Improve language list prioritization. (#3293)

Partially addresses #3277

app/src/main/java/com/keylesspalace/tusky/components/compose/ComposeActivity.kt

@@ -90,7 +90,7 @@ import com.keylesspalace.tusky.settings.PrefKeys
 import com.keylesspalace.tusky.util.APP_THEME_DEFAULT
 import com.keylesspalace.tusky.util.PickMediaFiles
 import com.keylesspalace.tusky.util.afterTextChanged
-import com.keylesspalace.tusky.util.getInitialLanguage
+import com.keylesspalace.tusky.util.getInitialLanguages
 import com.keylesspalace.tusky.util.getLocaleList
 import com.keylesspalace.tusky.util.getMediaSize
 import com.keylesspalace.tusky.util.hide
@@ -267,7 +267,7 @@ class ComposeActivity :
             binding.composeScheduleView.setDateTime(composeOptions?.scheduledAt)
         }
 
-        setupLanguageSpinner(getInitialLanguage(composeOptions?.language, accountManager.activeAccount))
+        setupLanguageSpinner(getInitialLanguages(composeOptions?.language, accountManager.activeAccount))
         setupComposeField(preferences, viewModel.startingText)
         setupContentWarningField(composeOptions?.contentWarning)
         setupPollView()
@@ -543,7 +543,7 @@ class ComposeActivity :
         )
     }
 
-    private fun setupLanguageSpinner(initialLanguage: String) {
+    private fun setupLanguageSpinner(initialLanguages: List<String>) {
         binding.composePostLanguageButton.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
             override fun onItemSelected(parent: AdapterView<*>, view: View?, position: Int, id: Long) {
                 viewModel.postLanguage = (parent.adapter.getItem(position) as Locale).modernLanguageCode
@@ -554,7 +554,7 @@ class ComposeActivity :
             }
         }
         binding.composePostLanguageButton.apply {
-            adapter = LocaleAdapter(context, android.R.layout.simple_spinner_dropdown_item, getLocaleList(initialLanguage))
+            adapter = LocaleAdapter(context, android.R.layout.simple_spinner_dropdown_item, getLocaleList(initialLanguages))
             setSelection(0)
         }
     }

app/src/main/java/com/keylesspalace/tusky/components/preference/AccountPreferencesFragment.kt

@@ -49,7 +49,7 @@ import com.keylesspalace.tusky.settings.makePreferenceScreen
 import com.keylesspalace.tusky.settings.preference
 import com.keylesspalace.tusky.settings.preferenceCategory
 import com.keylesspalace.tusky.settings.switchPreference
-import com.keylesspalace.tusky.util.getInitialLanguage
+import com.keylesspalace.tusky.util.getInitialLanguages
 import com.keylesspalace.tusky.util.getLocaleList
 import com.keylesspalace.tusky.util.getTuskyDisplayName
 import com.keylesspalace.tusky.util.makeIcon
@@ -197,7 +197,7 @@ class AccountPreferencesFragment : PreferenceFragmentCompat(), Injectable {
                 }
 
                 listPreference {
-                    val locales = getLocaleList(getInitialLanguage(null, accountManager.activeAccount))
+                    val locales = getLocaleList(getInitialLanguages(null, accountManager.activeAccount))
                     setTitle(R.string.pref_default_post_language)
                     // Explicitly add "System default" to the start of the list
                     entries = (

app/src/main/java/com/keylesspalace/tusky/util/LocaleUtils.kt

@@ -23,17 +23,18 @@ import java.util.Locale
 
 private const val TAG: String = "LocaleUtils"
 
-private fun mergeLocaleListCompat(list: MutableList<Locale>, localeListCompat: LocaleListCompat) {
+private fun LocaleListCompat.toList(): List<Locale> {
-    for (index in 0 until localeListCompat.size()) {
+    val list = mutableListOf<Locale>()
-        val locale = localeListCompat[index]
+    for (index in 0 until this.size()) {
-        if (locale != null && list.none { locale.language == it.language }) {
+        this[index]?.let { list.add(it) }
-            list.add(locale)
-        }
     }
+    return list
 }
 
 // Ensure that the locale whose code matches the given language is first in the list
-private fun ensureLanguageIsFirst(locales: MutableList<Locale>, language: String) {
+private fun ensureLanguagesAreFirst(locales: MutableList<Locale>, languages: List<String>) {
+    for (language in languages.reversed()) {
+        // Iterate prioritized languages in reverse to retain the order once bubbled to the top
         var currentLocaleIndex = locales.indexOfFirst { it.language == language }
         if (currentLocaleIndex < 0) {
             // Recheck against modern language codes
@@ -47,7 +48,7 @@ private fun ensureLanguageIsFirst(locales: MutableList<Locale>, language: String
                 // - Replying to a post in a language android doesn't know
                 locales.add(0, Locale(language))
                 Log.w(TAG, "Attempting to use unknown language tag '$language'")
-            return
+                continue
             }
         }
 
@@ -55,35 +56,24 @@ private fun ensureLanguageIsFirst(locales: MutableList<Locale>, language: String
             // Move preselected locale to the top
             locales.add(0, locales.removeAt(currentLocaleIndex))
         }
-}
-
-fun getInitialLanguage(language: String? = null, activeAccount: AccountEntity? = null): String {
-    return if (language.isNullOrEmpty()) {
-        // Account-specific language set on the server
-        if (activeAccount?.defaultPostLanguage?.isNotEmpty() == true) {
-            activeAccount.defaultPostLanguage
-        } else {
-            // Setting the application ui preference sets the default locale
-            AppCompatDelegate.getApplicationLocales()[0]?.language
-                ?: Locale.getDefault().language
-        }
-    } else {
-        language
     }
 }
 
