Add creative mode inventory as a mod

mods/creative_inventory/README.txt

+Minetest 0.4 mod: creative
+==========================
+
+Implements creative mode.
+
+Switch on by using the "creative_mode" setting.
+
+Registered items that
+- have a description, and
+- do not have the group not_in_creative_inventory
+are added to the creative inventory.
+
+License of source code and media files:
+---------------------------------------
+Copyright (C) 2012 Perttu Ahola (celeron55) <celeron55@gmail.com>
+
+This program is free software. It comes without any warranty, to
+the extent permitted by applicable law. You can redistribute it
+and/or modify it under the terms of the Do What The Fuck You Want
+To Public License, Version 2, as published by Sam Hocevar. See
+http://sam.zoy.org/wtfpl/COPYING for more details.
+

mods/creative_inventory/init.lua

+-- minetest/creative/init.lua
+
+local creative_inventory = {}
+
+-- Create detached creative inventory after loading all mods
+minetest.after(0, function()
+	local inv = minetest.create_detached_inventory("creative", {
+		allow_move = function(inv, from_list, from_index, to_list, to_index, count, player)
+			if minetest.setting_getbool("creative_mode") then
+				return count
+			else
+				return 0
+			end
+		end,
+		allow_put = function(inv, listname, index, stack, player)
+			if minetest.setting_getbool("creative_mode") then
+				return -1
+			else
+				return 0
+			end
+		end,
+		allow_take = function(inv, listname, index, stack, player)
+			if minetest.setting_getbool("creative_mode") then
+				return -1
+			else
+				return 0
+			end
+		end,
+		on_move = function(inv, from_list, from_index, to_list, to_index, count, player)
+		end,
+		on_put = function(inv, listname, index, stack, player)
+		end,
+		on_take = function(inv, listname, index, stack, player)
+			print(player:get_player_name().." takes item from creative inventory; listname="..dump(listname)..", index="..dump(index)..", stack="..dump(stack))
+			if stack then
+				print("stack:get_name()="..dump(stack:get_name())..", stack:get_count()="..dump(stack:get_count()))
+			end
+		end,
+	})
+	local creative_list = {}
+	for name,def in pairs(minetest.registered_items) do
+		if (not def.groups.not_in_creative_inventory or def.groups.not_in_creative_inventory == 0)
+				and def.description and def.description ~= "" then
+			table.insert(creative_list, name)
+		end
+	end
+	table.sort(creative_list)
+	inv:set_size("main", #creative_list)
+	for _,itemstring in ipairs(creative_list) do
+		local stack = ItemStack(itemstring)
+		-- Make a stack of the right number of items
+		local stack2 = nil
+		if stack:get_stack_max() == 1 then
+			stack2 = ItemStack(stack:get_name())
+		else
+			-- Insert half full so that a taken stack can be put back
+			stack2 = ItemStack(stack:get_name().." "..(stack:get_stack_max()/2))
+		end
+		inv:add_item("main", stack2)
+	end
+	creative_inventory.creative_inventory_size = #creative_list
+	print("creative inventory size: "..dump(creative_inventory.creative_inventory_size))
+end)
+
+creative_inventory.set_creative_formspec = function(player, start_i)
+	player:set_inventory_formspec("size[13,7.5]"..
+			--"image[6,0.6;1,2;player.png]"..
+			"list[current_player;main;5,3.5;8,4;]"..
+			"list[current_player;craft;8,0;3,3;]"..
+			"list[current_player;craftpreview;12,1;1,1;]"..
+			"list[detached:creative;main;0.3,0.5;4,6;"..tostring(start_i).."]"..
+			"button[0.3,6.5;1.9,1;creative_prev;<<]"..
+			"button[2.4,6.5;1.9,1;creative_next;>>]")
+end
+minetest.register_on_joinplayer(function(player)
+	-- If in creative mode, modify player's inventory forms
+	if not minetest.setting_getbool("creative_mode") then
+		return
+	end
+	creative_inventory.set_creative_formspec(player, 0)
+end)
+minetest.register_on_player_receive_fields(function(player, formname, fields)
+	if not minetest.setting_getbool("creative_mode") then
+		return
+	end
+	-- Figure out current page from formspec
+	local current_page = 0
+	local formspec = player:get_inventory_formspec()
+	local start_i = string.match(formspec, "list%[detached:creative;main;[%d.]+,[%d.]+;[%d.]+,[%d.]+;(%d+)%]")
+	start_i = tonumber(start_i) or 0
+
+	if fields.creative_prev then
+		start_i = start_i - 4*6
+	end
+	if fields.creative_next then
+		start_i = start_i + 4*6
+	end
+
+	if start_i < 0 then
+		start_i = start_i + 4*6
+	end
+	if start_i >= creative_inventory.creative_inventory_size then
+		start_i = start_i - 4*6
+	end
+		
+	if start_i < 0 or start_i >= creative_inventory.creative_inventory_size then
+		start_i = 0
+	end
+
+	creative_inventory.set_creative_formspec(player, start_i)
+end)
+