What is the best way to do GUIs in Clojure?

Marko_31141 0
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What is the best way to do GUIs in Clojure?

Is there an example of some functional Swing or SWT wrapper? Or some integration with JavaFX declarative GUI description which could be easily wrapped to s-expressions using some macrology?

Any tutorials?

lisp clojure user-interface java
17 Answers
user_912720

If you want to do GUI programming I'd point to Temperature Converter or the ants colony.

Many things in Swing are done by sub-classing, particularly if you are creating custom components. For that there are two essential functions/macros: proxy and gen-class.

Now I understand where you are going with the more Lispy way. I don't think there's anything like that yet. I would strongly advise against trying to build a grandiose GUI-building framework a-la CLIM, but to do something more Lispy: start writing your Swing application and abstract out your common patterns with macros. When doing that you may end up with a language to write your kind of GUIs, or maybe some very generic stuff that can be shared and grow.

One thing you lose when writing the GUIs in Clojure is the use of tools like Matisse. That can be a strong pointing to write some parts in Java (the GUI) and some parts in Clojure (the logic). Which actually makes sense as in the logic you'll be able to build a language for your kind of logic using macros and I think there's more to gain there than with the GUI. Obviously, it depends on your application.

J_Pablo_Fern225ndez_60680

From this page:

(import '(javax.swing JFrame JButton JOptionPane)) ;'
(import '(java.awt.event ActionListener))          ;'

(let [frame (JFrame. "Hello Swing")
     button (JButton. "Click Me")]
 (.addActionListener button
   (proxy [ActionListener] []
     (actionPerformed [evt]
       (JOptionPane/showMessageDialog  nil,
          (str "<html>Hello from <b>Clojure</b>. Button "
               (.getActionCommand evt) " clicked.")))))

 (.. frame getContentPane (add button))

 (doto frame
   (.setDefaultCloseOperation JFrame/EXIT_ON_CLOSE)
   .pack
   (.setVisible true)))

print("code sample");

And, of course, it would be worth looking at the interoperability section of clojure's website.

dsm_77800

There is a wrapper for MigLayout in clojure contrib. You can also take a look at this gist. I am basically putting up whatever code I am writing as I am learning swing/miglayout.

dsm's example re-written in a lispy way using contrib.swing-utils

(ns test
      (:import (javax.swing JButton JFrame))
      (:use (clojure.contrib
          [swing-utils :only (add-action-listener)])))

    (defn handler
      [event]
      (JOptionPane/showMessageDialog nil,
        (str "<html>Hello from <b>Clojure</b>. Button "
          (.getActionCommand event) " clicked.")))

    (let [ frame (JFrame. "Hello Swing") 
           button (JButton. "Click Me")  ]
      (add-action-listener button handler)
        (doto frame
          (.setDefaultCloseOperation JFrame/EXIT_ON_CLOSE)
          (.add button)
          (.pack)
          (.setVisible true)))
Abhijith_689630
Joe_W_34590

I've been developing a Java applet in which everything is written in Clojure except the applet code, which is written in Java. The applet invokes the Clojure code's callbacks of init, paint, etc from java's hooks for those methods that are defined by the applet model. So the code ends up being 99.999 percent Clojure and you don't have to think about the tiny Java piece at all for the most part.

There are some drawbacks to this approach, which I hope to discuss in more detail on the Clojure Google Group. I think the Clojure developers should include a native way of building applications. Presently you can do whatever GUI stuff you like from the REPL, but if you want a deliverable GUI application, it is necessary to write some Java to call the Clojure code. Also, it seems like the architecture of a Java Applet kind of forces you outside of Clojure's more idiomatic best practices, requiring you to use mutable state, etc.

But also, I am not very far along with Clojure yet and it might be the case that it is possible and I just haven't discovered how to do it correctly yet.

Admin1

Clojure and SWT is the best approach for doing GUI(s). Essentially, SWT is a plug and play style approach for developing software.

Berlin_Brown_105220

I know that you are hinting for classical desktop solutions, but web fits quite well with clojure. I've written a complete audio application where everything is hooked up so that if you add music to the audio folder it is reflected in the web UI. Just saying that Desktop application isn't the only way :)

Anders_Rune_Jensen_139950

cljfx is described as a

Declarative, functional and extensible wrapper of JavaFX inspired by better parts of react and re-frame

and JavaFx as

... an open source, next generation client application platform for desktop, mobile and embedded systems built on Java. It is a collaborative effort by many individuals and companies with the goal of producing a modern, efficient, and fully featured toolkit for developing rich client applications.

Its creator uses it to build reveal, and a hackernews demo that features various capabilities and some bundling for multiple OSs via jpackage.

You can get Clojure REPL-driven development with this by leveraging JavaFX to build UIs for desktop, mobile, and web.

user_3265160
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