stockpiles: disable gui/script when plugin is disabled

plugins/lua/stockpiles.lua

@@ -7,6 +7,7 @@ local _ENV = mkmodule('plugins.stockpiles')
  * stockpiles_list_settings(dir_path), list files in directory
  * stockpiles_load(file), with full path
  * stockpiles_save(file), with full path
+ * isEnabled()
 
 --]]
 --

plugins/stockpiles/stockpiles.cpp

@@ -494,6 +494,12 @@ static std::vector<std::string> clean_dfstock_list ( const std::string &path )
     return files;
 }
 
+static bool isEnabled( lua_State *L )
+{
+    Lua::Push(L,  is_enabled);
+    return 1;
+}
+
 static int stockpiles_list_settings ( lua_State *L )
 {
     auto path = luaL_checkstring ( L, 1 );

scripts/gui/stockpiles.lua

@@ -2,6 +2,10 @@
 
 local stock = require 'plugins.stockpiles'
 
+function check_enabled()
+    return stock.isEnabled()
+end
+
 function world_guard()
     if not dfhack.isMapLoaded() then
         qerror("World is not loaded")
@@ -9,6 +13,7 @@ function world_guard()
     end
     return true
 end
+
 function guard()
     if not string.match(dfhack.gui.getCurFocus(), '^dwarfmode/QueryBuilding/Some/Stockpile') then
         qerror("This script requires a stockpile selected in the 'q' mode")
@@ -39,7 +44,10 @@ function usage()
     print("")
 end
 
-if args.load then
+if not check_enabled() then
+    qerror("Stockpiles plugin not enabled. Enable it with: enable stockpiles")
+    return
+elseif args.load then
     if not guard() then return end
     stock.load_settings()
 elseif args.save then
@@ -52,4 +60,3 @@ elseif args.dir then
 else
     usage()
 end
-