Developers are seeking the most efficient way of creating expressive content in applications that appear on desktops, on the Internet, and on mobile devices. They need to build high-fidelity GUIs that operate seamlessly on multiple web browsers, operating systems, and devices, without having to port or rewrite their applications for each screen. To meet this goal, developers need to work efficiently with team members such as graphic designers and media authors to exchange audio, video, and other rich media assets. The JavaFX platform contains an essential set of tools and technologies that enable developers and designers to collaborate, create, and deploy applications with expressive content.

JavaFX is a full-fledged development platform for RIAs and has many advantages over other equivalent technologies in the market. Out of all, there are some key factors that differentiate JavaFX significantly.

JavaFX was originally known as F3 (Form Follows Function) and was a pet project of Christopher Oliver, a software engineer at Sun Microsystems who came onboard through Sun's acquisition of SeeBeyond. At the JavaOne 2007 conference, Sun officially launched F3 as the JavaFX platform, and it had an interpreter-based language by then. In July 2008, Sun launched its first preview version of JavaFX with its own compiler. JavaFX 1.0 was released in December 2008 with many more enhancements and optimizations to the platform.

JavaFX 1.1 was released in February 2009. Its primary focus was the mobile platform, and JavaFX was made fully functional on mobile devices, as demonstrated at the Mobile World Conference in February 2009.

Sun continued adding more features, optimizations, and performance improvements, and it released JavaFX 1.2 at the JavaOne 2009 conference. At press time, Sun is currently working on JavaFX 1.3, tentatively targeted to be released in early 2010.

The JavaFX 1.2.1 platform release includes various components, as illustrated in Figure 2-1. Let us see each one of them in detail.

Figure 2.1. The JavaFX platform: an overview

Figure 2-2 illustrates the bigger picture of how the JavaFX platform integrates different platform elements, the runtime, tools, and frameworks to deliver applications, content, and services to consumers using multiple devices.

Figure 2.2. The JavaFX Platform: the bigger picture

Here is a brief introduction to each of the elements illustrated in Figure 2-2:

With JavaFX Mobile, Sun is bringing expressiveness to the most powerful and pervasive mobile platform. On mobile devices, JavaFX runs directly on Java ME to take advantage of the platform's ubiquity, security, and highly capable feature-set. With JavaFX Mobile, developers and designers benefit from using the same JavaFX tools, such as the JavaFX SDK and the JavaFX Production Suite, that they have been using to create content for the desktop and browser. This makes it much easier to start creating mobile content, and it opens up the mobile device to a much wider pool of developers and designers.

Consumers today expect richer experiences on their mobile devices and also want their content to work well in bandwidth-constrained network environments and in offline modes. However, creating content for mobile devices typically requires highly specialized programming skills that many content and service providers may not have in-house. Moreover, as companies look to deliver their content and services to consumers across all of their devices (Mobile, Desktop, TV, and so on), they want to do so with a consistent and device appropriate user experience. Developers want an easier way to create rich and expressive content for mobile devices and want to be able to collaborate with team members such as graphics designers and media authors in an efficient manner that allows simple exchange of audio, video and other rich media assets. Device manufacturers want to enable richer experiences while leveraging their existing technology investments. Thus everyone from device manufacturers to service providers to developers to end consumers benefits from the combination of Java and JavaFX Mobile.

At one time we used to think of computers as the center of the Internet. But of late, the reach of the Internet has become entirely global and has gone well beyond just computers as a delivery mechanism, extending to a world of devices such as mobile phones, Internet billboards, set-top boxes, car dashboards, and more. All these devices touch consumers on a daily basis in every aspect of their lives, and consumers obviously want to stay connected wherever they are with whatever devices they have. Java as a technology caters to the needs of these consumers, and Java is presently deployed on billions of devices globally and has a developer base of over 6 million. JavaFX leverages the ubiquity of Java and hence allows JavaFX developers to reach a wider audience over more devices than any other technology.

JavaFX applications can be deployed and distributed in the following ways:

The JavaFX SDK contains a JavaFX Packager utility, which creates an application in a format that is specific for a target profile, either desktop or mobile. The NetBeans IDE incorporates this utility and is available to users when they choose an execution model.

This section will get you started using the NetBeans IDE to write a small "Hello World" program in JavaFX, compile it, and execute it on multiple platforms.

In this section, you will learn how to write a simple "Hello World" JavaFX application using NetBeans.

Figure 2.6. The Main.fx file in NetBeans

Notice that JavaFX Script code is included within the Main.fx file by default. This code, listed below, includes several import statements and object literals. These literals represent key concepts within the JavaFX application, and are described in detail after the code snippet.

