🚀 go-pugleaf

In article <1658@bdrc.bdrc.bd.com> jcl@bdrc.bd.com (John C. Lusth) writes:
>This question maybe a FAQ; if it is, I most humbly apologize and will
>wait anxiously for it to appear as it is not on site at the moment.
>
>How does one print using OWL?  The Borland documentation is very confusing
>to me (perhaps because I'm a windows newbie).  It seems to me that
>all I would need to do is instead of writing to a display context
>I would write to device context instead.  Windows should take
>care of everything else for me.  Thus, if I had a function that produced
>some output, I would send it a device context or a display context
>depending on where I wanted the output to go.  Am I being naive? 

	You're on the right track.  All you need is an hDC connected
	to either a printer or a client window.  For printing, use
	StartDoc/EndDoc and StartPage/EndPage around your code.
	See Petzold's book for details on how to do this.  You may
	also want a 'cancel' dialog box - this is all explained
	in his and other books as well.

>Another question is how to I get a device context?  The CreateDC function
>needs the driver name, the device name, and so on.  Why do I need to
>supply these things?  I just want output to go to the default printer.

	Use COMMDLG function PrintDlg() to get an hDC.  You can have
	it come up with the standard interactive display or you
	can have it just return an hDC for the default printer
	with no interaction.  Look at PD_RETURNDC (so it returns
	an hDC) and also PD_RETURNDEFAULT (for default printer,
	with no dialog box displayed).

My printing function looks like:
	void PrintMyPicture(HDC hdc,HWND hwnd);

so I can use it to process paint & print messages:
	case WM_PAINT:	hdc=BeginPaint(hwnd,&ps);
			PrintMyPicture(hdc,hwnd);
			EndPaint(hwnd,&ps);
			break;

	case WM_COMMAND:if(wparam==IDM_PRINT){
			  PrintDlg(&pd);
			  PrintMyPicture(pd.hDC,NULL);
			  DeleteDC(pd.hDC);
			}else{
			  ...
			}
			break;

Inside PrintMyPicture, I use hwnd to detect whether or not I
am drawing to the printer (hwnd==NULL) or if I am drawing to
the client area.  If I am drawing to the client area,
I use GetClientRect(hwnd,&rect) to get the dimensions of it and
if I am drawing to the printer, I use GetDeviceCaps(hdc,VERTSIZE)
(and HORZSIZE) to get the paper dimensions.  This assumes you
always want to scale your output to the printer page or client
area - it all depends on what you want to do.  With careful
planning, you can structure your code so the same routine
works for both.  I guess this is primarily for graphics - perhaps
it is more difficult for text (I don't do text, just pictures)
since you have to worry about scroll bars etc.  I dunno - maybe
it will work just as well.

Good luck.
-- 
John A. Grant						jagrant@emr1.emr.ca
Airborne Geophysics
Geological Survey of Canada, Ottawa