From 5ebf8f945050e9c74a3bb6784a0844d1fb68bdff Mon Sep 17 00:00:00 2001
From: red-001 <red-001@outlook.ie>
Date: Sat, 6 May 2017 20:12:44 +0100
Subject: [PATCH] [CSM] add `on_item_use` (#5544)

---
 builtin/client/register.lua     |  1 +
 clientmods/preview/init.lua     |  7 +++++++
 doc/client_lua_api.md           |  4 ++++
 src/game.cpp                    |  3 ++-
 src/script/cpp_api/s_client.cpp | 17 +++++++++++++++++
 src/script/cpp_api/s_client.h   |  3 +++
 6 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/builtin/client/register.lua b/builtin/client/register.lua
index b35ecc849..6b12ddec8 100644
--- a/builtin/client/register.lua
+++ b/builtin/client/register.lua
@@ -70,3 +70,4 @@ core.registered_on_formspec_input, core.register_on_formspec_input = make_regist
 core.registered_on_dignode, core.register_on_dignode = make_registration()
 core.registered_on_punchnode, core.register_on_punchnode = make_registration()
 core.registered_on_placenode, core.register_on_placenode = make_registration()
+core.registered_on_item_use, core.register_on_item_use = make_registration()
diff --git a/clientmods/preview/init.lua b/clientmods/preview/init.lua
index fb606b3f4..821f7c714 100644
--- a/clientmods/preview/init.lua
+++ b/clientmods/preview/init.lua
@@ -22,6 +22,13 @@ core.register_on_placenode(function(pointed_thing, node)
 	return false
 end)
 
+core.register_on_item_use(function(itemstack, pointed_thing)
+	print("The local player used an item!")
+	print("pointed_thing :" .. dump(pointed_thing))
+	print("item = " .. itemstack:get_name())
+	return false
+end)
+
 -- This is an example function to ensure it's working properly, should be removed before merge
 core.register_on_receiving_chat_messages(function(message)
 	print("[PREVIEW] Received message " .. message)
diff --git a/doc/client_lua_api.md b/doc/client_lua_api.md
index a4293500f..19947a525 100644
--- a/doc/client_lua_api.md
+++ b/doc/client_lua_api.md
@@ -669,6 +669,10 @@ Call these functions only at load time!
     * If any function returns true, the punch is ignored
 * `minetest.register_on_placenode(function(pointed_thing, node))`    
     * Called when a node has been placed
+* `minetest.register_on_item_use(func(item, pointed_thing))`
+    * Called when the local player uses an item.
+    * Newest functions are called first.
+    * If any function returns true, the item use is not sent to server.
 ### Sounds
 * `minetest.sound_play(spec, parameters)`: returns a handle
     * `spec` is a `SimpleSoundSpec`
diff --git a/src/game.cpp b/src/game.cpp
index 416320e5d..61282b463 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -3553,7 +3553,8 @@ void Game::processPlayerInteraction(f32 dtime, bool show_hud, bool show_debug)
 		runData.repeat_rightclick_timer = 0;
 
 	if (playeritem_def.usable && isLeftPressed()) {
-		if (getLeftClicked())
+		if (getLeftClicked() && (!client->moddingEnabled()
+				|| !client->getScript()->on_item_use(playeritem, pointed)))
 			client->interact(4, pointed);
 	} else if (pointed.type == POINTEDTHING_NODE) {
 		ToolCapabilities playeritem_toolcap =
diff --git a/src/script/cpp_api/s_client.cpp b/src/script/cpp_api/s_client.cpp
index 4bc368d1d..d5ec52407 100644
--- a/src/script/cpp_api/s_client.cpp
+++ b/src/script/cpp_api/s_client.cpp
@@ -207,6 +207,23 @@ bool ScriptApiClient::on_placenode(const PointedThing &pointed, const ItemDefini
 	return lua_toboolean(L, -1);
 }
 
+bool ScriptApiClient::on_item_use(const ItemStack &item, const PointedThing &pointed)
+{
+	SCRIPTAPI_PRECHECKHEADER
+
+	// Get core.registered_on_item_use
+	lua_getglobal(L, "core");
+	lua_getfield(L, -1, "registered_on_item_use");
+
+	// Push data
+	LuaItemStack::create(L, item);
+	push_pointed_thing(L, pointed);
+
+	// Call functions
+	runCallbacks(2, RUN_CALLBACKS_MODE_OR);
+	return lua_toboolean(L, -1);
+}
+
 void ScriptApiClient::setEnv(ClientEnvironment *env)
 {
 	ScriptApiBase::setEnv(env);
diff --git a/src/script/cpp_api/s_client.h b/src/script/cpp_api/s_client.h
index f252cf499..9133637a6 100644
--- a/src/script/cpp_api/s_client.h
+++ b/src/script/cpp_api/s_client.h
@@ -26,6 +26,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapnode.h"
 #include "itemdef.h"
 #include "util/string.h"
+#include "util/pointedthing.h"
+#include "lua_api/l_item.h"
 
 #ifdef _CRT_MSVCP_CURRENT
 #include <cstdint>
@@ -54,6 +56,7 @@ public:
 	bool on_dignode(v3s16 p, MapNode node);
 	bool on_punchnode(v3s16 p, MapNode node);
 	bool on_placenode(const PointedThing &pointed, const ItemDefinition &item);
+	bool on_item_use(const ItemStack &item, const PointedThing &pointed);
 
 	void setEnv(ClientEnvironment *env);
 };