(defonce app (atom nil))

(defn view
  [& args]
  (ui/label "hi"))

(reset! app (java2d/run (component/make-app #'view)))

Thanks!

@UPD88PGNT, You can try something like:

(defonce app (atom nil))

(defn view
  [& args]
  (ui/label "hi"))

(def window-info (java2d/run #'view))
(def repaint (::java2d/repaint window-info))

(add-watch #'view ::repaint
           (fn [_ _ _ _]
             (repaint)))

The issue is that component/make-app only works with components created with component/defui.

If you're not using defui and friends, then you can just pass the function.

Woa, neat. I forgot add-watch worked for more than just atoms.

(defui view
  [arg]
  (basic/textarea {:text "hi"}))

(defonce window (java2d/run
                  (component/make-app #'view {})))

((:membrane.java2d/repaint window))

It works if I copy over the example. I can figure this out.

Oh.

(defui view
  [{:keys [input]
    :or {input ""}}]
  (basic/textarea {:text input}))

No data there in the context.

It looks like you figured it out, but since textareas are stateful components, the :text property must be derived from some input property to "update" it.