🚀 Highlight words option

* Highlights the beginning of each word
* May help some people read faster|understand more
* Thickness option to change highlighting strength

Resolves: #109

app/src/main/java/ua/acclorite/book_story/domain/reader/ReaderTextAlignment.kt

@@ -1,7 +1,14 @@
 package ua.acclorite.book_story.domain.reader
 
-enum class ReaderTextAlignment {
-    START, JUSTIFY, CENTER, END
+import androidx.compose.runtime.Immutable
+import androidx.compose.ui.text.style.TextAlign
+
+@Immutable
+enum class ReaderTextAlignment(val textAlignment: TextAlign) {
+    START(TextAlign.Start),
+    JUSTIFY(TextAlign.Justify),
+    CENTER(TextAlign.Center),
+    END(TextAlign.End)
 }
 
 fun String.toTextAlignment(): ReaderTextAlignment {

app/src/main/java/ua/acclorite/book_story/presentation/core/components/common/HighlightedText.kt

@@ -0,0 +1,88 @@
+package ua.acclorite.book_story.presentation.core.components.common
+
+import androidx.compose.foundation.text.BasicText
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.text.withStyle
+import kotlin.math.roundToInt
+
+@Composable
+fun HighlightedText(
+    modifier: Modifier = Modifier,
+    text: AnnotatedString,
+    highlightThickness: FontWeight,
+    style: TextStyle
+) {
+    val highlightedText = remember(text, highlightThickness) {
+        buildAnnotatedString {
+            text.splitAnnotatedString().forEach { word ->
+                if (word.text.none { it.isLetter() }) {
+                    append(word)
+                    append(" ")
+                    return@forEach
+                }
+
+                val textWord = word.text.filterDigitsAtStartAndEnd()
+                val digitsAtStart = word.text.digitsAtStart()
+                val focusArea = when (textWord.length) {
+                    in 1..3 -> 1
+                    4 -> 2
+                    else -> (textWord.length * 0.5f).roundToInt()
+                } + digitsAtStart
+
+                if (digitsAtStart > 0) {
+                    append(word.subSequence(0, digitsAtStart))
+                }
+
+                withStyle(style = SpanStyle(fontWeight = highlightThickness)) {
+                    append(word.subSequence(digitsAtStart, focusArea))
+                }
+
+                append(word.subSequence(focusArea, word.text.length))
+                append(" ")
+            }
+        }
+    }
+
+    BasicText(
+        text = highlightedText,
+        modifier = modifier,
+        style = style,
+        overflow = TextOverflow.Ellipsis
+    )
+}
+
+private fun String.digitsAtStart(): Int {
+    var count = 0
+    for (char in this) {
+        if (!char.isLetter()) count++
+        else break
+    }
+    return count
+}
+
+private fun String.filterDigitsAtStartAndEnd(): String {
+    return dropWhile { !it.isLetter() }.dropLastWhile { !it.isLetter() }
+}
+
+private fun AnnotatedString.splitAnnotatedString(): List<AnnotatedString> {
+    val result = mutableListOf<AnnotatedString>()
+
+    val wordRegex = Regex("\\S+")
+    wordRegex.findAll(this).forEach { matchResult ->
+        val wordStart = matchResult.range.first
+        val wordEnd = matchResult.range.last + 1
+
+        val word = subSequence(wordStart, wordEnd)
+        result.add(word)
+    }
+
+    return result
+}

app/src/main/java/ua/acclorite/book_story/presentation/core/constants/DataStoreConstants.kt

@@ -45,6 +45,8 @@ object DataStoreConstants {
     val HORIZONTAL_GESTURE_SCROLL = doublePreferencesKey("horizontal_gesture_scroll")
     val HORIZONTAL_GESTURE_SENSITIVITY = doublePreferencesKey("horizontal_gesture_sensitivity")
     val BOTTOM_BAR_PADDING = intPreferencesKey("bottom_bar_padding")
+    val HIGHLIGHTED_READING = booleanPreferencesKey("highlighted_reading")
+    val HIGHLIGHTED_READING_THICKNESS = intPreferencesKey("highlighted_reading_thickness")
 
