gistfile1.lua

-- here's the function used to actually drag & reorder tags
local function tag_drag(t)
    local dr = mywibox[1]._drawable

    mousegrabber.run(function (_mouse)
                              for k, v in ipairs(_mouse.buttons) do
                                  if v then
                                      local x = _mouse.x
                                      local y = _mouse.y

                                      local widgets = dr:find_widgets(x,y)

                                      local target_tag = widgets[1].widget.tag

                                      if target_tag and t ~= target_tag then
                                          local idx = awful.tag.getidx(target_tag)
                                          awful.tag.move(idx, t)
                                      end
                                      return true
                                  end
                              end
                              return false
                          end, "fleur")
end

-- and to use it, simply bind it to some buttons
mytaglist.buttons = awful.util.table.join(
                    awful.button({ }, 1, function(t) awful.tag.viewonly(t); tag_drag(t) end),
-- .. and so on

-- copy & paste from original sources. the only change is remembering which tag corresponds to each widget
-- this needs to be passed as a parameter when creating the tag list
local function taglist_update(w, buttons, label, data, objects)
    print("update, we're home")
    -- update the widgets, creating them if needed
    w:reset()
    for i, o in ipairs(objects) do
        local cache = data[o]
        local ib, tb, bgb, m, l
        if cache then
            ib = cache.ib
            tb = cache.tb
            bgb = cache.bgb
            m   = cache.m
        else
            ib = wibox.widget.imagebox()
            tb = wibox.widget.textbox()
            bgb = wibox.widget.background()
            m = wibox.layout.margin(tb, 4, 4)
            l = wibox.layout.fixed.horizontal()

            -- All of this is added in a fixed widget
            l:fill_space(true)
            l:add(ib)
            l:add(m)

            -- remeber for which tag this widget is created
            tb.tag = o

            -- And all of this gets a background
            bgb:set_widget(l)

            bgb:buttons(common.create_buttons(buttons, o))

            data[o] = {
                ib = ib,
                tb = tb,
                bgb = bgb,
                m   = m
            }
        end

        local text, bg, bg_image, icon = label(o)
        -- The text might be invalid, so use pcall
        if not pcall(tb.set_markup, tb, text) then
            tb:set_markup("<i>&lt;Invalid text&gt;</i>")
        end
        bgb:set_bg(bg)
        if type(bg_image) == "function" then
            bg_image = bg_image(tb,o,m,objects,i)
        end
        bgb:set_bgimage(bg_image)
        ib:set_image(icon)
        w:add(bgb)
   end
end