Epic/mods/hopper/utility.lua

-- internationalization boilerplate
local MP = minetest.get_modpath(minetest.get_current_modname())
local S, NS = dofile(MP.."/intllib.lua")

-- Target inventory retrieval

-- looks first for a registration matching the specific node name, then for a registration
-- matching group and value, then for a registration matching a group and *any* value
hopper.get_registered_inventories_for = function(target_node_name)
   local output = hopper.containers[target_node_name]
   if output ~= nil then return output end

   local target_def = minetest.registered_nodes[target_node_name]
   if target_def == nil or target_def.groups == nil then return nil end

   for group, value in pairs(target_def.groups) do
      local registered_group = hopper.groups[group]
      if registered_group ~= nil then
         output = registered_group[value]
         if output ~= nil then return output end
         output = registered_group["all"]
         if output ~= nil then return output end
      end
   end

   return nil
end

hopper.get_eject_button_texts = function(pos, loc_X, loc_Y)
   if not hopper.config.eject_button_enabled then return "" end

   local eject_button_text, eject_button_tooltip
   if minetest.get_meta(pos):get_string("eject") == "true" then
      eject_button_text = S("Don't\nEject")
      eject_button_tooltip = S("This hopper is currently set to eject items from its output\neven if there isn't a compatible block positioned to receive it.\nClick this button to disable this feature.")
      local timer1 = minetest.get_node_timer(pos)
      if not timer1:is_started() then
         timer1:start(1.0)
      end
   else
      eject_button_text = S("Eject\nItems")
      eject_button_tooltip = S("This hopper is currently set to hold on to item if there\nisn't a compatible block positioned to receive it.\nClick this button to have it eject items instead.")
      local timer1 = minetest.get_node_timer(pos)
      if not timer1:is_started() then
         timer1:start(1.0)
      end
   end
   return "button_exit["..loc_X..","..loc_Y..";1,1;eject;"..eject_button_text.."]tooltip[eject;"..eject_button_tooltip.."]"
end

hopper.get_string_pos = function(pos)
   return pos.x .. "," .. pos.y .. "," ..pos.z
end

-- Apparently node_sound_metal_defaults is a newer thing, I ran into games using an older version of the default mod without it.
if default.node_sound_metal_defaults ~= nil then
   hopper.metal_sounds = default.node_sound_metal_defaults()
else
   hopper.metal_sounds = default.node_sound_stone_defaults()
end

-------------------------------------------------------------------------------------------
-- Inventory transfer functions

local delay = function(x)
   return (function() return x end)
end

local get_placer = function(player_name)
   if player_name ~= "" then
      return minetest.get_player_by_name(player_name) or {
         is_player = delay(true),
         get_player_name = delay(player_name),
         is_fake_player = ":hopper",
         get_wielded_item = delay(ItemStack(nil))
      }
   end
   return nil
end

-- Used to remove items from the target block and put it into the hopper's inventory
hopper.take_item_from = function(hopper_pos, target_pos, target_node, target_inventory_name)
   if target_inventory_name == nil then
      return
   end
   local target_def = minetest.registered_nodes[target_node.name]
   if not target_def then
      return
   end

   --hopper inventory
   local hopper_meta = minetest.get_meta(hopper_pos);
   local hopper_inv = hopper_meta:get_inventory()
   local placer = get_placer(hopper_meta:get_string("placer"))

   --source inventory
   local target_inv = minetest.get_meta(target_pos):get_inventory()
   local target_inv_size = target_inv:get_size(target_inventory_name)
   if target_inv:is_empty(target_inventory_name) == false then
      for i = 1,target_inv_size do
         local stack = target_inv:get_stack(target_inventory_name, i)
         local item = stack:get_name()
         if item ~= "" then
            if hopper_inv:room_for_item("main", item) then
               local stack_to_take = stack:take_item(1)
               if target_def.allow_metadata_inventory_take == nil
                 or placer == nil -- backwards compatibility, older versions of this mod didn't record who placed the hopper
                 or target_def.allow_metadata_inventory_take(target_pos, target_inventory_name, i, stack_to_take, placer) > 0 then
                  target_inv:set_stack(target_inventory_name, i, stack)
                  --add to hopper
                  hopper_inv:add_item("main", stack_to_take)
                  if target_def.on_metadata_inventory_take ~= nil and placer ~= nil then
                     target_def.on_metadata_inventory_take(target_pos, target_inventory_name, i, stack_to_take, placer)
                  end
                  break
               end
            end
         end
      end
      local timer1 = minetest.get_node_timer(hopper_pos)
      if not timer1:is_started() then
         timer1:start(1.0)
      end
      local timer2 = minetest.get_node_timer(target_pos)
      if not timer2:is_started() then
         timer2:start(1.0)
      end
   end
end

-- Used to put items from the hopper inventory into the target block
hopper.send_item_to = function(hopper_pos, target_pos, target_node, target_inventory_name, filtered_items)
   local hopper_meta = minetest.get_meta(hopper_pos)
   local target_def = minetest.registered_nodes[target_node.name]
   if not target_def then
      return false
   end

   local eject_item = hopper.config.eject_button_enabled and hopper_meta:get_string("eject") == "true" and target_def.buildable_to

   if not eject_item and not target_inventory_name then
      return false
   end

   --hopper inventory
   local hopper_meta = minetest.get_meta(hopper_pos);
   local hopper_inv = hopper_meta:get_inventory()
   if hopper_inv:is_empty("main") == true then
      return false
   end
   local hopper_inv_size = hopper_inv:get_size("main")
   local placer = get_placer(hopper_meta:get_string("placer"))

   --target inventory
   local target_inv = minetest.get_meta(target_pos):get_inventory()

   for i = 1,hopper_inv_size do
      local stack = hopper_inv:get_stack("main", i)
      local item = stack:get_name()
      if item ~= "" and (filtered_items == nil or filtered_items[item]) then
         if target_inventory_name then
            if target_inv:room_for_item(target_inventory_name, item) then
               local stack_to_put = stack:take_item(1)
               if target_def.allow_metadata_inventory_put == nil
               or placer == nil -- backwards compatibility, older versions of this mod didn't record who placed the hopper
               or target_def.allow_metadata_inventory_put(target_pos, target_inventory_name, i, stack_to_put, placer) > 0 then
                  hopper_inv:set_stack("main", i, stack)
                  --add to target node
                  target_inv:add_item(target_inventory_name, stack_to_put)
                  if target_def.on_metadata_inventory_put ~= nil and placer ~= nil then
                     target_def.on_metadata_inventory_put(target_pos, target_inventory_name, i, stack_to_put, placer)
                  end
                  local timer1 = minetest.get_node_timer(hopper_pos)
                  if not timer1:is_started() then
                     timer1:start(1.0)
                  end
                  local timer2 = minetest.get_node_timer(target_pos)
                  if not timer2:is_started() then
                     timer2:start(1.0)
                  end
                  return true
               end
            end
         elseif eject_item then
            local stack_to_put = stack:take_item(1)
            minetest.add_item(target_pos, stack_to_put)
            hopper_inv:set_stack("main", i, stack)
            local timer1 = minetest.get_node_timer(hopper_pos)
            if not timer1:is_started() then
               timer1:start(1.0)
            end
            local timer2 = minetest.get_node_timer(target_pos)
            if not timer2:is_started() then
               timer2:start(1.0)
            end
            return true
         end
      end
   end
   return false
end