State machines are just plain cool. They get right to the point without using conditionals.

The reason for the public access is that the methods are called by another object. Generally, when you have a return value, you can expect an external call(not if the call is made within the same class, of course).

thanks

Why not join Mystery Person and come with a non-dp example of changing view states and we can use it for refactoring.

Thanks,
Bill

I’ve been working on another State Design Pattern for a magazine article I’m doing, and I agree that greater variety of State dps (from me at least) would be a good thing.(The new one I’m working on has nothing to do with video, and Chandima pitched in and got the project back on track after I got stuck in the mud). It turns out that some tricky operations are involved when you get away from system level operations that can be found in NetStream objects.

Changing view states sounds like a great challenge. How about this?——hack together an example of what you have in mind, and I’ll work it into a State dp. In that way I can see exactly what you have in mind and you can see how to approach refactoring with a common ‘real world’ use that our readers can gain value from as well.

Kindest regards,
Bill

thanks for all your well written articles! Regarding the state pattern: The video player is a common, simple and useful example to demonstrate the pattern, however, it would be interesting to see an implementation of a more “tricky” example. For example, imagine a web application that has different view states and transitions (animations) from one state to the next. One would have to deal with asynchronous events (transitioning to the next state as soon as the animation is complete). In addition, mouse clicks from users must be blocked during the transition to prevent unwanted side effects with the animation. Overall, much more coordination would be necessary. Would there be separate “animationIn” or “animationOut” states etc., where and how are the events handled? I think this is a common scenario for a lot of flash sites, web apps and would make for a useful “real-world” example (video players are, of course, also very “real-world” but maybe a bit overused for the state pattern ;)