Fix EPUB and TXT document downloads

app/src/main/java/eu/kanade/presentation/reader/settings/GeneralSettingsPage.kt

@@ -53,7 +53,7 @@ internal fun ColumnScope.GeneralPage(viewModel: ReaderSettingsViewModel) {
                 selected = readerTheme == value,
                 onClick = {
                     viewModel.preferences.readerTheme.set(value)
-                    viewModel.requestTextSettingsReload()
+                    viewModel.requestTextAppearanceReload()
                 },
                 label = { Text(stringResource(labelRes)) },
             )

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt

@@ -374,10 +374,13 @@ class DownloadCache(
                                     when {
                                         // Ignore incomplete downloads
                                         it.name?.endsWith(Downloader.TMP_DIR_SUFFIX) == true -> null
+                                        it.name?.contains(".download.", ignoreCase = true) == true -> null
                                         // Folder of images
                                         it.isDirectory -> it.name
-                                        // CBZ files
+                                        // Archived or original document files
-                                        it.isFile && it.extension == "cbz" -> it.nameWithoutExtension
+                                        it.isFile && it.extension?.lowercase()?.let { extension ->
+                                            extension == "cbz" || extension in DOCUMENT_DOWNLOAD_EXTENSIONS
+                                        } == true -> it.nameWithoutExtension
                                         // Anything else is irrelevant
                                         else -> null
                                     }

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadManager.kt

@@ -405,8 +405,12 @@ class DownloadManager(
             .firstOrNull() ?: return
 
         var newName = provider.getChapterDirName(newChapter.name, newChapter.scanlator, newChapter.url)
-        if (oldDownload.isFile && oldDownload.extension == "cbz") {
+        if (oldDownload.isFile) {
-            newName += ".cbz"
+            oldDownload.extension?.lowercase()?.let { extension ->
+                if (extension == "cbz" || extension in DOCUMENT_DOWNLOAD_EXTENSIONS) {
+                    newName += ".$extension"
+                }
+            }
         }
 
         if (oldDownload.name == newName) return

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadProvider.kt

@@ -19,6 +19,8 @@ import tachiyomi.domain.storage.service.StorageManager
 import tachiyomi.i18n.MR
 import java.io.IOException
 
+internal val DOCUMENT_DOWNLOAD_EXTENSIONS = setOf("epub", "txt")
+
 /**
  * This class is used to provide the directories where the downloads should be saved.
  * It uses the following path scheme: /<root downloads dir>/<source name>/<manga>/<chapter>
@@ -250,11 +252,17 @@ class DownloadProvider(
             add(chapterDirName)
             // Archived chapters
             add("$chapterDirName.cbz")
+            DOCUMENT_DOWNLOAD_EXTENSIONS.forEach { extension ->
+                add("$chapterDirName.$extension")
+            }
 
             // any legacy names
             legacyChapterDirNames.forEach {
                 add(it)
                 add("$it.cbz")
+                DOCUMENT_DOWNLOAD_EXTENSIONS.forEach { extension ->
+                    add("$it.$extension")
+                }
             }
         }
     }

app/src/main/java/eu/kanade/tachiyomi/data/download/Downloader.kt

@@ -12,8 +12,16 @@ import eu.kanade.tachiyomi.data.download.model.Download
 import eu.kanade.tachiyomi.data.library.LibraryUpdateNotifier
 import eu.kanade.tachiyomi.data.notification.NotificationHandler
 import eu.kanade.tachiyomi.network.HttpException
+import eu.kanade.tachiyomi.network.await
 import eu.kanade.tachiyomi.source.UnmeteredSource
+import eu.kanade.tachiyomi.source.bookoasis.bookOasisDocumentDownloadRequest
+import eu.kanade.tachiyomi.source.bookoasis.isBookOasisSource
+import eu.kanade.tachiyomi.source.bookoasis.toBookOasisChapterRef
 import eu.kanade.tachiyomi.source.model.Page
+import eu.kanade.tachiyomi.source.kavita.detectKavitaDocumentFormat
+import eu.kanade.tachiyomi.source.kavita.isKavitaSource
+import eu.kanade.tachiyomi.source.kavita.kavitaDocumentDownloadRequest
+import eu.kanade.tachiyomi.source.kavita.toKavitaChapterId
 import eu.kanade.tachiyomi.source.online.HttpSource
 import eu.kanade.tachiyomi.util.storage.DiskUtil
 import eu.kanade.tachiyomi.util.storage.DiskUtil.NOMEDIA_FILE
@@ -44,6 +52,7 @@ import kotlinx.coroutines.supervisorScope
 import logcat.LogPriority
 import mihon.core.archive.ZipWriter
 import nl.adaptivity.xmlutil.serialization.XML
+import okhttp3.Request
 import okhttp3.Response
 import tachiyomi.core.common.i18n.stringResource
 import tachiyomi.core.common.util.lang.launchIO
@@ -339,9 +348,15 @@ class Downloader(
             download.chapter.scanlator,
             download.chapter.url,
         )
-        val tmpDir = mangaDir.createDirectory(chapterDirname + TMP_DIR_SUFFIX)!!
-
         try {
+            val remoteDocument = findRemoteDocument(download)
+            if (remoteDocument != null) {
+                downloadDocument(download, mangaDir, chapterDirname, remoteDocument)
+                return
+            }
+
+            val tmpDir = mangaDir.createDirectory(chapterDirname + TMP_DIR_SUFFIX)!!
+
             // If the page list already exists, start from the file
             val pageList = download.pages ?: run {
                 // Otherwise, pull page list from network and add them to download object
@@ -415,6 +430,85 @@ class Downloader(
         }
     }
 
