🚀 Nested Chapters in Reader

* Fixed issue with incorrect navigation
* Added Nested Chapters, e.g. Book -> Chapter

Resolves: #130

app/src/main/java/ua/acclorite/book_story/data/parser/DocumentParser.kt

@@ -164,7 +164,8 @@ class DocumentParser @Inject constructor(
                         ) {
                             readerText.add(
                                 0, ReaderText.Chapter(
-                                    title = formattedLine.clearAllMarkdown()
+                                    title = formattedLine.clearAllMarkdown(),
+                                    nested = false
                                 )
                             )
                             chapterAdded = true

app/src/main/java/ua/acclorite/book_story/data/parser/epub/EpubTextParser.kt

@@ -32,7 +32,7 @@ import javax.inject.Inject
 import kotlin.collections.set
 
 private const val EPUB_TAG = "EPUB Parser"
-private typealias Title = String
+private typealias Source = String
 
 private val dispatcher = Dispatchers.IO.limitedParallelism(3)
 
@@ -108,7 +108,7 @@ class EpubTextParser @Inject constructor(
     private suspend fun ZipFile.parseEpub(
         chapterEntries: List<ZipEntry>,
         imageEntries: List<ZipEntry>,
-        chapterTitleEntries: Map<Title, List<String>>?
+        chapterTitleEntries: Map<Source, ReaderText.Chapter>?
     ): List<ReaderText> {
 
         val readerText = mutableListOf<ReaderText>()
@@ -159,7 +159,7 @@ class EpubTextParser @Inject constructor(
         index: Int,
         entry: ZipEntry,
         imageEntries: List<ZipEntry>,
-        chapterTitleMap: Map<Title, List<String>>?
+        chapterTitleMap: Map<Source, ReaderText.Chapter>?
     ) {
         // Getting all text
         val content = zip.getInputStream(entry).bufferedReader().use { it.readText() }
@@ -176,22 +176,24 @@ class EpubTextParser @Inject constructor(
             chapterSource = entry.name,
             chapterTitleMap = chapterTitleMap
         ).apply {
-            val chapterTitle = this ?: run {
+            val chapter = this ?: run {
                 val firstVisibleText = readerText.firstOrNull { line ->
                     line is ReaderText.Text && line.line.text.containsVisibleText()
                 } as? ReaderText.Text ?: return
-                firstVisibleText.line.text
+
+                return@run ReaderText.Chapter(
+                    title = firstVisibleText.line.text,
+                    nested = false
+                )
             }
 
             readerText = readerText.dropWhile { line ->
-                (line is ReaderText.Text && line.line.text.lowercase() == chapterTitle.lowercase())
+                (line is ReaderText.Text && line.line.text.lowercase() == chapter.title.lowercase())
             }.toMutableList()
 
             readerText.add(
                 0,
-                ReaderText.Chapter(
+                chapter
-                    title = chapterTitle
-                )
             )
         }
 
@@ -213,7 +215,7 @@ class EpubTextParser @Inject constructor(
      */
     private suspend fun ZipFile.getChapterTitleMapFromToc(
         tocEntry: ZipEntry?
-    ): Map<Title, List<String>>? {
+    ): Map<Source, ReaderText.Chapter>? {
         val tocContent = tocEntry?.let {
             withContext(Dispatchers.IO) {
                 getInputStream(it)
@@ -222,18 +224,43 @@ class EpubTextParser @Inject constructor(
         val tocDocument = tocContent?.let { Jsoup.parse(it) }
 
         if (tocDocument == null) return null
-        var titleMap = mutableMapOf<Title, List<String>>()
+        var titleMap = mutableMapOf<Source, ReaderText.Chapter>()
 
         tocDocument.select("navPoint").forEach { navPoint ->
-            val title = navPoint.selectFirst("navLabel > text")?.text()?.trim()
+            val title = navPoint.selectFirst("navLabel > text")?.text()
-                ?: return@forEach
+                .let { title ->
+                    if (title.isNullOrBlank()) return@forEach
+                    title.trim()
+                }
+
             val source = navPoint.selectFirst("content")?.attr("src")?.trim()
-                .let {
+                .let { source ->
-                    if (it == null) return@forEach
+                    if (source.isNullOrBlank()) return@forEach
-                    Uri.parse(it).path ?: it
+                    Uri.parse(source).path ?: source
                 }.substringAfterLast(File.separator)
 
