This document discusses using FXML for building desktop applications in Clojure. It explores different options for the controller in FXML, including regular maps, defrecord, gen-class, and deftype. It also mentions virtual DOM approaches. The document dives into how deftype and gen-class are implemented in Clojure using ASM and bytecode generation. It proposes macros like fxml and fxml-controller that could generate the necessary classes to support FXML in Clojure.

1. Using FXML on Clojure
(fxml helloworld)
netpyoung@gmail.com
July 2018
#1

2. Do you have any Questions?
- If you have questions, during presentation.
- message on slack #clojure-sg with page #numer.
- https://clojurians.slack.com/messages/clojure-sg
- ex) #10 - what is blabla?
- I will answer after presentation.(for keep time)
- so, I can polish this slide from your feedbacks.
#2

3. ● EunPyoung Kim
● KOR -> JPN -> SGP-> ???
● Game Client Programmer. (since 2012.04 ~ )
● I like Lisp (not only clojure)
● I’m Lazy
○ because of that I like automatation (code generate also)
○ I like macro (but don't abuse)
● I like Emacs
○ Cursive
○ (Neo)Vim….?
● https://netpyoung.github.io/
#3

4. What I want & What I did.
● I want editor for future when I making game.
○ Cross platform desktop application
○ GUI designer.
● I didn’t make library.
● I just share other’s approach and my experience.
#4

5. Wait but why Clojure? (java,scala,kotlin...)
● I'm Game Client Programmer. I prefer typed language rather than dynamic.
● No Clojure? No Problem to me.
● But I just feel fun when I play with REPL.
● I love Lisp not only Clojure.
○ They Also love(?) Lisp.
■ https://www.slideshare.net/naughty_dog/statebased-scripting-in-uncharted-2-among-
thieves
■ https://www.youtube.com/watch?v=Hbexh-Jutvs
● I also like person who love Lisp, they's way of thinking is so flexible and
amazing, like language itself.
● I just choose Clojure compare each other Lisp directs.
#5

6. Desktop Application
● WPF
○ C#(ClojureCRL)
○ Windows only (but I like XAML. I hope it will be ported on dotnet core)
● JavaFX
○ Java(Clojure)
○ Cross Platform
○ SceneBuilder - GUI Editor
● Electron
○ Javascript(Clojurescript)
○ Cross Platform
○ gui editor??
● qt, wxwidgets, ...
#6

7. JavaFX
● Sun announces JavaOne 2007
● Open-sourced 2011
○ http://openjdk.java.net/projects/openjfx/
● August 2018
○ JDK 11, Oracle is making JavaFX easier to adopt by making the technology available as a
separate download, decoupled from the JDK.
○ https://blogs.oracle.com/java-platform-group/the-future-of-javafx-and-other-java-client-
roadmap-updates
● I’m not sure JavaFX will be popular or not.
○ If is it possible using WPF on osx - dotnet core, I will choose ClojureCLR.
#7

8. FXML
fxml
- language
- id
- action
scene builder
controller
#8

9. FXML
fxml
scene builder
controller
#9

10. FXML
fxml
scene builder
controller
img: https://www.callicoder.com/javafx-fxml-form-gui-tutorial/
#10

11. Java - Controller
#11

12. Java - Controller
#12

13. I Need Controller
but there are some issue.
● controller - @FXML attribute binding
○ binding Method
○ binding Field
○ binding initialize
● REPL driven developing
○ need to solving AOT problem
#13

14. #14
I Need Type for Controller

15. Controller
● regular map
● defrecord
● rerify
● proxy
● gen-class
● deftype
#15
Skip this things
(X) binding
method
(X) binding field

16. Controller
● regular map
● defrecord
● rerify
● proxy
● gen-class
● deftype
#16

17. gen-class
#17
binding field(?)

18. gen-class
● If you want to binding field with gen-class,
○ using .java both…..
● If I incorrect, message to me I will correct that.
#18

19. Controller
● regular map
● defrecord
● rerify
● proxy
● gen-class
● deftype
#19

20. #20

21. deftype
● dirty.. but works….
● I want to check fxml without relaunch application.
#21

22. ● (deftask build []
(comp (aot) (pom) (uber) (jar)))
● aot : Perform AOT compilation of Clojure namespaces
● pom: Create project pom.xml file
● uber: Add jar entries from dependencies to fileset
● jar: Build a jar file for the project
#22

23. reload
● Okay let’s boost with boot
○ https://github.com/boot-clj/boot
○ https://github.com/boot-clj/boot/pull/692
● danielsz/system
○ https://github.com/danielsz/system
#23