-fun getLocaleList(initialLanguage: String): List<Locale> {
+fun getInitialLanguages(language: String? = null, activeAccount: AccountEntity? = null): List<String> {
-    val locales = mutableListOf<Locale>()
+    val selected = listOfNotNull(language, activeAccount?.defaultPostLanguage)
-    mergeLocaleListCompat(locales, AppCompatDelegate.getApplicationLocales()) // configured app languages first
+    val system = AppCompatDelegate.getApplicationLocales().toList() +
-    mergeLocaleListCompat(locales, LocaleListCompat.getDefault()) // then configured system languages
+        LocaleListCompat.getDefault().toList()
-    locales.addAll( // finally, other languages
+
+    return (selected + system.map { it.language }).distinct().filter { it.isNotEmpty() }
+}
+
+fun getLocaleList(initialLanguages: List<String>): List<Locale> {
+    val locales = Locale.getAvailableLocales().filter {
         // Only "base" languages, "en" but not "en_DK"
-        Locale.getAvailableLocales().filter {
         it.country.isNullOrEmpty() &&
             it.script.isNullOrEmpty() &&
             it.variant.isNullOrEmpty()
-        }.sortedBy { it.displayName }
+    }.sortedBy { it.displayName }.toMutableList()
-    )
+    ensureLanguagesAreFirst(locales, initialLanguages)
-    ensureLanguageIsFirst(locales, initialLanguage)
     return locales
 }

app/src/test/java/com/keylesspalace/tusky/util/LocaleUtilsTest.kt

@@ -0,0 +1,82 @@
+package com.keylesspalace.tusky.util
+
+import androidx.appcompat.app.AppCompatDelegate
+import androidx.core.os.LocaleListCompat
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.keylesspalace.tusky.db.AccountEntity
+import org.junit.Assert
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito
+import org.robolectric.annotation.Config
+
+@Config(sdk = [28])
+@RunWith(AndroidJUnit4::class)
+class LocaleUtilsTest {
+    @Test
+    fun initialLanguagesContainReplySelectedAppAndSystem() {
+        val expectedLanguages = arrayOf<String?>("yi", "tok", "da", "fr", "sv", "kab")
+        val languages = getMockedInitialLanguages(expectedLanguages)
+        Assert.assertArrayEquals(expectedLanguages, languages.subList(0, expectedLanguages.size).toTypedArray())
+    }
+
+    @Test
+    fun whenReplyLanguageIsNull_DefaultLanguageIsFirst() {
+        val defaultLanguage = "tok"
+        val languages = getMockedInitialLanguages(arrayOf(null, defaultLanguage, "da", "fr", "sv", "kab"))
+        Assert.assertEquals(defaultLanguage, languages[0])
+    }
+
+    @Test
+    fun initialLanguagesAreDistinct() {
+        val defaultLanguage = "da"
+        val languages = getMockedInitialLanguages(arrayOf(defaultLanguage, defaultLanguage, "fr", defaultLanguage, "kab", defaultLanguage))
+        Assert.assertEquals(1, languages.count { it == defaultLanguage })
+    }
+
+    @Test
+    fun initialLanguageDeduplicationDoesNotReorder() {
+        val defaultLanguage = "da"
+
+        Assert.assertEquals(
+            defaultLanguage,
+            getMockedInitialLanguages(arrayOf(defaultLanguage, defaultLanguage, "fr", defaultLanguage, "kab", defaultLanguage))[0]
+        )
+        Assert.assertEquals(
+            defaultLanguage,
+            getMockedInitialLanguages(arrayOf(null, defaultLanguage, "fr", defaultLanguage, "kab", defaultLanguage))[0]
+        )
+    }
+
+    @Test
+    fun emptyInitialLanguagesAreDropped() {
+        val languages = getMockedInitialLanguages(arrayOf("", "", "fr", "", "kab", ""))
+        Assert.assertFalse(languages.any { it.isEmpty() })
+    }
+
+    private fun getMockedInitialLanguages(configuredLanguages: Array<String?>): List<String> {
+        val appLanguages = LocaleListCompat.forLanguageTags(configuredLanguages.slice(2 until 4).joinToString(","))
+        val systemLanguages = LocaleListCompat.forLanguageTags(configuredLanguages.slice(4 until configuredLanguages.size).joinToString(","))
+
+        Mockito.mockStatic(AppCompatDelegate::class.java).use { appCompatDelegate ->
+            appCompatDelegate.`when`<LocaleListCompat> { AppCompatDelegate.getApplicationLocales() }.thenReturn(appLanguages)
+
+            Mockito.mockStatic(LocaleListCompat::class.java).use { localeListCompat ->
+                localeListCompat.`when`<LocaleListCompat> { LocaleListCompat.getDefault() }.thenReturn(systemLanguages)
+
+                return getInitialLanguages(
+                    configuredLanguages[0],
+                    AccountEntity(
+                        id = 0,
+                        domain = "foo.bar",
+                        accessToken = "",
+                        clientId = null,
+                        clientSecret = null,
+                        isActive = true,
+                        defaultPostLanguage = configuredLanguages[1] ?: "",
+                    )
+                )
+            }
+        }
+    }
+}