+    private suspend fun findRemoteDocument(download: Download): RemoteDocument? {
+        val source = download.source
+        return when {
+            source.isBookOasisSource() -> download.chapter.url
+                .toBookOasisChapterRef()
+                ?.takeIf { it.format in DOCUMENT_DOWNLOAD_EXTENSIONS }
+                ?.let { ref -> RemoteDocument(ref.format, source.bookOasisDocumentDownloadRequest(ref)) }
+            source.isKavitaSource() -> download.chapter.url
+                .toKavitaChapterId()
+                ?.let { chapterId ->
+                    source.detectKavitaDocumentFormat(chapterId)?.let { format ->
+                        RemoteDocument(format, source.kavitaDocumentDownloadRequest(chapterId))
+                    }
+                }
+            else -> null
+        }
+    }
+
+    private suspend fun downloadDocument(
+        download: Download,
+        mangaDir: UniFile,
+        chapterDirname: String,
+        document: RemoteDocument,
+    ) {
+        val targetName = "$chapterDirname.${document.extension}"
+        val tempName = "$chapterDirname.download.${document.extension}"
+        mangaDir.findFile(tempName)?.delete()
+        val temp = mangaDir.createFile(tempName)
+            ?: error("Failed to create temporary document file")
+        val page = Page(0).apply {
+            status = Page.State.DownloadImage
+        }
+        download.pages = listOf(page)
+        download.status = Download.State.DOWNLOADING
+        notifier.onProgressChange(download)
+
+        try {
+            download.source.client.newCall(document.request).await().use { response ->
+                if (!response.isSuccessful) {
+                    throw IllegalStateException(
+                        "Document download failed: HTTP ${response.code}",
+                    )
+                }
+                temp.openOutputStream().use { output ->
+                    response.body.byteStream().use { input -> input.copyTo(output) }
+                }
+            }
+
+            if (temp.length() <= 0L) {
+                throw IllegalStateException("Document download returned an empty file")
+            }
+
+            mangaDir.findFile(targetName)?.delete()
+            if (!temp.renameTo(targetName)) {
+                val target = mangaDir.createFile(targetName)
+                    ?: error("Failed to create downloaded document file")
+                temp.openInputStream().use { input ->
+                    target.openOutputStream().use { output ->
+                        input.copyTo(output)
+                    }
+                }
+                temp.delete()
+            }
+        } catch (error: Throwable) {
+            temp.delete()
+            throw error
+        }
+
+        val target = mangaDir.findFile(targetName)
+            ?: error("Downloaded document file is missing")
+        page.uri = target.uri
+        page.status = Page.State.Ready
+        page.progress = 100
+        notifier.onProgressChange(download)
+        cache.addChapter(chapterDirname, mangaDir, download.manga)
+        DiskUtil.createNoMediaFile(mangaDir, context)
+        download.status = Download.State.DOWNLOADED
+    }
+
     /**
      * Gets the image from the filesystem if it exists or downloads it otherwise.
      *
@@ -740,5 +834,10 @@ class Downloader(
     }
 }
 
+private data class RemoteDocument(
+    val extension: String,
+    val request: Request,
+)
+
 // Arbitrary minimum required space to start a download: 200 MB
 private const val MIN_DISK_SPACE = 200L * 1024 * 1024

app/src/main/java/eu/kanade/tachiyomi/source/bookoasis/BookOasisCompat.kt

@@ -21,13 +21,40 @@ internal data class BookOasisChapterRef(
     val format: String,
 )
 
