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Semester 1/Programming 1/Java/examples/projects/chapter02/better-ticket-machine/README.TXT

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+Project: better-ticket-machine
+Authors: David Barnes and Michael Kölling
+
+This project is part of the material for the book
+
+   Objects First with Java - A Practical Introduction using BlueJ
+   Sixth edition
+   David J. Barnes and Michael Kölling
+   Pearson Education, 2016
+
+It is discussed in chapter 2.
+
+Purpose of project: To illustrate conditional statements.
+How to start this project: Create one or more TicketMachine objects.
+

Semester 1/Programming 1/Java/examples/projects/chapter02/better-ticket-machine/TicketMachine.ctxt

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+#BlueJ class context
+comment0.params=cost
+comment0.target=TicketMachine(int)
+comment0.text=\n\ Create\ a\ machine\ that\ issues\ tickets\ of\ the\ given\ price.\n
+comment1.params=
+comment1.target=int\ getPrice()
+comment1.text=\n\ @Return\ The\ price\ of\ a\ ticket.\n
+comment2.params=
+comment2.target=int\ getBalance()
+comment2.text=\n\ Return\ The\ amount\ of\ money\ already\ inserted\ for\ the\n\ next\ ticket.\n
+comment3.params=amount
+comment3.target=void\ insertMoney(int)
+comment3.text=\n\ Receive\ an\ amount\ of\ money\ from\ a\ customer.\n\ Check\ that\ the\ amount\ is\ sensible.\n
+comment4.params=
+comment4.target=void\ printTicket()
+comment4.text=\n\ Print\ a\ ticket\ if\ enough\ money\ has\ been\ inserted,\ and\n\ reduce\ the\ current\ balance\ by\ the\ ticket\ price.\ Print\n\ an\ error\ message\ if\ more\ money\ is\ required.\n
+comment5.params=
+comment5.target=int\ refundBalance()
+comment5.text=\n\ Return\ the\ money\ in\ the\ balance.\n\ The\ balance\ is\ cleared.\n
+numComments=6

Semester 1/Programming 1/Java/examples/projects/chapter02/better-ticket-machine/TicketMachine.java

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+/**
+ * TicketMachine models a ticket machine that issues
+ * flat-fare tickets.
+ * The price of a ticket is specified via the constructor.
+ * Instances will check to ensure that a user only enters
+ * sensible amounts of money, and will only print a ticket
+ * if enough money has been input.
+ * 
+ * @author David J. Barnes and Michael Kölling
+ * @version 2016.02.29
+ */
+public class TicketMachine
+{
+    // The price of a ticket from this machine.
+    private int price;
+    // The amount of money entered by a customer so far.
+    private int balance;
+    // The total amount of money collected by this machine.
+    private int total;
+
+    /**
+     * Create a machine that issues tickets of the given price.
+     */
+    public TicketMachine(int cost)
+    {
+        price = cost;
+        balance = 0;
+        total = 0;
+    }
+
+    /**
+     * @Return The price of a ticket.
+     */
+    public int getPrice()
+    {
+        return price;
+    }
+
+    /**
+     * Return The amount of money already inserted for the
+     * next ticket.
+     */
+    public int getBalance()
+    {
+        return balance;
+    }
+
+    /**
+     * Receive an amount of money from a customer.
+     * Check that the amount is sensible.
+     */
+    public void insertMoney(int amount)
+    {
+        if(amount > 0) {
+            balance = balance + amount;
+        }
+        else {
+            System.out.println("Use a positive amount rather than: " +
+                               amount);
+        }
+    }
+
+    /**
+     * Print a ticket if enough money has been inserted, and
+     * reduce the current balance by the ticket price. Print
+     * an error message if more money is required.
+     */
+    public void printTicket()
+    {
+        if(balance >= price) {
+            // Simulate the printing of a ticket.
+            System.out.println("##################");
+            System.out.println("# The BlueJ Line");
+            System.out.println("# Ticket");
+            System.out.println("# " + price + " cents.");
+            System.out.println("##################");
+            System.out.println();
+
+            // Update the total collected with the price.
+            total = total + price;
+            // Reduce the balance by the price.
+            balance = balance - price;
+        }
+        else {
+            System.out.println("You must insert at least: " +
+                               (price - balance) + " more cents.");
+                    
+        }
+    }
+
+    /**
+     * Return the money in the balance.
+     * The balance is cleared.
+     */
+    public int refundBalance()
+    {
+        int amountToRefund;
+        amountToRefund = balance;
+        balance = 0;
+        return amountToRefund;
+    }
+}

Semester 1/Programming 1/Java/examples/projects/chapter02/better-ticket-machine/package.bluej

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+#BlueJ package file
+objectbench.height=89
+objectbench.width=692
+package.editor.height=344
+package.editor.width=584
+package.editor.x=70
+package.editor.y=80
+package.numDependencies=0
+package.numTargets=1
+package.showExtends=true
+package.showUses=true
+project.charset=UTF-8
+readme.editor.height=609
+readme.editor.width=798
+readme.editor.x=53
+readme.editor.y=23
+target1.editor.height=661
+target1.editor.width=780
+target1.editor.x=53
+target1.editor.y=34
+target1.height=60
+target1.name=TicketMachine
+target1.naviview.expanded=false
+target1.showInterface=false
+target1.type=ClassTarget
+target1.typeParameters=
+target1.width=120
+target1.x=190
+target1.y=110