Improve Android read aloud TTS handling

composeApp/src/androidMain/AndroidManifest.xml

@@ -9,6 +9,12 @@
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK"/>
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
 
+    <queries>
+        <intent>
+            <action android:name="android.intent.action.TTS_SERVICE"/>
+        </intent>
+    </queries>
+
     <application
             android:allowBackup="true"
             android:icon="@mipmap/ic_launcher"

composeApp/src/androidMain/kotlin/net/sergeych/toread/ReadAloudPlatform.android.kt

@@ -18,6 +18,7 @@ import android.speech.tts.UtteranceProgressListener
 import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
 import androidx.core.content.ContextCompat
+import java.util.Locale
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
@@ -29,6 +30,7 @@ import kotlinx.coroutines.launch
 actual object ReadAloudPlatform {
     actual val isSupported: Boolean = true
     actual val state: StateFlow<ReadAloudState> = AndroidReadAloudEngine.state
+    actual val settingsState: StateFlow<ReadAloudSettingsState> = AndroidReadAloudEngine.settingsState
 
     actual fun prepare(bookTitle: String, sentences: List<ReadAloudSentence>, startIndex: Int) {
         val context = androidAppContext() ?: return
@@ -49,6 +51,21 @@ actual object ReadAloudPlatform {
     actual fun skip(delta: Int) {
         AndroidReadAloudEngine.skip(delta)
     }
+
+    actual fun refreshSettings() {
+        val context = androidAppContext() ?: return
+        AndroidReadAloudEngine.refreshSettings(context)
+    }
+
+    actual fun selectEngine(engineId: String?) {
+        val context = androidAppContext() ?: return
+        AndroidReadAloudEngine.selectEngine(context, engineId)
+    }
+
+    actual fun selectVoice(voiceId: String?) {
+        val context = androidAppContext() ?: return
+        AndroidReadAloudEngine.selectVoice(context, voiceId)
+    }
 }
 
 private object AndroidReadAloudEngine {
@@ -56,12 +73,22 @@ private object AndroidReadAloudEngine {
     private const val BeforePausePrefix = "read-aloud-before-"
     private const val SpeakPrefix = "read-aloud-speak-"
     private const val AfterPausePrefix = "read-aloud-after-"
+    private const val SettingsPrefs = "read_aloud_tts"
+    private const val SelectedEngineKey = "selected_engine"
+    private const val EngineChoiceMadeKey = "engine_choice_made"
+    private const val SelectedVoiceKey = "selected_voice"
+    private val RussianLocale = Locale.forLanguageTag("ru-RU")
 
     private val mutableState = MutableStateFlow(ReadAloudState())
     val state: StateFlow<ReadAloudState> = mutableState
+    private val mutableSettingsState = MutableStateFlow(ReadAloudSettingsState())
+    val settingsState: StateFlow<ReadAloudSettingsState> = mutableSettingsState
 
     private var tts: TextToSpeech? = null
     private var ttsReady = false
+    private var ttsEngineId: String? = null
+    private var engineProbe: TextToSpeech? = null
+    private var voiceProbe: TextToSpeech? = null
     private var shouldSpeakWhenReady = false
     private var bookTitle: String = ""
     private var sentences: List<ReadAloudSentence> = emptyList()
@@ -110,11 +137,100 @@ private object AndroidReadAloudEngine {
         }
     }
 
+    fun refreshSettings(context: Context) {
+        val appContext = context.applicationContext
+        mutableSettingsState.value = mutableSettingsState.value.copy(loading = true, message = null)
+        engineProbe?.shutdown()
+        var probe: TextToSpeech? = null
+        probe = TextToSpeech(appContext) { status ->
+            if (status != TextToSpeech.SUCCESS) {
+                mutableSettingsState.value = mutableSettingsState.value.copy(
+                    loading = false,
+                    message = "Could not load Android TTS engines.",
+                )
+                probe?.shutdown()
+                if (engineProbe === probe) engineProbe = null
+                return@TextToSpeech
+            }
+
+            val engines = probe?.engines.orEmpty()
+                .map { ReadAloudEngineOption(id = it.name, label = it.label ?: it.name) }
+                .sortedBy { it.label.lowercase() }
+            var selectedEngine = selectedEngineId(appContext).takeIf { saved ->
+                saved != null && engines.any { it.id == saved }
+            }
+            if (selectedEngine == null && !appContext.readAloudPrefs().getBoolean(EngineChoiceMadeKey, false)) {
+                selectedEngine = engines.firstOrNull { it.isRhVoice() }?.id
+                if (selectedEngine != null) {
+                    appContext.readAloudPrefs().edit().putString(SelectedEngineKey, selectedEngine).apply()
+                }
+            }
+            mutableSettingsState.value = mutableSettingsState.value.copy(
+                engines = engines,
+                selectedEngineId = selectedEngine,
+            )
+            probe?.shutdown()
+            if (engineProbe === probe) engineProbe = null
+            refreshVoices(appContext, selectedEngine)
+        }
+        engineProbe = probe
+    }
+
+    fun selectEngine(context: Context, engineId: String?) {
+        val appContext = context.applicationContext
+        appContext.readAloudPrefs()
+            .edit()
+            .putBoolean(EngineChoiceMadeKey, true)
+            .putStringOrRemove(SelectedEngineKey, engineId)
+            .remove(SelectedVoiceKey)
+            .apply()
+        resetTts()
+        mutableSettingsState.value = mutableSettingsState.value.copy(
+            selectedEngineId = engineId,
+            selectedVoiceId = null,
+            voices = emptyList(),
+            loading = true,
+            message = null,
+        )
+        refreshVoices(appContext, engineId)
+    }
+
+    fun selectVoice(context: Context, voiceId: String?) {
+        val appContext = context.applicationContext
+        appContext.readAloudPrefs()
+            .edit()
+            .putStringOrRemove(SelectedVoiceKey, voiceId)
+            .apply()
+        mutableSettingsState.value = mutableSettingsState.value.copy(selectedVoiceId = voiceId)
+        applyTtsConfiguration(appContext)
+        if (mutableState.value.playing && ttsReady) {
+            speakCurrent()
+        }
+    }
+
     private fun ensureTts(context: Context) {
-        if (tts != null) return
-        tts = TextToSpeech(context) { status ->
+        val appContext = context.applicationContext
+        val selectedEngine = selectedEngineId(appContext)
+        if (tts != null && ttsEngineId == selectedEngine) return
+        resetTts()
+        ttsEngineId = selectedEngine
+        tts = if (selectedEngine == null) {
+            TextToSpeech(appContext) { status ->
+                handleTtsInit(appContext, status)
+            }
+        } else {
+            TextToSpeech(
+                appContext,
+                { status -> handleTtsInit(appContext, status) },
+                selectedEngine,
+            )
+        }
+    }
+
+    private fun handleTtsInit(context: Context, status: Int) {
         ttsReady = status == TextToSpeech.SUCCESS
         if (ttsReady) {
+            applyTtsConfiguration(context)
             tts?.setOnUtteranceProgressListener(object : UtteranceProgressListener() {
                 override fun onStart(utteranceId: String?) = Unit
 
