EventHandler() { public void handle(ActionEvent actionEvent) { DVD d = new DVD(); // Now bring up the dialog box  Dialog dialog = new AddDVDDialog(primaryStage, "New DVD Details", d); Optional result = dialog.showAndWait(); if (result.isPresent()) { model.add(d); // Add the DVD to the model  update(model, model.getDvds().size() - 1); } } }); statsButton.setOnAction(new EventHandler() { public void handle(ActionEvent actionEvent) { // Now bring up the dialog box  Dialog dialog = new StatsDialog(primaryStage, model); dialog.showAndWait(); } }); deleteButton.setOnAction(new EventHandler() { public void handle(ActionEvent actionEvent) { if (tList.getSelectionModel().getSelectedItem() != null) { Alert alert = new Alert(Alert.AlertType.CONFIRMATION); alert.setTitle("Please Confirm"); alert.setHeaderText(null); alert.setContentText("Are you sure that you want to remove this DVD from the collection ?"); Optional result = alert.showAndWait(); if (result.get() == ButtonType.OK){ model.remove(tList.getSelectionModel().getSelectedItem().getTitle()); update(model, -1); } // model.remove(tList.getSelectionModel().getSelectedItem().getTitle());  //update(model, tList.getSelectionModel().getSelectedIndex());  } } }); tList.setOnMousePressed(new EventHandler() { public void handle(MouseEvent mouseEvent) { model.setSelectedDVD(tList.getSelectionModel().getSelectedIndex()); update(model, tList.getSelectionModel().getSelectedIndex()); } }); titleItem.setOnAction(new EventHandler() { public void handle(ActionEvent e) { model.sortByTitle(); ArrayList theList = model.getDvds(); tList.setItems(FXCollections.observableArrayList(theList)); update(model, tList.getSelectionModel().getSelectedIndex()); } }); yearItem.setOnAction(new EventHandler() { public void handle(ActionEvent e) { model.sortByYear(); ArrayList theList = model.getDvds(); tList.setItems(FXCollections.observableArrayList(theList)); update(model, tList.getSelectionModel().getSelectedIndex()); } }); lengthItem.setOnAction(new EventHandler() { public void handle(ActionEvent e) { model.sortByLength(); ArrayList theList = model.getDvds(); tList.setItems(FXCollections.observableArrayList(theList)); update(model, tList.getSelectionModel().getSelectedIndex()); } }); primaryStage.setTitle("My DVD Collection"); primaryStage.setScene(new Scene(topPane)); primaryStage.show(); } // Update the view to reflect the model  public void update(DVDCollection model, int selectedDVD) { ArrayList theList = model.getDvds(); tList.setItems(FXCollections.observableArrayList(theList)); DVD d = tList.getSelectionModel().getSelectedItem(); if (d != null) { tField.setText(d.getTitle()); yField.setText(""+d.getYear()); lField.setText(""+d.getDuration()); } else { tField.setText(""); yField.setText(""); lField.setText(""); } tList.getSelectionModel().select(selectedDVD); } public static void main(String[] args) { launch(args); } }