DMXGetWindowAttributes(3X)												DMXGetWindowAttributes(3X)

NAME

       DMXGetWindowAttributes - determine back-end window attributes

SYNOPSIS

       #include <X11/extensions/dmxext.h>

       Bool DMXGetWindowAttributes(Display *dpy,
				   Window window,
				   int *screen_count,
				   int available_count,
				   DMXWindowAttributes *attr);

DESCRIPTION

       When  calling  DMXGetWindowAttributes(), window specifies the window ID of a window on the Xdmx(1) server and available_count specifies the
       length of attr.

       The number of screens for which information is available will be returned in screen_count  and  information  about  those  screen  will	be
       returned  in  attr.   If  screen_count  is less than available_count, then information for all of the screens will be returned.	Otherwise,
       information for the first available_count screens will be returned.

       The DMXWindowAttributes structure is:

       typedef struct {
	   int		screen;
	   Window	window;
	   XRectangle	pos, vis;
       } DMXWindowAttributes;

       For each back-end X server that displays a portion of window, this structure contains the physical screen containing that portion, the win-
       dow  ID	on the back-end X server of the window containing that portion, the position and dimensions of the window on the back-end (pos, in
       screen coordinates), and the visible area of the window on the back-end (vis, in window-relative coordinates -- all zeros if the window	is
       not visible on the backend).

       To obtain more information about the physical screen use the DMXGetScreenAttributes(3X) call.

       Note that DMX allows multiple back-end windows to overlap in their view of the DMX logical window.  Further, a logical window does not have
       to be completely covered by back-end windows -- there may be gaps.

       As an example, consider a 500x500 window that spans the top two 1024x768 back-end displays (A and B) of a 2048x1536 DMX display composed of
       4 1024x768 back-end displays arranged in a cube:

	   A B
	   C D

       In this case, the DMXGetWindowAttributes call would return the following information for the 500x500 window:

       display A: 500x500 window at 1024-250,0 (relative to back end)
		  with 250x500 visible at 0,0 (relative to window origin)

       display B: 500x500 window at -250,0 (relative to back end)
		  with 250x500 visible at 250,0 (relative to window origin)

       display C: 500x500 window at 1024-250,-768 with 0x0 visible at 0,0

       display D: 500x500 window at -250,-768 with 0x0 visible at 0,0

RETURN VALUE

       DMXGetWindowAttributes() returns True unless there is a protocol error.

       DMXGetWindowAttributes() can generate BadWindow and BadAlloc errors.

NOTES

       Because this call transports a great deal of information over the wire, please call DMXGetScreenCount(3X) first, and make sure attr is suf-
       ficiently large.

       On a particular back-end server, it is possible that the associated window has not yet been mapped because  the	XMapWindow(3X)	call  that
       will  eventually map the window had been buffered by Xlib's normal buffering system.  To avoid this race condition, please call DMXSync(3X)
       before communicating directly with the back-end X server.

SEE ALSO

       DMXGetScreenCount(3X), DMXSync(3X), DMXGetScreenAttributes(3X), DMX(3X), Xdmx(1)

XFree86 							   Version 4.7.0					DMXGetWindowAttributes(3X)