     // Browse settings
     val BROWSE_FILES_STRUCTURE = stringPreferencesKey("browse_files_structure")

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderContent.kt

@@ -4,9 +4,11 @@ import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
 import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.TextUnit
 import ua.acclorite.book_story.domain.library.book.Book
@@ -46,6 +48,8 @@ fun ReaderContent(
     horizontalGesture: ReaderHorizontalGesture,
     horizontalGestureScroll: Float,
     horizontalGestureSensitivity: Dp,
+    highlightedReading: Boolean,
+    highlightedReadingThickness: FontWeight,
     paragraphHeight: Dp,
     sidePadding: Dp,
     bottomBarPadding: Dp,
@@ -55,6 +59,7 @@ fun ReaderContent(
     lineHeight: TextUnit,
     fontStyle: FontStyle,
     textAlignment: ReaderTextAlignment,
+    horizontalAlignment: Alignment.Horizontal,
     fontSize: TextUnit,
     letterSpacing: TextUnit,
     paragraphIndentation: TextUnit,
@@ -107,6 +112,8 @@ fun ReaderContent(
         horizontalGesture = horizontalGesture,
         horizontalGestureScroll = horizontalGestureScroll,
         horizontalGestureSensitivity = horizontalGestureSensitivity,
+        highlightedReading = highlightedReading,
+        highlightedReadingThickness = highlightedReadingThickness,
         paragraphHeight = paragraphHeight,
         sidePadding = sidePadding,
         bottomBarPadding = bottomBarPadding,
@@ -116,6 +123,7 @@ fun ReaderContent(
         lineHeight = lineHeight,
         fontStyle = fontStyle,
         textAlignment = textAlignment,
+        horizontalAlignment = horizontalAlignment,
         fontSize = fontSize,
         letterSpacing = letterSpacing,
         paragraphIndentation = paragraphIndentation,

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderLayout.kt

@@ -12,9 +12,11 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.TextUnit
 import androidx.compose.ui.unit.coerceAtLeast
@@ -40,6 +42,8 @@ fun ReaderLayout(
     horizontalGesture: ReaderHorizontalGesture,
     horizontalGestureScroll: Float,
     horizontalGestureSensitivity: Dp,
+    highlightedReading: Boolean,
+    highlightedReadingThickness: FontWeight,
     paragraphHeight: Dp,
     sidePadding: Dp,
     backgroundColor: Color,
@@ -48,6 +52,7 @@ fun ReaderLayout(
     lineHeight: TextUnit,
     fontStyle: FontStyle,
     textAlignment: ReaderTextAlignment,
+    horizontalAlignment: Alignment.Horizontal,
     fontSize: TextUnit,
     letterSpacing: TextUnit,
     paragraphIndentation: TextUnit,
@@ -156,12 +161,15 @@ fun ReaderLayout(
                     lineHeight = lineHeight,
                     fontStyle = fontStyle,
                     textAlignment = textAlignment,
+                    horizontalAlignment = horizontalAlignment,
                     fontSize = fontSize,
                     letterSpacing = letterSpacing,
                     sidePadding = sidePadding,
                     paragraphIndentation = paragraphIndentation,
                     fullscreenMode = fullscreenMode,
                     doubleClickTranslation = doubleClickTranslation,
+                    highlightedReading = highlightedReading,
+                    highlightedReadingThickness = highlightedReadingThickness,
                     toolbarHidden = toolbarHidden,
                     openTranslator = openTranslator,
                     menuVisibility = menuVisibility

