ActionScript 3.0 Design Patterns.pdf - VideoTutorials-bg.com

Now that you have an abstract Strategy design pattern where you can see the arrangement
of the different parts, an illustration where you can see all of the connections,
delegation and interactions in a single view will give you an overview of the process.
Figure 11-3 shows the connections between the different parts, all in one view.
Figure 11-3. Delegation connections
In Figure 11-3, note how the call:
thinker.doStrategy( );
is delegated. The thinker instance in the TestStrategy class is typed as a Context type
and instantiated as a ConcreteContext object. The doStrategy( ) method is created in
the Context class, and so that would be the first place to look, as the arrow from
doStrategy( ) in the TestStrategy class to the doStrategy( ) in the Context class
shows.
However, in the Context class the doStrategy( ) method has delegated the details to
the think( ) method, so we need to look elsewhere. In the ConcreteStrategy class, you
can see the details of the think( ) method. Because the ConcreteContext strategy is
instantiated in the thinker instance, it actually did the work, but since ConcreteContext
is a subclass of Context, the delegation is structured in the Context class.
Finally, we can trace the delegation framework back to the Strategy interface.
Because the origin of the think( ) method is in the Strategy class, we can see how it
is a delegate of the Context class.
Minimalist Abstract State Pattern | 405