Add multilingual and internationalization support

app/src/main/java/dev/sebaubuntu/athena/AthenaApplication.kt

@@ -6,11 +6,16 @@
 package dev.sebaubuntu.athena
 
 import android.app.Application
+import android.content.Context
+import android.content.res.Configuration
 import com.google.android.material.color.DynamicColors
+import dev.sebaubuntu.athena.models.Preference
 import dev.sebaubuntu.athena.repositories.PreferencesRepository
 import dev.sebaubuntu.athena.utils.ModulesManager
 import dev.sebaubuntu.athena.utils.PreferencesManager
 import kotlinx.coroutines.MainScope
+import kotlinx.coroutines.runBlocking
+import java.util.Locale
 
 class AthenaApplication : Application() {
     val coroutineScope = MainScope()
@@ -26,4 +31,47 @@ class AthenaApplication : Application() {
 
         DynamicColors.applyToActivitiesIfAvailable(this)
     }
+
+    override fun attachBaseContext(base: Context) {
+        val languageTag = try {
+            runBlocking {
+                preferencesManager.getValue(
+                    Preference.Companion.primitivePreference("language", "system")
+                )
+            }
+        } catch (e: Exception) {
+            "system"
+        }
+
+        savedLanguageTag = languageTag
+
+        super.attachBaseContext(
+            wrapContextWithLocale(base, languageTag)
+        )
+    }
+
+    companion object {
+        @Volatile
+        var savedLanguageTag: String = "system"
+
+        fun wrapContextWithLocale(context: Context, languageTag: String): Context {
+            if (languageTag == "system") return context
+
+            val config = Configuration(context.resources.configuration)
+            config.setLocale(localeFromTag(languageTag))
+            return context.createConfigurationContext(config)
+        }
+
+        private fun localeFromTag(tag: String): Locale {
+            return when (tag) {
+                "id" -> Locale("in", "ID")
+                "he" -> Locale("iw", "IL")
+                "zh-CN" -> Locale("zh", "CN")
+                "zh-TW" -> Locale("zh", "TW")
+                "pt-BR" -> Locale("pt", "BR")
+                "pt-PT" -> Locale("pt", "PT")
+                else -> Locale(tag)
+            }
+        }
+    }
 }

app/src/main/java/dev/sebaubuntu/athena/MainActivity.kt

@@ -5,6 +5,7 @@
 
 package dev.sebaubuntu.athena
 
+import android.content.Context
 import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
@@ -17,6 +18,14 @@ import dev.sebaubuntu.athena.utils.PermissionsManager
 class MainActivity : ComponentActivity() {
     private val permissionsManager = PermissionsManager(this)
 
+    override fun attachBaseContext(newBase: Context) {
+        super.attachBaseContext(
+            AthenaApplication.wrapContextWithLocale(
+                newBase, AthenaApplication.savedLanguageTag
+            )
+        )
+    }
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 

app/src/main/java/dev/sebaubuntu/athena/repositories/PreferencesRepository.kt

@@ -40,5 +40,10 @@ class PreferencesRepository(
         true,
     ).asPreferenceHolder()
 
+    val language = primitivePreference(
+        "language",
+        "system",
+    ).asPreferenceHolder()
+
     private fun <T> Preference<T>.asPreferenceHolder() = PreferenceHolder(this)
 }

app/src/main/java/dev/sebaubuntu/athena/ui/screens/SettingsScreen.kt

@@ -7,43 +7,61 @@ package dev.sebaubuntu.athena.ui.screens
 
 import android.content.Intent
 import android.os.Build
+import androidx.activity.ComponentActivity
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.annotation.DrawableRes
 import androidx.annotation.StringRes
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.heightIn
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.wrapContentSize
 import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.selection.selectable
+import androidx.compose.foundation.selection.selectableGroup
 import androidx.compose.material3.AlertDialogDefaults
 import androidx.compose.material3.BasicAlertDialog
+import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.ListItem
 import androidx.compose.material3.ListItemDefaults
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.RadioButton
 import androidx.compose.material3.SnackbarResult
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.Role
 import androidx.compose.ui.unit.dp
 import androidx.core.net.toUri
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
+import dev.sebaubuntu.athena.AthenaApplication
 import dev.sebaubuntu.athena.R
 import dev.sebaubuntu.athena.core.models.Result
 import dev.sebaubuntu.athena.models.Theme
@@ -54,6 +72,31 @@ import dev.sebaubuntu.athena.ui.composables.PreferenceCategoryCard
 import dev.sebaubuntu.athena.ui.composables.PreferenceListItem
 import dev.sebaubuntu.athena.ui.composables.SwitchPreferenceListItem
 import dev.sebaubuntu.athena.viewmodels.SettingsViewModel
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import java.util.Locale
+
+private val languageTags = listOf(
+    "system", "af", "ar", "ca", "cs", "da", "de", "el", "en", "eo", "es",
+    "fa", "fi", "fr", "hi", "hu", "id", "it", "he", "ja", "ko", "nl", "no",
+    "pl", "pt-BR", "pt-PT", "ro", "ru", "sr", "sv", "ta", "tr", "uk", "vi",
+    "zh-CN", "zh-TW"
+)
+
+private fun languageDisplayName(tag: String): String {
+    if (tag == "system") return "System default"
+    val locale = when (tag) {
+        "id" -> Locale("in", "ID")
+        "he" -> Locale("iw", "IL")
+        "zh-CN" -> Locale("zh", "CN")
+        "zh-TW" -> Locale("zh", "TW")
+        "pt-BR" -> Locale("pt", "BR")
+        "pt-PT" -> Locale("pt", "PT")
+        else -> Locale(tag)
+    }
+    return locale.getDisplayName(locale)
+}
 
