13. JavaFX

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13. JavaFX
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JavaFX Intro

• Sun's answer to
• the popularity of scripting languages
• problems with Java GUI
• AWT is very basic
• Swing is too complex, too cumbersome, too
  voluminous and gained therefore little popularity
• problems with RIA and multimedia in Java
• JavaSound is too low-level
• JMF (Java Media Framework) is virtually
  unsupported
• Java 2D is good, but follows different design
  than other media packages
• Image IO is good, also follows different design
• Java 3D is completely separate, self-contained
  software monolith
• Java never really made it to the desktop
• But, the building blocks are there

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Building Blocks

• Java language itself
• very popular
• over 6Mio. developers
• major industry support (IBM, Google, Oracle
  almost everyone, except Microsoft)
• many universities adopted Java as prime teaching
  language
• most programming books now use Java
• widely used
• server-side web programming
• cell phones
• TV set-top boxes
• Rich set of libraries, e.g.,
• Remote Method Invocation (RMI)
• XML Web Services (JAX-WS).
• Applets
• supported by most browsers
• either directly with ltappletgt tag
• or at least as using the Java plug-in
• some PC's have Java pre-installed
• but not as widely available as Flash

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Features

• Separate scripting language "JavaFX Script"
• Multiplatform
• browsers
• desktop
• cell phones
• TV settop boxes
• Multimedia
• text
• GUI widgets
• graphics in 2D and 3D
• animations
• audio and video
• Integration for graphic designers
• Adobe Photoshop and Illustrator plugins for
  JavaFX
• direct manipulation of assets, animation paths,
  etc.
• Drag to install

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Concepts

• Based on Java and Java tools
• JDK
• Swing GUI
• applets
• Java plugin
• WebStart
• Scripting-like, but compiled
• efficient
• no eval() support
• Supported by NetBeans IDE
• preview
• building into jar files with ant and jnlp files
• Scripts can
• directly use Java classes (e.g. all of JDK)

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JavaFX Script

• Syntax more like JavaScript then Java
• less cryptic
• function instead of method
• var (resp. var for constants) instead of
  declaration via type
• Object-oriented
• classes
• e.g., var home Address street "1 Main
  Street" city "Honolulu" zip "HI 96813"
• inheritance
• e.g., var student student name "John Wu"
  address home
• override function
• properties
• encapsulation
• public, (private is default) , protected ,
  package, public-read, public-init
• anonymous functions
• e.g., action function () nextTick ()

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JavaFX Script Highlights

• Variables
• can, but don't need to be typed
• entire expressions can be "interpolated into a
  string using expression
• e.g., "4545"
• strings can be enclosed in " as well as in '
• Types
• String, Number, Integer, Boolean, Duration, Void,
  Null
• e.g., var delay Duration 50ms // s, m, h also
  valid suffixes
• Boolean operators not, and, or
• Arrays and called Sequences
• var nums 1..5 // same as var nums
  1,2,3,4,5
• various operations, such as appending, inserting,
  deleting elements, as well as subsequences
• Statements
• for (variable in sequence)
• e.g., for (i in 1..10)

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Binding

• Keyword bind associates a variable with the value
  of a bound expression
• bound expressions
• variable
• expression
• function call
• bound function
• when the variable 's value changes, the code of
  the bound expression is re-evaluated
• Binding is used for
• animation
• handling interactions with GUI widgets
• e.g., transforms Rotate angle bind seconds
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• see java.sun.com/javafx/1/tutorials/core/dataBind
  ing/index.html

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Potential Problems

• On many PCs, applets are not installed
• compare with Flash which has 90 penetration
• Downloading Java takes a lot of time
• Swing packages are huge
• Java upgrades are relatively frequent
• upgrades ( downloads) are necessary
• Competition
• Adobe Flex
• not free