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderLayoutText.kt

@@ -3,8 +3,10 @@ package ua.acclorite.book_story.presentation.reader
 import androidx.activity.ComponentActivity
 import androidx.compose.foundation.lazy.LazyItemScope
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.TextUnit
 import ua.acclorite.book_story.domain.reader.FontWithName
@@ -22,12 +24,15 @@ fun LazyItemScope.ReaderLayoutText(
     lineHeight: TextUnit,
     fontStyle: FontStyle,
     textAlignment: ReaderTextAlignment,
+    horizontalAlignment: Alignment.Horizontal,
     fontSize: TextUnit,
     letterSpacing: TextUnit,
     sidePadding: Dp,
     paragraphIndentation: TextUnit,
     fullscreenMode: Boolean,
     doubleClickTranslation: Boolean,
+    highlightedReading: Boolean,
+    highlightedReadingThickness: FontWeight,
     toolbarHidden: Boolean,
     openTranslator: (ReaderEvent.OnOpenTranslator) -> Unit,
     menuVisibility: (ReaderEvent.OnMenuVisibility) -> Unit
@@ -44,7 +49,9 @@ fun LazyItemScope.ReaderLayoutText(
             ReaderLayoutTextChapter(
                 chapter = textEntry,
                 fontColor = fontColor,
-                sidePadding = sidePadding
+                sidePadding = sidePadding,
+                highlightedReading = highlightedReading,
+                highlightedReadingThickness = highlightedReadingThickness
             )
         }
 
@@ -58,12 +65,15 @@ fun LazyItemScope.ReaderLayoutText(
                 lineHeight = lineHeight,
                 fontStyle = fontStyle,
                 textAlignment = textAlignment,
+                horizontalAlignment = horizontalAlignment,
                 fontSize = fontSize,
                 letterSpacing = letterSpacing,
                 sidePadding = sidePadding,
                 paragraphIndentation = paragraphIndentation,
                 fullscreenMode = fullscreenMode,
                 doubleClickTranslation = doubleClickTranslation,
+                highlightedReading = highlightedReading,
+                highlightedReadingThickness = highlightedReadingThickness,
                 toolbarHidden = toolbarHidden,
                 openTranslator = openTranslator,
                 menuVisibility = menuVisibility

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderLayoutTextChapter.kt

@@ -7,25 +7,45 @@ import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 import ua.acclorite.book_story.domain.reader.ReaderText.Chapter
+import ua.acclorite.book_story.presentation.core.components.common.HighlightedText
 
 @Composable
 fun ReaderLayoutTextChapter(
     chapter: Chapter,
     fontColor: Color,
-    sidePadding: Dp
+    sidePadding: Dp,
+    highlightedReading: Boolean,
+    highlightedReadingThickness: FontWeight
 ) {
     Spacer(modifier = Modifier.height(22.dp))
-    Text(
-        text = chapter.title,
-        style = MaterialTheme.typography.headlineMedium,
-        color = fontColor,
-        modifier = Modifier.padding(horizontal = sidePadding)
-    )
+    if (highlightedReading) {
+        HighlightedText(
+            text = rememberSaveable(saver = AnnotatedString.Saver) {
+                buildAnnotatedString { append(chapter.title) }
+            },
+            highlightThickness = highlightedReadingThickness,
+            style = MaterialTheme.typography.headlineMedium.copy(
+                color = fontColor
+            ),
+            modifier = Modifier.padding(horizontal = sidePadding)
+        )
+    } else {
+        Text(
+            text = chapter.title,
+            style = MaterialTheme.typography.headlineMedium,
+            color = fontColor,
+            modifier = Modifier.padding(horizontal = sidePadding)
+        )
+    }
     Spacer(modifier = Modifier.height(16.dp))
     HorizontalDivider(color = fontColor.copy(0.4f))
     Spacer(modifier = Modifier.height(16.dp))

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderLayoutTextParagraph.kt

@@ -13,14 +13,16 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontSynthesis
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.LineBreak
-import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextIndent
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.TextUnit
 import ua.acclorite.book_story.domain.reader.FontWithName
 import ua.acclorite.book_story.domain.reader.ReaderText.Text
 import ua.acclorite.book_story.domain.reader.ReaderTextAlignment
+import ua.acclorite.book_story.presentation.core.components.common.HighlightedText
 import ua.acclorite.book_story.presentation.core.util.noRippleClickable
 import ua.acclorite.book_story.ui.reader.ReaderEvent
 
