test script for "smooth" resize a bar

test.lua

w = weechat

w.register("test", "singalaut", "0.1", "WTFPL", "", "", "")

function resize_bar_start_cb(_, _, tb)
   local ptr_bar = w.bar_search(tb._bar_name)
   if ptr_bar == "" then
      return w.WEECHAT_RC_OK
   end
   -- bar_window is not bar with type window but an area of screen that is
   -- occupied by a bar.
   local h_bar, h_area = w.hdata_get("bar"), w.hdata_get("bar_window")
   local ptr_area = w.hdata_pointer(h_bar, ptr_bar, "bar_window")
   -- if empty, that means it's a not a root bar
   -- we have to find a bar area that is inside current window first
   if ptr_area == "" then
      local h_win = w.hdata_get("window")
      ptr_area = w.hdata_pointer(h_win, tb._window, "bar_windows")
      while ptr_area ~= "" do
         local ptr_this_bar = w.hdata_pointer(h_area, ptr_area, "bar")
         if ptr_this_bar == ptr_bar then
            break
         end
         ptr_area = w.hdata_pointer(h_area, ptr_area, "next_bar_window")
      end
   end
   if ptr_area ~= "" then
      current_bar = {
         name = tb._bar_name,
         pointer = ptr_bar,
         area = ptr_area,
         position= w.config_string(w.config_get("weechat.bar."..tb._bar_name..".position")),
         width = w.hdata_integer(h_area, ptr_area, "width"),
         height = w.hdata_integer(h_area, ptr_area, "height"),
         size = w.hdata_integer(h_area, ptr_area, "current_size")
      }
      w.bar_set(ptr_bar, "size_max", 0)
   end
   return w.WEECHAT_RC_OK
end

function resize_bar_cb(_, _, tb)
   if current_bar then
      if tb._bar_name ~= current_bar.name then
         current_bar = nil
         return w.WEECHAT_RC_OK
      end
      local distance = 0
      local x, y, x2, y2 = tonumber(tb._x), tonumber(tb._y),
                           tonumber(tb._x2), tonumber(tb._y2)
      if current_bar.position == "top" then
         distance = y2 - y
      elseif current_bar.position == "bottom" then
         distance = y - y2
      elseif current_bar.position == "left" then
         distance = x2 - x
      elseif current_bar.position == "right" then
         distance = x - x2
      end
      if distance ~= 0 then
         local new_size = current_bar.size + distance
         w.bar_set(current_bar.pointer, "size", new_size > 0 and new_size or 0)
      end
   end
   return w.WEECHAT_RC_OK
end

w.hook_hsignal("resize_bar_start", "resize_bar_start_cb", "")
w.hook_hsignal("resize_bar", "resize_bar_cb", "")
w.key_bind("mouse", {
           ["@bar(*):*-event-down"] = "hsignal:resize_bar_start",
           ["@bar(*):*-event-drag"] = "hsignal:resize_bar"
        })