Lazy load available languages

vector/src/main/java/im/vector/riotx/features/settings/VectorLocale.kt

@@ -24,7 +24,9 @@ import androidx.preference.PreferenceManager
 import im.vector.riotx.R
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import timber.log.Timber
 import java.util.Locale
 
@@ -40,9 +42,9 @@ object VectorLocale {
     private val defaultLocale = Locale("en", "US")
 
     /**
-     * The supported application languages
+     * The cache of supported application languages
      */
-    val supportedLocales = mutableListOf<Locale>()
+    private val supportedLocales = mutableListOf<Locale>()
 
     /**
      * Provides the current application locale
@@ -75,11 +77,6 @@ object VectorLocale {
 
             saveApplicationLocale(applicationLocale)
         }
-
-        // init the known locales in background
-        GlobalScope.launch(Dispatchers.IO) {
-            initApplicationLocales(context)
-        }
     }
 
     /**
@@ -167,11 +164,9 @@ object VectorLocale {
     }
 
     /**
-     * Provides the supported application locales list
-     *
-     * @param context the context
+     * Init the supported application locales list
      */
-    private fun initApplicationLocales(context: Context) {
+    private fun initApplicationLocales() {
         val knownLocalesSet = HashSet<Triple<String, String, String>>()
 
         try {
@@ -262,4 +257,20 @@ object VectorLocale {
             append("]")
         }
     }
+
+    fun loadLocales(listener: Listener): Job {
+        return GlobalScope.launch(Dispatchers.Main) {
+            if (supportedLocales.isEmpty()) {
+                // init the known locales in background
+                withContext(Dispatchers.IO) {
+                    initApplicationLocales()
+                }
+            }
+            listener.onLoaded(supportedLocales)
+        }
+    }
+
+    interface Listener {
+        fun onLoaded(locales: List<Locale>)
+    }
 }

vector/src/main/java/im/vector/riotx/features/settings/locale/LocalePickerController.kt

@@ -17,7 +17,10 @@
 package im.vector.riotx.features.settings.locale
 
 import com.airbnb.epoxy.TypedEpoxyController
+import com.airbnb.mvrx.Incomplete
+import com.airbnb.mvrx.Success
 import im.vector.riotx.R
+import im.vector.riotx.core.epoxy.loadingItem
 import im.vector.riotx.core.epoxy.noResultItem
 import im.vector.riotx.core.epoxy.profiles.profileSectionItem
 import im.vector.riotx.core.resources.StringProvider
@@ -37,40 +40,49 @@ class LocalePickerController @Inject constructor(
     override fun buildModels(data: LocalePickerViewState?) {
         val list = data?.locales ?: return
 
-        if (list.isEmpty()) {
-            noResultItem {
-                id("noResult")
-                text(stringProvider.getString(R.string.no_result_placeholder))
+        profileSectionItem {
+            id("currentTitle")
+            title(stringProvider.getString(R.string.choose_locale_current_locale_title))
+        }
+        localeItem {
+            id(data.currentLocale.toString())
+            title(VectorLocale.localeToLocalisedString(data.currentLocale).capitalize(data.currentLocale))
+            if (vectorPreferences.developerMode()) {
+                subtitle(VectorLocale.localeToLocalisedStringInfo(data.currentLocale))
             }
-        } else {
-            profileSectionItem {
-                id("currentTitle")
-                title(stringProvider.getString(R.string.choose_locale_current_locale_title))
-            }
-            localeItem {
-                id(data.currentLocale.toString())
-                title(VectorLocale.localeToLocalisedString(data.currentLocale).capitalize(data.currentLocale))
-                if (vectorPreferences.developerMode()) {
-                    subtitle(VectorLocale.localeToLocalisedStringInfo(data.currentLocale))
+            clickListener { listener?.onUseCurrentClicked() }
+        }
+        profileSectionItem {
+            id("otherTitle")
+            title(stringProvider.getString(R.string.choose_locale_other_locales_title))
+        }
+        when (list) {
+            is Incomplete -> {
+                loadingItem {
+                    id("loading")
+                    loadingText(stringProvider.getString(R.string.choose_locale_loading_locales))
                 }
-                clickListener { listener?.onUseCurrentClicked() }
             }
-            profileSectionItem {
-                id("otherTitle")
-                title(stringProvider.getString(R.string.choose_locale_other_locales_title))
-            }
-            list
-                    .filter { it.toString() != data.currentLocale.toString() }
-                    .forEach {
-                        localeItem {
-                            id(it.toString())
-                            title(VectorLocale.localeToLocalisedString(it).capitalize(it))
-                            if (vectorPreferences.developerMode()) {
-                                subtitle(VectorLocale.localeToLocalisedStringInfo(it))
-                            }
-                            clickListener { listener?.onLocaleClicked(it) }
-                        }
+            is Success    ->
+                if (list().isEmpty()) {
+                    noResultItem {
+                        id("noResult")
+                        text(stringProvider.getString(R.string.no_result_placeholder))
                     }
+                } else {
+                    list()
+                            .filter { it.toString() != data.currentLocale.toString() }
+                            .forEach {
+                                localeItem {
+                                    id(it.toString())
+                                    title(VectorLocale.localeToLocalisedString(it).capitalize(it))
+                                    if (vectorPreferences.developerMode()) {
+                                        subtitle(VectorLocale.localeToLocalisedStringInfo(it))
+                                    }
+                                    clickListener { listener?.onLocaleClicked(it) }
+                                }
+                            }
+                }
         }
     }
 