@@ -34,12 +36,15 @@ fun LazyItemScope.ReaderLayoutTextParagraph(
     lineHeight: TextUnit,
     fontStyle: FontStyle,
     textAlignment: ReaderTextAlignment,
+    horizontalAlignment: Alignment.Horizontal,
     fontSize: TextUnit,
     letterSpacing: TextUnit,
     sidePadding: Dp,
     paragraphIndentation: TextUnit,
     fullscreenMode: Boolean,
     doubleClickTranslation: Boolean,
+    highlightedReading: Boolean,
+    highlightedReadingThickness: FontWeight,
     toolbarHidden: Boolean,
     openTranslator: (ReaderEvent.OnOpenTranslator) -> Unit,
     menuVisibility: (ReaderEvent.OnMenuVisibility) -> Unit
@@ -50,55 +55,90 @@ fun LazyItemScope.ReaderLayoutTextParagraph(
             .fillMaxWidth()
             .padding(horizontal = sidePadding),
         verticalArrangement = Arrangement.Center,
-        horizontalAlignment = when (textAlignment) {
-            ReaderTextAlignment.START, ReaderTextAlignment.JUSTIFY -> Alignment.Start
-            ReaderTextAlignment.CENTER -> Alignment.CenterHorizontally
-            ReaderTextAlignment.END -> Alignment.End
-        }
+        horizontalAlignment = horizontalAlignment
     ) {
-        BasicText(
-            text = paragraph.line,
-            modifier = Modifier.then(
-                if (doubleClickTranslation && toolbarHidden) {
-                    Modifier.noRippleClickable(
-                        onDoubleClick = {
-                            openTranslator(
-                                ReaderEvent.OnOpenTranslator(
-                                    textToTranslate = paragraph.line.text,
-                                    translateWholeParagraph = true,
-                                    activity = activity
+        if (highlightedReading) {
+            HighlightedText(
+                text = paragraph.line,
+                highlightThickness = highlightedReadingThickness,
+                modifier = Modifier.then(
+                    if (doubleClickTranslation && toolbarHidden) {
+                        Modifier.noRippleClickable(
+                            onDoubleClick = {
+                                openTranslator(
+                                    ReaderEvent.OnOpenTranslator(
+                                        textToTranslate = paragraph.line.text,
+                                        translateWholeParagraph = true,
+                                        activity = activity
+                                    )
                                 )
-                            )
-                        },
-                        onClick = {
-                            menuVisibility(
-                                ReaderEvent.OnMenuVisibility(
-                                    show = !showMenu,
-                                    fullscreenMode = fullscreenMode,
-                                    saveCheckpoint = true,
-                                    activity = activity
+                            },
+                            onClick = {
+                                menuVisibility(
+                                    ReaderEvent.OnMenuVisibility(
+                                        show = !showMenu,
+                                        fullscreenMode = fullscreenMode,
+                                        saveCheckpoint = true,
+                                        activity = activity
+                                    )
                                 )
-                            )
-                        }
-                    )
-                } else Modifier
-            ),
-            style = TextStyle(
-                fontFamily = fontFamily.font,
-                textAlign = when (textAlignment) {
-                    ReaderTextAlignment.START -> TextAlign.Start
-                    ReaderTextAlignment.JUSTIFY -> TextAlign.Justify
-                    ReaderTextAlignment.CENTER -> TextAlign.Center
-                    ReaderTextAlignment.END -> TextAlign.End
-                },
-                textIndent = TextIndent(firstLine = paragraphIndentation),
-                fontStyle = fontStyle,
-                letterSpacing = letterSpacing,
-                fontSize = fontSize,
-                lineHeight = lineHeight,
-                color = fontColor,
-                lineBreak = LineBreak.Paragraph
+                            }
+                        )
+                    } else Modifier
+                ),
+                style = TextStyle(
+                    fontFamily = fontFamily.font,
+                    fontSynthesis = FontSynthesis.All,
+                    textAlign = textAlignment.textAlignment,
+                    textIndent = TextIndent(firstLine = paragraphIndentation),
+                    fontStyle = fontStyle,
+                    letterSpacing = letterSpacing,
+                    fontSize = fontSize,
+                    lineHeight = lineHeight,
+                    color = fontColor,
+                    lineBreak = LineBreak.Paragraph
+                )
             )
-        )
+        } else {
+            BasicText(
+                text = paragraph.line,
+                modifier = Modifier.then(
+                    if (doubleClickTranslation && toolbarHidden) {
+                        Modifier.noRippleClickable(
+                            onDoubleClick = {
+                                openTranslator(
+                                    ReaderEvent.OnOpenTranslator(
+                                        textToTranslate = paragraph.line.text,
+                                        translateWholeParagraph = true,
+                                        activity = activity
+                                    )
+                                )
+                            },
+                            onClick = {
+                                menuVisibility(
+                                    ReaderEvent.OnMenuVisibility(
+                                        show = !showMenu,
+                                        fullscreenMode = fullscreenMode,
+                                        saveCheckpoint = true,
+                                        activity = activity
+                                    )
+                                )
+                            }
+                        )
+                    } else Modifier
+                ),
+                style = TextStyle(
+                    fontFamily = fontFamily.font,
+                    textAlign = textAlignment.textAlignment,
+                    textIndent = TextIndent(firstLine = paragraphIndentation),
+                    fontStyle = fontStyle,
+                    letterSpacing = letterSpacing,
+                    fontSize = fontSize,
+                    lineHeight = lineHeight,
+                    color = fontColor,
+                    lineBreak = LineBreak.Paragraph
+                )
+            )
+        }
     }
 }