+private fun HttpSource.bookOasisServerBase(): String {
+    val normalized = baseUrl.trimEnd('/')
+    return when {
+        normalized.endsWith("/app-opds-adult", ignoreCase = true) ->
+            normalized.dropLast("/app-opds-adult".length)
+        normalized.endsWith("/app-opds", ignoreCase = true) ->
+            normalized.dropLast("/app-opds".length)
+        else -> normalized
+    }
+}
+
+internal fun HttpSource.bookOasisDocumentDownloadRequest(ref: BookOasisChapterRef): Request {
+    val downloadUrl = buildString {
+        append(bookOasisServerBase())
+        append("/app-opds/download/")
+        append(ref.dbType)
+        append('/')
+        append(ref.bookId)
+    }
+
+    return Request.Builder()
+        .url(downloadUrl)
+        .headers(headers)
+        .get()
+        .build()
+}
+
 internal fun Source.isBookOasisSource(): Boolean {
     return this::class.java.name.startsWith(BOOKOASIS_PACKAGE_PREFIX)
 }
 
 internal fun String.toBookOasisChapterRef(): BookOasisChapterRef? {
     val path = substringBefore('?')
-    val match = Regex("""^/api/media/books/(\d+)/info$""").matchEntire(path) ?: return null
+    val match = Regex("""^/(?:app-opds(?:-adult)?/)?api/media/books/(\d+)/info$""").matchEntire(path) ?: return null
     val params = parseQueryParameters(this)
     val format = params["bo_format"]?.lowercase() ?: return null
     if (format !in DOCUMENT_FORMATS) return null

app/src/main/java/eu/kanade/tachiyomi/source/kavita/KavitaCompat.kt

@@ -1,12 +1,61 @@
 package eu.kanade.tachiyomi.source.kavita
 
+import eu.kanade.tachiyomi.network.await
 import eu.kanade.tachiyomi.source.Source
+import eu.kanade.tachiyomi.source.online.HttpSource
+import okhttp3.Request
+import org.json.JSONObject
+import java.util.Locale
 
 private const val KAVITA_PACKAGE_PREFIX = "eu.kanade.tachiyomi.extension.all.kavita."
 
 internal fun Source.isKavitaSource(): Boolean =
     this::class.java.name.startsWith(KAVITA_PACKAGE_PREFIX)
 
+private fun HttpSource.kavitaApiBase(): String {
+    val normalized = baseUrl.trimEnd('/')
+    return if (normalized.endsWith("/api", ignoreCase = true)) normalized else "$normalized/api"
+}
+
+internal suspend fun HttpSource.detectKavitaDocumentFormat(chapterId: Int): String? {
+    val apiBase = kavitaApiBase()
+    val request = Request.Builder()
+        .url("$apiBase/Chapter?chapterId=$chapterId")
+        .headers(headers)
+        .get()
+        .build()
+
+    client.newCall(request).await().use { response ->
+        if (!response.isSuccessful) return null
+
+        val body = response.body.string()
+        if (body.isBlank()) return null
+
+        val files = JSONObject(body).optJSONArray("files") ?: return null
+        for (i in 0 until files.length()) {
+            val file = files.optJSONObject(i) ?: continue
+            val extension = file.optString("extension")
+                .ifBlank { file.optString("filePath") }
+                .substringAfterLast('.')
+                .trim()
+                .trimStart('.')
+                .lowercase(Locale.ROOT)
+            if (extension == "epub" || extension == "txt") return extension
+            if (file.optInt("format", -1) == 3) return "epub"
+        }
+    }
+    return null
+}
+
+internal fun HttpSource.kavitaDocumentDownloadRequest(chapterId: Int): Request {
+    val apiBase = kavitaApiBase()
+    return Request.Builder()
+        .url("$apiBase/Download/chapter?chapterId=$chapterId")
+        .headers(headers)
+        .get()
+        .build()
+}
+
 /**
  * Kavita extension chapter URLs are normally /Chapter/{id}. Keep compatibility
  * with older/alternate forms used by reading lists and previous releases.

