\input texinfo
@setfilename clojurefx
@settitle ClojureFX Manual

@copying
This manual is for ClojureFX, version 0.4.0.

Copyright @copyright{} 2016-2018 Daniel Ziltener.
@end copying

@titlepage
@title ClojureFX Manual
@author Daniel Ziltener

@page
@vskip 0pt plus 1filll
@insertcopying

@end titlepage

@contents

@c@ifnottex
@node Top
@top ClojureFX

This is the documentation to ClojureFX, version 0.5.0.
@c@end ifnottex

@menu
* Installation and deployment:: adding ClojureFX and probably tools.jar to your build tool.
* Getting started::             the little ceremony necessary to get a window ``up and running''.
* Coding a scenegraph::         for everyone who wants to write an UI the old-school way.
* FXML and controllers::        loading FXML files and generating a controller.
* Event handling::              a short chapter about handling events.
* Roadmap::                     what's up next?.
* Index::.
@end menu

@node Installation and deployment
@chapter Installation and deployment

The first, straightforward part of this is to add the dependency to your @file{project.clj} or @file{build.boot}, which consists simply of adding @code{[clojurefx "0.5.0"]}.

For the users of @emph{OpenJDK} 7 and 8, @emph{OpenJFX}, the opensource implementation of JavaFX, is not included. Luckily, many Linux distributions ship a separate OpenJFX package by now, but for those that don't, the OpenJDK wiki has an article @uref{https://wiki.openjdk.java.net/display/OpenJFX/Building+OpenJFX, ``Building OpenJFX''}. Starting with OpenJDK 9, JavaFX is available as a library. Alternatively, you can of course install the Oracle JDK manually.

@node Getting started
@chapter Getting started

@code{(require '[clojurefx.clojurefx :as fx])}

To get the JavaFX environment up and running, you can't just initialize some classes and fire up a window, as is the case with Swing; you first have to initialise the environment. For this, you have two choices: either use a ``nasty hack'' Oracle themselves show, or go down the Java road and subclass @indicateurl{javafx.application.Application}.

For the ``nasty hack'', you have to add a @code{defonce} @emph{before} you import JavaFX classes (so, best suited for a @file{core.clj} ns). You can then manually create a @code{Stage} and add a @code{Scene} to it.

@code{(defonce force-toolkit-init (javafx.embed.swing.JFXPanel.))}

Alternatively, and preferredly, you can use @code{start-app}:

@lisp
(ns example.core
  (:require [clojurefx.clojurefx :as fx])
  (:gen-class))

(defn init []
  nil)

(defn start [^javafx.stage.Stage stage]
  (.show stage))

(defn stop []
  nil)

(defn -main [& args]
    (fx/start-app init start stop))
@end lisp

@node Core API
@section Core API

@deffn clojurefx.clojurefx run-now code
This macro runs the code given on the JavaFX thread and blocks the current thread until the execution has finished.
@end deffn

@deffn clojurefx.clojurefx run-later code
This macro runs the code given on the JavaFX thread and immediately returns. Prefixing the s-exp with an @@ has the same effect as using @code{run-now}.
@end deffn

@deffn clojurefx.clojurefx fi interface args & code
This macro is used to use a Clojure function as a functional interface. The interface name is needed: @code{(fx/fi javafx.event.Event [event] eventhandling-code)}
@end deffn

@deffn clojurefx.clojurefx connect instance function args & code
This macro is used to use a Clojure function as a functional interface. The function must be written in kebab case: @code{(fx/connect btn set-on-action [event] (do-something-with event))}
@end deffn

@deffn clojurefx.clojurefx find-child-by-class node clazz
With this function, you can find an element / elements in a scenegraph by one of its CSS classes.
@end deffn

@deffn clojurefx.clojurefx find-child-by-id node id
Analogous to find-child-by-class, but to find an element by fx:id.
@end deffn

@node Coding a scenegraph
@chapter Coding a scenegraph

You can write a scenegraph in-code using the @code{compile} function. It is straightforward, alternating between the class name and the element's properties. Make sure though to either use @code{start-app} function or first initialize the toolkit:

@code{(defonce force-toolkit-init (javafx.embed.swing.JFXPanel.))}

There are no further dependencies for this, since the calls are made using Clojure's reflection API. Let's look at an example:

@lisp
(require '[clojurefx.clojure :refer [compile]])
(compile [Scene @{:root [VBox @{:id "TopLevelVBox"
                                        :children [Label @{:text "Hi!"@}
                                                   Label @{:text "I'm ClojureFX!"@}
                                                   HBox @{:id "HorizontalBox"
                                                         :children [Button @{:text "Alright."@}]@}]@}]@}])
@end lisp

@node Scenegraph API
@section API

@deffn clojurefx.clojurefx compile code
Turns the Hiccup-like tree into a JavaFX-Node.
@end deffn

@node FXML and controllers
@chapter FXML and controllers

@code{(require '[clojurefx.fxml :as fxml])}

@acronym{FXML} is an @acronym{XML} format describing a JavaFX user interface. It also allows defining action handlers and, similar to HTML, inline scripting via script tags. You can find an introduction @uref{https://docs.oracle.com/javase/8/javafx/api/javafx/fxml/doc-files/introduction_to_fxml.html, on this site}.

