Chapter 28. Threads, Touches, Drawing, and a Simple Game

So far throughout the book, we have concentrated on using the diverse range of UI widgets provided by the Android API. In conventional apps, this is almost always the best way to do things.

For example, why would we want to reinvent a widget that has been designed and refined by experts?

Lots of Android apps, however, are not based on this conventional appearance. Think of the multitude of kids' or artists' drawing apps. And what about the best selling category on Google Play: games?

In this chapter, we will look at and play with the skills and Android classes that are needed to build apps of this type. The topics for this chapter are:

• Threads: How to run more than one block of code simultaneously
• Drawing: How we use the Canvas and Paint classes for pixels, lines, shapes, and custom text, including a mini app
• Screen touches: Detecting and responding to screen touches that are not on a UI widget
• Pong: Combining the first...