You are right about the mistakes in default units functions. Thank you for the hint!

By the way, the forum is a better place to discuss about these issues.

I am trying to use your TPrintPreview in a C++Builder 2010 runtime environment. I place the component on a panel using:

PrintPreview= new TPrintPreview(PreviewPanel->Handle);
PrintPreview->Width = PreviewPanel->ClientWidth;
PrintPreview->Height= PreviewPanel->ClientHeight;

and everything seems to work fine, except when the PreviewPanel is resized. After a resize the horizontal scroll bar moves out of sight and the right margin of the vertical scroll bar also moves out of sight. When I investigate the heights of PrintPreview and PreviewPanel, the PrintPreview is usually 26 pixels larger than the PreviewPanel, which explains the problem. I haven’t investigated the widths but something similar but with less pixels difference must be happening there.

Do you think you can solve this?

By the way, I found a possible mistake in

function TPrintPreview.GetSystemDefaultUnits: TUnits;
function TPrintPreview.GetUserDefaultUnits: TUnits;

it looks like the calls to GetLocaleInfo() should be interchanged:
GetSystemDefaultUnits has:
GetLocaleInfo(LOCALE_USER_DEFAULT, LOCALE_IMEASURE, Data, 2);
GetUserDefaultUnits has:
GetLocaleInfo(LOCALE_SYSTEM_DEFAULT, LOCALE_IMEASURE, Data, 2);

Thanks!
Johan
Netherlands