 /**
  * App settings screen.
@@ -84,6 +127,11 @@ fun SettingsScreen(
             PreferenceCategoryCard(
                 titleStringResId = R.string.settings_general,
             ) {
+                LanguagePreferenceListItem(
+                    preferenceHolder = settingsViewModel.language,
+                    onPreferenceChange = settingsViewModel::setPreferenceValue,
+                )
+
                 EnumPreferenceListItem(
                     preferenceHolder = settingsViewModel.theme,
                     onPreferenceChange = settingsViewModel::setPreferenceValue,
@@ -122,6 +170,116 @@ fun SettingsScreen(
     }
 }
 
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun LanguagePreferenceListItem(
+    preferenceHolder: dev.sebaubuntu.athena.repositories.PreferencesRepository.PreferenceHolder<String>,
+    onPreferenceChange: (dev.sebaubuntu.athena.repositories.PreferencesRepository.PreferenceHolder<String>, String) -> Unit,
+) {
+    val currentTag by preferenceHolder.collectAsStateWithLifecycle("system")
+    var dialogOpened by remember { mutableStateOf(false) }
+    val scope = rememberCoroutineScope()
+    val context = LocalContext.current
+
+    if (dialogOpened) {
+        var selectedTag by remember { mutableStateOf(currentTag) }
+
+        BasicAlertDialog(
+            onDismissRequest = { dialogOpened = false }
+        ) {
+            Surface(
+                modifier = Modifier
+                    .fillMaxWidth(0.9f)
+                    .heightIn(max = 500.dp),
+                shape = MaterialTheme.shapes.large,
+                tonalElevation = AlertDialogDefaults.TonalElevation,
+            ) {
+                Column(
+                    modifier = Modifier.fillMaxSize()
+                ) {
+                    Text(
+                        text = "Language",
+                        style = MaterialTheme.typography.headlineSmall,
+                        modifier = Modifier.padding(20.dp)
+                    )
+
+                    LazyColumn(
+                        modifier = Modifier.weight(1f),
+                    ) {
+                        items(languageTags) { tag ->
+                            Row(
+                                modifier = Modifier
+                                    .fillMaxWidth()
+                                    .height(48.dp)
+                                    .selectable(
+                                        selected = (tag == selectedTag),
+                                        onClick = { selectedTag = tag },
+                                        role = Role.RadioButton
+                                    )
+                                    .padding(horizontal = 20.dp),
+                                verticalAlignment = Alignment.CenterVertically,
+                            ) {
+                                RadioButton(
+                                    selected = tag == selectedTag,
+                                    onClick = null,
+                                )
+                                Text(
+                                    text = languageDisplayName(tag),
+                                    modifier = Modifier.padding(start = 16.dp),
+                                    color = MaterialTheme.colorScheme.onSurface,
+                                    style = MaterialTheme.typography.bodyLarge,
+                                )
+                            }
+                        }
+                    }
+
+                    Row(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .padding(8.dp),
+                        horizontalArrangement = Arrangement.End
+                    ) {
+                        TextButton(
+                            onClick = { dialogOpened = false }
+                        ) {
+                            Text(stringResource(android.R.string.cancel))
+                        }
+                        TextButton(
+                            onClick = {
+                                if (selectedTag != currentTag) {
+                                    scope.launch(Dispatchers.IO) {
+                                        preferenceHolder.setValue(selectedTag)
+                                        AthenaApplication.savedLanguageTag = selectedTag
+                                        withContext(Dispatchers.Main) {
+                                            (context as ComponentActivity).recreate()
+                                        }
+                                    }
+                                }
+                                dialogOpened = false
+                            }
+                        ) {
+                            Text(stringResource(android.R.string.ok))
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    ListItem(
+        headlineContent = {
+            Text(text = "Language")
+        },
+        supportingContent = {
+            Text(text = languageDisplayName(currentTag))
+        },
+        modifier = Modifier.clickable { dialogOpened = true },
+        colors = ListItemDefaults.colors(
+            containerColor = Color.Transparent,
+        ),
+    )
+}
+
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 private fun ExportDataCard(
@@ -329,4 +487,4 @@ private fun AboutLinkIconButton(
             contentDescription = stringResource(nameStringResId),
         )
     }
-}
+}

app/src/main/java/dev/sebaubuntu/athena/viewmodels/SettingsViewModel.kt

@@ -35,6 +35,7 @@ class SettingsViewModel(
     // General
     val theme = preferencesRepository.theme
     val dynamicColors = preferencesRepository.dynamicColors
+    val language = preferencesRepository.language
 
     // Export data
     private val _exportDataStatus = MutableSharedFlow<ExportDataStatus?>()