ClojureFX provides an idiomatic interface to load FXML files, and in this new version can even generate a controller class for you at runtime.

@node Loading FXML files
@section Loading FXML files

So you created an @acronym{FXML} file, probably with the SceneBuilder, and obviously now want to use it in your application. Doing so looks tedious in the JavaFX docs, but it is actually straightforward. All you need is some place to add the loaded Node - this could be the Scene object, or simply any JavaFX Parent element. The loader function returns a pure javafx.scene.Node-based object.

@lisp
(require '[clojurefx.fxml :as fxml])
(def mainwindow (fxml/load-fxml "resources/fxml/mainwindow.fxml"))
     ;; => javafx.scene.Node
(.setContent my-scroll-pane mainwindow)
@end lisp

You're already good to go!

@node Generating controller classes
@section Generating controller classes

When creating an @acronym{FXML} file, you have built-in features to bind properties and call functions in an associated controller class. Before actually writing any Clojure, let's see how you can prepare your @acronym{FXML} file to get the most out of it.

First, at your outermost element in the file, you have to tell it the class name of its @acronym{JVM} sibling it is going to call. For that, open it, and add the @option{fx:controller} attribute: @code{fx:controller="ch.lyrion.MyController"}. It is not very important how you name the class, as long as it has a package and doesn't exist anywhere else.

To bind any element to your new controller (in the form of a @code{Property}), you need the @option{fx:id} attribute. Let's try it with that label: @code{<Label fx:id="MyLabel" />}. That way, you'll always have access to it as long as you have the controller instance with you. Note that the CamelCase will be automatically converted to kebab-case when using the designated accessors from ClojureFX!

Next, you can define action handlers. Note that ``@emph{Special Handlers}'' (@uref{https://docs.oracle.com/javase/8/javafx/api/javafx/fxml/doc-files/introduction_to_fxml.html#collections_and_property_handlers, as defined here}) are not yet fully supported; I'm working on them! You simply provide the attribute, e.g. an @option{onAction} attribute, with the method name prefixed with a pound sign; note that the method name CamelCase will be automatically converted to kebab-case. E.g. @code{<Button onAction="#buttonClicked" />} will call @code{(button-clicked controller-instance event)} in the namespace you provided (see below).

Now, finally, it is time to weld the parts together. But wait! Your @acronym{FXML} file doesn't have any companion, no controller class, let alone the @code{ch.lyrion.MyController} we told it to look for!
No worries, we got you covered. @ref{load-fxml-with-controller} has your and your file's back. It doesn't just load the @acronym{FXML} and returns a @code{Node}, it also parses the source and generates your file's companion on the fly. For that, it needs a couple more infos than @code{load-fxml} though: first, of course, the file path, but also the fully qualified clojure function in @code{String} form that will be called when the class gets initialized by JavaFX. Note that all action handlers defined above also have to be in the namespace of that function.

@node FXML scripting
@section FXML scripting

Unfortunately, FXML scripting is currently broken (outdated JSR-223 implementation). Stay tuned!

@node FXML API
@section API

@anchor{load-fxml}
@deffn clojurefx.fxml load-fxml filename
With this command, ClojureFX loads an FXML file and returns it as a @uref{https://docs.oracle.com/javase/8/javafx/api/javafx/scene/Node.html, javafx.scene.Node}. Note that the filename will be parsed by @code{clojure.io/resource} before loading.
@end deffn

@anchor{generate-controller}
@deffn clojurefx.fxml generate-controller filename init-fn
Generates a controller using the @code{fx:id} definitions in the given @file{filename}.
@end deffn

@anchor{load-fxml-with-controller}
@deffn clojurefx.fxml load-fxml-with-controller filename init-fn
Like @ref{load-fxml}, but also generates and loads an accompanying controller class using @ref{generate-controller}.
@end deffn

@node Event handling
@chapter Event handling

@strong{Coming soon.}

@node Roadmap
@chapter Roadmap

@itemize @bullet
@item Allow for non-ActionEvent binding.
@item Testing and fixing Scenegraph coding API.
@item Fixing JSR-223 implementation.
@end itemize

@node Index
@unnumbered Index

@printindex fn

@bye