Thanks for the response. Yeah, I used SwingWorker just for education's sake. I'm just trying to figure out the best practices to do for Clojure/Swing in the future. The last question was about something I read on one of Sun's Swing tutorials--the text-sampler-gui function calls a bunch of Swing constructors like JLabel's, and I read somewhere that I should do those things only in the "event dispatch thread", and that SwingUtilities.invokeLater(Runnable) would make that work. But I'm not sure if I get it yet; why would I need to do that? Is it always better to invokeLater in the main thread?
On Jan 27, 9:08 am, Keith Bennett <keithrbenn...@gmail.com> wrote: > samppi - > > I don't suggest using SwingWorker for this unless you just want to > practice using it for education's sake. The calculation time is > effectively zero in an application like this where actions are user- > triggered, so using SwingWorker is a case of unnecessary and premature > optimization...and the calculation is so trivial, the overhead of > starting a new thread is likely to exceed the time it takes to perform > the calculation. > > I'm not sure I understand your question at the end of the message, > because I don't know what you are referring to by the "text-sampler- > gui" thread, but I assume you mean the entire Swing app...if so, then > no, you can start a Swing GUI from the main thread, and it will > automatically start and use the UI thread. Usually that consists of > calling the frame's setVisible method, which starts everything going. > > - Keith Bennett > > On Jan 24, 11:45 pm, samppi <rbysam...@gmail.com> wrote: > > > I'm trying to learn Swing, so I'm writing the most robust Celsius > > converter app that I can. I've separated the conversion work into a > > separate SwingWorker thread, so this requires Java 6. Does anyone have > > any suggestions? > > > (ns org.sample.play-with-swing.multithreaded-celsius-converter > > (:import [javax.swing JFrame JLabel JTextField JButton SwingWorker > > SwingUtilities] > > [java.awt.event ActionListener] > > [java.awt GridLayout])) > > > (defn convert-c-to-f [celsius-text] > > (when-not (empty? celsius-text) > > (let [c (Double/parseDouble celsius-text)] > > (str (+ 32 (* 1.8 c)))))) > > > (defn c-to-f-worker [celsius-text-field fahrenheit-text-field] > > (proxy [SwingWorker] [] > > (doInBackground [] > > (convert-c-to-f (.getText celsius-text-field))) > > (done [] > > (.setText fahrenheit-text-field (.get this))))) > > > (defn celsius-gui [] > > (let [frame (JFrame. "Celsius Converter") > > celsius-text-field (JTextField.) > > celsius-label (JLabel. "Celsius") > > convert-button (JButton. "℃ to ℉") > > fahrenheit-label (JLabel. "Fahrenheit") > > fahrenheit-text-field (JTextField.)] > > (.addActionListener convert-button > > (proxy [ActionListener] [] > > (actionPerformed [event] > > (.execute (c-to-f-worker celsius-text-field fahrenheit- > > text-field))))) > > (doto frame > > (.setDefaultCloseOperation JFrame/EXIT_ON_CLOSE) > > (.setLayout (GridLayout. 3 2 3 3)) > > (.add celsius-text-field) > > (.add celsius-label) > > (.add fahrenheit-text-field) > > (.add fahrenheit-label) > > (.add convert-button) > > (.setSize 300 100) > > (.setVisible true)))) > > > ; For thread safety, does the text-sampler-gui thread have to be > > invoked from the event > > ; dispatch thread? > > (SwingUtilities/invokeLater celsius-gui) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