/*
 * Main.fx
 *
 */

package helloworld;

import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.text.Text;
import javafx.scene.text.Font;

/**
 * @author Lawrence & Praveen
 */

Stage {
title: "Hello JavaFX"
    width: 250
    height: 80
    scene: Scene {
        content: Text {
            font : Font {
                size : 16
            }
            x: 10, y: 30
            content: "Hello World from JavaFX"
        }
    }
}

The following object literals are created by default:

The concepts of stage and scene can easily be related back to real-world scenarios in which a stage is normally a platform on which a scene would be presented, and a scene is normally created by various actors. So in this case, a scene is composed of actors such as text, and the scene is shown from within a stage. The JavaFX developers deliberately defined the APIs to be in sync with the real-world scenario to keep the platform simple, easy-to-understand, and intuitive to even nonprogrammers.

Running Your Application Using NetBeans

There are thee modes in which you can deploy this application using NetBeans: standalone, browser/Java Web Start, and Mobile Emulator. Let's see each one of them in detail.

Standalone Mode

The default mode set in NetBeans in the standalone mode, and running the project as-is without modifying any configuration parameters will run the application in standalone mode.

There are two ways to do this: First, you can just click the

The output of our application run in standalone mode would look like Figure 2-7.

Figure 2.7. The output of Main.fx

Browser/Java Web Start Mode

To run our "Hello World" application on the browser, right-click on the project and go to Properties. As shown in Figure 2-8, choose Run option from the list on the left and click the Run In Browser radio button for Application Execution Model.

Figure 2.8. NetBeans: Running in Browser mode

To run it as a Java Web Start application, choose Web Start Execution as the Application Execution Model, as shown in Figure 2-9.

Figure 2.9. NetBeans: Running in Web Start mode

After choosing the application execution model, choose Application from the list on the left side and set the appropriate width and height for the applet, as shown in Figure 2-10.

Figure 2.10. NetBeans: Setting application properties

The project is now all set for executing on the browser, so just right-click and select Run Project or press F6 if this is the Main project. NetBeans will automatically open up the default browser on your platform and run the application.

Mobile Emulator

To run the "Hello World" program on Mobile Emulator, choose Run in Mobile Emulator as the Application Execution Model, as shown in Figure 2-11.

Figure 2.11. NetBeans: Running in Mobile Emulator mode

After choosing the execution model, just right-click and select Run Project or press F6 if this is the Main project. You will see the output shown in Figure 2-12.

Figure 2.12. Output of Main.fx on Mobile Emulator (Windows)

Note

fx is the file extension for a JavaFX program. JavaFX also has a compiler and an interpreter. javafxc is the JavaFX compiler, which converts a JavaFX program to .class files (byte code); javafx is the JavaFX interpreter, which takes the .class file and executes it.

At this point, you may compare our JavaFX Script program with a Java or C/C++ application and wonder where the entry point is. In JavaFX, there is no need to bother about the entry point; it is taken care by the JavaFX runtime engine, because JavaFX is a "declarative programming language" (one that determines its path of execution at runtime). However, in certain cases, you will need a run() method to be included in your application; you'll learn more about that in later chapters.

<JAVAFX_HOME>/bin/javafxpackager -src c:helloworld -appClass helloworld.Main -profile DESKTOP -appWidth 250  -appHeight 80  -draggable

<JAVA_HOME>/bin/javaws Main.jnlp

<JAVAFX_HOME>/bin/javafx -classpath Main.jar helloworld.Main

<JAVAFX_HOME>/bin/javafxpackager -src "c:helloword" -appClass helloworld.Main -profile MOBILE

<JAVAFX_HOME>/emulator/bin/emulator -Xdescriptor:Main.jad

When writing code in any language, it is important to remember to include written comments about what each line or group of statements is doing. To keep the JavaFX interpreter from trying to execute this text, you must hide it between comment characters. Table 2-1 shows the two types of comments available in JavaFX.

The type of comment you use and the purpose you use it for are entirely up to you, the programmer. Two styles of commenting programs are the Sun Microsystems and Microsoft styles. Most of the Sun documentation uses the following style for multiple lines, because it is useful with the automatic document generator that comes with the Java Development Kit:

JavaDoc Style
 /**
     *  this is a multi-lined comment
     *  for the following class
     *
     */

The JavaDoc Style tag tells the document generator to use the comments as text in the resulting HTML file that is created automatically from source code. It is nice to get into the habit of using it.

In this chapter, we have introduced what JavaFX technology is all about, including its advantages, platform components, and the bigger picture of where this technology fits in. We have also taken you through a tour of how to use the technology to develop a simple "Hello World" application through the NetBeans IDE as well as in standalone mode, and you learned how to deploy the application for the desktop, browser, Java Web Start and emulator. In the next chapter, we will dive into the JavaFX Script language to explore the data types it offers to programmers.