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt

@@ -57,6 +57,7 @@ import eu.kanade.tachiyomi.util.storage.DiskUtil
 import eu.kanade.tachiyomi.util.storage.cacheImageDir
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -186,6 +187,12 @@ class ReaderViewModel(
      */
     private var loader: ChapterLoader? = null
 
+    /**
+     * Only the newest text repagination request is allowed to finish. Slider
+     * changes can arrive faster than a large TXT/EPUB chapter can be rebuilt.
+     */
+    private var textRepaginationJob: Job? = null
+
     /**
      * The time the chapter was started reading
      */
@@ -841,17 +848,26 @@ class ReaderViewModel(
         if (chapter.pageLoader?.usesTextReaderStyle != true) return
         if (chapter.pages?.any { it is TextReaderPage } != true) return
         val chapterLoader = loader ?: return
-        val requestedPage = (state.value.currentPage - 1).coerceAtLeast(0)
-        val oldLastIndex = (chapter.pages?.lastIndex ?: 0).coerceAtLeast(0)
-        val readingProgress = if (oldLastIndex == 0) 0f else requestedPage.toFloat() / oldLastIndex
 
-        viewModelScope.launchIO {
+        val oldPageCount = chapter.pages?.size?.coerceAtLeast(1) ?: 1
+        val requestedPage = chapter.requestedPage.coerceIn(0, oldPageCount - 1)
+        // Anchor at the middle of the visible page so position remains stable
+        // when font size/spacing changes the total page count.
+        val readingProgress = ((requestedPage + 0.5f) / oldPageCount)
+            .coerceIn(0f, 0.999999f)
+
+        textRepaginationJob?.cancel()
+        textRepaginationJob = viewModelScope.launchIO {
             try {
                 val oldLoader = chapterLoader.reloadTextChapter(chapter, readingProgress) ?: return@launchIO
-                eventChannel.send(Event.ReloadTextViewerChapters)
+
-                // Give old visible holders time to detach before closing resources such as EpubReader.
+                // Resource cleanup must survive cancellation by the next slider value.
-                delay(2000)
+                viewModelScope.launchNonCancellable {
-                oldLoader.recycle()
+                    delay(750)
+                    oldLoader.recycle()
+                }
+
+                eventChannel.trySend(Event.ReloadTextViewerChapters)
             } catch (e: Throwable) {
                 if (e is CancellationException) throw e
                 logcat(LogPriority.ERROR, e) { "Failed to repaginate text reader style" }

app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/BookOasisFilePageLoader.kt

@@ -4,11 +4,11 @@ import android.content.Context
 import com.hippo.unifile.UniFile
 import eu.kanade.tachiyomi.network.await
 import eu.kanade.tachiyomi.source.bookoasis.BookOasisChapterRef
+import eu.kanade.tachiyomi.source.bookoasis.bookOasisDocumentDownloadRequest
 import eu.kanade.tachiyomi.source.online.HttpSource
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.setting.TextReaderStyle
 import mihon.core.archive.epubReader
-import okhttp3.Request
 import java.io.File
 import java.io.IOException
 
@@ -68,19 +68,7 @@ internal class BookOasisFilePageLoader(
         val temp = File(cacheDir, "${target.name}.part")
         if (temp.exists()) temp.delete()
 
-        val downloadUrl = buildString {
+        val request = source.bookOasisDocumentDownloadRequest(ref)
-            append(source.baseUrl.trimEnd('/'))
-            append("/api/media/books/")
-            append(ref.bookId)
-            append("/download?type=")
-            append(ref.dbType)
-        }
-
-        val request = Request.Builder()
-            .url(downloadUrl)
-            .headers(source.headers)
-            .get()
-            .build()
 
         source.client.newCall(request).await().use { response ->
             if (!response.isSuccessful) {

app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/ChapterLoader.kt

@@ -22,7 +22,8 @@ import tachiyomi.domain.source.model.StubSource
 import tachiyomi.i18n.MR
 import tachiyomi.source.local.LocalSource
 import tachiyomi.source.local.io.Format
-import kotlin.math.roundToInt
+import kotlinx.coroutines.currentCoroutineContext
+import kotlinx.coroutines.ensureActive
 
 /**
  * Loader used to retrieve the [PageLoader] for a given chapter.
@@ -90,10 +91,14 @@ class ChapterLoader(
                     throw Exception(context.stringResource(MR.strings.page_list_empty_error))
                 }
 
+                // If a newer slider value cancelled this rebuild while getPages()
+                // was working, do not publish stale pages into the active chapter.
+                currentCoroutineContext().ensureActive()
+
                 val oldLoader = chapter.pageLoader
                 chapter.pageLoader = newLoader
-                chapter.requestedPage = (readingProgress * pages.lastIndex)
+                chapter.requestedPage = (readingProgress.coerceIn(0f, 0.999999f) * pages.size)
-                    .roundToInt()
+                    .toInt()
                     .coerceIn(0, pages.lastIndex)
                 chapter.state = ReaderChapter.State.Loaded(pages)
                 oldLoader

app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/DownloadPageLoader.kt

@@ -11,7 +11,10 @@ import eu.kanade.tachiyomi.source.model.Page
 import eu.kanade.tachiyomi.ui.reader.model.ReaderChapter
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import mihon.core.archive.archiveReader
+import mihon.core.archive.epubReader
+import tachiyomi.core.common.storage.extension
 import tachiyomi.domain.manga.model.Manga
+import eu.kanade.tachiyomi.ui.reader.setting.ReaderPreferences
 import uy.kohesive.injekt.injectLazy
 
