Hi,

I'm a newcomer to Android and am still trying to get my head around the framework - so bear with me!

If you have say an application with a 'main' view and 2 different types of list 'view' which all need to be displayed independently, does each "view" have to be implemented by a separate class derived from Activity (or ListActivity in the case of lists) ?

More generally if I have an application with N Activities that all need access to an 'engine' class, I've read on other forums that I'd have to implement the Engine using a Singleton pattern to allow the different activities to access to the engine

Is this is the only/best/recommended way to do it in the Android? Are there alternatives - just out of interest? I understand that you can use Bundle to pass information between classes, but this doesn't apply to more complex objects. Using a contentProvider doesn't seeem appropriate for what I want to do either.

thanks

Well.. a singleton is a good and common way of serving those needs but there isnt a best way.. and to say whether this is recommended for your needs or not is hard to say without knowing what exactly you want to achieve
But i can say for sure that this isnt the only way. As far as i understand the architecture of services (haven't use them yet) i think running some sort of Engine Service thats running in background would be a way too. The other activitys just binding on that service and use it or interact with it with some kind of selfmade protocol.
I use the bundle way at the moment because its easy and fits my needs.. and i send a relative huge and complex
objekt in the bundle.
I just have implemented serializable interface in all the classes of the objekt and bundled it after that... just works perfect

And to the view question.. its up to you.. you can implement those lists as plain views and then hide and show them when you have to... or you use a own listactivity and start and close it when you have to.
The listactivity is just a convenient class for a simple way of creating an app that just needs a list or is based on a list.

Greets
Padde

Thanks for the answer, I hadn't thought of using a service. You've given me some good food for thought.

nice one!

cheers.