@@ -139,7 +255,6 @@ private object AndroidReadAloudEngine {
             stop()
         }
     }
-    }
 
     private fun speakCurrent() {
         val sentence = sentences.getOrNull(currentIndex) ?: run {
@@ -156,7 +271,7 @@ private object AndroidReadAloudEngine {
         } else {
             TextToSpeech.QUEUE_FLUSH
         }
-        tts?.speak(sentence.text, queueMode, params, "$SpeakPrefix$currentIndex")
+        tts?.speak(sentence.spokenText, queueMode, params, "$SpeakPrefix$currentIndex")
         if (sentence.pauseAfterMillis > 0) {
             tts?.playSilentUtterance(sentence.pauseAfterMillis, TextToSpeech.QUEUE_ADD, "$AfterPausePrefix$currentIndex")
         }
@@ -182,7 +297,106 @@ private object AndroidReadAloudEngine {
             stop()
         }
     }
+
+    private fun refreshVoices(context: Context, engineId: String?) {
+        voiceProbe?.shutdown()
+        var probe: TextToSpeech? = null
+        probe = if (engineId == null) {
+            TextToSpeech(context) { status ->
+                handleVoiceProbeInit(context, probe, status)
             }
+        } else {
+            TextToSpeech(
+                context,
+                { status -> handleVoiceProbeInit(context, probe, status) },
+                engineId,
+            )
+        }
+        voiceProbe = probe
+    }
+
+    private fun handleVoiceProbeInit(context: Context, probe: TextToSpeech?, status: Int) {
+        if (status != TextToSpeech.SUCCESS) {
+            mutableSettingsState.value = mutableSettingsState.value.copy(
+                loading = false,
+                message = "Could not load voices for the selected TTS engine.",
+            )
+            probe?.shutdown()
+            if (voiceProbe === probe) voiceProbe = null
+            return
+        }
+
+        val voices = probe?.voices.orEmpty()
+            .mapNotNull { voice ->
+                val locale = voice.locale ?: return@mapNotNull null
+                ReadAloudVoiceOption(
+                    id = voice.name,
+                    label = voice.name,
+                    localeTag = locale.toLanguageTag(),
+                    networkRequired = voice.isNetworkConnectionRequired,
+                )
+            }
+            .filter { !it.networkRequired }
+            .sortedWith(
+                compareByDescending<ReadAloudVoiceOption> { it.localeTag.startsWith("ru", ignoreCase = true) }
+                    .thenBy { it.localeTag }
+                    .thenBy { it.label.lowercase() },
+            )
+        val savedVoice = selectedVoiceId(context).takeIf { saved ->
+            saved != null && voices.any { it.id == saved }
+        }
+        mutableSettingsState.value = mutableSettingsState.value.copy(
+            voices = voices,
+            selectedVoiceId = savedVoice,
+            loading = false,
+            message = if (voices.isEmpty()) "No offline voices reported by the selected TTS engine." else null,
+        )
+        if (savedVoice == null && selectedVoiceId(context) != null) {
+            context.readAloudPrefs().edit().remove(SelectedVoiceKey).apply()
+        }
+        probe?.shutdown()
+        if (voiceProbe === probe) voiceProbe = null
+    }
+
+    private fun applyTtsConfiguration(context: Context) {
+        val selectedVoice = selectedVoiceId(context)
+        val voice = selectedVoice?.let { voiceName ->
+            tts?.voices?.firstOrNull { it.name == voiceName && !it.isNetworkConnectionRequired }
+        }
+        if (voice != null) {
+            tts?.voice = voice
+        } else {
+            tts?.setLanguage(RussianLocale)
+        }
+    }
+
+    private fun resetTts() {
+        shouldSpeakWhenReady = false
+        ttsReady = false
+        ttsEngineId = null
+        tts?.stop()
+        tts?.shutdown()
+        tts = null
+    }
+
+    private fun selectedEngineId(context: Context): String? =
+        context.readAloudPrefs().getString(SelectedEngineKey, null)
+
+    private fun selectedVoiceId(context: Context): String? =
+        context.readAloudPrefs().getString(SelectedVoiceKey, null)
+
+    private fun Context.readAloudPrefs() =
+        getSharedPreferences(SettingsPrefs, Context.MODE_PRIVATE)
+
+    private fun ReadAloudEngineOption.isRhVoice(): Boolean =
+        id.contains("rhvoice", ignoreCase = true) || label.contains("RHVoice", ignoreCase = true)
+}
+
+private fun android.content.SharedPreferences.Editor.putStringOrRemove(
+    key: String,
+    value: String?,
+): android.content.SharedPreferences.Editor =
+    if (value == null) remove(key) else putString(key, value)
 
 class ReadAloudService : Service() {
     private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Main.immediate)

composeApp/src/commonMain/kotlin/net/sergeych/toread/ReadAloudPlatform.kt

@@ -8,6 +8,7 @@ data class ReadAloudSentence(
     val start: Int,
     val endExclusive: Int,
     val text: String,
+    val spokenText: String = text,
     val pauseBeforeMillis: Long = 0,
     val pauseAfterMillis: Long = 0,
 )
@@ -18,12 +19,37 @@ data class ReadAloudState(
     val sentenceIndex: Int? = null,
 )
 
