From 787f2bde0259c4418ac6396993aef8b73505be4b Mon Sep 17 00:00:00 2001
From: lynxnb <niccolo.betto@gmail.com>
Date: Mon, 6 Feb 2023 18:21:44 +0100
Subject: [PATCH] Enable localization for app strings

A setting has been added to override the system default language, should a user want a different language for the app.
---
 app/build.gradle                              |  7 +++
 app/src/main/AndroidManifest.xml              | 10 +++++
 .../skyline/preference/LanguagePreference.kt  | 44 +++++++++++++++++++
 app/src/main/res/values/strings.xml           |  2 +
 app/src/main/res/xml/app_preferences.xml      |  4 ++
 app/src/main/res/xml/locales_config.xml       | 19 ++++++++
 6 files changed, 86 insertions(+)
 create mode 100644 app/src/main/java/emu/skyline/preference/LanguagePreference.kt
 create mode 100644 app/src/main/res/xml/locales_config.xml

diff --git a/app/build.gradle b/app/build.gradle
index c8a67aac..0dda02c2 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -40,6 +40,13 @@ android {
 
         // Only enable separate process for release builds
         manifestPlaceholders += [emulationProcess: ""]
+
+        def locales = ["en", "de", "el", "es", "es-419", "fr", "hu", "id", "it", "ja", "ko", "pl", "ru", "ta", "zh-Hans", "zh-Hant"]
+
+        // Add available locales to the build config so that they can be accessed from the app
+        buildConfigField "String[]", "AVAILABLE_APP_LANGUAGES", "new String[]{\"" + locales.join("\",\"") + "\"}"
+        // Uncomment the following line whenever AAPT2 will properly support BCP47 language tags
+        //resourceConfigurations += locales
     }
 
     /* JVM Bytecode Options */
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 9700d9d2..a5f3218f 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -20,6 +20,7 @@
         android:icon="@drawable/logo_skyline"
         android:isGame="true"
         android:label="${appLabel}"
+        android:localeConfig="@xml/locales_config"
         android:supportsRtl="true"
         android:theme="@style/AppTheme"
         tools:ignore="GoogleAppIndexingWarning,UnusedAttribute">
@@ -116,6 +117,15 @@
             </intent-filter>
         </provider>
 
+        <service
+            android:name="androidx.appcompat.app.AppLocalesMetadataHolderService"
+            android:enabled="false"
+            android:exported="false">
+            <meta-data
+                android:name="autoStoreLocales"
+                android:value="true" />
+        </service>
+
         <meta-data
             android:name="com.android.graphics.injectLayers.enable"
             android:value="true" />
diff --git a/app/src/main/java/emu/skyline/preference/LanguagePreference.kt b/app/src/main/java/emu/skyline/preference/LanguagePreference.kt
new file mode 100644
index 00000000..445b6433
--- /dev/null
+++ b/app/src/main/java/emu/skyline/preference/LanguagePreference.kt
@@ -0,0 +1,44 @@
+/*
+ * SPDX-License-Identifier: MPL-2.0
+ * Copyright © 2023 Skyline Team and Contributors (https://github.com/skyline-emu/)
+ */
+
+package emu.skyline.preference
+
+import android.content.Context
+import android.util.AttributeSet
+import androidx.appcompat.app.AppCompatDelegate
+import androidx.core.os.LocaleListCompat
+import androidx.preference.ListPreference
+import androidx.preference.Preference.OnPreferenceChangeListener
+import androidx.preference.Preference.SummaryProvider
+import emu.skyline.BuildConfig
+import emu.skyline.R
+import java.util.*
+
+private const val SystemLanguage = "syslang"
+
+class LanguagePreference @JvmOverloads constructor(context : Context, attrs : AttributeSet? = null, defStyleAttr : Int = androidx.preference.R.attr.preferenceStyle) : ListPreference(context, attrs, defStyleAttr) {
+    init {
+        entries = arrayOf(systemEntry) + BuildConfig.AVAILABLE_APP_LANGUAGES.map { Locale.forLanguageTag(it).run { getDisplayName(this) } }
+        entryValues = arrayOf(SystemLanguage) + BuildConfig.AVAILABLE_APP_LANGUAGES
+
+        value = AppCompatDelegate.getApplicationLocales()[0]?.toLanguageTag() ?: SystemLanguage
+
+        onPreferenceChangeListener = OnPreferenceChangeListener { _, newValue ->
+            if (newValue == SystemLanguage) {
+                AppCompatDelegate.setApplicationLocales(LocaleListCompat.getEmptyLocaleList())
+            } else {
+                val newLocale = LocaleListCompat.forLanguageTags(newValue as String)
+                AppCompatDelegate.setApplicationLocales(newLocale)
+            }
+            true
+        }
+
+        summaryProvider = SummaryProvider<ListPreference> {
+            AppCompatDelegate.getApplicationLocales()[0]?.displayName ?: systemEntry
+        }
+    }
+
+    private val systemEntry : String get() = context.getString(R.string.app_language_default)
+}
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index b0beb3b1..61e12817 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -41,6 +41,8 @@
     <!-- Settings - Appearance -->
     <string name="appearance">Appearance</string>
     <string name="theme">Theme</string>
+    <string name="app_language">App Language</string>
+    <string name="app_language_default">Use System Default</string>
     <string name="layout_type">Game Display Layout</string>
     <string name="sort_apps_by">Games Sorting Order</string>
     <string name="group_by_format">Group Games By Format</string>
diff --git a/app/src/main/res/xml/app_preferences.xml b/app/src/main/res/xml/app_preferences.xml
index 472a0862..ee23aefb 100644
--- a/app/src/main/res/xml/app_preferences.xml
+++ b/app/src/main/res/xml/app_preferences.xml
@@ -28,6 +28,10 @@
             app:key="app_theme"
             app:title="@string/theme"
             app:useSimpleSummaryProvider="true" />
+        <emu.skyline.preference.LanguagePreference
+            app:key="app_language"
+            app:persistent="false"
+            app:title="@string/app_language" />
         <emu.skyline.preference.IntegerListPreference
             android:defaultValue="1"
             android:entries="@array/layout_type"
diff --git a/app/src/main/res/xml/locales_config.xml b/app/src/main/res/xml/locales_config.xml
new file mode 100644
index 00000000..a4aba190
--- /dev/null
+++ b/app/src/main/res/xml/locales_config.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<locale-config xmlns:android="http://schemas.android.com/apk/res/android">
+    <locale android:name="en" /> <!-- English (default) -->
+    <locale android:name="de" /> <!-- German -->
+    <locale android:name="el" /> <!-- Greek -->
+    <locale android:name="es" /> <!-- Spanish -->
+    <locale android:name="es-419" /> <!-- Latin American Spanish -->
+    <locale android:name="fr" /> <!-- French -->
+    <locale android:name="hu" /> <!-- Hungarian -->
+    <locale android:name="id" /> <!-- Indonesian -->
+    <locale android:name="it" /> <!-- Italian -->
+    <locale android:name="ja" /> <!-- Japanese -->
+    <locale android:name="ko" /> <!-- Korean -->
+    <locale android:name="pl" /> <!-- Polish -->
+    <locale android:name="ru" /> <!-- Russian -->
+    <locale android:name="ta" /> <!-- Tamil -->
+    <locale android:name="zh-Hans" /> <!-- Simplified Chinese -->
+    <locale android:name="zh-Hant" /> <!-- Traditional Chinese -->
+</locale-config>