Add an item pick up callback (2) (#7712)

Co-authored-by: SmallJoker <mk939@ymail.com>
Co-authored-by: Jude Melton-Houghton <jwmhjwmh@gmail.com>

games/devtest/mods/testitems/init.lua

@@ -53,3 +53,111 @@ minetest.register_craftitem("testitems:overlay_global", {
 })
 
 
+--
+-- Item callbacks
+--
+
+minetest.register_craftitem("testitems:callback_1", {
+	description = "Callback test item 1\n(Use/Drop + Sneak to switch to item 2)",
+	inventory_image = "testitems_callback_1.png",
+	wield_image = "testitems_callback_1.png",
+
+	on_secondary_use = function(itemstack, user, pointed_thing)
+		minetest.log("[testitems:callback_1 on_secondary_use] " .. itemstack:get_name())
+		local ctrl = user and user:get_player_control() or {}
+		if ctrl.sneak then
+			itemstack = ItemStack(itemstack)
+			itemstack:set_name("testitems:callback_2")
+			return itemstack
+		end
+	end,
+
+	on_drop = function(itemstack, dropper, pos)
+		minetest.log("[testitems:callback_1 on_drop] " .. itemstack:get_name())
+		local ctrl = dropper and dropper:get_player_control() or {}
+		if ctrl.sneak then
+			itemstack = ItemStack(itemstack)
+			itemstack:set_name("testitems:callback_2")
+		end
+
+		return minetest.item_drop(itemstack, dropper, pos)
+	end,
+
+	on_pickup = function(itemstack, picker, pointed_thing, ...)
+		minetest.log("[testitems:callback_1 on_pickup]")
+		assert(pointed_thing.ref:get_luaentity().name == "__builtin:item")
+		local ctrl = picker and picker:get_player_control() or {}
+		if ctrl.aux1 then
+			-- Debug message
+			minetest.log(dump({...}))
+		end
+		if ctrl.sneak then
+			-- Pick up one item of the other kind at once
+			local taken = itemstack:take_item()
+			taken:set_name("testitems:callback_2")
+			local leftover = minetest.item_pickup(taken, picker, pointed_thing, ...)
+			leftover:set_name("testitems:callback_1")
+			itemstack:add_item(leftover)
+			return itemstack
+		elseif ctrl.up then
+			-- Don't pick up
+			return
+		elseif ctrl.left then
+			-- Eat it
+			return minetest.do_item_eat(2, nil, itemstack, picker, pointed_thing)
+		else
+			-- Normal: pick up everything
+			return minetest.item_pickup(itemstack, picker, pointed_thing, ...)
+		end
+	end,
+
+	on_use = function(itemstack, user, pointed_thing)
+		minetest.log("[testitems:callback_1 on_use] " .. itemstack:get_name())
+		local ctrl = user and user:get_player_control() or {}
+		if ctrl.sneak then
+			itemstack = ItemStack(itemstack)
+			itemstack:set_name("testitems:callback_2")
+			return itemstack
+		end
+	end,
+
+	after_use = function(itemstack, user, node, digparams) -- never called
+		minetest.log("[testitems:callback_1 after_use]")
+		local ctrl = user and user:get_player_control() or {}
+		if ctrl.up then
+			itemstack = ItemStack(itemstack)
+			itemstack:set_name("testitems:callback_2")
+			return itemstack
+		end
+	end,
+})
+
+minetest.register_craftitem("testitems:callback_2", {
+	description = "Callback test item 2\n(Use to switch to item 1)",
+	inventory_image = "testitems_callback_2.png",
+	wield_image = "testitems_callback_2.png",
+
+	on_use = function(itemstack, user, pointed_thing)
+		minetest.log("[testitems:callback_2 on_use]")
+		itemstack = ItemStack(itemstack)
+		itemstack:set_name("testitems:callback_1")
+		return itemstack
+	end,
+})
+
+minetest.register_on_item_pickup(function(itemstack, picker, pointed_thing, time_from_last_punch, ...)
+	assert(not pointed_thing or pointed_thing.ref:get_luaentity().name == "__builtin:item")
+
+	local item_name = itemstack:get_name()
+	if item_name ~= "testitems:callback_1" and item_name ~= "testitems:callback_2" then
+		return
+	end
+	minetest.log("["..item_name.." register_on_item_pickup]")
+
+	local ctrl = picker and picker:get_player_control() or {}
+	if item_name == "testitems:callback_2" and not ctrl.sneak then
+		-- Same here. Pick up the other item type.
+		itemstack:set_name("testitems:callback_1")
+		return picker:get_inventory():add_item("main", itemstack)
+	end
+end)