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DMXGetWindowAttributes(3)                   DragonFly Library Functions Manual


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
       window 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(3) 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(3) first, and make sure attr is
       sufficiently large.

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


SEE ALSO

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

X Version 11                     libdmx 1.1.3        DMXGetWindowAttributes(3)

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