+data class ReadAloudEngineOption(
+    val id: String,
+    val label: String,
+)
+
+data class ReadAloudVoiceOption(
+    val id: String,
+    val label: String,
+    val localeTag: String,
+    val networkRequired: Boolean,
+)
+
+data class ReadAloudSettingsState(
+    val engines: List<ReadAloudEngineOption> = emptyList(),
+    val selectedEngineId: String? = null,
+    val voices: List<ReadAloudVoiceOption> = emptyList(),
+    val selectedVoiceId: String? = null,
+    val loading: Boolean = false,
+    val message: String? = null,
+)
+
 expect object ReadAloudPlatform {
     val isSupported: Boolean
     val state: StateFlow<ReadAloudState>
+    val settingsState: StateFlow<ReadAloudSettingsState>
 
     fun prepare(bookTitle: String, sentences: List<ReadAloudSentence>, startIndex: Int)
     fun play()
     fun stop()
     fun skip(delta: Int)
+    fun refreshSettings()
+    fun selectEngine(engineId: String?)
+    fun selectVoice(voiceId: String?)
 }

composeApp/src/commonMain/kotlin/net/sergeych/toread/ReaderContent.kt

@@ -93,11 +93,7 @@ internal fun ContinuousBookReader(
     val hyphenation = remember { HyphenationRegistry() }
     val scope = rememberCoroutineScope()
     val textLineMetricsByItem = remember(contentPlan) { mutableStateMapOf<Int, TextLineMetrics>() }
-    val contentPadding = if (isAndroidPlatform()) {
-        PaddingValues(start = 0.dp, top = 6.dp, end = 0.dp, bottom = 6.dp)
-    } else {
-        PaddingValues(horizontal = 4.dp, vertical = 6.dp)
-    }
+    val contentPadding = PaddingValues(6.dp)
 
     LazyColumn(
         state = listState,
@@ -174,10 +170,8 @@ internal fun ContinuousBookReader(
                     hyphenation = hyphenation,
                     style = readerParagraphTextStyle(book.language),
                     highlightedRange = highlightedRange,
-                    /* Justify adds extra padding to the end, which hardly can be removed */
                     textAlign = TextAlign.Justify,
-                    // so we add 6.dp to make it look symmetric
-                    modifier = Modifier.padding(start = (element.depth * 8).dp + 6.dp, end = 0.dp),
+                    modifier = Modifier.padding(start = (element.depth * 8).dp, end = 0.dp),
                     onTextLayout = { textLineMetricsByItem[itemIndex] = it.toTextLineMetrics() },
                 )
                 is ReaderElement.Subtitle -> ReaderText(
@@ -444,7 +438,7 @@ private fun ReaderPane(book: Fb2Book, section: Fb2Section?, modifier: Modifier =
                     language = book.language,
                     hyphenation = hyphenation,
                     style = readerParagraphTextStyle(book.language),
-                    textAlign = TextAlign.Justify,
+                    textAlign = TextAlign.Unspecified,
                 )
                 is Fb2Block.Subtitle -> ReaderText(
                     text = block.content,
@@ -473,7 +467,7 @@ private fun ReaderText(
 ) {
     val highlightColor = MaterialTheme.colorScheme.secondaryContainer
     val annotatedText = text.toAnnotatedString(language, hyphenation, highlightedRange, highlightColor)
-    val needsSoftHyphenPaintWorkaround = isDesktopPlatform()
+    val needsSoftHyphenPaintWorkaround = isDesktopPlatform
     var textLayout by remember(annotatedText) { mutableStateOf<TextLayoutResult?>(null) }
     val desktopHyphenColor = MaterialTheme.colorScheme.onSurface
     val desktopHyphenGutter = 8.dp
@@ -525,19 +519,22 @@ private fun ReaderText(
 @Composable
 private fun readerParagraphTextStyle(language: String?): TextStyle =
     MaterialTheme.typography.bodyLarge.copy(
-        fontWeight = if( isAndroidPlatform()) FontWeight(350) else FontWeight.Normal,
-        fontSize = if( isAndroidPlatform()) 21.sp else 18.sp,
-        lineHeight = 28.sp,
-        hyphens = if (isAndroidPlatform()) Hyphens.Auto else Hyphens.Unspecified,
-        lineBreak = if (isAndroidPlatform()) LineBreak.Paragraph else LineBreak.Unspecified,
+        fontWeight = if( isAndroidPlatform) FontWeight(350) else FontWeight.Normal,
+        fontSize = if( isAndroidPlatform) 19.sp else 18.sp,
+        lineHeight = 26.sp,
+        letterSpacing = if (isAndroidPlatform) 0.sp else MaterialTheme.typography.bodyLarge.letterSpacing,
+        hyphens = if (isAndroidPlatform) Hyphens.Auto else Hyphens.Unspecified,
+        lineBreak = if (isAndroidPlatform) LineBreak.Paragraph else LineBreak.Unspecified,
         localeList = language?.takeIf(String::isNotBlank)?.let { LocaleList(Locale(it)) },
     )
 
-private fun isAndroidPlatform(): Boolean =
+private val isAndroidPlatform: Boolean by lazy {
     getPlatform().name.startsWith("Android")
+}
 
