DMXGetWindowAttributes(3)

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, infor-
       mation 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
       window  ID  on the back-end X server of the window containing that por-
       tion, 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 com-
       posed of 4 1024x768 back-end displays arranged in a cube:

           A B
           C D

       In this case, the DMXGetWindowAttributes call would return the  follow-
       ing 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  suffi-
       ciently 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)

X Version 11                     libdmx 1.0.2       DMXGetWindowAttributes(3X)