xvi Introduction Goal of This Book This book is intended to show off some interesting visual effects that can be implemented in JavaFX. The chapters explore particle effects, realistic animations driven by physics, and a number of other techniques. The first set of chapters look at each effect in isolation, and then the last chapters look at some of these effects in combination. The book concludes by presenting an entire sample application. The book's goal is to provide a developer with a number of new tools that can be used to spruce up an old application or used in a new application. Given the newness of JavaFX at the time this book was written, I suspect that most developers are in the evaluation phase, exploring whether JavaFX is a worthwhile technology for some new project. I hope some of the effects in this book will convince you that JavaFX has a lot of promise. While always keeping the needs of developers in mind, I will also spend some time looking at why applications require graphics at all, and how leveraging experts in visual design and user experience will greatly improve the end result. This book was written by first messing around with JavaFX code to produce something interesting, then writing a little about it, and finally cleaning up the source code with the help of my technical reviewer. I bring this up to point out that the accompanying source code is really the heart of this book; it drove the content of these chapters. For the book to achieve its goal, I believe it is best consumed with the code handy. Go fire up NetBeans and run the example code as you get to each chapter, I think it will add a lot. Besides, this book is in black and white, while many of the examples are rich in color. Who This Book Is For This book is not an introduction to JavaFX. I assume you have played around with JavaFX already and hopefully have written an application or two. JavaFX is different enough from Java and other common languages that I urge anyone interested in this book to spend some time with JavaFX first. Just becoming familiar with the numerous curly and square brackets that get littered throughout JavaFX source code is a good start. This will help you to understand the concepts being presented, instead of fighting with syntax. JavaFX code can be surprisingly short and powerful, but some of that brevity comes with a cost in clarity or obviousness. Additionally I expect you, the reader, to have some experience with computer graphics, such as coordinate systems, polygons, transformations, colors and gradients, and trigonometry. If you feel that brushing up on any of these topics is worth your while, I would like to recommend the online course "Computer Sc-Computer Graphics" from the Indian Institute of Technology Madras (IIT Madras) by Download at WoweBook.com ■ INTRODUCTION xvii professor Dr. Sukhendu Das. The class is presented on YouTube at the following URL: http://www.youtube.com/view_play_list?p=338D19C40D6D1732 If you are a JavaFX expert already and just want to get to the effects, jump to Chapter 2 – but come back and read the section Designers and Developers in Chapter 1 sometime. Who This book Is By I think it is worth giving a little bit of background on my development history. My hope is that by sharing where I come from as a developer, you will be able to better understand my opinions and my interest in JavaFX. Like so many of us, I started playing with computers at a young age. My early, pre-career computer programming was mostly in BASIC and Pascal. Using these tools, I tried in vain to reproduce a number of video games I was very fond of. I had neither the time nor the experience to create anything of any real value, but I learned a lot about 2D graphics in the process. In college I was introduced to Java and fell in love with the language and with Swing. When I graduated I got a number of contract jobs writing Swing applications. This was a great experience, since I had to learn the hard way about things such as testing code and the truth about cross-platform deployment, and, most important, it taught me about how users use applications. I remember presenting a new feature to a client; I think it was a tool that laid out printed labels. My client sat down at my app and starting clicking randomly; he had no idea how to use the “clever” interface I had devised. I tried to explain how some combination of mouse gestures and key presses produced the desired results. He didn’t get it and I rewrote it. This showed me the value of using standard things such as buttons, sliders, and wizards to meet the expectation of the user. This is not to say there is no place for innovation, of course there is; computer interfaces have been evolving since they were invented, but the changes come in small steps. Later, a small company that specializes in Rich Internet Applications (RIAs) hired me. This was my first experience working with user experience designers who have made it their career to understand how people use applications, and to create interfaces that meet those expectations. Most of these designers don’t know how to code; they create PDF documents explaining the interface and a developer implements it. There is an example of one of these wire frame documents in Chapter 2 in the section Designers and Developers, where I explain how they are used. Working at a company that put design first showed me the importance of having these specialists involved in a project. Many developers and graphical designers use the term “developer ugly” to refer to the quick and dirty graphics that developers create while in the process of getting the app to work. Developer ugly can also apply to user experience decisions as well. I don’t intend to say that all developers lack the skills or the design sense to create nice-looking images or elegant UIs. I am pointing out that when you have your head down in the code, worrying about thread synchronization or something, it is not the best time to create an icon for a button. Just as graphic designers have all day to iterate over their creations, a user experience designer has all day to contemplate the UI. So I say, let specialists do their job. And of course, great projects take shape when all of the specialists work together. So now my day job is implementing designs by other people, and at night I continue to try and create simple but fun video games. It is this endless tinkering that led me to JavaFX and to write this book. So while I try to address design issues as they come up in this book, my primary concern is getting it to work. I hope that the techniques in this book will enable a developer presented with a design challenge to say, “We can do that.” ■ INTRODUCTION xviii Chapter Overview The following is a brief description of each chapter. Most of the chapters present a stand-alone effect and show how it is implemented. Feel free to read the chapters out of order, except for the last two, Chapters 10 and 11. Those two chapters rely on the foundation presented in the earlier chapters. Chapter 1 briefly investigates why user interfaces work the way that they do by looking at them in a historical context. It further explains the roles of designers and developers and offers some suggestions on how they can work together. The chapter finishes by showing how this collaboration works when using JavaFX. Chapter 2 shows how to implement a particle effect in JavaFX. We look at how particles are animated and how they can be blended together to create some surprisingly nice results. The sample code that accompanies this chapter is a playground for testing different combinations of properties of a particle effect. Chapter 3 introduces how JavaFX can create animations, which are handy for transitioning the user from one panel to another. These transitions are common in RIAs and cell phones, and JavaFX is very capable of reproducing these effects. Chapter 4 reviews lighting in JavaFX and how the different types of lighting affect the appearance of a node. The chapter also explores how lights can be animated to create a number of compelling visuals. Chapter 5 looks at the Interpolator API in Java FX and shows how it can be extended to create new interpolators. The source for this chapter is an application for testing the effects of using different interpolators and is fully explained. The last part of the chapter shows how interpolators can be used in conjunction with the transitions from chapter 3. Chapter 6 shows how to include an open source physics engine call Phys2d in your application. This chapter uses a number of examples to show how the physics engine is used and how JavaFX can be used as a presentation layer for the simulation. Chapter 7 presents a technique where animations created with other tools can be used in a JavaFX application. The code provides a pattern for efficiently loading a large number of images and animating them. Chapter 8 looks at gradients in JavaFX and how they can be animated. The animation of gradients in JavaFX is a little different than other animations in JavaFX and explains how they work. A final example shows why you might want to use animated graphics in your application. Chapter 9 combines Java Sound and JavaFX to create visualizations of audio in a JavaFX scene. This chapter covers the basics of using Java Sound as well as how to expose the audio stream in a JavaFX- friendly way. Chapter 10 combines the techniques from Chapter 2 on particles and Chapter 6 on physics to show how the two can be used together to create some interesting animations. Chapter 11 presents an entire JavaFX application called Clown Cannon reviewing the design process for the application and how the techniques from the previous chapters are combined. How the application manages its state is also explored. . book is not an introduction to JavaFX. I assume you have played around with JavaFX already and hopefully have written an application or two. JavaFX is different. xvi Introduction Goal of This Book This book is intended to show off some interesting visual effects that can be implemented in JavaFX. The chapters