Window Skinning?

Strict

Const HTCAPTION = 2
Const RGN_XOR = 3

Extern "Win32"
	Function SetWindowRgn(hWnd, hRgn, bRedraw)
	Function CreateRectRgn(nLeftRect, nTopRect, nRightRect, nBottomRect)
	Function CombineRgn(hrgnDest, hrgnSrc1, hrgnSrc2, fnCombineMode)
End Extern

Local skinPmap:TPixmap = LoadPixmapPNG(LoadBank("http::homepage.ntlworld.com/mollymole/storage/skin.png"))
If skinPmap = Null Then RuntimeError "Oi...Where's me picture?"

Local window:TGadget = CreateWindow("", 100, 100, skinPmap.width, skinPmap.height, Null, WINDOW_HIDDEN)

SkinWindow(window, skinPmap)

ShowGadget(window)
Local canvas:TGadget = CreateCanvas(0, 0, ClientWidth(window), ClientHeight(window), window)
Local hWnd = QueryGadget(window, QUERY_HWND) 

Repeat
	Select WaitEvent()
		Case EVENT_MOUSEDOWN 
			ReleaseCapture()
			SendMessageA(hWnd, WM_NCLBUTTONDOWN, HTCAPTION, Null)
	
		Case EVENT_KEYDOWN
			If CurrentEvent.data = 27 Then End
		
		Case EVENT_GADGETPAINT
			SetGraphics CanvasGraphics(canvas)
			DrawPixmap skinPmap, 0, 0
	
			Flip		
	End Select
Forever

End

Function SkinWindow(window:TGadget, skin:TPixmap)
	Local rectRgn = CreateRectRgn(0, 0, GadgetWidth(window), GadgetHeight(window))
	Local hWnd = QueryGadget(window, QUERY_HWND_CLIENT)
	
	For Local pixY=0 Until skin.height
		Local startFlag = 0
		Local startX = 0
		Local maskLine, pixX
		
		For pixX=0 Until skin.width
			Local argb = ReadPixel(skin, pixX, pixY) 		
	
			If argb & $ff000000 = 0
				If startFlag = 0
					startFlag = 1
					startX = pixX
				EndIf
			Else
				If startFlag
					startFlag = 0
					maskLine = CreateRectRgn(startX, pixY, pixX, pixY + 1)
					CombineRgn(rectrgn, rectrgn, maskLine, RGN_XOR)
					DeleteObject(maskLine)
				EndIf
			EndIf 			
		Next
		If startFlag
			maskLine = CreateRectRgn(startX, pixY, pixX, pixY + 1)
			CombineRgn(rectrgn, rectrgn, maskLine, RGN_XOR)
			DeleteObject(maskLine)
		EndIf
	Next
	
	SetWindowRgn(hWnd, rectrgn, True)
End Function