Design Patterns Explained

Example 15-1 Java Code Fragment: Decorator (continued)
Chapter 15 • The Decorator Pattern 247
Component myST;
// Get chain of Decorators and SalesTicket built by
// another object that knows the rules to use.
// This may be done in constructor instead of
// each time this is called.
myST= Configuration.getSalesTicket()
// Print Ticket with headers and footers as needed
myST.prtTicket 0 ; } }
If I want the sales ticket to look like:
HEADER 1
SALES TICKET
FOOTER 1
Then Configuration.getsalesTicket returns
return( new Headerl( new Footerl( new SalesTicket())};
This creates a Headerl object trailed by a Footerl object trailed by a
SalesTicket object.
If I want the sales ticket to look like:
HEADER 1
HEADER 2 SALES
TICKET FOOTER 1
Then Configuration.getsalesTicket returns
return( new Headerl( new Header2 (new Footerl(
new SalesTicket ())});
What happens in
the code