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderScaffold.kt

@@ -10,11 +10,13 @@ import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.TextUnit
 import ua.acclorite.book_story.domain.library.book.Book
@@ -52,6 +54,8 @@ fun ReaderScaffold(
     horizontalGesture: ReaderHorizontalGesture,
     horizontalGestureScroll: Float,
     horizontalGestureSensitivity: Dp,
+    highlightedReading: Boolean,
+    highlightedReadingThickness: FontWeight,
     paragraphHeight: Dp,
     sidePadding: Dp,
     bottomBarPadding: Dp,
@@ -61,6 +65,7 @@ fun ReaderScaffold(
     lineHeight: TextUnit,
     fontStyle: FontStyle,
     textAlignment: ReaderTextAlignment,
+    horizontalAlignment: Alignment.Horizontal,
     fontSize: TextUnit,
     letterSpacing: TextUnit,
     paragraphIndentation: TextUnit,
@@ -141,6 +146,8 @@ fun ReaderScaffold(
             horizontalGesture = horizontalGesture,
             horizontalGestureScroll = horizontalGestureScroll,
             horizontalGestureSensitivity = horizontalGestureSensitivity,
+            highlightedReading = highlightedReading,
+            highlightedReadingThickness = highlightedReadingThickness,
             paragraphHeight = paragraphHeight,
             sidePadding = sidePadding,
             backgroundColor = backgroundColor,
@@ -149,6 +156,7 @@ fun ReaderScaffold(
             lineHeight = lineHeight,
             fontStyle = fontStyle,
             textAlignment = textAlignment,
+            horizontalAlignment = horizontalAlignment,
             fontSize = fontSize,
             letterSpacing = letterSpacing,
             paragraphIndentation = paragraphIndentation,

app/src/main/java/ua/acclorite/book_story/presentation/settings/reader/reading_speed/ReadingSpeedSubcategory.kt

@@ -9,6 +9,8 @@ import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.stringResource
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.presentation.settings.components.SettingsSubcategory
+import ua.acclorite.book_story.presentation.settings.reader.reading_speed.components.HighlightedReadingOption
+import ua.acclorite.book_story.presentation.settings.reader.reading_speed.components.HighlightedReadingThicknessOption
 import ua.acclorite.book_story.presentation.settings.reader.reading_speed.components.PerceptionExpanderOption
 import ua.acclorite.book_story.presentation.settings.reader.reading_speed.components.PerceptionExpanderPaddingOption
 import ua.acclorite.book_story.presentation.settings.reader.reading_speed.components.PerceptionExpanderThicknessOption
@@ -25,6 +27,14 @@ fun LazyListScope.ReadingSpeedSubcategory(
         showTitle = showTitle,
         showDivider = showDivider
     ) {
+        item {
+            HighlightedReadingOption()
+        }
+
+        item {
+            HighlightedReadingThicknessOption()
+        }
+
         item {
             PerceptionExpanderOption()
         }

app/src/main/java/ua/acclorite/book_story/presentation/settings/reader/reading_speed/components/HighlightedReadingOption.kt