 /**
@@ -27,9 +30,12 @@ internal class DownloadPageLoader(
 
     private val context: Context by injectLazy()
 
-    private var archivePageLoader: ArchivePageLoader? = null
+    private var pageLoader: PageLoader? = null
+    private val readerPreferences: ReaderPreferences by injectLazy()
 
     override var isLocal: Boolean = true
+    override val usesTextReaderStyle: Boolean
+        get() = pageLoader?.usesTextReaderStyle == true
 
     override suspend fun getPages(): List<ReaderPage> {
         val dbChapter = chapter.chapter
@@ -41,7 +47,11 @@ internal class DownloadPageLoader(
             source,
         )
         return if (chapterPath?.isFile == true) {
-            getPagesFromArchive(chapterPath)
+            when (chapterPath.extension?.lowercase()) {
+                "epub" -> getPagesFromEpub(chapterPath)
+                "txt" -> getPagesFromText(chapterPath)
+                else -> getPagesFromArchive(chapterPath)
+            }
         } else {
             getPagesFromDirectory()
         }
@@ -49,11 +59,30 @@ internal class DownloadPageLoader(
 
     override fun recycle() {
         super.recycle()
-        archivePageLoader?.recycle()
+        pageLoader?.recycle()
+        pageLoader = null
     }
 
     private suspend fun getPagesFromArchive(file: UniFile): List<ReaderPage> {
-        val loader = ArchivePageLoader(file.archiveReader(context)).also { archivePageLoader = it }
+        val loader = ArchivePageLoader(file.archiveReader(context)).also { pageLoader = it }
+        return loader.getPages()
+    }
+
+    private suspend fun getPagesFromEpub(file: UniFile): List<ReaderPage> {
+        val loader = EpubPageLoader(
+            file.epubReader(context),
+            readerPreferences.textReaderStyle(context),
+            context.cacheDir,
+        ).also { pageLoader = it }
+        return loader.getPages()
+    }
+
+    private suspend fun getPagesFromText(file: UniFile): List<ReaderPage> {
+        val loader = TextPageLoader(
+            file,
+            readerPreferences.textReaderStyle(context),
+            context.cacheDir,
+        ).also { pageLoader = it }
         return loader.getPages()
     }
 
@@ -69,6 +98,6 @@ internal class DownloadPageLoader(
     }
 
     override suspend fun loadPage(page: ReaderPage) {
-        archivePageLoader?.loadPage(page)
+        pageLoader?.loadPage(page)
     }
 }

app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/KavitaCompatPageLoader.kt

@@ -4,16 +4,15 @@ import android.content.Context
 import com.hippo.unifile.UniFile
 import eu.kanade.tachiyomi.data.cache.ChapterCache
 import eu.kanade.tachiyomi.network.await
+import eu.kanade.tachiyomi.source.kavita.detectKavitaDocumentFormat
+import eu.kanade.tachiyomi.source.kavita.kavitaDocumentDownloadRequest
 import eu.kanade.tachiyomi.source.online.HttpSource
 import eu.kanade.tachiyomi.ui.reader.model.ReaderChapter
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.setting.TextReaderStyle
 import mihon.core.archive.epubReader
-import okhttp3.Request
-import org.json.JSONObject
 import java.io.File
 import java.io.IOException
-import java.util.Locale
 
 /**
  * Compatibility loader for Kavita document chapters.
@@ -42,7 +41,7 @@ internal class KavitaCompatPageLoader(
     override suspend fun getPages(): List<ReaderPage> {
         check(!isRecycled)
 
-        val format = detectDocumentFormat()
+        val format = source.detectKavitaDocumentFormat(chapterId)
         val loader = when (format) {
             "epub", "txt" -> createDocumentLoader(format)
             else -> HttpPageLoader(chapter, source, chapterCache)
@@ -67,51 +66,6 @@ internal class KavitaCompatPageLoader(
         super.recycle()
     }
 