-            titleMap[source] = (titleMap[source] ?: emptyList()) + title
+            val parent = navPoint.parent()
+                .let { parent ->
+                    if (parent == null) return@let null
+                    if (!parent.tagName().equals("navPoint", ignoreCase = true)) return@let null
+
+                    val parentSource = parent.selectFirst("content")?.attr("src")?.trim()
+                        .let { parentSource ->
+                            if (parentSource.isNullOrBlank()) return@forEach
+                            Uri.parse(parentSource).path ?: parentSource
+                        }.substringAfterLast(File.separator)
+                    if (parentSource == source) return@let null
+                    return@let parentSource
+                }
+
+            val chapter = ReaderText.Chapter(
+                title = titleMap[source]?.title.run {
+                    if (this == null) return@run title
+                    return@run "$this / $title"
+                },
+                nested = titleMap[source]?.nested ?: (parent != null)
+            )
+            titleMap[source] = chapter
         }
 
         return titleMap
@@ -246,14 +273,12 @@ class EpubTextParser @Inject constructor(
      */
     private fun getChapterTitleFromToc(
         chapterSource: String,
-        chapterTitleMap: Map<String, List<String>>?
+        chapterTitleMap: Map<Source, ReaderText.Chapter>?
-    ): String? {
+    ): ReaderText.Chapter? {
         if (chapterTitleMap.isNullOrEmpty()) return null
-        return chapterTitleMap
+        return chapterTitleMap.getOrElse(chapterSource.substringAfterLast(File.separator)) {
-            .getOrElse(chapterSource.substringAfterLast(File.separator)) { null }
+            null
-            ?.joinToString(separator = " / ")
+        }
-            ?.ifBlank { null }
-            ?.trim()
     }
 
     /**

app/src/main/java/ua/acclorite/book_story/data/parser/fb2/Fb2TextParser.kt

@@ -125,7 +125,8 @@ class Fb2TextParser @Inject constructor(
                             if (!chapterAdded && line.clearAllMarkdown().isNotBlank()) {
                                 readerText.add(
                                     0, ReaderText.Chapter(
-                                        title = line.clearAllMarkdown()
+                                        title = line.clearAllMarkdown(),
+                                        nested = false
                                     )
                                 )
                                 chapterAdded = true

app/src/main/java/ua/acclorite/book_story/data/parser/pdf/PdfTextParser.kt

@@ -128,7 +128,8 @@ class PdfTextParser @Inject constructor(
                             if (!chapterAdded && line.clearAllMarkdown().isNotBlank()) {
                                 readerText.add(
                                     0, ReaderText.Chapter(
-                                        title = line.clearAllMarkdown()
+                                        title = line.clearAllMarkdown(),
+                                        nested = false
                                     )
                                 )
                                 chapterAdded = true

app/src/main/java/ua/acclorite/book_story/data/parser/txt/TxtTextParser.kt

@@ -44,7 +44,8 @@ class TxtTextParser @Inject constructor(
                                 if (!chapterAdded && line.clearAllMarkdown().isNotBlank()) {
                                     readerText.add(
                                         0, ReaderText.Chapter(
-                                            title = line.clearAllMarkdown()
+                                            title = line.clearAllMarkdown(),
+                                            nested = false
                                         )
                                     )
                                     chapterAdded = true

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

@@ -0,0 +1,16 @@
+/*
+ * Book's Story — free and open-source Material You eBook reader.
+ * Copyright (C) 2024-2025 Acclorite
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package ua.acclorite.book_story.domain.reader
+
+import androidx.compose.runtime.Immutable
+
+@Immutable
+data class ExpandableChapter(
+    val parent: ReaderText.Chapter,
+    val expanded: Boolean,
+    val chapters: List<ReaderText.Chapter>?
+)

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

@@ -9,11 +9,16 @@ package ua.acclorite.book_story.domain.reader
 import androidx.compose.runtime.Immutable
 import androidx.compose.ui.graphics.ImageBitmap
 import androidx.compose.ui.text.AnnotatedString
+import java.util.UUID
 
