Add a system region setting

Needed for games such as AC:NH.
The `Auto` option automatically selects a region based on the currently selected system language.

Co-Authored-By: Timotej Leginus <35149140+timleg002@users.noreply.github.com>

app/src/main/cpp/skyline/common/android_settings.h

@@ -34,6 +34,7 @@ namespace skyline {
             isDocked = ktSettings.GetBool("isDocked");
             usernameValue = std::move(ktSettings.GetString("usernameValue"));
             systemLanguage = ktSettings.GetInt<skyline::language::SystemLanguage>("systemLanguage");
+            systemRegion = ktSettings.GetInt<skyline::region::RegionCode>("systemRegion");
             forceTripleBuffering = ktSettings.GetBool("forceTripleBuffering");
             disableFrameThrottling = ktSettings.GetBool("disableFrameThrottling");
             gpuDriver = ktSettings.GetString("gpuDriver");

app/src/main/cpp/skyline/common/language.h

@@ -106,4 +106,53 @@ namespace skyline {
 
         #undef LANGUAGES
     }
+
+    namespace region {
+        /**
+         * @brief The list of all regions
+         * @url https://switchbrew.org/wiki/Settings_services#RegionCode_2
+         */
+        enum class RegionCode : i32 {
+            Auto = -1, // Automatically determine region based on the selected language
+            Japan = 0,
+            Usa = 1,
+            Europe = 2,
+            Australia = 3,
+            HongKongTaiwanKorea = 4,
+            China = 5,
+        };
+
+        /**
+         * @brief Returns the region code for the given system language
+         */
+        constexpr region::RegionCode GetRegionCodeForSystemLanguage(language::SystemLanguage systemLanguage) {
+            switch (systemLanguage) {
+                case language::SystemLanguage::Japanese:
+                    return region::RegionCode::Japan;
+                case language::SystemLanguage::AmericanEnglish:
+                case language::SystemLanguage::CanadianFrench:
+                case language::SystemLanguage::LatinAmericanSpanish:
+                case language::SystemLanguage::BrazilianPortuguese:
+                    return region::RegionCode::Usa;
+                case language::SystemLanguage::French:
+                case language::SystemLanguage::German:
+                case language::SystemLanguage::Italian:
+                case language::SystemLanguage::Spanish:
+                case language::SystemLanguage::Dutch:
+                case language::SystemLanguage::Portuguese:
+                case language::SystemLanguage::Russian:
+                case language::SystemLanguage::BritishEnglish:
+                    return region::RegionCode::Europe;
+                case language::SystemLanguage::Chinese:
+                case language::SystemLanguage::SimplifiedChinese:
+                case language::SystemLanguage::TraditionalChinese:
+                    return region::RegionCode::China;
+                case language::SystemLanguage::Taiwanese:
+                case language::SystemLanguage::Korean:
+                    return region::RegionCode::HongKongTaiwanKorea;
+                default:
+                    throw exception("Invalid system language: {}", systemLanguage);
+            }
+        }
+    }
 }

app/src/main/cpp/skyline/common/settings.h

@@ -62,6 +62,7 @@ namespace skyline {
         Setting<bool> isDocked; //!< If the emulated Switch should be handheld or docked
         Setting<std::string> usernameValue; //!< The user name to be supplied to the guest
         Setting<language::SystemLanguage> systemLanguage; //!< The system language
+        Setting<region::RegionCode> systemRegion; //!< The system region
 
         // Display
         Setting<bool> forceTripleBuffering; //!< If the presentation engine should always triple buffer even if the swapchain supports double buffering

app/src/main/cpp/skyline/services/settings/ISettingsServer.cpp

@@ -3,6 +3,7 @@
 
 #include <common/language.h>
 #include "ISettingsServer.h"
+#include <common/settings.h>
 
 namespace skyline::service::settings {
     ISettingsServer::ISettingsServer(const DeviceState &state, ServiceManager &manager) : BaseService(state, manager) {}
@@ -23,4 +24,14 @@ namespace skyline::service::settings {
         response.Push<i32>(constant::NewLanguageCodeListSize);
         return {};
     }
+
+    Result ISettingsServer::GetRegionCode(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
+        region::RegionCode regionCode{*state.settings->systemRegion};
+
+        if (regionCode == region::RegionCode::Auto)
+            regionCode = region::GetRegionCodeForSystemLanguage(*state.settings->systemLanguage);
+
+        response.Push(regionCode);
+        return {};
+    }
 }

app/src/main/cpp/skyline/services/settings/ISettingsServer.h

@@ -24,6 +24,11 @@ namespace skyline::service::settings {
          */
         Result MakeLanguageCode(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response);
 