@@ -0,0 +1,29 @@
+package ua.acclorite.book_story.presentation.settings.reader.reading_speed.components
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import ua.acclorite.book_story.R
+import ua.acclorite.book_story.presentation.core.components.settings.SwitchWithTitle
+import ua.acclorite.book_story.ui.main.MainEvent
+import ua.acclorite.book_story.ui.main.MainModel
+
+@Composable
+fun HighlightedReadingOption() {
+    val mainModel = hiltViewModel<MainModel>()
+    val state = mainModel.state.collectAsStateWithLifecycle()
+
+    SwitchWithTitle(
+        selected = state.value.highlightedReading,
+        title = stringResource(id = R.string.highlighted_reading_option),
+        description = stringResource(id = R.string.highlighted_reading_option_desc),
+        onClick = {
+            mainModel.onEvent(
+                MainEvent.OnChangeHighlightedReading(
+                    !state.value.highlightedReading
+                )
+            )
+        }
+    )
+}

app/src/main/java/ua/acclorite/book_story/presentation/settings/reader/reading_speed/components/HighlightedReadingThicknessOption.kt

@@ -0,0 +1,31 @@
+package ua.acclorite.book_story.presentation.settings.reader.reading_speed.components
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import ua.acclorite.book_story.R
+import ua.acclorite.book_story.presentation.core.components.settings.SliderWithTitle
+import ua.acclorite.book_story.ui.main.MainEvent
+import ua.acclorite.book_story.ui.main.MainModel
+import ua.acclorite.book_story.ui.theme.ExpandingTransition
+
+@Composable
+fun HighlightedReadingThicknessOption() {
+    val mainModel = hiltViewModel<MainModel>()
+    val state = mainModel.state.collectAsStateWithLifecycle()
+
+    ExpandingTransition(visible = state.value.highlightedReading) {
+        SliderWithTitle(
+            value = state.value.highlightedReadingThickness to "pt",
+            fromValue = 1,
+            toValue = 5,
+            title = stringResource(id = R.string.highlighted_reading_thickness_option),
+            onValueChange = {
+                mainModel.onEvent(
+                    MainEvent.OnChangeHighlightedReadingThickness(it)
+                )
+            }
+        )
+    }
+}

app/src/main/java/ua/acclorite/book_story/ui/main/MainEvent.kt

@@ -47,4 +47,6 @@ sealed class MainEvent {
     data class OnChangeHorizontalGestureScroll(val value: Float) : MainEvent()
     data class OnChangeHorizontalGestureSensitivity(val value: Float) : MainEvent()
     data class OnChangeBottomBarPadding(val value: Int) : MainEvent()
+    data class OnChangeHighlightedReading(val value: Boolean) : MainEvent()
+    data class OnChangeHighlightedReadingThickness(val value: Int) : MainEvent()
 }

app/src/main/java/ua/acclorite/book_story/ui/main/MainModel.kt

@@ -398,6 +398,22 @@ class MainModel @Inject constructor(
                     it.copy(bottomBarPadding = this)
                 }
             )
+
+            is MainEvent.OnChangeHighlightedReading -> handleDatastoreUpdate(
+                key = DataStoreConstants.HIGHLIGHTED_READING,
+                value = event.value,
+                updateState = {
+                    it.copy(highlightedReading = this)
+                }
+            )
+
+            is MainEvent.OnChangeHighlightedReadingThickness -> handleDatastoreUpdate(
+                key = DataStoreConstants.HIGHLIGHTED_READING_THICKNESS,
+                value = event.value,
+                updateState = {
+                    it.copy(highlightedReadingThickness = this)
+                }
+            )
         }
     }
 

app/src/main/java/ua/acclorite/book_story/ui/main/MainState.kt

@@ -90,6 +90,8 @@ data class MainState(
     val horizontalGestureScroll: Float = provideDefaultValue { 0.7f },
     val horizontalGestureSensitivity: Float = provideDefaultValue { 0.6f },
     val bottomBarPadding: Int = provideDefaultValue { 0 },
+    val highlightedReading: Boolean = provideDefaultValue { false },
+    val highlightedReadingThickness: Int = provideDefaultValue { 3 },
 
