OpenEuphoria

Re: Print Preview - Pete Lomax

• Posted by Pete Lomax <petelomax at blueyonder.co.uk> Oct 07, 2003
• 381 views

On Tue, 7 Oct 2003 19:10:41 +1000, Tony Steward <tsteward at dodo.com.au>
wrote:

>
>
>Hello Pete,
>I downloaded you files but when I click on the tutorial icon & some
>others I get the following error:
>
>C:\EUPHORIA\include\machine.e:102 in function allocate()=20
>type_check failure, n is 0=20
>    n =3D 0
>
>... called from C:\tony\pp\pprg.ew:307 in function Fa() =20
>    Fb =3D 0
>
I think that's because the default printer name on your system is
blank, which I didn't expect.

Can you run the following code snippet, if it fails make the +1 change
as shown on line 38 and re-try, thanks. If it works OK I'll put a new
version up.

Regards,
Pete

include win32lib.ew

constant=20
iwinspool =3D open_dll("winspool.drv"),
iEnumPrinters =3D define_c_func(iwinspool,"EnumPrintersA",

{C_INT,C_INT,C_INT,C_INT,C_INT,C_INT,C_INT},C_INT),
PRINTER_ENUM_DEFAULT =3D 1

global function peeksz(atom pStr) -- peek string zero
-- return from allocated memory a string terminated by zero
integer c,i
sequence str
	str =3D {}
	i =3D 1 c=3D1
	c =3D peek(pStr)
	while c !=3D 0 do
		str =3D str & c
		c =3D peek(pStr+i)
		i =3D i + 1
	end while
	return str
end function

function getDefaultPrinterName()
-- return default printer name
atom pPInfo5, pNeeded, pReturned, ok, needed
sequence PrinterName

	pNeeded =3D allocate(4)
	mem_set(pNeeded,0,4)
	pReturned =3D allocate(4)
	mem_set(pReturned,0,4)
	-- first try to know how many bytes needed for pPInfo5
	ok =3D c_func(iEnumPrinters,{PRINTER_ENUM_DEFAULT,
							   NULL,5,0,0,pNeeded,pReturned})
	needed =3D peek4u(pNeeded)
	pPInfo5 =3D allocate(needed)
--	pPInfo5 =3D allocate(needed+1)	-- Tony Steward 7/10/03
	mem_set(pPInfo5,0,needed)
	ok =3D
c_func(iEnumPrinters,{PRINTER_ENUM_DEFAULT,NULL,5,pPInfo5,needed,
							   pNeeded,pReturned})
	free(pNeeded)
	free(pReturned)
	PrinterName=3D{}
	if ok then
		PrinterName =3D peeksz(peek4u(pPInfo5))
	end if
	free(pPInfo5)
	return PrinterName
end function
puts(1,getDefaultPrinterName())
puts(1,"\nPress Enter to exit\n")
if getc(0) then end if