170 | Chapter 4: Decorator Pattern
For this particular application, we’re not concerned with separating the individual
costs. In fact, we want each cost to be accumulated with the others, including the
cost of the concrete component we’re decorating. So while the string value needs the
tilde (~) for demarcation purposes, we don’t need it for the numeric value.
Setting Up the User Interface
The largest single class we’re going to use is the one to create the user interface. The
line numbers appear in the Example 4-48 for the purpose of referencing lines in the
code. A lot of the work done by this class, namedDeal, is to set up the interface
objects. These include the radio button, checkbox, and button components. Addi-
tionally, a good hunk of code is required for the text field output window and for-
matting for the output. So while the interface to the decorator pattern may look
unwieldy, it’s not decorator pattern’s fault. In fact, only thegetCar( )(beginning on
line 115) andgetOptions( )(beginning on line146) private functions are employed to
pull out the information generated by the Decorator pattern.
To get a handle on what the class does, enter the code from Example 4-48 and save it
asDeal.as.
}
override public function getInformation( ):String
{
return auto.getInformation( ) + " MP3 Player~";
}
override public function price( ):Number
{
return 267.55 + auto.price( );
}
}
}
Example 4-48. Deal.as
1 package
2 {
3 import fl.controls.CheckBox;
4 import fl.controls.RadioButton;
5 import fl.controls.Button;
6 import flash.display.Sprite;
7 import flash.display.MovieClip;
8 import flash.events.MouseEvent;
9 import flash.text.TextField;
10 import flash.text.TextFormat;
11
12 public class Deal extends Sprite
13 {
14 internal var checks:Array=[];
15 internal var cars:Array=[];Example 4-47. MP3.as (continued)