Add language dropdown to compose view (#2651)

* Add UI for selecting post language

* Apply selected language when sending status

* Save/restore post language with drafts

* Fall back to english if the configured language isn't found in the locale list (no-NB)

* Remove comment about no_NB

* Move language dropdown to top of compose view

* Preserve language when redrafting

* Set default language to target post's language when replying

* Add Tusky license header to new source file

* Tweak language dropdown button width

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

@@ -35,6 +35,7 @@ import android.view.KeyEvent
 import android.view.MenuItem
 import android.view.View
 import android.view.ViewGroup
+import android.widget.AdapterView
 import android.widget.ImageButton
 import android.widget.LinearLayout
 import android.widget.PopupMenu
@@ -65,6 +66,7 @@ import com.keylesspalace.tusky.BaseActivity
 import com.keylesspalace.tusky.BuildConfig
 import com.keylesspalace.tusky.R
 import com.keylesspalace.tusky.adapter.EmojiAdapter
+import com.keylesspalace.tusky.adapter.LocaleAdapter
 import com.keylesspalace.tusky.adapter.OnEmojiSelectedListener
 import com.keylesspalace.tusky.components.compose.dialog.makeCaptionDialog
 import com.keylesspalace.tusky.components.compose.dialog.showAddPollDialog
@@ -244,6 +246,7 @@ class ComposeActivity :
             binding.composeScheduleView.setDateTime(composeOptions?.scheduledAt)
         }
 
+        setupLanguageSpinner(getInitialLanguage(composeOptions?.language))
         setupComposeField(preferences, viewModel.startingText)
         setupContentWarningField(composeOptions?.contentWarning)
         setupPollView()
@@ -476,6 +479,40 @@ class ComposeActivity :
         binding.addPollTextActionTextView.setOnClickListener { openPollDialog() }
     }
 
+    private fun setupLanguageSpinner(initialLanguage: String?) {
+        val locales = Locale.getAvailableLocales()
+            .filter { it.country.isNullOrEmpty() && it.script.isNullOrEmpty() && it.variant.isNullOrEmpty() } // Only "base" languages, "en" but not "en_DK"
+        var currentLocaleIndex = locales.indexOfFirst { it.language == initialLanguage }
+        if (currentLocaleIndex < 0) {
+            Log.e(TAG, "Error looking up language tag '$initialLanguage', falling back to english")
+            currentLocaleIndex = locales.indexOfFirst { it.language == "en" }
+        }
+
+        val context = this
+        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).language
+            }
+
+            override fun onNothingSelected(parent: AdapterView<*>) {
+                parent.setSelection(locales.indexOfFirst { it.language == getInitialLanguage() })
+            }
+        }
+        binding.composePostLanguageButton.apply {
+            adapter = LocaleAdapter(context, android.R.layout.simple_spinner_dropdown_item, locales)
+            setSelection(currentLocaleIndex)
+        }
+    }
+
+    private fun getInitialLanguage(language: String? = null): String {
+        return if (language.isNullOrEmpty()) {
+            // Setting the application ui preference sets the default locale
+            Locale.getDefault().language
+        } else {
+            language
+        }
+    }
+
     private fun setupActionBar() {
         setSupportActionBar(binding.toolbar)
         supportActionBar?.run {
@@ -793,6 +830,10 @@ class ComposeActivity :
         return length
     }
 
+    @VisibleForTesting
+    val selectedLanguage: String?
+        get() = viewModel.postLanguage
+
     private fun updateVisibleCharactersLeft() {
         val remainingLength = maximumTootCharacters - calculateTextLength()
         binding.composeCharactersLeftView.text = String.format(Locale.getDefault(), "%d", remainingLength)
@@ -1128,7 +1169,8 @@ class ComposeActivity :
         var scheduledAt: String? = null,
         var sensitive: Boolean? = null,
         var poll: NewPoll? = null,
-        var modifiedInitialState: Boolean? = null
+        var modifiedInitialState: Boolean? = null,
+        var language: String? = null,
     ) : Parcelable
 
     companion object {

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

@@ -68,6 +68,7 @@ class ComposeViewModel @Inject constructor(
     private var replyingStatusAuthor: String? = null
     private var replyingStatusContent: String? = null
     internal var startingText: String? = null
+    internal var postLanguage: String? = null
     private var draftId: Int = 0
     private var scheduledTootId: String? = null
     private var startingContentWarning: String = ""
@@ -261,7 +262,8 @@ class ComposeViewModel @Inject constructor(
             mediaDescriptions = mediaDescriptions,
             poll = poll.value,
             failedToSend = false,
-            scheduledAt = scheduledAt.value
+            scheduledAt = scheduledAt.value,
+            language = postLanguage,
         )
     }
 
@@ -308,7 +310,8 @@ class ComposeViewModel @Inject constructor(
                     draftId = draftId,
                     idempotencyKey = randomAlphanumericString(16),
                     retries = 0,
-                    mediaProcessed = mediaProcessed
+                    mediaProcessed = mediaProcessed,
+                    language = postLanguage,
                 )
 
                 serviceClient.sendToot(tootToSend)
@@ -426,6 +429,7 @@ class ComposeViewModel @Inject constructor(
         draftId = composeOptions?.draftId ?: 0
         scheduledTootId = composeOptions?.scheduledTootId
         startingText = composeOptions?.content
+        postLanguage = composeOptions?.language
 
         val tootVisibility = composeOptions?.visibility ?: Status.Visibility.UNKNOWN
         if (tootVisibility.num != Status.Visibility.UNKNOWN.num) {