AndroidTM programming is an attractive proposition. There are more Androidusers than any other smartphone or tablet and this makes it a potentially hugemarket. Android devices are relatively cheap and this makes it suitable forimplementing smaller scale projects. Finally the tools that you need are freeto download and use and you don’t need anyone's permission to get started.The only difficulty is that Android is a tough system to master. It is easyenough to get started as Android Studio will build you a Hello World app in afew minutes, but what you do next is more difficult. You can get asurprisingly long way in Android programming by simply copying andpasting code from other programs that roughly do what you want, but theresults are usually unreliable and disappointing. To create a good app there isno substitute for understanding how the system works and appreciating itsstrong points and its limitations.This book aims not only to show you how common tasks are done inAndroid, but to make sure that you understand why they are done in aparticular way. This means covering not just the “what” but also the “why”.The good news is that this isn’t as difficult as you might expect becauseAndroid does have repeating patterns and ways of doing things and once youhave seen something in action you find it generalizes to components youhaven’t encountered.This isn’t a book full of complete examples and case studies. In fact theexamples are stripped down to their bare minimum to avoid having to presentlines of irrelevant and repetitious code and to let you see what is essential. Italso isn’t a complete treatment of everything Android. A single book thatcovered every aspect of the Android system would be too large to pick up andcarry. Instead it tackles the things you need to know to write a simple app. Itfocuses on creating the user interface (UI) because this is what you spendmost of your time working on even if the app in question…