I'm not sure I understand the transaction that's taking place here.

examples/cluster.c

@@ -283,7 +283,7 @@ int main(int argc, char **argv) {
      */
     draw_gauge_cluster_bg(bg, display, screen, width, height);
 
-    XSelectInput(display, win, ExposureMask | ButtonPressMask | KeyPressMask);
+    printf("XSelectInput %d\n", XSelectInput(display, win, ExposureMask | ButtonPressMask | KeyPressMask));
     XMapWindow(display, win);
 
     /*

include/hexagram/window.h

@@ -7,11 +7,16 @@
                                     ButtonReleaseMask | ExposureMask    | \
                                     StructureNotifyMask)
 
+#define HEXAGRAM_WINDOW_GC_FLAGS (GCForeground | GCBackground | \
+                                  GCGraphicsExposures)
+
 typedef struct _hexagram_window hexagram_window;
 
 hexagram_window *hexagram_window_new_x11(const char *display,
-                                         int width,
-                                         int height);
+                                         unsigned int width,
+                                         unsigned int height);
+
+int hexagram_window_get_display_fd(hexagram_window *window);
 
 int hexagram_window_show(hexagram_window *window);
 

src/Makefile

@@ -7,10 +7,10 @@ CC		= $(CROSS)cc
 CFLAGS		+= -fPIC -I$(INCLUDE_PATH)
 LDFLAGS		=
 
-HEADERS		= dict.h hash.h can.h capture.h pcapng.h module.h sim.h
+HEADERS		= dict.h hash.h can.h capture.h pcapng.h module.h window.h sim.h
 HEADERS_LOCAL	= util.h
 
-OBJS		= dict.o hash.o can.o capture.o pcapng.o module.o sim.o
+OBJS		= dict.o hash.o can.o capture.o pcapng.o module.o window.o sim.o
 
 VERSION_MAJOR	= 0
 VERSION_MINOR	= 0.1