// "arg->i" stores the number of tags to shift right (positive value)
//          or left (negative value)
void
shiftview(const Arg *arg)
{
  Arg a;
  Client *c;
  size_t ntags = tagcount;
  bool visible = false;
  int i = arg->i;
  int count = 0;
  int nextseltags, curseltags = selmon->tagset[selmon->seltags];

  do {
    if (i > 0) // left circular shift
      nextseltags = (curseltags << i) | (curseltags >> (ntags - i));
    else // right circular shift
      nextseltags = curseltags >> (- i) | (curseltags << (ntags + i));

    // Check if the tag is visible
    wl_list_for_each(c, &clients, link) {
      if (c->mon == selmon && nextseltags & c->tags) {
        visible = true;
        break;
      }
    }

    i += arg->i;
  } while (!visible && ++count <= ntags);

  if (count <= ntags) {
    a.i = nextseltags;
    view(&a);
  }
}