-private fun isDesktopPlatform(): Boolean =
+private val isDesktopPlatform: Boolean by lazy {
     getPlatform().name.startsWith("Java")
+}
 
 private fun TextLayoutResult.endsAtSoftHyphen(text: String, line: Int): Boolean {
     val end = getLineEnd(line, visibleEnd = false)
@@ -663,6 +660,7 @@ private fun AnnotatedString.Builder.appendWithHighlight(
 internal fun buildReaderContentPlan(book: Fb2Book): ReaderContentPlan {
     val elements = mutableListOf<ReaderElement>()
     val sentences = mutableListOf<ReadAloudSentence>()
+    var pendingPauseBeforeMillis = 0L
 
     fun addTextSentences(
         itemIndex: Int,
@@ -670,17 +668,27 @@ internal fun buildReaderContentPlan(book: Fb2Book): ReaderContentPlan {
         pauseBeforeMillis: Long = 0,
         pauseAfterMillis: Long = 0,
     ) {
-        text.plainText().sentenceRanges().forEach { range ->
-            val sentenceText = text.plainText().substring(range.start, range.endExclusive).trim()
-            if (sentenceText.isNotEmpty()) {
+        val plainText = text.plainText()
+        if (plainText.isReadAloudPauseBreak()) {
+            pendingPauseBeforeMillis = max(pendingPauseBeforeMillis, StarBreakPauseMillis)
+            return
+        }
+
+        plainText.sentenceRanges().forEach { range ->
+            val sentenceText = plainText.substring(range.start, range.endExclusive).trim()
+            val spokenText = sentenceText.toReadAloudSpokenText()
+            if (spokenText.isNotEmpty()) {
+                val effectivePauseBefore = pauseBeforeMillis + pendingPauseBeforeMillis
+                pendingPauseBeforeMillis = 0L
                 sentences += ReadAloudSentence(
                     index = sentences.size,
                     itemIndex = itemIndex,
                     start = range.start,
                     endExclusive = range.endExclusive,
                     text = sentenceText,
-                    pauseBeforeMillis = pauseBeforeMillis,
-                    pauseAfterMillis = pauseAfterMillis,
+                    spokenText = spokenText,
+                    pauseBeforeMillis = effectivePauseBefore,
+                    pauseAfterMillis = pauseAfterMillis + range.pauseAfterMillis,
                 )
             }
         }
@@ -698,9 +706,10 @@ internal fun buildReaderContentPlan(book: Fb2Book): ReaderContentPlan {
                 start = 0,
                 endExclusive = section.title!!.length,
                 text = section.title!!,
-                pauseBeforeMillis = HeadingPauseBeforeMillis,
+                pauseBeforeMillis = HeadingPauseBeforeMillis + pendingPauseBeforeMillis,
                 pauseAfterMillis = HeadingPauseAfterMillis,
             )
+            pendingPauseBeforeMillis = 0L
         }
         section.readableBlocks().forEach { block ->
             val itemIndex = elements.size
@@ -756,11 +765,22 @@ internal sealed interface ReaderElement {
 private data class ReaderSentenceRange(
     val start: Int,
     val endExclusive: Int,
+    val pauseAfterMillis: Long = 0L,
 )
 
 private fun Fb2Text.plainText(): String =
     spans.joinToString(separator = "") { it.text }
 
+private fun String.isReadAloudPauseBreak(): Boolean {
+    val compact = trim()
+    return compact.length >= 3 && compact.all { it == '*' || it.isWhitespace() }
+}
+
+private fun String.toReadAloudSpokenText(): String =
+    replace(Regex("\\.{2,}"), ".")
+        .replace('…', '.')
+        .trim()
+
 private fun String.sentenceRanges(): List<ReaderSentenceRange> {
     val ranges = mutableListOf<ReaderSentenceRange>()
     var start = 0
@@ -773,9 +793,15 @@ private fun String.sentenceRanges(): List<ReaderSentenceRange> {
     var index = start
     while (index < length) {
         if (this[index].isSentenceTerminator()) {
-            var end = index + 1
+            val terminatorEnd = sentenceTerminatorEnd(index)
+            val pauseAfterMillis = if (hasReadAloudEllipsisAt(index, terminatorEnd)) {
+                EllipsisPauseAfterMillis
+            } else {
+                0L
+            }
+            var end = terminatorEnd
             while (end < length && this[end] in "\"'»”’)]}") end += 1
-            ranges += ReaderSentenceRange(start, end)
+            ranges += ReaderSentenceRange(start, end, pauseAfterMillis)
             start = end
             skipLeadingWhitespace()
             index = start
@@ -789,11 +815,23 @@ private fun String.sentenceRanges(): List<ReaderSentenceRange> {
     return ranges
 }
 
+private fun String.sentenceTerminatorEnd(index: Int): Int {
+    if (this[index] != '.') return index + 1
+    var end = index + 1
+    while (end < length && this[end] == '.') end += 1
+    return end
+}
+
+private fun String.hasReadAloudEllipsisAt(index: Int, terminatorEnd: Int): Boolean =
+    this[index] == '…' || (this[index] == '.' && terminatorEnd - index >= 2)
+
 private fun Char.isSentenceTerminator(): Boolean =
     this == '.' || this == '!' || this == '?' || this == '…'
 
 private const val HeadingPauseBeforeMillis = 1_000L
 private const val HeadingPauseAfterMillis = 600L
+private const val StarBreakPauseMillis = 1_200L
+private const val EllipsisPauseAfterMillis = 350L
 
 private fun List<Fb2Section>.flattenSections(depth: Int = 0): List<ChapterEntry> =
     flatMapIndexed { index, section ->

composeApp/src/commonMain/kotlin/net/sergeych/toread/ReaderScreen.kt

@@ -21,6 +21,8 @@ import androidx.compose.material.icons.filled.PlayArrow
 import androidx.compose.material.icons.filled.Replay
 import androidx.compose.material.icons.filled.Settings
 import androidx.compose.material.icons.filled.Stop
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.DropdownMenu
 import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.ExperimentalMaterial3Api
@@ -34,6 +36,7 @@ import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
@@ -74,7 +77,9 @@ internal fun BookView(
     var restored by remember(fileId) { mutableStateOf(false) }
     var markedRead by remember(fileId) { mutableStateOf(false) }
     var readAloudPanelVisible by remember(fileId) { mutableStateOf(false) }
+    var readAloudSettingsVisible by remember(fileId) { mutableStateOf(false) }
     val readAloudState by ReadAloudPlatform.state.collectAsState()
+    val readAloudSettings by ReadAloudPlatform.settingsState.collectAsState()
     val platformName = getPlatform().name
     val showShareAction = platformName.startsWith("Android")
     val showViewFileAction = platformName.startsWith("Java")
@@ -249,11 +254,24 @@ internal fun BookView(
                         },
                         onBack = { ReadAloudPlatform.skip(-1) },
                         onForward = { ReadAloudPlatform.skip(1) },
+                        onSettings = {
+                            ReadAloudPlatform.refreshSettings()
+                            readAloudSettingsVisible = true
+                        },
                     )
                 }
             }
         }
     }
+
+    if (readAloudSettingsVisible) {
+        ReadAloudSettingsDialog(
+            state = readAloudSettings,
+            onDismiss = { readAloudSettingsVisible = false },
+            onEngineSelected = { ReadAloudPlatform.selectEngine(it) },
+            onVoiceSelected = { ReadAloudPlatform.selectVoice(it) },
+        )
+    }
 }
 
