My attempt at what the abstract factory pattern would look like in Clojure

abstract-factory.clj

(defn draw-ui [{:keys [label casing content]}]
  (let [pad (Math/floor (/ (- (Math/max (count label) (count (or (:label content) "")))
                              (+ 2 (Math/min (count label) (count (or (:label content) "")))))
                           2))]
    (println (str "|" (if (= :upper casing)
                        (.toUpperCase label)
                        (.toLowerCase label)) "|" \newline
                  "|" (reduce (fn [a b] (str a " ")) "" label) "|" \newline
                  (when content
                    (str "|" (apply str (repeat pad \space))
                         (str "|" (if (= :upper (:casing content))
                                    (.toUpperCase (:label content))
                                    (.toLowerCase (:label content))) "|")
                         (when (even? (count (:label content))) " ")
                         (apply str (repeat pad \space)) "|" \newline))
                  "|" (reduce (fn [a b] (str a "_")) "" label) "|"))))

(defprotocol UiMaker
  (make-button [this label])
  (make-window [this label]))

(defrecord UpperCaseUI []
  UiMaker
  (make-button [this label]
               {:type :button
                :label label
                :content nil
                :casing :upper})
  (make-window [this label]
               {:type :window
                :label label
                :content nil
                :casing :upper}))

(defrecord LowerCaseUI []
  UiMaker
  (make-button [this label]
               {:type :button
                :label label
                :content nil
                :casing :lower})
  (make-window [this label]
               {:type :window
                :label label
                :content nil
                :casing :lower}))

(defrecord MixedCaseUI []
  UiMaker
  (make-button [this label]
               {:type :button
                :label label
                :content nil
                :casing :upper})
  (make-window [this label]
               {:type :window
                :label label
                :content nil
                :casing :lower}))

(defn assoc-button [window button]
  (assoc window :content button))

(let [abstract-factory (->UpperCaseUI)
      btn (make-button abstract-factory "Ok")
      window (make-window abstract-factory "Test Window")]
  (draw-ui (assoc-button window btn)))

(println)

(let [abstract-factory (->LowerCaseUI)
      btn (make-button abstract-factory "Ok")
      window (make-window abstract-factory "Test Window")]
  (draw-ui (assoc-button window btn)))

(println)

(let [abstract-factory (->MixedCaseUI)
      btn (make-button abstract-factory "Okay")
      window (make-window abstract-factory "Test Window")]
  (draw-ui (assoc-button window btn)))