Manual De App Inventor

Foreword

Our consumer culture gives us all sorts of opportunities for entertainment, pleasure and sometimes even learning. However, by and large, these are passive activities. That’s OK—we all like to kick back sometimes and be entertained—but it shouldn’t be the whole picture. In addition to the appeal of consuming, there’s the satisfaction of producing—that is, of creating. It’s the joy andpride that results when we draw a picture, build a model airplane, or bake some bread. The high-tech objects (like cell phones, tablet computers, TVs, etc.) that we use today to consume entertainment and information are black boxes to most of us. Their workings are incomprehensible and, while there are capabilities in some of them that enable the user to draw pictures, make videos, etc., they arenot, in and of themselves, creative media. In other words, most people can’t create the apps that run on these gadgets. What if we could change that? What if we could take creative control of our everyday gadgets, like cell phones? What if building an app for your cell phone was as easy as drawing a picture or baking a loaf of bread? What if we could close the gap between the objects of ourconsumer culture and the media of our creative lives? For one, it could demystify those objects. Rather than being black boxes, impenetrable to our sight, they become objects that can be tinkered with. They become objects capable of our understanding. We gain a less passive and more creative relationship to them, and we get to play with these devices in a much deeper, more significant way when we canactually build things for them. When Hal Abelson first spoke to me about the idea that became App Inventor, we talked about the unique motivating force that cell phones could have in education. He wondered if we could use that motivating force to help introduce students to concepts in computer science. As we built it and tried it in classes like Dave Wolber’s, we started to realize that somethingeven more powerful was happening: App Inventor was starting to turn students from consumers to creators. Students thought it was fun

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and exhilarating to build apps for their phones! When one of Dave’s students built the simple but powerful “No Texting While Driving” app, we really started to imagine what would happen if anybody, not just professional software engineers, couldbuild an app. So we worked hard to make App Inventor easier and more fun to use. We’ve worked to make it more powerful (but still simple) as well. And we’re continuing this work—App Inventor is still a beta product and we have exciting plans for it. The authors of this book are truly world-class educators and software engineers. I’d like to personally thank them for their work in building, testing,and documenting the App Inventor for Android product and, of course, for writing this wonderful book. Now go, unleash your creativity and build an app! —Mark Friedman Tech Lead and Manager of the App Inventor for Android project, Google

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Preface

You’re on your regular running route, just jogging along, and an idea for the next killer mobile app hits you. All the way home, you don’t evencare what your time is, all you can think about is getting your idea out there. But how exactly do you do that? You’re no programmer, and that would take years, and time is money, and…well, someone has probably done it already anyway. Just like that, your idea is dead in the water. Now imagine a different world, where creating apps doesn’t require years of programming experience, where artists,scientists, humanitarians, health-care workers, attorneys, firefighters, marathon runners, football coaches, and people from all walks of life can create apps. Imagine a world where you can transform ideas into prototypes without hiring programmers, where you can make apps that work specifically for you, where you can adapt mobile computing to fit your personal needs. This is the world of App...