Book Image

Mastering Android Studio 3

By : Kyle Mew
Book Image

Mastering Android Studio 3

By: Kyle Mew

Overview of this book

Android Studio is an Integrated Development Environment (IDE) designed for developing Android apps. As with most development processes, Android keeps resources and logic nicely separated, and so this book covers the management of imagery and other resources, and the development and testing tools provided by the IDE. After introducing the software, the book moves straight into UI development using the sophisticated, WYSIWYG layout editor and XML code to design and test complex interfaces for a wide variety of screen configurations. With activity design covered, the book continues to guide the reader through application logic development, exploring the latest APIs provided by the SDK. Each topic will be demonstrated by working code samples that can be run on a device or emulator. One of Android Studio's greatest features is the large number of third-party plugins available for it, and throughout the book we will be exploring the most useful of these, along with samples and libraries that can be found on GitHub. The final module of the book deals with the final stages of development: building and distribution. The book concludes by taking the reader through the registration and publication processes required by Google. By the time you have finished the book, you will be able to build faster, smoother, and error-free Android applications, in less time and with fewer complications than you ever thought possible.
Table of Contents (10 chapters)

Logcat filters

One of the simplest, but nevertheless the most useful debugging, techniques is the simple inclusion of a Logcat filter. This can be used to report variable values or simply keep track of which methods are being called. This is of particular use when keeping track of processes that are not visibly apparent, such as services, broadcast receivers and callbacks that have no obvious impact on the UI.

Perhaps the very simplest debug tool available, and useful when we are in a hurry and just want to check for a single value or event, is to include a line like:

System.out.println("Something happened here"); 

This is only an on the fly solution as the output will be buried in among the rest of the Logcat text. Far easier to manage is to configure a Logcat filter. The following short exercise demonstrates how this is done:

  1. Start a new project, or open a new one...