I am having trouble wrapping my head around game design. On the android platform, I have an activity and set its content view with a custom surface view. The custom surface view acts as my panel and I create instances of all classes and do all the drawing and calculation in there.

Question: Should I instead create the instances of other classes in my activity?

Now I create a custom thread class that handles the game loop.

Question: How do I use this one class in all my activities? Or do I have to create a separate thread each time?

In my previous game, I had multiple levels that had to create an instance of the thread class and in the thread class I had to set constructor methods for each separate level and in the loop use a switch statement to check which level it needs to render and update. Sorry if that sounds confusing.

I just want to know if the method I am using is inefficient (which it probably is) and how to go about designing it the correct way. I have read many tutorials out there and I am still having lots of trouble with this particular topic. Maybe a link to a some tutorials that explain this? Thanks.