module SWDc(drawInBitmap) where

import Graphics.UI.WXCore

drawInBitmap :: DC a -> Rect -> (DC () -> IO ()) -> IO (IO (Bitmap ()))
drawInBitmap dc view draw = do
	bitmap <- bitmapCreateEmpty (rectSize view) (-1)
	memdc <- do p <- memoryDCCreateCompatible dc; return (objectCast p)
	memoryDCSelectObject memdc bitmap
	brush <- dcGetBackground dc
	let restOfDraw = do
		drawBuffered brush memdc
		memoryDCSelectObject memdc nullBitmap
		memoryDCDelete memdc
		return bitmap
	return restOfDraw

  where
     drawBuffered brush memdc
      = do -- set the device origin for scrolled windows
           dcSetDeviceOrigin memdc (pointFromVec (vecNegate (vecFromPoint (rectTopLeft view))))
           dcSetClippingRegion memdc view
           -- set the background to the owner brush
           dcSetBackground memdc brush
           if (wxToolkit == WxMac)
	    then withBrushStyle brushTransparent (dcSetBrush memdc)
	    else dcSetBrush memdc brush
           dcClearRect (downcastDC memdc) view
	   -- and finally do the drawing!
           draw (downcastDC memdc) -- down cast
           dcSetBrush memdc nullBrush
           brushDelete brush
           return ()


           -- blit the memdc into the owner dc.
--           dcBlit dc view memdc (rectTopLeft view) wxCOPY False