 @Composable
@@ -372,6 +390,7 @@ private fun ReadAloudPanel(
     onPlayStop: () -> Unit,
     onBack: () -> Unit,
     onForward: () -> Unit,
+    onSettings: () -> Unit,
 ) {
     Surface(
         tonalElevation = 3.dp,
@@ -396,9 +415,95 @@ private fun ReadAloudPanel(
             IconButton(onClick = onForward) {
                 Icon(Icons.Filled.FastForward, contentDescription = "Next sentence")
             }
-            IconButton(onClick = {}, enabled = false) {
+            IconButton(onClick = onSettings) {
                 Icon(Icons.Filled.Settings, contentDescription = "Read aloud settings")
             }
         }
     }
 }
+
+@Composable
+private fun ReadAloudSettingsDialog(
+    state: ReadAloudSettingsState,
+    onDismiss: () -> Unit,
+    onEngineSelected: (String?) -> Unit,
+    onVoiceSelected: (String?) -> Unit,
+) {
+    var engineMenuOpen by remember { mutableStateOf(false) }
+    var voiceMenuOpen by remember { mutableStateOf(false) }
+    val selectedEngineLabel = state.engines.firstOrNull { it.id == state.selectedEngineId }?.label ?: "System default"
+    val selectedVoiceLabel = state.voices.firstOrNull { it.id == state.selectedVoiceId }
+        ?.let { "${it.label} (${it.localeTag})" }
+        ?: "Auto Russian"
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Read aloud") },
+        text = {
+            Column {
+                Text("TTS engine", style = MaterialTheme.typography.labelMedium)
+                Box {
+                    TextButton(onClick = { engineMenuOpen = true }) {
+                        Text(selectedEngineLabel)
+                    }
+                    DropdownMenu(expanded = engineMenuOpen, onDismissRequest = { engineMenuOpen = false }) {
+                        DropdownMenuItem(
+                            text = { Text("System default") },
+                            onClick = {
+                                engineMenuOpen = false
+                                onEngineSelected(null)
+                            },
+                        )
+                        state.engines.forEach { engine ->
+                            DropdownMenuItem(
+                                text = { Text(engine.label) },
+                                onClick = {
+                                    engineMenuOpen = false
+                                    onEngineSelected(engine.id)
+                                },
+                            )
+                        }
+                    }
+                }
+
+                Text("Offline voice", style = MaterialTheme.typography.labelMedium)
+                Box {
+                    TextButton(onClick = { voiceMenuOpen = true }, enabled = !state.loading && state.voices.isNotEmpty()) {
+                        Text(selectedVoiceLabel)
+                    }
+                    DropdownMenu(expanded = voiceMenuOpen, onDismissRequest = { voiceMenuOpen = false }) {
+                        DropdownMenuItem(
+                            text = { Text("Auto Russian") },
+                            onClick = {
+                                voiceMenuOpen = false
+                                onVoiceSelected(null)
+                            },
+                        )
+                        state.voices.forEach { voice ->
+                            DropdownMenuItem(
+                                text = { Text("${voice.label} (${voice.localeTag})") },
+                                onClick = {
+                                    voiceMenuOpen = false
+                                    onVoiceSelected(voice.id)
+                                },
+                            )
+                        }
+                    }
+                }
+
+                if (state.loading) {
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        CircularProgressIndicator()
+                        Text("Loading voices...", modifier = Modifier.padding(start = 12.dp))
+                    }
+                }
+                state.message?.let { Text(it, color = MaterialTheme.colorScheme.error) }
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = onDismiss) {
+                Text("Done")
+            }
+        },
+    )
+}

composeApp/src/commonTest/kotlin/net/sergeych/toread/ReadAloudContentPlanTest.kt

@@ -0,0 +1,58 @@
+package net.sergeych.toread
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import net.sergeych.toread.fb2.Fb2Block
+import net.sergeych.toread.fb2.Fb2Book
+import net.sergeych.toread.fb2.Fb2Section
+import net.sergeych.toread.fb2.Fb2Text
+import net.sergeych.toread.fb2.Fb2TextSpan
+
+class ReadAloudContentPlanTest {
+    @Test
+    fun starBreakAddsPauseBeforeNextSpokenSentence() {
+        val plan = buildReaderContentPlan(
+            Fb2Book(
+                title = "Book",
+                sections = listOf(
+                    Fb2Section(
+                        blocks = listOf(
+                            paragraph("Before."),
+                            paragraph("* * *"),
+                            paragraph("After."),
+                        ),
+                    ),
+                ),
+            ),
+        )
+
+        assertEquals(listOf("Before.", "After."), plan.sentences.map { it.text })
+        assertEquals(0L, plan.sentences[0].pauseBeforeMillis)
+        assertEquals(1_200L, plan.sentences[1].pauseBeforeMillis)
+    }
+
+    @Test
+    fun ellipsisIsCollapsedForSpeechAndAddsShortPause() {
+        val plan = buildReaderContentPlan(
+            Fb2Book(
+                title = "Book",
+                sections = listOf(
+                    Fb2Section(blocks = listOf(paragraph("Wait... Go.. Stop… Done."))),
+                ),
+            ),
+        )
+
+        assertEquals(
+            listOf("Wait...", "Go..", "Stop…", "Done."),
+            plan.sentences.map { it.text },
+        )
+        assertEquals(
+            listOf("Wait.", "Go.", "Stop.", "Done."),
+            plan.sentences.map { it.spokenText },
+        )
+        assertEquals(listOf(350L, 350L, 350L, 0L), plan.sentences.map { it.pauseAfterMillis })
+    }
+
+    private fun paragraph(text: String): Fb2Block.Paragraph =
+        Fb2Block.Paragraph(Fb2Text(listOf(Fb2TextSpan(text))))
+}