-    private suspend fun detectDocumentFormat(): String? {
-        val apiBase = source.baseUrl.trimEnd('/') + "/api"
-        val request = Request.Builder()
-            .url("$apiBase/Chapter?chapterId=$chapterId")
-            .headers(source.headers)
-            .get()
-            .build()
-
-        source.client.newCall(request).await().use { response ->
-            if (!response.isSuccessful) {
-                // Preserve the extension's normal behavior when chapter metadata
-                // cannot be queried. It may still be readable as image content.
-                return null
-            }
-
-            val body = response.body.string()
-            if (body.isBlank()) return null
-
-            val chapterJson = JSONObject(body)
-            val files = chapterJson.optJSONArray("files") ?: return null
-            for (i in 0 until files.length()) {
-                val file = files.optJSONObject(i) ?: continue
-                val extension = normalizeExtension(
-                    file.optString("extension").ifBlank { file.optString("filePath") },
-                )
-                if (extension == "epub" || extension == "txt") {
-                    return extension
-                }
-
-                // Current Kavita format enum: EPUB == 3. TXT has no dedicated
-                // enum value in upstream Kavita, so it is detected by extension.
-                if (file.optInt("format", -1) == 3) {
-                    return "epub"
-                }
-            }
-        }
-        return null
-    }
-
-    private fun normalizeExtension(value: String): String =
-        value.substringAfterLast('.', value)
-            .trim()
-            .trimStart('.')
-            .lowercase(Locale.ROOT)
-
     private suspend fun createDocumentLoader(format: String): PageLoader {
         val file = getOrDownloadDocument(format)
         val uniFile = UniFile.fromFile(file)
@@ -132,12 +86,7 @@ internal class KavitaCompatPageLoader(
         val temp = File(cacheDir, "${target.name}.part")
         if (temp.exists()) temp.delete()
 
-        val apiBase = source.baseUrl.trimEnd('/') + "/api"
+        val request = source.kavitaDocumentDownloadRequest(chapterId)
-        val request = Request.Builder()
-            .url("$apiBase/Download/chapter?chapterId=$chapterId")
-            .headers(source.headers)
-            .get()
-            .build()
 
         source.client.newCall(request).await().use { response ->
             if (!response.isSuccessful) {

app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/TextPageRenderer.kt

@@ -16,13 +16,10 @@ import java.io.ByteArrayInputStream
 import java.io.ByteArrayOutputStream
 import java.io.InputStream
 import java.io.Reader
+import kotlin.math.roundToInt
 
 internal object TextPageRenderer {
-    private const val PAGE_WIDTH = 1440
+    private const val MARGIN_DP = 32f
-    private const val PAGE_HEIGHT = 2160
-    private const val MARGIN = 96
-    private const val CONTENT_WIDTH = PAGE_WIDTH - (MARGIN * 2)
-    private const val CONTENT_HEIGHT = PAGE_HEIGHT - (MARGIN * 2)
     private const val STREAM_BUFFER_CHARS = 64 * 1024
     private const val STREAM_READ_CHARS = 8 * 1024
 
@@ -101,7 +98,8 @@ internal object TextPageRenderer {
     private fun calculatePageSlices(text: String, style: TextReaderStyle): List<PageSlice> {
         if (text.isEmpty()) return emptyList()
 
-        val layout = createLayout(text, style)
+        val metrics = resolveLayoutMetrics(style)
+        val layout = createLayout(text, style, metrics.contentWidth)
         if (layout.lineCount == 0) return listOf(PageSlice(0, text.length))
 
         val pages = mutableListOf<PageSlice>()
@@ -111,7 +109,7 @@ internal object TextPageRenderer {
             var endLine = startLine
             while (
                 endLine + 1 < layout.lineCount &&
-                layout.getLineBottom(endLine + 1) - startTop <= CONTENT_HEIGHT
+                layout.getLineBottom(endLine + 1) - startTop <= metrics.contentHeight
             ) {
                 endLine++
             }
@@ -125,13 +123,14 @@ internal object TextPageRenderer {
     }
 
     fun render(text: String, style: TextReaderStyle): InputStream {
-        val bitmap = Bitmap.createBitmap(PAGE_WIDTH, PAGE_HEIGHT, Bitmap.Config.ARGB_8888)
+        val metrics = resolveLayoutMetrics(style)
+        val bitmap = Bitmap.createBitmap(metrics.pageWidth, metrics.pageHeight, Bitmap.Config.ARGB_8888)
         val canvas = Canvas(bitmap)
         val (backgroundColor, _) = resolveColors(style)
         canvas.drawColor(backgroundColor)
         canvas.save()
-        canvas.translate(MARGIN.toFloat(), MARGIN.toFloat())
+        canvas.translate(metrics.horizontalMargin.toFloat(), metrics.verticalMargin.toFloat())
-        createLayout(text, style).draw(canvas)
+        createLayout(text, style, metrics.contentWidth).draw(canvas)
         canvas.restore()
 
         val output = ByteArrayOutputStream()
@@ -140,25 +139,46 @@ internal object TextPageRenderer {
         return ByteArrayInputStream(output.toByteArray())
     }
 
