JavaFXScript

JavaFX Script Weiqi Gao St. Louis Java Users Group July 12, 2007

About Me Principal Software Engineer at OCI Java programmer since 1998 (1.1.4) Member of St. Louis JUG steering committee since 2003 Like to explore programming languages Write a weblog at http://www.weiqigao.com/blog/

JavaFX Script, What Is It? Announced at JavaOne 2007, JavaFX is a new Sun product family JavaFX Script is a member of the family created by Christopher Oliver of Sun will leverage the ubiquity of Java will deliver high-impact rich media and content to desktop, mobile devices, set-top boxes JavaFX Mobile is another member of the family Java on a Linux based open source phone

JavaFX Script: Characteristics declarative statically typed first-class functions list comprehensions incremental dependency-based evaluation calling to Java APIs packages, classes, inheritance separate compilation and deployment units

Why? It is fun It feels easy It feels robust It feels powerful It feels productive It promises a wide delivery options Ignoring “why didn't you do this in JRuby?” — Priceless

Getting Started Official Website (tar ball, svn, mailing lists, forums, language spec, tutorials) http://openjfx.dev.java.net Christopher Oliver's weblog (back ground articles, demos, news) http://blogs.sun.com/chrisoliver/ Community wiki (world editable) http://jfx.wikia.com/wiki/Main_Page Currently under an evaluation license, will be released as Open Source

Getting JavaFX Script From java.net OpenJFX project page via svn via .tgz or .zip Tar balls are made from svn every two to three weeks three so far New features are added in each drop

A Look Inside $ tar zxvf OpenJFX-200706181411.tgz [...] $ ls branches LICENSE README tags trunk $ ls trunk bin demos doc lib src www $ ls trunk/bin javafx.bat javafx.sh javafxstart.bat javafxstart.sh $ ls trunk/demos demo javafxpad projects README studiomoto tesla tutorial $ ls trunk/lib Filters.jar javafxrt.jar swing-layout.jar

Hello World $ cat hello.fx import java.lang.System; System.out.println("Hello, world"); $ javafx.sh hello.fx compile thread: Thread[AWT-EventQueue-0,6,main] compile 0.01 Hello, world init: 0.036

JavaFX: The Language A very rough language reference for JavaFX is available from the OpenJFX project on java.net Many clarifications are sought and given on the mailing list Some questions on the mailing list resulted in tightening up of the language I found it useful to peruse through the JavaFX library source files

Packages and Imports package com.weiqigao.jugdemo; import java.lang.System as Sys; The package statement has the same meaning as in Java. The import statement has additional functionalities aliasing class name can appear anywhere importing a JavaFX file searches and runs the file

Classes JavaFX has four basic types String Boolean Number Integer User can define classes public class Foo { }

Attributes Classes can have attributes, member functions and member operations public class Foo { attribute str: String; attribute boo: Boolean?; attribute num: Number*; attribute int: Integer+; }

Functions and Operations Classes can have member functions and member operations public class Foo { public function fun(input: String): String; public operation opr(input: Number): Number; }

Initializers Attribute, member function and member operation initializers are defined outside the class definition (like in C++) attribute Foo.str = “init”; function Foo.fun(input) { return “{input}{input}”; } operation Foo.opr(input) { return 2 * input; }

Objects Objects are instantiated with JavaFX object literal notation Foo { str: “Hi” boo: true num: [3.14, 6.28] int: [1024] } Foo {str: “Hi”, int: [9216]}

Variables, Named Instances A variable is introduced by the var keyword Variable types are inferred from initializer var str = “Hi”; // String var nums = [1..10]; // Number* Named instances are global INS:Foo = { str: “Hi” };

Double Meaning of var Inside an object literal, var: names the current instance (odd syntax) class Foo { attribute bar: Bar; } class Bar { attribute foo: Foo; } var foo = Foo { var: me bar: Bar { foo: me } }

Functions Functions may contain several variable declarations followed by one return statement Functions are first-class citizens function addN(n) { return function (x) = x + n; } println(addN(5)(10));

Operations Operations may contain more than one statements Operations have side effects operation foo(i) { println(i); println(i*i); } foo(10);

Expressions Relational operators ==, <>, <, >, <=, >= Boolean operators and, or, not Arithmetic operators +, -, *, /, %, +=, -=, *=, /=, %= Other operators sizeof, indexof, if/then/else, select, foreach, new, opr(), instanceof, this, bind, :, [], format as, <<>>, {}, (expr), reverse, [1,3..99]

Statements Statement may appear at the top level or inside operations if/else if/else, while, try/catch/finally, throw, break, continue and return are like those in Java, but braces are required, and anything can be thrown or caught do statements farm work off the EDT (everything else is on EDT) do later is like invokeLater

Statements for statement is more powerful and supports list-comprehension style syntax for (i in [1..3], j in [1..i] where (i + j) % 2 == 0) { println(“i: {i}, j: {j}”); }

