1   // joi/4/estore/ShoppingCart.java  
2   //
3   //
4   // Copyright 2003 Bill Campbell and Ethan Bolker
5   
6   /**
7    * A ShoppingCart keeps track of a customer's purchases.
8    *
9    * @see EStore
10   * @version 4
11   */
12  
13  public class ShoppingCart
14  {
15      /// replace these two fields by a single ArrayList 
16      private int count; // number of Items in this ShoppingCart
17      private int cost;  // total cost of Items in this ShoppingCart
18      
19      /**
20       * Construct a new empty ShoppingCart.
21       */
22  
23      public ShoppingCart()
24      {
25          count = 0; 
26          cost  = 0;
27      }
28  
29      /**
30       * Add an Item to this ShoppingCart.
31       *
32       * @param item the Item to add.
33       */
34  
35      public void addItem( Item item )
36      {
37          /// this code just keeps track of the totals
38          /// replace it with code that adds the item to the list
39          count++; 
40          this.cost += item.getCost(); // Java idiom: a += b means a = a + b 
41      }
42  
43      /**
44       * Return an Item from this ShoppingCart.
45       *
46       * @param item the Item to return.
47       */
48  
49      public void returnItem( Item item )
50      {
51          /// look through the list looking for Item
52          /// remove it if it's there
53      }
54  
55      /** 
56       * What happens when this ShoppingCart is asked how many
57       * Items it contains.
58       *
59       * @return the number of items in this ShoppingCart.
60       */
61  
62      public int getCount()
63      {
64          /// get this information from the list,
65          /// since the count field no longer exists
66          return count;
67      }
68  
69      /** 
70       * What happens when this ShoppingCart is asked the total
71       * cost of the Items it contains.
72       *
73       * @return the total cost of the items in this ShoppingCart.
74       */
75      public int getCost()
76      {
77          /// get this information from the list,
78          /// since the cost field no longer exists
79          return cost;
80      }
81  
82      /**
83       * Write the contents of this ShoppingCart to a Terminal.
84       *
85       * @param t the Terminal to use for output.
86       */
87  
88      public void showContents( Terminal t) 
89      {
90          /// work to do here ...
91          t.println("  [sorry, can't yet print ShoppingCart contents]");
92      }
93  }
94