It seems that our ArrayList, BaseAdapter, and ListView combination, while versatile and timesaving, does not persist when the app is quit. In Chapter 15, Android Intent and Persistence, we will add the Settings menu and look at two separate solutions to save data in a persistent way. One for simple data, such as the Settings screen options and one for more complex data, such as the objects in ArrayList.

In Chapter 16, UI Animations, we will also add some simple animations to Note To Self that make the user's experience more visually pleasing. We will also experiment with an animation mini app.

The addition of pleasing sounds can enhance an app as well as give audible feedback to the user that the action they just took was successful. In Chapter 17, Sound FX and Supporting Different Versions of Android we will add sound to Note To Self, as well as experiment with sounds in a mini app.

It might seem worthwhile if noteList was a class of its own. Actually, it probably should be. It would make a lot of sense to have a class that held ArrayList and provided us access to that list with a getter method. Furthermore, it would allow us to put into effect other best practices. As an example, we could ensure that we only ever have one noteList, and wherever this notelist is accessed from, throughout our app, there would be no danger of creating a second, third, or fourth list.

You have learned many new classes and concepts in the last few chapters, and you will learn a lot more in the next three. Therefore, I thought I would defer the discussion of the Java singleton, which helps us achieve all these things, until Chapter 18, Design Patterns, Fragments, and the Real World, where we will also discuss design patterns that are useful for Android and programming in general.