added yl_speak_up.input_add_trade_simple

trade_simple.lua

@@ -5,7 +5,89 @@ yl_speak_up.trade_fail_fs = "size[6,2]"..
                 "label[0.2,0.5;Ups! The trade is not possible.\nPlease notify an admin.]"..
 		"button_exit[2,1.5;1,0.9;exit;Exit]"
 
--- TODO: when closing the formspec: give the items in the pay slot back
+
+-- the player wants to add a simple trade; handle formspec input
+yl_speak_up.input_add_trade_simple = function(player, formname, fields)
+	if(not(player)) then
+		return 0
+	end
+	local pname = player:get_player_name()
+	-- the trade can only be changed in edit mode
+	if(yl_speak_up.edit_mode[pname] ~= yl_speak_up.speak_to[pname].n_id
+	  or not(yl_speak_up.speak_to[pname].n_id)) then
+		return 0
+	end
+
+	-- we return from showing an error message (the player may not have noticed
+	-- a chat message while viewing a formspec)
+	if(fields.back_from_error_msg) then
+		minetest.show_formspec(pname, "yl_speak_up:add_trade_simple",
+			yl_speak_up.get_fs_trade_simple(player))
+		return
+	end
+
+	-- which trade are we talking about?
+	local trade = yl_speak_up.trade[pname]
+
+	local d_id = yl_speak_up.speak_to[pname].d_id
+	local n_id = yl_speak_up.speak_to[pname].n_id
+
+	-- this also contains the inventory list "setup" where the player placed the items
+	local trade_inv = minetest.get_inventory({type="detached", name="yl_speak_up_player_"..pname})
+
+	-- fields.abort_trade_simple can be ignored as it is similar to ESC
+
+	local pay = trade_inv:get_stack("setup", 1)
+	local buy = trade_inv:get_stack("setup", 2)
+
+	-- store the new trade
+	if(fields.store_trade_simple) then
+		local error_msg = ""
+		-- check for error conditions
+		if(pay:is_empty()) then
+			error_msg = "What shall the customer pay?\nWe don't give away stuff for free here!"
+		elseif(buy:is_empty()) then
+			error_msg = "What shall your NPC sell?\nCustomers won't pay for nothing!"
+		elseif(pay:get_wear() > 0 or buy:get_wear() > 0) then
+			error_msg = "Selling used items is not possible."
+		elseif(not(minetest.registered_items[ pay:get_name() ])
+		    or not(minetest.registered_items[ buy:get_name() ])) then
+			error_msg = "Unkown items cannot be traded."
+		elseif(pay:get_name() == buy:get_name()) then
+			error_msg = "Selling *and* buying the same item\nat the same time makes no sense."
+		else
+			-- TODO: *can* we store the trade?
+			-- TODO no trade stored for that option yet?
+			error_msg = "So far so good!"
+		end
+		-- show error message (that leads back to this formspec)
+		if(error_msg) then
+			minetest.show_formspec(pname, "yl_speak_up:add_trade_simple",
+				"size[6,2]"..
+				"label[0.2,0.5;"..error_msg.."]"..
+				"button[2,1.5;1,0.9;back_from_error_msg;Back]")
+			return
+		end
+	end
+
+	-- give the items back to the player (he took them from his inventory and had no
+	-- real chance to put them elsewhere - so there really ought to be room enough)
+	local player_inv = player:get_inventory()
+	if( player_inv:room_for_item("main", pay)) then
+		player_inv:add_item("main", pay)
+		trade_inv:set_stack("setup", 1, "")
+	end
+	if( player_inv:room_for_item("main", buy)) then
+		player_inv:add_item("main", buy)
+		trade_inv:set_stack("setup", 2, "")
+	end
+
+	-- TODO: or show the trade we just stored directly?
+	-- ..and go back to the edit options formspec
+	minetest.show_formspec(pname, "yl_speak_up:edit_option_dialog",
+		yl_speak_up.get_fs_edit_option_dialog(player, n_id, d_id, trade.o_id))
+end
+
 
 -- can this trade be made? called in allow_take
 yl_speak_up.can_trade_simple = function(player, count)
@@ -140,8 +222,9 @@ yl_speak_up.get_fs_trade_simple = function(player, player_gives, npc_gives)
 	-- the NPCs' inventory
 	local npc_inv = minetest.get_inventory({type="detached", name="yl_speak_up_npc_"..tostring(trade.n_id)})
 
-	-- show edit button for the owner
-	if(yl_speak_up.may_edit_npc(player, trade.n_id)) then
+	-- show edit button for the owner if in edit_mode
+	if(yl_speak_up.may_edit_npc(player, trade.n_id)
+	  and (yl_speak_up.edit_mode[pname] == yl_speak_up.speak_to[pname].n_id)) then
 		formspec = formspec..
 			"button[0.2,1.6;0.8,0.9;edit_trade_simple;Edit]"..
 			"tooltip[edit_trade_simple;Edit this trade. You can do so only "..
@@ -242,6 +325,23 @@ minetest.register_on_joinplayer(function(player, last_login)
 			if(listname == "buy") then
 				return 0
 			end
+			-- do not allow used items or items with metadata in the setup slots
+			-- (they can't really be traded later on anyway)
+			if(listname == "setup") then
+				if(stack:get_wear() > 0) then
+					minetest.chat_send_player(player:get_player_name(),
+						"Your NPC accepts only undammaged items. "..
+						"Trading dammaged items would be unfair.")
+					return 0
+				end
+				-- items with metadata cannot be traded
+				if(yl_speak_up.check_stack_has_meta(player, stack)) then
+					minetest.chat_send_player(player:get_player_name(),
+						"Your NPC cannot sell items that contain "..
+						"additional (meta-) data.")
+					return 0
+				end
+			end
 			return stack:get_count()
 		end,
 	        allow_take = function(inv, listname, index, stack, player)