gui-sample.clj

(ns gui-sample
  (:import [javax.swing JFrame JButton]
           [java.awt.event ActionListener]))

(defn build-gui [title message]
  (let [frame (JFrame. title)
        button (JButton. "CLICK")]
    (.addActionListener button
                        (proxy [ActionListener] []
                          (actionPerformed [evt]
                                           (println message))))
    (.. frame getContentPane (add button))
    (.pack frame)
    (.setVisible frame true)
    frame))
    

gui-sample2.clj

(ns gui-sample
  (:import [javax.swing JFrame JButton]
           [java.awt.event ActionListener]))

(defn build-gui [title message]
  (let [frame (JFrame. title)
        button (JButton. "CLICK")
        px (proxy [ActionListener] []
                          (actionPerformed [evt]
                                           (println message)))]
    (.addActionListener button px)
    (.. frame getContentPane (add button))
    (.pack frame)
    (.setVisible frame true)
    px))
    
(update-proxy p {"actionPerformed" (fn [this evt] (println "foo!"))})