for (i = 0; i < self->n_buttons; ++i) {
window_remove(self->button[i].window);
XDestroyWindow(obt_display, self->button[i].window);
for (i = 0; i < self->n_buttons; ++i) {
window_remove(self->button[i].window);
XDestroyWindow(obt_display, self->button[i].window);