+CompositedScreen *find_screen_by_window(Compositor *compositor, Window w)
+{
+ unsigned i, j;
+
+ for(i=0; i<compositor->nscreens; ++i)
+ for(j=0; j<compositor->screens[i].nwindows; ++j)
+ if(compositor->screens[i].windows[j].window==w)
+ return &compositor->screens[i];
+
+ return NULL;
+}
+