how to set the hbox width and height in haskell with gtk2hs

[zerop2]

i can not search the attributes in hbox, how to set width and height of hbox

so that png image can evenly distributed in four boxes of screen and displayed in fit hbox size




import Graphics.Rendering.Chart.Easy
import Graphics.Rendering.Chart.Backend.Cairo
import Graphics.UI.Gtk
--import Graphics.UI.Gtk.Layout.BackgroundContainer
--import Graphics.UI.Gtk.Board.BoardLink
import Graphics.UI.Gtk.Display.Image
import Graphics.UI.Gtk.Gdk.Screen
signal :: [Double] -> [(Double,Double)]
signal xs = [ (x,(sin (x*3.14159/45) + 1) / 2 * (sin (x*3.14159/5))) | x <- xs ]


hello =
toFile def "example1_big.png" $ do
layout_title .= "Amplitude Modulation"
setColors [opaque blue, opaque red]
plot (line "am" [signal [0,(0.5)..400]])
plot (points "am points" (signal [0,7..400]))


main :: IO ()
main = do
hello
initGUI
window <- windowNew
bgBac1 <- imageNewFromFile "example1_big.png"
bgBac2 <- imageNewFromFile "example1_big.png"
bgBac3 <- imageNewFromFile "example1_big.png"
bgBac4 <- imageNewFromFile "example1_big.png"
col <- vBoxNew False 2
containerAdd window col
row0 <- hBoxNew False 2
boxPackStart col row0 PackNatural 1
row1 <- hBoxNew False 2
boxPackStart col row1 PackNatural 2
boxPackStart row0 bgBac1 PackNatural 0
boxPackStart row0 bgBac2 PackNatural 1
boxPackStart row1 bgBac3 PackNatural 0
boxPackStart row1 bgBac4 PackNatural 1
Graphics.UI.Gtk.set row0 [ containerWidth := 300 ]
Graphics.UI.Gtk.set row1 [ containerWidth := 300 ]
Just screen <- screenGetDefault
rootwindow <- screenGetRootWindow screen
size <- drawableGetSize rootwindow
widgetSetSizeRequest window (fst size) (snd size)
widgetShowAll window
onDestroy window mainQuit
mainGUI