 @Immutable
 sealed class ReaderText {
     @Immutable
-    data class Chapter(val title: String) : ReaderText()
+    data class Chapter(
+        val id: UUID = UUID.randomUUID(),
+        val title: String,
+        val nested: Boolean
+    ) : ReaderText()
 
     @Immutable
     data class Text(val line: AnnotatedString) : ReaderText()

app/src/main/java/ua/acclorite/book_story/presentation/core/components/modal_drawer/ModalDrawerSelectableItem.kt

@@ -18,6 +18,7 @@ import androidx.compose.material3.LocalTextStyle
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
@@ -54,7 +55,8 @@ fun ModalDrawerSelectableItem(
             .clickable(enabled = enabled) {
                 onClick()
             }
-            .padding(horizontal = 18.dp, vertical = 18.dp)
+            .padding(horizontal = 18.dp, vertical = 18.dp),
+        verticalAlignment = Alignment.CenterVertically
     ) {
         CompositionLocalProvider(
             LocalContentColor provides if (selected) MaterialTheme.colorScheme.onSecondaryContainer

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

@@ -6,24 +6,32 @@
 
 package ua.acclorite.book_story.presentation.reader
 
+import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.lazy.itemsIndexed
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.ArrowDropUp
+import androidx.compose.material3.Icon
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.mutableStateListOf
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.rotate
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import ua.acclorite.book_story.R
+import ua.acclorite.book_story.domain.reader.ExpandableChapter
 import ua.acclorite.book_story.domain.reader.ReaderText.Chapter
 import ua.acclorite.book_story.presentation.core.components.common.StyledText
 import ua.acclorite.book_story.presentation.core.components.modal_drawer.ModalDrawer
 import ua.acclorite.book_story.presentation.core.components.modal_drawer.ModalDrawerSelectableItem
 import ua.acclorite.book_story.presentation.core.components.modal_drawer.ModalDrawerTitleItem
 import ua.acclorite.book_story.presentation.core.util.calculateProgress
+import ua.acclorite.book_story.presentation.core.util.noRippleClickable
 import ua.acclorite.book_story.ui.reader.ReaderEvent
+import ua.acclorite.book_story.ui.theme.ExpandingTransition
 
 @Composable
 fun ReaderChaptersDrawer(
@@ -34,15 +42,43 @@ fun ReaderChaptersDrawer(
     scrollToChapter: (ReaderEvent.OnScrollToChapter) -> Unit,
     dismissDrawer: (ReaderEvent.OnDismissDrawer) -> Unit
 ) {
-    val currentChapterIndex = remember(chapters, currentChapter) {
+    val expandableChapters = remember(show, chapters, currentChapter) {
-        derivedStateOf {
+        mutableStateListOf<ExpandableChapter>().apply {
-            chapters.indexOf(currentChapter).takeIf { it != -1 } ?: 0
+            var index = 0
+            while (index < chapters.size) {
+                val chapter = chapters.getOrNull(index) ?: continue
+                when (chapter.nested) {
+                    false -> {
+                        val children = chapters.drop(index + 1).takeWhile { it.nested }
+                        add(
+                            ExpandableChapter(
+                                parent = chapter,
+                                expanded = chapter.id == currentChapter?.id ||
+                                        children.any { it.id == currentChapter?.id },
+                                chapters = children.takeIf { it.isNotEmpty() }
+                            )
+                        )
+                        index += children.size + 1
+                    }
+
+                    true -> {
+                        add(
+                            ExpandableChapter(
+                                parent = chapter.copy(nested = false),
+                                expanded = false,
+                                chapters = null
+                            )
+                        )
+                        index++
+                    }
+                }
+            }
         }
     }
 
