🚀 go-pugleaf

In article <1993Jan7.141729.2931@brandonu.ca> dueck@brandonu.ca writes:
>I have an application that draws graphics in a window. I want to save the
>contents of the window across task switches so they can be restored when my
>application is reactivated. At what point should I take a snapshot of the
>screen? 
	When you receive WM_PAINT and draw your screen, also save
	the whole thing as a bitmap.  If you get WM_SIZE, then kill
	the bitmap, it is now invalid.  You may also kill it when
	you change the picture yourself.

	Subsequently, when you get WM_PAINT messages, if the bitmap
	still exists, then BitBlt it to the screen, to redraw:

	static HBITMAP hbitmap=NULL;
	...
		case WM_PAINT:	if(hbitmap){
				  BitBlt using hbitmap
				}else{
				  hdc=BeginPaint(...)
				  DrawMyPicture();
				  hbitmap=SaveMyPictureAsBitmap();
				  EndPaint(...);
				}
				break;

	If you need more details, e-mail me and I'll send you some code.
-- 
John A. Grant						jagrant@emr1.emr.ca
Airborne Geophysics
Geological Survey of Canada, Ottawa