-    private fun createLayout(text: String, style: TextReaderStyle): StaticLayout {
+    private fun createLayout(
+        text: String,
+        style: TextReaderStyle,
+        contentWidth: Int,
+    ): StaticLayout {
         val (_, textColor) = resolveColors(style)
         val paint = TextPaint().apply {
             isAntiAlias = true
             color = textColor
-            textSize = style.fontSize * 3f
+            textSize = style.fontSizePx.coerceAtLeast(1f)
             typeface = style.fontFamily.androidFamilyName
                 ?.let { Typeface.create(it, Typeface.NORMAL) }
                 ?: Typeface.DEFAULT
         }
-        val styledText = addParagraphSpacing(text, style.paragraphSpacing * 3)
+        val styledText = addParagraphSpacing(text, style.paragraphSpacingPx)
         return StaticLayout.Builder
-            .obtain(styledText, 0, styledText.length, paint, CONTENT_WIDTH)
+            .obtain(styledText, 0, styledText.length, paint, contentWidth)
             .setAlignment(Layout.Alignment.ALIGN_NORMAL)
             .setIncludePad(true)
             .setLineSpacing(0f, style.lineSpacingPercent / 100f)
             .build()
     }
 
+    private fun resolveLayoutMetrics(style: TextReaderStyle): LayoutMetrics {
+        val pageWidth = style.pageWidthPx.coerceAtLeast(1)
+        val pageHeight = style.pageHeightPx.coerceAtLeast(1)
+        val requestedMargin = (MARGIN_DP * style.density).roundToInt().coerceAtLeast(1)
+        val horizontalMargin = requestedMargin.coerceAtMost(((pageWidth - 1) / 2).coerceAtLeast(0))
+        val verticalMargin = requestedMargin.coerceAtMost(((pageHeight - 1) / 2).coerceAtLeast(0))
+
+        return LayoutMetrics(
+            pageWidth = pageWidth,
+            pageHeight = pageHeight,
+            horizontalMargin = horizontalMargin,
+            verticalMargin = verticalMargin,
+            contentWidth = (pageWidth - horizontalMargin * 2).coerceAtLeast(1),
+            contentHeight = (pageHeight - verticalMargin * 2).coerceAtLeast(1),
+        )
+    }
+
     private fun resolveColors(style: TextReaderStyle): Pair<Int, Int> {
         val useDark = when (style.readerTheme) {
             0 -> false
@@ -205,6 +225,15 @@ internal object TextPageRenderer {
         }
     }
 
+    private data class LayoutMetrics(
+        val pageWidth: Int,
+        val pageHeight: Int,
+        val horizontalMargin: Int,
+        val verticalMargin: Int,
+        val contentWidth: Int,
+        val contentHeight: Int,
+    )
+
     private data class PageSlice(
         val start: Int,
         val endExclusive: Int,

app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/TextReaderPage.kt

@@ -5,9 +5,8 @@ import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.setting.TextReaderStyle
 
 /**
- * A rendered text page whose style can be changed without rebuilding the chapter.
+ * A rendered text page whose visual style can be refreshed cheaply while layout-affecting
- * Page boundaries remain stable during the live preview; a full repagination is done
+ * changes trigger a debounced chapter repagination to rebuild page boundaries.
- * once when the settings dialog is dismissed.
  */
 internal class TextReaderPage(
     index: Int,

app/src/main/java/eu/kanade/tachiyomi/ui/reader/setting/ReaderPreferences.kt

@@ -3,6 +3,7 @@ package eu.kanade.tachiyomi.ui.reader.setting
 import android.content.Context
 import android.content.res.Configuration
 import android.os.Build
+import android.util.TypedValue
 import androidx.compose.ui.graphics.BlendMode
 import dev.icerock.moko.resources.StringResource
 import dev.zacsweers.metro.AppScope
@@ -137,15 +138,44 @@ class ReaderPreferences(
         }
     }
 