composeApp/src/jvmMain/kotlin/net/sergeych/toread/ReadAloudPlatform.jvm.kt

@@ -7,9 +7,14 @@ actual object ReadAloudPlatform {
     actual val isSupported: Boolean = false
     private val mutableState = MutableStateFlow(ReadAloudState())
     actual val state: StateFlow<ReadAloudState> = mutableState
+    private val mutableSettingsState = MutableStateFlow(ReadAloudSettingsState())
+    actual val settingsState: StateFlow<ReadAloudSettingsState> = mutableSettingsState
 
     actual fun prepare(bookTitle: String, sentences: List<ReadAloudSentence>, startIndex: Int) = Unit
     actual fun play() = Unit
     actual fun stop() = Unit
     actual fun skip(delta: Int) = Unit
+    actual fun refreshSettings() = Unit
+    actual fun selectEngine(engineId: String?) = Unit
+    actual fun selectVoice(voiceId: String?) = Unit
 }

composeApp/src/webMain/kotlin/net/sergeych/toread/ReadAloudPlatform.web.kt

@@ -7,9 +7,14 @@ actual object ReadAloudPlatform {
     actual val isSupported: Boolean = false
     private val mutableState = MutableStateFlow(ReadAloudState())
     actual val state: StateFlow<ReadAloudState> = mutableState
+    private val mutableSettingsState = MutableStateFlow(ReadAloudSettingsState())
+    actual val settingsState: StateFlow<ReadAloudSettingsState> = mutableSettingsState
 
     actual fun prepare(bookTitle: String, sentences: List<ReadAloudSentence>, startIndex: Int) = Unit
     actual fun play() = Unit
     actual fun stop() = Unit
     actual fun skip(delta: Int) = Unit
+    actual fun refreshSettings() = Unit
+    actual fun selectEngine(engineId: String?) = Unit
+    actual fun selectVoice(voiceId: String?) = Unit
 }

docs/russian-hyphenation-rules.md

@@ -0,0 +1,181 @@
+# Russian Hyphenation Rules
+
+This document defines the rule set for the Russian hyphenation plugin. The
+implementation should return the original word with soft hyphens inserted at
+preferred transfer points. Tests may render soft hyphens as `-` for readability.
+
+The goal is not perfect dictionary hyphenation. The goal is a deterministic,
+readable rule set that avoids invalid transfers and produces better break points
+than the current vowel/consonant heuristic.
+
+## Character Classes
+
+Use lowercase character checks for classification.
+
+- Vowels: `а е ё и о у ы э ю я`
+- Consonants: Russian letters except vowels, `ь`, `ъ`, and `й`
+- Non-syllabic letters: `ь ъ`
+- Semivowel: `й`
+
+Only hyphenate words made of Russian letters. Leave mixed words, words with
+digits, existing soft hyphens, and abbreviations unchanged. Short words are
+hyphenated only when they pass the same legal side-length and vowel filters as
+longer words.
+
+## Hard Legal Filters
+
+A candidate break is illegal if any of these is true:
+
+- Either side would have fewer than 2 letters.
+- Either side would contain no vowel.
+- The right side starts with `ь`, `ъ`, `й`, or `ы`.
+- The left side ends before `ь` or `ъ`; that is, do not split `под-ъезд` or
+  `бол-ьшой`. Prefer `подъ-езд`, `боль-шой`.
+- The left side ends before `й`; that is, do not split `ма-йор` or `во-йна`.
+  Prefer `май-ор`, `вой-на`.
+- The break separates a consonant from a following vowel: reject `люб-овь`,
+  `паст-ух`, `реб-ята`. Prefer `лю-бовь`, `па-стух` or `пас-тух`, `ре-бята`
+  or `ребя-та`.
+
+## Candidate Generation
+
+Work between adjacent vowel nuclei. For each span from one vowel to the next,
+choose preferred break candidates from the consonant cluster between them.
+
+### Adjacent Vowels
+
+If two vowels are adjacent, allow a break between them when both resulting parts
+pass the legal filters.
+
+Examples:
+
+- `поэт` -> `по-эт`
+- `академия` -> `ака-де-мия` and not `а-кадемия` or `академи-я`
+
+### One Consonant Between Vowels
+
+For `V C V`, break before the consonant.
+
+Examples:
+
+- `молоко` -> `мо-ло-ко`
+- `корова` -> `ко-ро-ва`
+- `переход` -> `пе-ре-ход`
+
+### Two Consonants Between Vowels
+
+For `V C C V`, prefer a break between the consonants.
+
+Examples:
+
+- `лампа` -> `лам-па`
+- `гордый` -> `гор-дый`
+- `письмо` -> `пись-мо`
+
+If the cluster contains `й`, `ь`, or `ъ`, keep that letter on the left and break
+after it when legal.
+
+Examples:
+
+- `майор` -> `май-ор`
+- `подъезд` -> `подъ-езд`
+- `большой` -> `боль-шой`
+
+### Three Or More Consonants Between Vowels
+
+For longer clusters, prefer the latest break that still leaves a pronounceable
+left part, but keep common inseparable starts on the right:
+
+- Keep `ст`, `ск`, `сп`, `сн`, `сл`, `см`, `св` together on the right when
+  possible.
+- Keep stop/liquid pairs together on the right when possible: `бр`, `бл`,
+  `вр`, `вл`, `гр`, `гл`, `др`, `тр`, `кр`, `кл`, `пр`, `пл`, `фр`, `фл`.
+- Otherwise prefer splitting before the last consonant in the cluster.
+
+Examples:
+
+- `сестра` -> `се-стра`
+- `острый` should not use `о-стрый`, because the left side is too short
+- `родство` -> `род-ство`
+- `чувство` -> `чув-ство`
+- `предложение` -> `пред-ло-же-ние`
+
+## Double Consonants
+
+When two identical consonants stand between vowels, prefer splitting between
+them.
+
+Examples:
+
+- `масса` -> `мас-са`
+- `длинный` -> `длин-ный`
+- `касса` -> `кас-са`
+
+Do not force this rule when the double consonant starts a root after a prefix.
+Without a dictionary, this exception is hard to detect, so implementation may
+leave such words to the general cluster logic.
+
+## Prefix-Like Boundaries
+
+Without a morphology dictionary, treat these as preferred heuristics only.
+
+If a word starts with a common prefix and the following part is legal, prefer a
+break after the prefix:
+
+- `без`, `бес`, `воз`, `вос`, `вз`, `вс`, `из`, `ис`, `низ`, `нис`, `раз`,
+  `рас`, `роз`, `рос`, `от`, `об`, `объ`, `под`, `подъ`, `пред`, `пере`,
+  `при`, `про`, `над`, `сверх`, `меж`
+
+Examples:
+
+- `подбить` -> `под-бить`
+- `размах` -> `раз-мах`
+- `предложение` -> `пред-ло-же-ние`
+- `подъезд` -> `подъ-езд`
+
+Do not create a right side starting with `ы`; prefer later legal breaks.
+
+Examples:
+
+- `разыскать` -> `ра-зыскать` or `разыс-кать`, not `раз-ыскать`
+- `розыгрыш` -> `ро-зыгрыш` or `розыг-рыш`, not `роз-ыгрыш`
+
+## Ranking
+
+A word may have several legal break points. The plugin should insert all good
+breaks, but it should avoid noisy low-quality breaks. Use this ranking:
+
+1. Prefix boundary, if legal.
+2. Double consonant split between vowels.
+3. Syllable breaks from adjacent vowel and consonant-cluster rules.
+4. Longer-cluster fallback break before the last consonant.
+
+Reject candidates that are legal but awkward when a better candidate is within
+one character and both candidates divide the same vowel-to-vowel span.
+
+## Example Expectations
+
+These strings use `-` where the implementation will insert `SoftHyphen`.
+
+```text
+молоко -> мо-ло-ко
+корова -> ко-ро-ва
+яблоко -> яб-ло-ко
+повествование -> по-вест-во-ва-ние
+предложение -> пред-ло-же-ние
+компьютер -> компью-тер
+подъезд -> подъ-езд
+большой -> боль-шой
+майор -> май-ор
+масса -> мас-са
+длинный -> длин-ный
+разыскать -> ра-зыс-кать
+розыгрыш -> ро-зыг-рыш
+```
+
+## Non-Goals
+
+- Full dictionary-level hyphenation.
+- Stress-aware syllabification.
+- Exact morpheme detection for every prefix/root boundary.
+- Hyphenating proper abbreviations and mixed-script technical identifiers.

