code improvements

* create all hotbar images on load
* round hotbar size before clamping
* move migration function to bottom of file
* check if player is online in chat command
* return message from chat command instead of sending chat message

init.lua

@@ -1,52 +1,39 @@
-local storage = minetest.get_mod_storage()
-local themename = ""
 
+local storage = minetest.get_mod_storage()
+
+local themename = ""
 if minetest.global_exists("dreambuilder_theme") then
 	themename = dreambuilder_theme.name.."_"
 end
 
-local base_img = themename.."gui_hb_bg_1.png"
+local hotbar_selected_image = themename.."gui_hotbar_selected.png"
-local imgref_len = string.len(base_img) + 8 -- accounts for the stuff in the string.format() below.
+local hotbar_image = {}
+do
+	local hotbar_slot = themename.."gui_hb_bg_1.png"
+	local str = ""
+	for i = 0, 31 do
+		str = str..string.format(":%i,0=%s", i*64, hotbar_slot)
+		hotbar_image[i+1] = string.format("[combine:%ix64%s", (i+1)*64, str)
+	end
+end
+
 local hotbar_size_default = 16
 
-local img = {}
-for i = 0, 31 do
-	img[i+1] = string.format(":%04i,0=%s", i*64, base_img)
-end
-local hb_img = table.concat(img)
-
 local function validate_size(s)
-	local size = s and tonumber(s) or hotbar_size_default
+	local size = tonumber(s) or hotbar_size_default
-	return math.floor(0.5 + math.max(1, math.min(size, 32)))
+	return math.max(1, math.min(math.floor(size + 0.5), 32))
 end
 
 hotbar_size_default = validate_size(minetest.settings:get("hotbar_size"))
 
-local function migrate_file2modstorage()
-	local path = minetest.get_worldpath()..DIR_DELIM.."hotbar_settings"
-	local f = io.open(path, "r")
-	if f then
-		local hotbar_sizes = minetest.deserialize(f:read("*all"))
-		f:close()
-		local counter = 0
-		for name, size in pairs(hotbar_sizes) do
-			if size ~= hotbar_size_default then
-				storage:set_int(name, tonumber(size))
-				counter = counter + 1
-			end
-		end
-		os.remove(path)
-		minetest.log("action", "[dreambuilder_hotbar] Migrated " .. counter .. " player hotbars to modstorage")
-	end
-end
-
 local function get_hotbar_size(player)
 	local name = player:get_player_name()
 	local meta = player:get_meta()
 	local size = meta:get_int("hotbar_size")
-	if size == 0 then -- not present
+	if size == 0 then
+		-- Migrate from modstorage if present
 		size = storage:get_int(name)
-		if size ~= 0 then -- migrate
+		if size ~= 0 then
 			storage:set_string(name, "")
 			meta:set_int("hotbar_size", size)
 		end
@@ -56,8 +43,8 @@ end
 
 local function update_hotbar(player, hotbar_size)
 	player:hud_set_hotbar_itemcount(hotbar_size)
-	player:hud_set_hotbar_selected_image(themename.."gui_hotbar_selected.png")
+	player:hud_set_hotbar_selected_image(hotbar_selected_image)
-	player:hud_set_hotbar_image("[combine:"..(hotbar_size*64).."x64"..string.sub(hb_img, 1, hotbar_size*imgref_len))
+	player:hud_set_hotbar_image(hotbar_image[hotbar_size])
 end
 
 local function set_hotbar_size(player, size)
@@ -81,11 +68,33 @@ end)
 
 minetest.register_chatcommand("hotbar", {
 	params = "<size>",
-	description = "Sets the size of your hotbar, from 1 to 32 slots, default " .. hotbar_size_default,
+	description = "Sets the size of your hotbar, from 1 to 32 slots. Default " .. hotbar_size_default,
 	func = function(name, slots)
-		local size = set_hotbar_size(minetest.get_player_by_name(name), slots)
+		local player = minetest.get_player_by_name(name)
-		minetest.chat_send_player(name, "[_] Hotbar size set to " ..size.. ".")
+		if not player then
+			return false, "Player is not online."
+		end
+		local size = set_hotbar_size(player, slots)
+		return true, "Hotbar size set to "..size
 	end
 })
 
-migrate_file2modstorage()
+-- Migrate hotbar settings from file to modstorage
+local function migrate_storage()
+	local path = minetest.get_worldpath()..DIR_DELIM.."hotbar_settings"
+	local file = io.open(path, "r")
+	if file then
+		local hotbar_sizes = minetest.deserialize(file:read("*all"))
+		file:close()
+		local count = 0
+		for name, size in pairs(hotbar_sizes) do
+			if size ~= hotbar_size_default then
+				storage:set_int(name, tonumber(size))
+				count = count + 1
+			end
+		end
+		os.remove(path)
+		minetest.log("action", "[dreambuilder_hotbar] Migrated "..count.." player hotbars to modstorage")
+	end
+end
+migrate_storage()