     ModalDrawer(
         show = show,
-        startIndex = currentChapterIndex.value,
+        startIndex = chapters.indexOf(currentChapter).takeIf { it != -1 } ?: 0,
         onDismissRequest = { dismissDrawer(ReaderEvent.OnDismissDrawer) },
         header = {
             ModalDrawerTitleItem(
@@ -50,13 +86,65 @@ fun ReaderChaptersDrawer(
             )
         }
     ) {
-        itemsIndexed(chapters, key = { index, _ -> index }) { index, chapter ->
+        expandableChapters.forEach { expandableChapter ->
-            val selected = rememberSaveable(index, currentChapterIndex) {
+            item {
-                index == currentChapterIndex.value
+                ModalDrawerSelectableItem(
+                    selected = expandableChapter.parent.id == currentChapter?.id,
+                    onClick = {
+                        scrollToChapter(
+                            ReaderEvent.OnScrollToChapter(
+                                chapter = expandableChapter.parent
+                            )
+                        )
+                        dismissDrawer(ReaderEvent.OnDismissDrawer)
+                    }
+                ) {
+                    StyledText(
+                        text = expandableChapter.parent.title,
+                        modifier = Modifier.weight(1f),
+                        maxLines = 1
+                    )
+
+                    if (expandableChapter.parent == currentChapter) {
+                        Spacer(modifier = Modifier.width(18.dp))
+                        StyledText(text = "${currentChapterProgress.calculateProgress(0)}%")
                     }
 
+                    if (!expandableChapter.chapters.isNullOrEmpty()) {
+                        Spacer(modifier = Modifier.width(18.dp))
+                        Icon(
+                            imageVector = Icons.Outlined.ArrowDropUp,
+                            modifier = Modifier
+                                .size(24.dp)
+                                .noRippleClickable {
+                                    expandableChapters.indexOf(expandableChapter)
+                                        .also { chapterIndex ->
+                                            if (chapterIndex == -1) return@noRippleClickable
+                                            expandableChapters[chapterIndex] =
+                                                expandableChapter.copy(
+                                                    expanded = !expandableChapter.expanded
+                                                )
+                                        }
+                                }
+                                .rotate(
+                                    animateFloatAsState(
+                                        targetValue = if (expandableChapter.expanded) 0f else -180f
+                                    ).value
+                                ),
+                            contentDescription = stringResource(
+                                id = if (expandableChapter.expanded) R.string.collapse_content_desc
+                                else R.string.expand_content_desc
+                            )
+                        )
+                    }
+                }
+            }
+
+            if (!expandableChapter.chapters.isNullOrEmpty()) {
+                items(expandableChapter.chapters) { chapter ->
+                    ExpandingTransition(visible = expandableChapter.expanded) {
                         ModalDrawerSelectableItem(
-                selected = selected,
+                            selected = chapter.id == currentChapter?.id,
                             onClick = {
                                 scrollToChapter(
                                     ReaderEvent.OnScrollToChapter(
@@ -66,14 +154,20 @@ fun ReaderChaptersDrawer(
                                 dismissDrawer(ReaderEvent.OnDismissDrawer)
                             }
                         ) {
+                            Spacer(modifier = Modifier.width(18.dp))
+
                             StyledText(
                                 text = chapter.title,
                                 modifier = Modifier.weight(1f),
                                 maxLines = 1
                             )
-                if (selected) {
+
+                            if (chapter == currentChapter) {
                                 Spacer(modifier = Modifier.width(18.dp))
-                    StyledText(text = "${currentChapterProgress.calculateProgress(1)}%")
+                                StyledText(text = "${currentChapterProgress.calculateProgress(0)}%")
+                            }
+                        }
+                    }
                 }
             }
         }

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

@@ -49,7 +49,9 @@ fun LazyItemScope.ReaderLayoutTextChapter(
             modifier = Modifier
                 .padding(horizontal = sidePadding)
                 .fillMaxWidth(),
-            style = MaterialTheme.typography.headlineMedium.copy(
+            style = (if (!chapter.nested) MaterialTheme.typography.headlineMedium
+            else MaterialTheme.typography.headlineSmall)
+                .copy(
                     color = fontColor,
                     textAlign = chapterTitleAlignment.textAlignment
                 ),

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

@@ -480,5 +480,7 @@
     <string name="show_less_content_desc">Показати менше</string>
     <string name="show_more_content_desc">Показати більше</string>
     <string name="edit_content_desc">Редагувати поле</string>
+    <string name="expand_content_desc">Розгорнути</string>
+    <string name="collapse_content_desc">Згорнути</string>
 
 </resources>

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

@@ -639,5 +639,7 @@
     <string name="show_less_content_desc">Show less</string>
     <string name="show_more_content_desc">Show more</string>
     <string name="edit_content_desc">Edit field</string>
+    <string name="expand_content_desc">Expand</string>
+    <string name="collapse_content_desc">Collapse</string>
 
 </resources>