Re: [Dev-C++] Help Please. ( Scrolling the client area with graphics)

[<or...@vp...>]

OROSZI Bal=E1zs wrote:
> Added to this:
> Note that Windows can move the entire contents of a window, and you onl=
y=20
> need to repaint the "invalid" rectangle (a small portion) of your=20
> window, giving you great speedups (and to avoid flicker). Though you=20
> have to calculate that rectangle yourself. Process the scrollbar=20
> messages, and retrieve the amount that was scrolled, then use the=20
> ScrollWindowEx() function to move the contents of your window (your=20
> lines, etc.), then repaint the invalid rectangle (using BitBlt if you=20
> painted to a bitmap, or any other method). The invalid rectangle is wha=
t=20
> you scrolled into view.

A little correction:
After you got the amount to the scroll, call ScrollWindowEx() with the SW=
_INVALIDATE flag=20
then call UpdateWindow().
In your WM_PAINT message processor, use the PAINTSTRUCT's rcPaint rect, t=
hat holds the=20
invalid rect.

This way you don't need to calculate the rectangle yourself.

If you're stuck, look here for a complete example:
http://msdn.microsoft.com/library/default.asp?url=3D/library/en-us/shellc=
c/platform/commctls/scrollbars/usingscrollbars.asp

--
Greetings,
   Bal=E1zs