[Haskell-cafe] gtk2hs: adding widget during runtime

[Gary Klindt]

Hello Haskellers,

currently I work with the gtk2hs library to create a graphical user 
interface. Everything works fine, but there is one problem:
How can I insert widgets into boxes during runtime?

I tried something like:

main = do
     initGUI
     window <- windowNew

     box <- vBoxNew True 0

     l1 <- labelNew $ Just "label eins"
     bc <- buttonNewWithLabel "insert!"
     onClicked bc $ (\b -> do lh <- labelNew $ Just "neues label!"
                              boxPackStart b lh PackNatural 0
                              widgetQueueDraw lh
                              widgetQueueDraw b ) box

     boxPackStart box l1 PackNatural 0
     boxPackStart box bc PackNatural 0

     containerAdd window box

     widgetShowAll window
     onDestroy window mainQuit
     mainGUI

That compiles fine, but the GUI never shows a "neues label!".

What I want is a widget W, which takes a list L, and produces sub 
widgets for each element. There are also some Entry widgets and a button 
B. By clicking on that button B, I want to add an element to the list L, 
and add a sub widget to the widget W.

Thank you for reading,
Gary