Expose preferences to Lua

changelog

@@ -127,6 +127,9 @@ Version 1.13.5+dev:
      it would produce a new object that did not compare equal to any others.)
    * Lua dialog functions now support the stacked widget and the unit preview pane
    * New wesnoth.show_menu function shows a dropdown menu at the mouse location
+   * New table wesnoth.preferences that gives read-write access to game preferences.
+     The table is not iterable, but you can read and change preferences with
+     predefined names.
    * Lua attack proxy has new read_only field which is true for unit_type attacks
      If true, attempts to change the attack will result in an error.
    * The name field in Lua attack proxy is now writable

projectfiles/VC12/wesnoth.vcxproj

@@ -2916,6 +2916,13 @@
       <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Test_Debug|Win32'">$(IntDir)Scripting\</ObjectFileName>
       <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Test_Release|Win32'">$(IntDir)Scripting\</ObjectFileName>
     </ClCompile>
+    <ClCompile Include="..\..\src\scripting\lua_preferences.cpp">
+      <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">$(IntDir)Scripting\</ObjectFileName>
+      <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='ReleaseDEBUG|Win32'">$(IntDir)Scripting\</ObjectFileName>
+      <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Test_Debug|Win32'">$(IntDir)Scripting\</ObjectFileName>
+      <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Debug_with_VLD|Win32'">$(IntDir)Scripting\</ObjectFileName>
+      <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Test_Release|Win32'">$(IntDir)Scripting\</ObjectFileName>
+    </ClCompile>
     <ClCompile Include="..\..\src\scripting\lua_race.cpp">
       <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Debug_with_VLD|Win32'">$(IntDir)Scripting\</ObjectFileName>
       <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">$(IntDir)Scripting\</ObjectFileName>
@@ -4362,6 +4369,7 @@
     <ClInclude Include="..\..\src\scripting\lua_kernel_base.hpp" />
     <ClInclude Include="..\..\src\scripting\lua_map_location_ops.hpp" />
     <ClInclude Include="..\..\src\scripting\lua_pathfind_cost_calculator.hpp" />
+    <ClInclude Include="..\..\src\scripting\lua_preferences.hpp" />
     <ClInclude Include="..\..\src\scripting\lua_race.hpp" />
     <ClInclude Include="..\..\src\scripting\lua_rng.hpp" />
     <ClInclude Include="..\..\src\scripting\lua_team.hpp" />

projectfiles/VC12/wesnoth.vcxproj.filters

@@ -1526,6 +1526,9 @@
     <ClCompile Include="..\..\src\wesnoth.cpp" />
     <ClCompile Include="..\..\src\wesnothd_connection.cpp" />
     <ClCompile Include="..\..\src\wml_exception.cpp" />
+    <ClCompile Include="..\..\src\scripting\lua_preferences.cpp">
+      <Filter>Scripting</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\src\addon\client.hpp">
@@ -2935,6 +2938,9 @@
     <ClInclude Include="..\..\src\wesnothd_connection_error.hpp" />
     <ClInclude Include="..\..\src\wml_exception.hpp" />
     <ClInclude Include="..\..\src\wml_separators.hpp" />
+    <ClInclude Include="..\..\src\scripting\lua_preferences.hpp">
+      <Filter>Scripting</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <CustomBuild Include="..\..\src\tests\test_sdl_utils.hpp">

src/CMakeLists.txt

@@ -919,6 +919,7 @@ set(wesnoth-main_SRC
 	scripting/lua_gui2.cpp
 	scripting/lua_kernel_base.cpp
 	scripting/lua_map_location_ops.cpp
+	scripting/lua_preferences.cpp
 	scripting/lua_race.cpp
 	scripting/lua_rng.cpp
 	scripting/lua_team.cpp

src/SConscript

@@ -524,6 +524,7 @@ wesnoth_sources = Split("""
     scripting/lua_gui2.cpp
     scripting/lua_kernel_base.cpp
     scripting/lua_map_location_ops.cpp
+    scripting/lua_preferences.cpp
     scripting/lua_race.cpp
     scripting/lua_rng.cpp
     scripting/lua_team.cpp

src/scripting/lua_kernel_base.cpp

@@ -33,6 +33,7 @@
 #include "scripting/lua_formula_bridge.hpp"
 #include "scripting/lua_gui2.hpp"
 #include "scripting/lua_map_location_ops.hpp"
+#include "scripting/lua_preferences.hpp"
 #include "scripting/lua_rng.hpp"
 #include "scripting/push_check.hpp"
 