     // Browse Settings
     val browseFilesStructure: BrowseFilesStructure = provideDefaultValue {
@@ -295,6 +297,14 @@ data class MainState(
                     bottomBarPadding = provideValue(
                         BOTTOM_BAR_PADDING
                     ) { bottomBarPadding },
+
+                    highlightedReading = provideValue(
+                        HIGHLIGHTED_READING
+                    ) { highlightedReading },
+
+                    highlightedReadingThickness = provideValue(
+                        HIGHLIGHTED_READING_THICKNESS
+                    ) { highlightedReadingThickness },
                 )
             }
         }

app/src/main/java/ua/acclorite/book_story/ui/reader/ReaderScreen.kt

@@ -19,12 +19,14 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.em
 import androidx.compose.ui.unit.sp
@@ -162,6 +164,22 @@ data class ReaderScreen(val bookId: Int) : Screen, Parcelable {
         val horizontalGestureSensitivity = remember(mainState.value.horizontalGestureSensitivity) {
             (36f + mainState.value.horizontalGestureSensitivity * (4f - 36f)).dp
         }
+        val highlightedReadingThickness = remember(mainState.value.highlightedReadingThickness) {
+            when (mainState.value.highlightedReadingThickness) {
+                2 -> FontWeight.W600
+                3 -> FontWeight.W700
+                4 -> FontWeight.W800
+                5 -> FontWeight.W900
+                else -> FontWeight.W500
+            }
+        }
+        val horizontalAlignment = remember(mainState.value.textAlignment) {
+            when (mainState.value.textAlignment) {
+                ReaderTextAlignment.START, ReaderTextAlignment.JUSTIFY -> Alignment.Start
+                ReaderTextAlignment.CENTER -> Alignment.CenterHorizontally
+                ReaderTextAlignment.END -> Alignment.End
+            }
+        }
 
         val density = LocalDensity.current
         val layoutDirection = LocalLayoutDirection.current
@@ -309,6 +327,8 @@ data class ReaderScreen(val bookId: Int) : Screen, Parcelable {
             horizontalGesture = mainState.value.horizontalGesture,
             horizontalGestureScroll = mainState.value.horizontalGestureScroll,
             horizontalGestureSensitivity = horizontalGestureSensitivity,
+            highlightedReading = mainState.value.highlightedReading,
+            highlightedReadingThickness = highlightedReadingThickness,
             paragraphHeight = paragraphHeight,
             sidePadding = sidePadding,
             bottomBarPadding = bottomBarPadding,
@@ -318,6 +338,7 @@ data class ReaderScreen(val bookId: Int) : Screen, Parcelable {
             lineHeight = lineHeight,
             fontStyle = fontStyle,
             textAlignment = mainState.value.textAlignment,
+            horizontalAlignment = horizontalAlignment,
             fontSize = mainState.value.fontSize.sp,
             letterSpacing = letterSpacing,
             paragraphIndentation = paragraphIndentation,

app/src/main/res/values-uk/strings.xml

@@ -191,6 +191,9 @@
     <string name="horizontal_gesture_scroll_option">Частка прокрутки</string>
     <string name="horizontal_gesture_sensitivity_option">Чутливість</string>
     <string name="bottom_bar_padding_option">Відступ нижньої панелі</string>
+    <string name="highlighted_reading_option">Підсвічування слів</string>
+    <string name="highlighted_reading_option_desc">Підсвічувати початок кожного слова</string>
+    <string name="highlighted_reading_thickness_option">Товщина підсвічування</string>
 
     <!-- Browse -->
     <string name="browse_files_structure_option">Структура файлів</string>

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

@@ -246,6 +246,9 @@
     <string name="horizontal_gesture_scroll_option">Scroll fraction</string>
     <string name="horizontal_gesture_sensitivity_option">Sensitivity</string>
     <string name="bottom_bar_padding_option">Bottom bar margin</string>
+    <string name="highlighted_reading_option">Highlight words</string>
+    <string name="highlighted_reading_option_desc">Highlight the beginning of each word</string>
+    <string name="highlighted_reading_thickness_option">Highlight thickness</string>
 
     <!-- Browse -->
     <string name="browse_files_structure_option">Files structure</string>