Book Image

Google App Inventor

By : Ralph Roberts
Book Image

Google App Inventor

By: Ralph Roberts

Overview of this book

<center><iframe src="http://www.youtube.com/embed/UgRhYG_bvW8" width="500" height="315" frameborder="0"></iframe></center> <p>The number of mobile apps has grown exponentially in the last two years. If you want to join the crowd, Google’s App Inventor is the easiest and best tool for you to get started with. It is a tool to create Android phone apps and uses a graphical user interface, and drag and drop methods to create apps. It’s so simple that anyone can build an app.<br /><br />Learn how Google App Inventor eliminates the mystery around programming. It is a visual language, where we simply drag and drop blocks (graphic elements representing blocks of code) in various combinations to give us applications that run on our phones or other Android-based devices. No programming background is required. Playing with blocks has never been more fun!<br /><br />The emphasis is on creating apps that work and that you understand fully. The first part of the book gives you a sound foundation in the basics, and lots of tips on how to use App Inventor. The second part is all about creating complete apps ready for real world use. The book includes apps that communicate, use databases to remember, surf the Web and other networks, use GPS and various sensors on your phone, and let you write or play games.</p>
Table of Contents (19 chapters)
Google App Inventor
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface

Definition blocks


On the left side of the Blocks Editor screen, we have two columns of blocks. Left-click on the column tab—Built-In or My Blocks—to reveal the headings (we call them "drawers" in each of those two categories (see the following screenshot for location):

Starting a new app in Designer then opening the Blocks Editor and clicking on the My Blocks tab shows us that there is very little in it initially. The My Definitions drawer is empty because we have not defined anything yet (but will in this section). The Screen1 has a number of blocks relating to screen control in it because the Screen1 component exists by default. Currently, only one Screen component per app is possible.

One quick note about the statement, "only one Screen component per app is possible". Those of you with a little programming experience are already screaming (and rightly so) "you can't do anything with just one screen!" Well, not to worry—we can have as many virtual screens as we like, and I'll show you...