@@ -397,7 +398,10 @@ lua_kernel_base::lua_kernel_base(CVideo * video)
 	lua_newtable(L);
 	luaL_setfuncs(L, map_callbacks, 0);
 	lua_setfield(L, -2, "map_location");
-	lua_pop(L,1);
+	lua_pop(L, 1);
+
+	// Create the preferences table.
+	cmd_log_ << lua_preferences::register_table(L);
 
 	// Add mersenne twister rng wrapper
 	cmd_log_ << "Adding rng tables...\n";

src/scripting/lua_preferences.cpp

@@ -0,0 +1,78 @@
+#include "lua_preferences.hpp"
+
+#include <lua/lua.h>
+#include <lua/lauxlib.h>
+#include <preferences.hpp>
+
+/**
+ * The __index metamethod.
+ * Parameter 1: the preference table.
+ * Parameter 2: preference name, must be a string.
+ * Returns: preference value. Returned as a string regardless of the type of the preference.
+ * If there isn't such a preference, returns an empty string.
+ */
+static int impl_preferences_get(lua_State* L)
+{
+	std::string preference_name = luaL_checkstring(L, 2);
+	lua_pushstring(L, preferences::get(preference_name).c_str());
+	return 1;
+}
+
+/**
+ * The __newindex metamethod.
+ * Parameter 1: the preference table.
+ * Parameter 2: preference name, must be a string.
+ * Parameter 3: preference value. Can be a string, boolean or integer.
+ * Returns nothing.
+ */
+static int impl_preferences_set(lua_State* L)
+{
+	std::string preference_name = luaL_checkstring(L, 2);
+	int type = lua_type(L, 3);
+
+	switch (type)
+	{
+	case LUA_TSTRING:
+		preferences::set(preference_name, luaL_checkstring(L, 3));
+		break;
+	case LUA_TBOOLEAN:
+		preferences::set(preference_name, lua_toboolean(L, 3) == 1);
+		break;
+	case LUA_TNUMBER:
+		preferences::set(preference_name, luaL_checkint(L, 3));
+		break;
+	default:
+		return luaL_typerror(L, 3, "string/boolean/number");
+		break;
+	}
+
+	return 0;
+}
+
+namespace lua_preferences
+{
+	std::string register_table(lua_State* L)
+	{
+		// Push the wesnoth table to the stack
+		lua_getglobal(L, "wesnoth");
+
+		// Create the preferences table
+		lua_newtable(L);
+		lua_pushcfunction(L, impl_preferences_get);
+		lua_setfield(L, -2, "__index");
+		lua_pushcfunction(L, impl_preferences_set);
+		lua_setfield(L, -2, "__newindex");
+
+		// Set the table as its own metatable
+		lua_pushvalue(L, -1);
+		lua_setmetatable(L, -2);
+
+		// Assign the table to wesnoth.preferences
+		lua_setfield(L, -2, "preferences");
+
+		// Pop the wesnoth table from the stack
+		lua_pop(L, 1);
+
+		return "Adding preferences table...\n";
+	}
+}

src/scripting/lua_preferences.hpp

@@ -0,0 +1,27 @@
+/*
+   Copyright (C) 2016 by Jyrki Vesterinen <sandgtx@gmail.com>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#ifndef SCRIPTING_LUA_UNIT_PREFERENCES_HPP
+#define SCRIPTING_LUA_UNIT_PREFERENCES_HPP
+
+#include <string>
+
+struct lua_State;
+
+namespace lua_preferences
+{
+	std::string register_table(lua_State* L);
+}
+
+#endif