ActionScript 3.0 Design Patterns

Example: Print Shop | 75

The class structure is very similar to the minimalist example shown in Figure 2-3.

The products will be print jobs that will be created and the creators will be the print

centers (see class diagram in Figure 2-6).

Product Classes: Print Jobs

The product classes don’t do anything at this point, but in a real application they will

initiate billing and dispatch print jobs to a print server. The print job classes belong

to the printcenters package. Example 2-8 shows the IPrintjob interface that

declares a parameterized method calledstart( )that takes a file name of a document

to print.

Figure 2-5. Project window for the print shop example

Figure 2-6. Class diagram for the print shop example

Client PrintCenter

print()

createPrintjob()

print() {

..

printjob=createPrintjob()

..

IPrintjob }

LowVoIPrintCenter

factoryMethod()

InkjetPrintjob

WorkgroupPrintjob HighVoIPrintCenter

createPrintjob()