Listview watermark

[Guest]

Hi,

I was looking for a way to use a static background image on a listview. I mean static, scrolling must not scroll the background image too.
Did a forum search and got little about the subject, so after playing got this and wanted to post for the records:

* Subclass the listview:
* In listview proc intercept %WM_VSCROLL and invalidaterect hwnd, BYVAL 0, 1 there.
* Intercept %WM_ERASEBKGND, createDC, bitblt (or stretchblt), deletedc.

oldproc = SetWindowLong(hlistview, %GWL_WNDPROC, CODEPTR(ListviewProc))
ListviewProc 0, 0, oldproc , 0
...

'this assumes globals bitmap handle on hbackground and a bitmapinfo struc in bmpbackground

FUNCTION listviewProc(BYVAL hWnd AS LONG, BYVAL wMsg AS LONG, BYVAL wParam AS LONG, BYVAL lParam AS LONG) EXPORT AS LONG
       static oldproc as dword
       local hBmpDC as long, rc as rect
       if hwnd = 0 then oldproc = wparam: exit function

    SELECT CASE AS LONG wmsg
           CASE %WM_VSCROLL
                invalidaterect hwnd, BYVAL 0, 1
           CASE %WM_ERASEBKGND
                getclientrect hwnd, rc
                hBmpDC = CreateCompatibleDC(wparam)
                SelectObject hBmpDC, hbackground
                stretchBlt wparam, 0, 0, rc.nright - rc.nleft, rc.nbottom - rc.ntop, hBmpDC, 0, 0, bmpbackground.bmwidth, bmpbackground.bmheight, %SRCCOPY
                DeleteDC hBmpDC
                FUNCTION = 1: EXIT FUNCTION   
           CASE %WM_DESTROY
                SetWindowLong(hWnd, %GWL_WNDPROC, OldProc)
    END SELECT
    FUNCTION = CallWindowProc(OldProc, hwnd, wMsg, wParam, lParam)
END FUNCTION

Regards, GdS