vector/src/main/java/im/vector/riotx/features/settings/locale/LocalePickerViewModel.kt

@@ -19,28 +19,30 @@ package im.vector.riotx.features.settings.locale
 import com.airbnb.mvrx.ActivityViewModelContext
 import com.airbnb.mvrx.FragmentViewModelContext
 import com.airbnb.mvrx.MvRxViewModelFactory
+import com.airbnb.mvrx.Success
 import com.airbnb.mvrx.ViewModelContext
 import com.squareup.inject.assisted.Assisted
 import com.squareup.inject.assisted.AssistedInject
 import im.vector.riotx.core.extensions.exhaustive
 import im.vector.riotx.core.platform.VectorViewModel
 import im.vector.riotx.features.settings.VectorLocale
+import kotlinx.coroutines.Job
+import java.util.Locale
 
 class LocalePickerViewModel @AssistedInject constructor(
         @Assisted initialState: LocalePickerViewState
-) : VectorViewModel<LocalePickerViewState, LocalePickerAction, LocalePickerViewEvents>(initialState) {
+) : VectorViewModel<LocalePickerViewState, LocalePickerAction, LocalePickerViewEvents>(initialState),
+        VectorLocale.Listener {
 
     @AssistedInject.Factory
     interface Factory {
         fun create(initialState: LocalePickerViewState): LocalePickerViewModel
     }
 
+    private var loadingJob: Job? = null
+
     init {
-        setState {
-            copy(
-                    locales = VectorLocale.supportedLocales
-            )
-        }
+        loadingJob = VectorLocale.loadLocales(this)
     }
 
     companion object : MvRxViewModelFactory<LocalePickerViewModel, LocalePickerViewState> {
@@ -65,4 +67,17 @@ class LocalePickerViewModel @AssistedInject constructor(
         VectorLocale.saveApplicationLocale(action.locale)
         _viewEvents.post(LocalePickerViewEvents.RestartActivity)
     }
+
+    override fun onLoaded(locales: List<Locale>) {
+        setState {
+            copy(
+                    locales = Success(locales)
+            )
+        }
+    }
+
+    override fun onCleared() {
+        super.onCleared()
+        loadingJob?.cancel()
+    }
 }

vector/src/main/java/im/vector/riotx/features/settings/locale/LocalePickerViewState.kt

@@ -16,11 +16,13 @@
 
 package im.vector.riotx.features.settings.locale
 
+import com.airbnb.mvrx.Async
 import com.airbnb.mvrx.MvRxState
+import com.airbnb.mvrx.Uninitialized
 import im.vector.riotx.features.settings.VectorLocale
 import java.util.Locale
 
 data class LocalePickerViewState(
         val currentLocale: Locale = VectorLocale.applicationLocale,
-        val locales: List<Locale> = emptyList()
+        val locales: Async<List<Locale>> = Uninitialized
 ) : MvRxState

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

@@ -2395,5 +2395,6 @@ Not all features in Riot are implemented in RiotX yet. Main missing (and coming
 
     <string name="choose_locale_current_locale_title">Current language</string>
     <string name="choose_locale_other_locales_title">Other available languages</string>
+    <string name="choose_locale_loading_locales">Loading available languages…</string>
 
 </resources>