24. #24

25. It’s works
● But……. It looks so weird.
● definterface only used one per deftype
● Code structure also Dirty
○ we can avoid this problem using macro… but… Is this really valuable??
#25

26. What’s the Next
● regular map
● defrecord
● rerify
● proxy
● gen-class
● deftype
#26

27. FTW! Virtual Dom
● regular map
● defrecord
● rerify
● proxy
● gen-class
● deftype
● Virtual DOM
#27
Virtual DOM

28. in java
● There is https://github.com/netopyr/reduxfx
#28

29. in clojure
● fn-fx
○ https://github.com/halgari/fn-fx
○ https://www.youtube.com/watch?v=hJ8GZxhsaVQ
● like redux, single data direction.
● Java 10 Parser and Abstract Syntax Tree for Java – https://javaparser.org
● - https://github.com/javaparser/javaparser : Java source text -> AST
● - https://github.com/forge/roaster : A Java Parser library that allows easy
parsing and formatting of Java source files
● - https://github.com/ronmamo/reflections : Java runtime metadata analysis
#29

30. #30

31. Wait…. I want to use FXML
● I’m tired to write UI code……
● I want that take over this task to UI designer.
#31

32. ● regular map
● defrecord
● rerify
● proxy
● gen-class
● deftype
● Virtual DOM
● Custom Type
Controller
#32
Custom Type

33. How to implement gen-class in Clojure.
https://github.com/clojure/clojure/blob/master/src/clj/clojure/genclass.clj
(defmacro gen-class
(generate-class options-map)
(defn- generate-class [options-map]
(let [cv (clojure.lang.Compiler/classWriter)
#33

34. How to implement deftype in clojure
https://github.com/clojure/clojure/blob/master/src/clj/clojure/core_deftype.clj
(defmacro deftype
(emit-deftype*
(defn- emit-deftype*
`(deftype*
#34

35. How to implement deftype in clojure
https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Compiler.java
static final Symbol DEFTYPE = Symbol.intern("deftype*");
ClassWriter cw
ClassVisiter cv = cw;
#35

36. What is ClassWriter?
https://github.com/clojure/clojure/blob/master/src/jvm/clojure/asm/ClassWriter.java
ASM
https://github.com/consulo/objectweb-
asm/blob/master/src/main/java/org/jetbrains/org/objectweb/asm/ClassWriter.java
#36

37. ASM
● https://asm.ow2.io/
● ASM is an all purpose Java bytecode manipulation and analysis framework. It
can be used to modify existing classes or to dynamically generate classes,
directly in binary form.
● It can be used to modify existing classes or to dynamically generate classes,
directly in binary form
● ref:
○ https://www.infoq.com/presentations/asm-cglib-javassist-2
○ https://www.slideshare.net/ashleypuls/bytecode-manipulation
#37

38. bytecode
● JVM Bytecode for Dummies (and the Rest of Us Too)
○ https://www.youtube.com/watch?v=rPyqB1l4gko
#38

39. #39

40. #40

41. wait! insn
● Functional JVM bytecode generation for Clojure.
● https://github.com/jgpc42/insn
#41

42. clojurefx
● I found interesting library.
● https://github.com/zilti/clojurefx
#42

43. (defn load-fxml-with-controller
[filename init-fn]
(generate-controller filename init-fn)
(load-fxml filename))
#43

44. FXML -> input-stream -> javafx.fxml.FXMLLoader
FXML -> input-stream
-> xml/parse -> tree-seq (for finding id, handler)
-> Do Something
-> ClassLoader
#44

45. Do Something
cw =org.objectweb.asm.ClassWriter
.visitCode
.visitMethodInsn
.visitEnd
.visitField
.visitAnnotation
.visitEnd
.visitEnd
bytes = cw.toBytesArray
ClassLoader.getSystemClassLoader() // java.lang.ClassLoader
.defineClass(name, bytes, 0, bytes.length)
#45

46. How about this? defmacro fxml
(defmacro fxml [fxml-name]
….
)
(def fxml-helloworld (fxml helloworld))
#46

47. How about this? fxml-controller
(defmacro fxml-controller [...]
….
)
(def controller
(fxml-controller [lbl_count]
(onBtnDown [evt] …)
(onBtnUp [evt] …)))
#47

48. Resources
● github : https://github.com/netpyoung/pt.using-fxml-on-clojure
#48

49. Questions
ex) #10 - what is blabla?
#49

50. Thank you
50