Arguments: window
Returns an integer that identifies the device-context of
window if it has one, or nil otherwise. A device-context is a construct used
in the Windows API to specify a set of parameters that are used when
drawing on a window. A common graphics application does not normally
need to deal with a window's device-context directly, but if you need
to pass the window to a winapi function that calls for the window's
device-context (or hDC), then you should pass the integer returned by
this function for that argument. See also windows:handle, which
returns the window's "handle".
Every non-control window in common graphics (and every lisp-widget window) is automatically assigned a device-context, which it keeps until it is closed. Controls supplied by the OS (all controls except lisp-widgets), on the other hand, are not automatically given device-contexts in lisp since it is normally only the OS rather than lisp that draws on the control. If you do want to draw directly on a non-lisp control, then you must give the window of the control a device-context while drawing on it. The easy way to do this is to wrap a call to with-device-context around the code that draws on the control.
Common Graphics and IDE documentation is described in About Common Graphics and IDE documentation in cgide.htm.
The documentation is described in introduction.htm and the index is in index.htm.
Copyright (c) 1998-2000, Franz Inc. Berkeley, CA., USA. All rights reserved.
Created 2000.10.5.