shared/src/commonMain/kotlin/net/sergeych/toread/text/Hyphenation.kt

@@ -29,22 +29,23 @@ class HyphenationRegistry(
     private fun hyphenate(text: String, plugin: HyphenationPlugin): String = buildString(text.length + text.length / 12) {
         var wordStart = -1
 
-        fun flushWord(end: Int) {
+        fun flushToken(end: Int) {
             if (wordStart >= 0) {
-                append(plugin.hyphenateWord(text.substring(wordStart, end)))
+                val token = text.substring(wordStart, end)
+                append(if (SoftHyphen !in token && token.all(Char::isLetter)) plugin.hyphenateWord(token) else token)
                 wordStart = -1
             }
         }
 
         text.forEachIndexed { index, char ->
-            if (char.isLetter()) {
+            if (char.isLetterOrDigit() || char == SoftHyphen) {
                 if (wordStart < 0) wordStart = index
             } else {
-                flushWord(index)
+                flushToken(index)
                 append(char)
             }
         }
-        flushWord(text.length)
+        flushToken(text.length)
     }
 }
 
@@ -71,18 +72,123 @@ object RussianHyphenationPlugin : HyphenationPlugin {
     override val languageTags: Set<String> = setOf("ru", "rus")
 
     override fun hyphenateWord(word: String): String {
-        if (word.length < 6 || SoftHyphen in word) return word
-        val breaks = mutableListOf<Int>()
-        for (index in 2 until word.lastIndex) {
-            val prev = word[index - 1]
-            val current = word[index]
-            val next = word[index + 1]
-            if (current.isRussianVowel() && next.isRussianConsonant()) breaks += index + 1
-            if (prev.isRussianVowel() && current.isRussianConsonant() && next.isRussianVowel()) breaks += index
+        if (SoftHyphen in word || !word.isRussianWord() || word.isLikelyAbbreviation()) return word
+
+        val lower = word.lowercase()
+        val candidates = mutableSetOf<Int>()
+        addRussianPrefixBreak(lower, candidates)
+        addRussianSyllableBreaks(lower, candidates)
+
+        return insertBreaks(word, candidates.filter { lower.isLegalRussianBreak(it) }, minPrefix = 2, minSuffix = 2)
     }
-        return insertBreaks(word, breaks, minPrefix = 2, minSuffix = 2)
+
+    private fun addRussianPrefixBreak(word: String, candidates: MutableSet<Int>) {
+        RussianPrefixes.firstOrNull { prefix -> word.startsWith(prefix) }
+            ?.length
+            ?.let(candidates::add)
+    }
+
+    private fun addRussianSyllableBreaks(word: String, candidates: MutableSet<Int>) {
+        val vowelIndexes = word.indices.filter { word[it].isRussianVowel() }
+        vowelIndexes.zipWithNext().forEach { (leftVowel, rightVowel) ->
+            val clusterStart = leftVowel + 1
+            val clusterEnd = rightVowel
+            val clusterLength = clusterEnd - clusterStart
+            when {
+                clusterLength == 0 -> candidates += rightVowel
+                clusterLength == 1 -> {
+                    val consonant = word[clusterStart]
+                    candidates += if (consonant.isRussianJoiner()) clusterStart + 1 else clusterStart
+                }
+                clusterLength == 2 -> {
+                    val joiner = (clusterStart until clusterEnd).firstOrNull { word[it].isRussianJoiner() }
+                    candidates += if (joiner != null) joiner + 1 else clusterStart + 1
+                }
+                else -> addRussianClusterBreak(word, clusterStart, clusterEnd, candidates)
             }
         }
+    }
+
+    private fun addRussianClusterBreak(
+        word: String,
+        clusterStart: Int,
+        clusterEnd: Int,
+        candidates: MutableSet<Int>,
+    ) {
+        val cluster = word.substring(clusterStart, clusterEnd)
+        val joiner = (clusterStart until clusterEnd).firstOrNull { word[it].isRussianJoiner() }
+        if (joiner != null) {
+            if (joiner < clusterEnd - 1) candidates += joiner + 1
+            return
+        }
+
+        if (cluster == "ств") {
+            candidates += clusterStart + 2
+            return
+        }
+
+        if (cluster.endsWith("ств")) {
+            candidates += clusterEnd - 3
