# File lib/rumai/wm.rb, line 178
    def focus aView = nil
      if exist? and not focus?
        (aView ? [aView] : self.views).each do |v|
          if a = self.area(v)
            v.focus
            a.focus

            # slide focus from the current client onto this client
            arr = a.client_ids
            src = arr.index Client.curr.id
            dst = arr.index @id

            distance = (src - dst).abs
            direction = src < dst ? :down : :up

            distance.times do
              v.ctl.write "select #{direction}"
            end

            break
          end
        end
      end
    end