Sequences (Arrays) Arrays (to be renamed Sequences) is a key data structure of JavaFX var a = [1, 2, 3, 4, 5, 6, 7]; var i = a[3]; // by index var j = a[. % 2 == 0]; // [2, 4, 6] var k = a[indexof . % 2 == 0]; var aa = [a, a]; // flattened var b = ([] == null); // true var s = sizeof a; // 7

List Comprehension List comprehension can be done in two ways: foreach and select var ns = [1, 2, 3, 4, 5]; var ss = ["3","4","5","6","7"]; var c = select n from n in ns, s in ss where s == “{n}”; // [3, 4, 5] var d = foreach (n in ns, s in ss where s == “{n}”) n; // [3, 4, 5] var e = select n*n from n in [1..10]; // [1, 4, 9, ... 100]

Sequence Manipulation var a = [1]; insert 2 into a; // [1,2] insert 0 as first into a; // [0,1,2] delete a[1]; // [0,2] insert 3 before a[1]; // [0,3,2] delete a[. == 0]; // [3,2] insert 4 after a[. > 2]; // [3,4,2] delete a; // []

Classes Revisited Bidirectional relation class Foo { attribute bar: Bar inverse foo; } class Bar { attribute foo: Foo inverse bar; } var f = Foo {}; // f.bar is null var b = Bar {foo: f}; // f.bar is b

Classes Revisited Triggers are called when their triggering events happen class Foo { attribute ns: Number* } trigger on (new Foo) { /* ... */ } trigger on (Foo.ns[old]=new) { } trigger on insert n into Foo.ns { } trigger on delete n from Foo.ns { }

Classes Revisited Multiple inheritance Implementing Java interfaces Abstract class Classes with undefined member functions or operations can still be instantiated To make a class abstract, use ... class Foo { ... } var foo = Foo {}; // Error

Reflection As in Java, the .class operator is the key to the reflective world var x = Foo { str: “Hello” }; var c = x.class; var attrs = c.Attributes; var opers = c.Operations; var v = x[attrs[Name=='str']]; var w = opers[Name=='opr'](x, “Hi”);

The Bind Operater The bind operator provide support for incremental evaluation and lazy evaluation All attributes of JavaFX classes are observable var x1=Foo{a:1, b:2, c:3}; var x2=Foo{ a:x1.a b:bind x1.b, c:bind lazy x1.c };

JavaFX Script: Widget Set LayoutManagers GridPanel, GridBagPanel, FlowPanel, BorderPanel, Box, StackPanel, CardPanel, GroupPanel Borders EmptyBorder, LineBorder, BevelBorder, SoftBevelBorder, MatteBorder, TitledBorder Menus MenuBar, Menu, MenuItem, RadioButtonMenuItem

JavaFX Script: Widget Set Widgets Label, SimpleLabel, Button, TabbedPane, ListBox, SplitPane, RadioButton, ToggleButton, ButtonGroup, ComboBox, Tree, Table, Spinner Text components TextField, PasswordField, TextArea, EditorPane, TextPane

JavaFX Script: 2D Primitives Canvas Shapes Rect, Circle, Ellipse, Line, Polyline, Polygon, Arc, CubicCurve, QuadCurve, Star, Text, Path (MoveTo, LineTo, Hline, Vline, CurveTo, QuadTo, ClosePath) Painting Stroke, Fill, Gradient, Pattern Transformations translate, rotate, scale, skew

JavaFX Script: 2D Primitives Group Swing components View Images ImageView Transparency opacity Filters Shadow, Blur, Noise, ShapeBurst

JavaFX Script: 2D Primitives MouseEvents onMouseEntered, etc. Area operations Add, Subtract, Intersect, XOR Clipping User defined graphics objects CompositeNode Animation The dur (duration) operator Shape Morphing

Animation: The dur operator The documentation for the dur operator is sparse and the syntax is still being worked out var x = [0, 0.1 .. 1.0] dur 1000 linear while shouldStop continue if shouldRepeat;

Deployment As JavaFX Script applications Install JavaFX Script on target machine and run “javafx.sh MyApp.fx” from the command line As Java applications Bundle JavaFX Script runtime, MyApp.fx, and a bootstrap Java class in a jar Install the JRE on target machines and run “java -jar MyApp.jar” As Java Web Start downloads This is how Chris Oliver delivers his apps

Deployment As Java applets It's not easy, but can be done The promised improved JRE will make applets competitive again The bootstrap Java class for JavaFX JSR 223 engine for JavaFX Script Bundled within the tarball putting a Java object into a Binding require a “name:Type” key To run a JavaFX Script file simply eval the “import MyApp.fx” string

Future Sun is working on a JavaFX Scripts compiler Sun is working on tools to support JavaFX development. Plug-ins are available for NetBeans 5.5 and 6.0, and Eclipse 3.2 Sun is working on making JavaFX Script runnable on Java based mobile devices and set-top boxes Sun is working on a faster-downloading, faster-starting-up JRE A JavaFX Script painter is available from ReportMill, http://www.reportmill.com/jfx

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