1 /* cc transient.c -o transient -lX11 */

     2 

     3 #include <stdlib.h>

     4 #include <unistd.h>

     5 #include <X11/Xlib.h>

     6 #include <X11/Xutil.h>

     7 

     8 int main(void) {

     9 	Display *d;

    10 	Window r, f, t = None;

    11 	XSizeHints h;

    12 	XEvent e;

    13 

    14 	d = XOpenDisplay(NULL);

    15 	if (!d)

    16 		exit(1);

    17 	r = DefaultRootWindow(d);

    18 

    19 	f = XCreateSimpleWindow(d, r, 100, 100, 400, 400, 0, 0, 0);

    20 	h.min_width = h.max_width = h.min_height = h.max_height = 400;

    21 	h.flags = PMinSize | PMaxSize;

    22 	XSetWMNormalHints(d, f, &h);

    23 	XStoreName(d, f, "floating");

    24 	XMapWindow(d, f);

    25 

    26 	XSelectInput(d, f, ExposureMask);

    27 	while (1) {

    28 		XNextEvent(d, &e);

    29 

    30 		if (t == None) {

    31 			sleep(5);

    32 			t = XCreateSimpleWindow(d, r, 50, 50, 100, 100, 0, 0, 0);

    33 			XSetTransientForHint(d, t, f);

    34 			XStoreName(d, t, "transient");

    35 			XMapWindow(d, t);

    36 			XSelectInput(d, t, ExposureMask);

    37 		}

    38 	}

    39 

    40 	XCloseDisplay(d);

    41 	exit(0);

    42 }