1DMXGetWindowAttributes(3) Library Functions Manual DMXGetWindowAttributes(3)
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6 DMXGetWindowAttributes - determine back-end window attributes
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9 #include <X11/extensions/dmxext.h>
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11 Bool DMXGetWindowAttributes(Display *dpy,
12 Window window,
13 int *screen_count,
14 int available_count,
15 DMXWindowAttributes *attr);
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18 When calling DMXGetWindowAttributes(), window specifies the window ID
19 of a window on the Xdmx(1) server and available_count specifies the
20 length of attr.
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22 The number of screens for which information is available will be
23 returned in screen_count and information about those screen will be
24 returned in attr. If screen_count is less than available_count, then
25 information for all of the screens will be returned. Otherwise, infor‐
26 mation for the first available_count screens will be returned.
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28 The DMXWindowAttributes structure is:
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30 typedef struct {
31 int screen;
32 Window window;
33 XRectangle pos, vis;
34 } DMXWindowAttributes;
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36 For each back-end X server that displays a portion of window, this
37 structure contains the physical screen containing that portion, the
38 window ID on the back-end X server of the window containing that por‐
39 tion, the position and dimensions of the window on the back-end (pos,
40 in screen coordinates), and the visible area of the window on the back-
41 end (vis, in window-relative coordinates -- all zeros if the window is
42 not visible on the backend).
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44 To obtain more information about the physical screen use the
45 DMXGetScreenAttributes(3) call.
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47 Note that DMX allows multiple back-end windows to overlap in their view
48 of the DMX logical window. Further, a logical window does not have to
49 be completely covered by back-end windows -- there may be gaps.
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51 As an example, consider a 500x500 window that spans the top two
52 1024x768 back-end displays (A and B) of a 2048x1536 DMX display com‐
53 posed of 4 1024x768 back-end displays arranged in a cube:
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55 A B
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58 In this case, the DMXGetWindowAttributes call would return the follow‐
59 ing information for the 500x500 window:
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61 display A: 500x500 window at 1024-250,0 (relative to back end)
62 with 250x500 visible at 0,0 (relative to window origin)
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64 display B: 500x500 window at -250,0 (relative to back end)
65 with 250x500 visible at 250,0 (relative to window origin)
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67 display C: 500x500 window at 1024-250,-768 with 0x0 visible at 0,0
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69 display D: 500x500 window at -250,-768 with 0x0 visible at 0,0
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72 DMXGetWindowAttributes() returns True unless there is a protocol error.
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74 DMXGetWindowAttributes() can generate BadWindow and BadAlloc errors.
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77 Because this call transports a great deal of information over the wire,
78 please call DMXGetScreenCount(3) first, and make sure attr is suffi‐
79 ciently large.
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81 On a particular back-end server, it is possible that the associated
82 window has not yet been mapped because the XMapWindow(3) call that will
83 eventually map the window had been buffered by Xlib's normal buffering
84 system. To avoid this race condition, please call DMXSync(3) before
85 communicating directly with the back-end X server.
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88 DMXGetScreenCount(3), DMXSync(3), DMXGetScreenAttributes(3), DMX(3),
89 Xdmx(1)
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93X Version 11 libdmx 1.1.4 DMXGetWindowAttributes(3)