Book Image

Android 3.0 Application Development Cookbook

By : Kyle Merrifield Mew
Book Image

Android 3.0 Application Development Cookbook

By: Kyle Merrifield Mew

Overview of this book

<p>Android is a mobile operating system that runs on a staggering number of smartphones and tablets. Android offers developers the ability to build extremely rich and innovative applications written using the Java programming language. Among the number of books that have been published on the topic, what&rsquo;s missing is a thoroughly practical, hands-on book that takes you straight to getting your job done without boring you with too much theory.<br /><br />Android 3.0 Application Development Cookbook will take you straight to the information you need to get your applications up and running. This book is written to provide you with the shortest possible route between an idea and a working application. <br /><br />Work through the book from start to finish to become an Android expert, or use it as a reference book by applying recipes directly to your project.<br /><br />This book covers every aspect of mobile app development, starting with major application components and screen layout and design, before moving on to how to manage sensors such as internal gyroscopes and near field communications. Towards the end, it delves into smartphone multimedia capabilities as well as graphics and animation, web access, and GPS. <br /><br />Whether you are writing your first app or your hundredth, this is a book that you will come back to time and time again, with its many tips and tricks on the rich features of Android 3.</p>
Table of Contents (18 chapters)
Android 3.0 Application Development Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Defining and enforcing permissions


As anyone who has downloaded and installed an Android application will have seen, certain actions such as accessing the Internet or receiving SMS require explicit permissions from the user at the point of installation. This is because the default security only allows application processes to run isolated from each other unless specified.

Getting ready

We will be returning to the Android Manifest XML file in this recipe to set our permissions, but we will need a screen with a Button, to trigger our action and some Java code to give our application something to do.

Start a new Android project in Eclipse and edit the main.xml file in the res/layout folder so that it contains a Button with an ID@+id/button is fine.

How to do it...

  1. Inside our main activity Java file, declare a Button widget and reference the XML in the usual way with findViewById():

    mButton = (Button) findViewById(R.id.button);
  2. Create a click listener with an onClick() method and have it start the...