gistfile1.hs

-- GUILibrary.hs
-- アイコン画像を取得
getIcon :: String -> IO String
getIcon url = do
  let outFile = "./icon/" ++ urlEncode url
  fileExist <- doesFileExist outFile
  if fileExist
    then return outFile
    else do
      let request = defaultGETRequest $ fromJust $ parseURI url
      iconImage <- getResponseBody =<< simpleHTTP request
      fin <- openBinaryFile outFile WriteMode
      hPutStr fin iconImage
      hClose fin
      return outFile

-- HshstterMain.hs(IconTableはHashTable String String、GUI.IconはPixbufの、それぞれ型シノニム)
-- アイコンのPixbufを取得
getIconImage :: IconTable -> Tweet -> IO GUI.Icon
getIconImage iconTable twt = do
  icon <- Hash.lookup iconTable (profile_image_url twt)
  pixbufNewFromFile =<< case icon of {Nothing -> getAndRegisterIcon; Just ic -> return ic}
      where getAndRegisterIcon = do
              ic <- getIcon (profile_image_url twt)
              Hash.insert iconTable (profile_image_url twt) ic
              return ic