🚀 go-pugleaf

All,

I hope someone can be of some assistance.  I have scoured Google with every
combination of this topic without finding any clues.  Please follow my
thoughts through to completion before attempting to post since I'm not even
very clear in my own mind what is exactly happening.  I would like to
instruct Windows (or the VCL ... not sure which) to not scroll the canvas of
a window when a resize event occurs.

Here is the scenario.  I have a panel which draws an image beneath all child
controls that is located at the bottom right of the panel.  When the user
resizes the panel (using a splitter to the left of the panel) the image is
first scrolled to the left (due to internal Windows or VCL logic) and then
the panel is invalidated and repainted which my panel then paints the image
back in the appropriate location.

While this doesn't appear to be too much of a problem it causes an annoying
distortion for a fraction of a second that any user can visually pick up on.
DoubleBuffered and FullRepaint properties have no affect.  I have also tried
using WM_SETREDRAW to no avail.

To see this for yourself create an application and place a panel aligned
left, a splitter aligned left (ResizeStyle set to rsUpdate), and a TImage
aligned client (Stretch set to true).  Put a rather large graphic in TImage
so the affect can be easily seen.  Move the splitter rapidly and watch the
graphic push/scroll and then redraw itself correctly.  Or, alternatively, if
you use Windows Messenger you can see the same effect of its lower right
aligned graphic by rapidly resizing the form from the left.

To sum up, I would like to instruct Windows to not scroll a window's device
context on a resize.  I would prefer that garbage pixels be left behind
until the subsequent paint operation can be performed.

TIA,
- Clayton