+            return
+        }
+
+        val onsetBreak = (clusterStart until clusterEnd)
+            .firstOrNull { index -> RussianRightOnsets.any { onset -> word.startsWith(onset, index) } }
+        candidates += onsetBreak ?: (clusterEnd - 1)
+    }
+}
+
+private val RussianPrefixes = listOf(
+    "сверх",
+    "подъ",
+    "пере",
+    "пред",
+    "без",
+    "бес",
+    "воз",
+    "вос",
+    "низ",
+    "нис",
+    "раз",
+    "рас",
+    "роз",
+    "рос",
+    "под",
+    "при",
+    "про",
+    "над",
+    "меж",
+    "вз",
+    "вс",
+    "из",
+    "ис",
+    "от",
+    "об",
+)
+
+private val RussianRightOnsets = listOf(
+    "ст",
+    "ск",
+    "сп",
+    "сн",
+    "сл",
+    "см",
+    "св",
+    "бр",
+    "бл",
+    "вр",
+    "вл",
+    "гр",
+    "гл",
+    "др",
+    "тр",
+    "кр",
+    "кл",
+    "пр",
+    "пл",
+    "фр",
+    "фл",
+)
 
 const val SoftHyphen: Char = '\u00AD'
 
@@ -107,4 +213,24 @@ private fun Char.isConsonant(): Boolean = isLetter() && !isVowel()
 private fun Char.isRussianVowel(): Boolean = lowercaseChar() in "аеёиоуыэюя"
 
 private fun Char.isRussianConsonant(): Boolean =
-    lowercaseChar() in "бвгджзйклмнпрстфхцчшщ"
+    lowercaseChar() in "бвгджзклмнпрстфхцчшщ"
+
+private fun Char.isRussianJoiner(): Boolean = lowercaseChar() in "йьъ"
+
+private fun Char.isRussianLetter(): Boolean = lowercaseChar() in "абвгдеёжзийклмнопрстуфхцчшщъыьэюя"
+
+private fun String.isRussianWord(): Boolean = all(Char::isRussianLetter)
+
+private fun String.isLikelyAbbreviation(): Boolean = length > 1 && all { it.isUpperCase() }
+
+private fun String.isLegalRussianBreak(index: Int): Boolean {
+    if (index < 2 || length - index < 2) return false
+    if (take(index).none(Char::isRussianVowel) || drop(index).none(Char::isRussianVowel)) return false
+
+    val left = this[index - 1]
+    val right = this[index]
+    if (right.lowercaseChar() in "ьъйы") return false
+    if (right.isRussianJoiner()) return false
+    if (left.isRussianConsonant() && right.isRussianVowel()) return false
+    return true
+}

shared/src/commonTest/kotlin/net/sergeych/toread/text/HyphenationTest.kt

@@ -1,13 +1,16 @@
 package net.sergeych.toread.text
 
 import kotlin.test.Test
+import kotlin.test.assertEquals
 import kotlin.test.assertNotEquals
 import kotlin.test.assertTrue
 
 class HyphenationTest {
+    private val hyphenation = HyphenationRegistry()
+
     @Test
     fun selectsEnglishPluginByLanguage() {
-        val hyphenated = HyphenationRegistry().hyphenate("composition", "en")
+        val hyphenated = hyphenation.hyphenate("composition", "en")
 
         assertNotEquals("composition", hyphenated)
         assertTrue(SoftHyphen in hyphenated)
@@ -15,9 +18,41 @@ class HyphenationTest {
 
     @Test
     fun selectsRussianPluginByLanguage() {
-        val hyphenated = HyphenationRegistry().hyphenate("повествование", "ru")
+        val hyphenated = hyphenation.hyphenate("повествование", "ru")
 
         assertNotEquals("повествование", hyphenated)
         assertTrue(SoftHyphen in hyphenated)
     }
+
+    @Test
+    fun suggestsRussianHyphensAtReadableBreaks() {
+        mapOf(
+            "молоко" to "мо-ло-ко",
+            "корова" to "ко-ро-ва",
+            "яблоко" to "яб-ло-ко",
+            "повествование" to "по-вест-во-ва-ние",
+            "предложение" to "пред-ло-же-ние",
+            "компьютер" to "компью-тер",
+            "подъезд" to "подъ-езд",
+            "большой" to "боль-шой",
+            "майор" to "май-ор",
+            "масса" to "мас-са",
+            "длинный" to "длин-ный",
+            "разыскать" to "ра-зыс-кать",
+            "розыгрыш" to "ро-зыг-рыш",
+        ).forEach { (word, expected) ->
+            assertEquals(expected, word.hyphenatedRu())
+        }
+    }
+
+    @Test
+    fun keepsRussianWordsWithoutLegalReadableBreaksUnchanged() {
+        listOf("дом", "мир", "стол", "семья", "СССР", "testовый", "книга123").forEach { word ->
+            assertEquals(word, word.hyphenatedRu())
+        }
+        assertEquals("ко-рова", "ко${SoftHyphen}рова".hyphenatedRu())
+    }
+
+    private fun String.hyphenatedRu(): String =
+        hyphenation.hyphenate(this, "ru").replace(SoftHyphen, '-')
 }