mpv_in_rc.lua

    { rule = { class = "mpv" },
                        callback = function(c)
                            local w_area = screen[ c.screen ].workarea
                            awful.util.spawn_with_shell("mocp -P")
                            c:geometry( { width = 600, height = 450 } )
                            c:geometry( { x = w_area.width - c:geometry().width, y = w_area.height - c:geometry().height } )
                            c:add_signal("property::fullscreen", function() if not c.fullscreen then c.ontop = true end end)
                        end,
                        properties = { ontop = true, floating = true, maximized_horizontal = false, maximized_vertical = false, switchtotag = false, tag = tags[1][4], sticky = true } },