-    fun textReaderStyle(context: Context) = TextReaderStyle(
+    fun textReaderStyle(context: Context): TextReaderStyle {
-        fontSize = textFontSize.get(),
+        val displayMetrics = context.resources.displayMetrics
-        lineSpacingPercent = textLineSpacing.get(),
+        val rawWidth = displayMetrics.widthPixels.coerceAtLeast(1)
-        paragraphSpacing = textParagraphSpacing.get(),
+        val rawHeight = displayMetrics.heightPixels.coerceAtLeast(1)
-        fontFamily = textFontFamily.get(),
+
-        readerTheme = readerTheme.get(),
+        // Keep the same physical page proportions as the device while capping the
-        automaticDark = (context.resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK) ==
+        // raster size so high-resolution phones do not create oversized bitmaps.
-            Configuration.UI_MODE_NIGHT_YES,
+        val renderScale = minOf(
-    )
+            1f,
+            TEXT_READER_MAX_RENDER_WIDTH / rawWidth.toFloat(),
+            TEXT_READER_MAX_RENDER_HEIGHT / rawHeight.toFloat(),
+        )
+
+        return TextReaderStyle(
+            fontSize = textFontSize.get(),
+            lineSpacingPercent = textLineSpacing.get(),
+            paragraphSpacing = textParagraphSpacing.get(),
+            fontFamily = textFontFamily.get(),
+            readerTheme = readerTheme.get(),
+            automaticDark = (context.resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK) ==
+                Configuration.UI_MODE_NIGHT_YES,
+            pageWidthPx = (rawWidth * renderScale).roundToInt().coerceAtLeast(1),
+            pageHeightPx = (rawHeight * renderScale).roundToInt().coerceAtLeast(1),
+            density = displayMetrics.density * renderScale,
+            fontSizePx = TypedValue.applyDimension(
+                TypedValue.COMPLEX_UNIT_SP,
+                textFontSize.get().toFloat(),
+                displayMetrics,
+            ) * renderScale,
+            paragraphSpacingPx = (
+                TypedValue.applyDimension(
+                    TypedValue.COMPLEX_UNIT_DIP,
+                    textParagraphSpacing.get().toFloat(),
+                    displayMetrics,
+                ) * renderScale
+                ).roundToInt(),
+        )
+    }
 
     // endregion
 
@@ -336,6 +366,9 @@ class ReaderPreferences(
         const val WEBTOON_PADDING_MIN = 0
         const val WEBTOON_PADDING_MAX = 25
 
+        private const val TEXT_READER_MAX_RENDER_WIDTH = 1440
+        private const val TEXT_READER_MAX_RENDER_HEIGHT = 2400
+
         const val MILLI_CONVERSION = 100
 
         val TapZones = listOf(
@@ -399,4 +432,9 @@ data class TextReaderStyle(
     val fontFamily: ReaderPreferences.TextFontFamily,
     val readerTheme: Int,
     val automaticDark: Boolean,
+    val pageWidthPx: Int,
+    val pageHeightPx: Int,
+    val density: Float,
+    val fontSizePx: Float,
+    val paragraphSpacingPx: Int,
 )

app/src/main/java/eu/kanade/tachiyomi/ui/reader/setting/ReaderSettingsViewModel.kt

@@ -32,20 +32,49 @@ class ReaderSettingsViewModel(
         .stateIn(viewModelScope, SharingStarted.Lazily, null)
 
     private var textSettingsReloadJob: Job? = null
+    private var textAppearanceReloadJob: Job? = null
     private var textSettingsDirty = false
 
+    /**
+     * Layout-affecting text settings are previewed quickly, then the chapter is
+     * repaginated after a short debounce. This keeps the slider responsive while
+     * ensuring the number of characters/lines on a page follows the new style.
+     */
     fun requestTextSettingsReload() {
         textSettingsDirty = true
         textSettingsReloadJob?.cancel()
         textSettingsReloadJob = viewModelScope.launch {
-            delay(200)
+            delay(250)
             onTextSettingsPreview()
+            textSettingsDirty = false
+            onTextSettingsCommit()
             textSettingsReloadJob = null
         }
     }
 
+    /**
+     * Theme-only changes do not affect page boundaries, so avoid an unnecessary
+     * full repagination.
+     */
+    fun requestTextAppearanceReload() {
+        textAppearanceReloadJob?.cancel()
+        textAppearanceReloadJob = viewModelScope.launch {
+            delay(50)
+            onTextSettingsPreview()
+            textAppearanceReloadJob = null
+        }
+    }
+
     fun flushTextSettingsReload() {
-        if (!textSettingsDirty) return
+        val hadPendingAppearanceReload = textAppearanceReloadJob != null
+        textAppearanceReloadJob?.cancel()
+        textAppearanceReloadJob = null
+        if (!textSettingsDirty) {
+            if (hadPendingAppearanceReload) {
+                onTextSettingsPreview()
+            }
+            return
+        }
         textSettingsReloadJob?.cancel()
         textSettingsReloadJob = null
         onTextSettingsPreview()