Coding the PongActivity class
In this project, as discussed previously, we will have multiple classes. Four to be exact. The Activity class provided by the Android API is the class that interacts with the operating system. We have already seen how the OS interacts with onCreate when the player clicks the app icon to start an app (or our game). Furthermore, we have seen how the operating system calls the onTouchEvent method when the user interacts with the screen, giving us the opportunity to make our game respond appropriately.
As this game is more complicated and needs to respond in real-time it is necessary to use a slightly more in-depth structure. At first this seems like a complication but in the long run, it makes our code more simple and easy to understand.
Rather than have a class called Pong (analogous to SubHunter) that does everything, we will have a class which just handles start-up and shutdown of our game as well as help a bit with initialization by getting the screen resolution...
