minetest_select_item/init.lua

select_item = {}
local get_items = function()
	local it = {}
	for itemstring, itemdef in pairs(minetest.registered_items) do
		table.insert(it, {itemstring=itemstring, itemdef=itemdef})
	end
	return it
end

local check_item = function(itemstring, filter)
	local itemdef = minetest.registered_items[itemstring]
	if itemstring == "air" or itemstring == "ignore" or itemstring == "unknown" then
		return false
	end
	if itemdef.description == nil or itemdef.description == "" then
		return false
	end
	if itemdef.groups ~= nil and itemdef.groups.not_in_creative_inventory ~= nil then
		return false
	end
	return true
end

local xsize = 18
local ysize = 9

select_item.select_item = function(playername, filter, page)
	local form = "size["..xsize..","..(ysize+1).."]"
	local items = get_items()
	local x = 0
	local y = 0.5
	if page == nil then page = 1 end
	local start = 1 + (page-1) * xsize * ysize
	form = form .. "label[0,0;Select an item:]"
	for i=start, #items do
		local itemstring = items[i].itemstring
		local itemdef = items[i].itemdef
		if check_item(itemstring, filter) then
			local name = "item_"..itemstring
			form = form .. "item_image_button["..x..","..y..";1,1;"..itemstring..";"..name..";]"

			x = x + 1
			if x >= xsize then
				x = 0
				y = y + 1
				if y >= ysize then
					break
				end
			end
		end
	end
	local ynav = (ysize + 0.5)
	form = form .. "button[0,"..ynav..";1,1;previous;<]"
	form = form .. "button[1,"..ynav..";1,1;next;>]"
	form = form .. "button_exit["..(xsize-2)..","..ynav..";2,1;cancel;Cancel]"
	minetest.show_formspec(playername, "select_item:page"..page, form)
end

local callbacks = {}
select_item.register_callback = function(callback)
	table.insert(callbacks, callback)
end

minetest.register_on_player_receive_fields(function(player, formname, fields)
	if string.sub(formname, 1, 16) == "select_item:page" then
		local playername = player:get_player_name()
		local item
		for field,_ in pairs(fields) do
			if string.sub(field, 1, 5) == "item_" then
				item = string.sub(field, 6, string.len(field))
				break
			end
		end
		if item then
			for i=1,#callbacks do
				callbacks[i](playername, item)
			end
		end
		local page = tonumber(string.sub(formname, 17, string.len(formname)))
		if page ~= nil then
			if fields.previous and page > 1 then
				select_item.select_item(player:get_player_name(), nil, page - 1)
			elseif fields.next then
				local items = get_items()
				local maxpage = (#items / (xsize*ysize))
				if page + 1 < maxpage then
					select_item.select_item(playername, nil, page + 1)
				end
			end
		end
	end
end)