+        /**
+         * @brief Returns the user-selected region's code
+         */
+        Result GetRegionCode(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response);
+
         /**
          * @brief Reads the available language codes that an application can use (post 4.0.0)
          */
@@ -32,6 +37,7 @@ namespace skyline::service::settings {
         SERVICE_DECL(
             SFUNC(0x1, ISettingsServer, GetAvailableLanguageCodes),
             SFUNC(0x2, ISettingsServer, MakeLanguageCode),
+            SFUNC(0x4, ISettingsServer, GetRegionCode),
             SFUNC(0x5, ISettingsServer, GetAvailableLanguageCodes2)
         )
     };

app/src/main/java/emu/skyline/utils/NativeSettings.kt

@@ -16,6 +16,7 @@ class NativeSettings(context : Context, pref : PreferenceSettings) {
     var isDocked : Boolean = pref.isDocked
     var usernameValue : String = pref.usernameValue
     var systemLanguage : Int = pref.systemLanguage
+    var systemRegion : Int = pref.systemRegion
 
     // Display
     var forceTripleBuffering : Boolean = pref.forceTripleBuffering

app/src/main/java/emu/skyline/utils/PreferenceSettings.kt

@@ -26,6 +26,7 @@ class PreferenceSettings @Inject constructor(@ApplicationContext private val con
     var isDocked by sharedPreferences(context, true)
     var usernameValue by sharedPreferences(context, context.getString(R.string.username_default))
     var systemLanguage by sharedPreferences(context, 1)
+    var systemRegion by sharedPreferences(context, -1)
 
     // Display
     var forceTripleBuffering by sharedPreferences(context, true)

app/src/main/res/values/array.xml

@@ -38,24 +38,42 @@
         <item>臺語 (Taiwanese)</item>
     </string-array>
     <integer-array name="system_languages_val">
-        <item>1</item>
-        <item>12</item>
-        <item>2</item>
-        <item>13</item>
-        <item>3</item>
-        <item>5</item>
-        <item>14</item>
-        <item>4</item>
-        <item>8</item>
-        <item>9</item>
-        <item>17</item>
-        <item>10</item>
-        <item>0</item>
-        <item>6</item>
-        <item>16</item>
-        <item>15</item>
-        <item>7</item>
-        <item>11</item>
+        <item>1</item>  <!-- American English -->
+        <item>12</item> <!-- British English -->
+        <item>2</item>  <!-- French -->
+        <item>13</item> <!-- Canadian French -->
+        <item>3</item>  <!-- German -->
+        <item>5</item>  <!-- Spanish -->
+        <item>14</item> <!-- Latin American Spanish -->
+        <item>4</item>  <!-- Italian -->
+        <item>8</item>  <!-- Dutch -->
+        <item>9</item>  <!-- Portuguese -->
+        <item>17</item> <!-- Brazilian Portuguese -->
+        <item>10</item> <!-- Russian -->
+        <item>0</item>  <!-- Japanese -->
+        <item>6</item>  <!-- Chinese -->
+        <item>16</item> <!-- Traditional Chinese -->
+        <item>15</item> <!-- Simplified Chinese -->
+        <item>7</item>  <!-- Korean -->
+        <item>11</item> <!-- Taiwanese -->
+    </integer-array>
+    <string-array name="system_region">
+        <item>Auto</item>
+        <item>Japan</item>
+        <item>The Americas</item>
+        <item>Europe</item>
+        <item>Australia / New Zealand</item>
+        <item>Hong Kong / Taiwan / South Korea</item>
+        <item>China</item>
+    </string-array>
+    <integer-array name="system_region_val">
+        <item>-1</item> <!-- Auto -->
+        <item>0</item>  <!-- Japan -->
+        <item>1</item>  <!-- The Americas -->
+        <item>2</item>  <!-- Europe -->
+        <item>3</item>  <!-- Australia / New Zealand -->
+        <item>4</item>  <!-- Hong Kong / Taiwan / South Korea -->
+        <item>5</item>  <!-- China -->
     </integer-array>
     <string-array name="aspect_ratios">
         <item>16:9 (Switch, Recommended)</item>

app/src/main/res/values/strings.xml

@@ -47,6 +47,7 @@
     <string name="username">Username</string>
     <string name="username_default">@string/app_name</string>
     <string name="system_language">System language</string>
+    <string name="system_region">System region</string>
     <!-- Settings - Keys -->
     <string name="keys">Keys</string>
     <string name="prod_keys">Production Keys</string>

app/src/main/res/xml/preferences.xml

@@ -78,6 +78,13 @@
             app:refreshRequired="true"
             app:title="@string/system_language"
             app:useSimpleSummaryProvider="true" />
+        <emu.skyline.preference.IntegerListPreference
+            android:defaultValue="-1"
+            android:entries="@array/system_region"
+            android:entryValues="@array/system_region_val"
+            app:key="system_region"
+            app:title="@string/system_region"
+            app:useSimpleSummaryProvider="true" />
     </PreferenceCategory>
     <PreferenceCategory
         android:key="category_presentation"