Auto download next unread chapters while reading (#1174)

* Add auto download for next chapters

* Change downloaded text in transition to icon

* Change auto download while reading to download when exiting reader

* change transition icon to compound

* split downloadNew and downloadWhileReading setting

* remove unused requestDownloadNextChapters

* pass down downloadManager and manga to transitionView

* removes useless settings

* improves download next chapters

* download only if 20% of chapter is read

* Add download if any chapter read during last session

* move downloadManager to viewer and isAnyPrevChapterDownloaded to companion object

app/src/main/java/eu/kanade/tachiyomi/data/preference/PreferencesHelper.kt

@@ -304,13 +304,15 @@ class PreferencesHelper(val context: Context) {
 
     fun pinnedCatalogues() = flowPrefs.getStringSet("pinned_catalogues", mutableSetOf())
 
-    fun downloadNewChapters() = flowPrefs.getBoolean(Keys.downloadNew, false)
-
     fun saveChaptersAsCBZ() = flowPrefs.getBoolean("save_chapter_as_cbz", true)
 
+    fun downloadNewChapters() = flowPrefs.getBoolean(Keys.downloadNew, false)
+
     fun downloadNewChaptersInCategories() = flowPrefs.getStringSet(Keys.downloadNewCategories, emptySet())
     fun excludeCategoriesInDownloadNew() = flowPrefs.getStringSet(Keys.downloadNewCategoriesExclude, emptySet())
 
+    fun autoDownloadAfterReading() = flowPrefs.getInt("auto_download_after_reading", 0)
+
     fun defaultCategory() = prefs.getInt(Keys.defaultCategory, -1)
 
     fun skipRead() = prefs.getBoolean(Keys.skipRead, false)

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

@@ -23,6 +23,7 @@ import eu.kanade.tachiyomi.source.SourceManager
 import eu.kanade.tachiyomi.source.model.Page
 import eu.kanade.tachiyomi.source.online.HttpSource
 import eu.kanade.tachiyomi.ui.base.presenter.BasePresenter
+import eu.kanade.tachiyomi.ui.manga.chapter.ChapterItem
 import eu.kanade.tachiyomi.ui.reader.chapter.ReaderChapterItem
 import eu.kanade.tachiyomi.ui.reader.loader.ChapterLoader
 import eu.kanade.tachiyomi.ui.reader.model.ReaderChapter
@@ -40,6 +41,7 @@ import eu.kanade.tachiyomi.util.system.ImageUtil
 import eu.kanade.tachiyomi.util.system.executeOnIO
 import eu.kanade.tachiyomi.util.system.launchIO
 import eu.kanade.tachiyomi.util.system.launchUI
+import eu.kanade.tachiyomi.util.system.toInt
 import eu.kanade.tachiyomi.util.system.withUIContext
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -107,6 +109,13 @@ class ReaderPresenter(
      */
     private val isLoadingAdjacentChapterRelay = BehaviorRelay.create<Boolean>()
 
+    companion object {
+        /**
+         * To check if any chapter of the current reading session was downloaded
+         */
+        private var isAnyPrevChapterDownloaded = false
+    }
+
     /**
      * Chapter list for the active manga. It's retrieved lazily and should be accessed for the first
      * time in a background thread to avoid blocking the UI.
@@ -168,8 +177,14 @@ class ReaderPresenter(
         val currentChapters = viewerChaptersRelay.value
         if (currentChapters != null) {
             currentChapters.unref()
-            saveChapterProgress(currentChapters.currChapter)
-            saveChapterHistory(currentChapters.currChapter)
+            val currentChapter = currentChapters.currChapter
+            saveChapterProgress(currentChapter)
+            saveChapterHistory(currentChapter)
+            val currentChapterPageCount = currentChapter.chapter.last_page_read + currentChapter.chapter.pages_left
+            if ((currentChapter.chapter.last_page_read + 1.0) / currentChapterPageCount > 0.33 || isAnyPrevChapterDownloaded) {
+                downloadNextChapters()
+            }
+            isAnyPrevChapterDownloaded = false
         }
     }
 
@@ -493,6 +508,9 @@ class ReaderPresenter(
                     (hasExtraPage && selectedChapter.pages?.lastIndex?.minus(1) == page.index)
                 )
         ) {
+            if (!isAnyPrevChapterDownloaded) {
+                isAnyPrevChapterDownloaded = downloadManager.isChapterDownloaded(selectedChapter.chapter, manga!!)
+            }
             selectedChapter.chapter.read = true
             updateTrackChapterAfterReading(selectedChapter)
             deleteChapterIfNeeded(selectedChapter)
@@ -505,6 +523,45 @@ class ReaderPresenter(
         }
     }
 
+    private fun downloadNextChapters() {
+        val manga = manga ?: return
+        val chaptersNumberToDownload = preferences.autoDownloadAfterReading().get()
+        if (chaptersNumberToDownload == 0 || !manga.favorite) return
+        val currentChapter = viewerChapters?.currChapter ?: return
+        val isChapterDownloaded = downloadManager.isChapterDownloaded(currentChapter.chapter, manga)
+        if (isChapterDownloaded || isAnyPrevChapterDownloaded) {
+            downloadAutoNextChapters(chaptersNumberToDownload, !isChapterDownloaded && !currentChapter.chapter.read)
+        }
+    }
+
+    private fun downloadAutoNextChapters(choice: Int, includeCurrentChapter: Boolean) {
+        val chaptersToDownload = getNextUnreadChaptersSorted(includeCurrentChapter).take(choice)
+        if (chaptersToDownload.isNotEmpty()) {
+            downloadChapters(chaptersToDownload)
+        }
+    }
+
+    private fun getNextUnreadChaptersSorted(includeCurrentChapter: Boolean): List<ChapterItem> {
+        val currentChapterId = getCurrentChapter()?.chapter?.id
+        val chapterSort = ChapterSort(manga!!, chapterFilter, preferences)
+
+        val chapters = chapterList.map { ChapterItem(it.chapter, manga!!) }
+            .filter { !it.read || it.id == currentChapterId }
+            .distinctBy { it.name }
+            .sortedWith(chapterSort.sortComparator(true))
+
+        val currentChapterIndex = chapters.indexOfFirst { it.id == currentChapterId }
+        return chapters.takeLast(chapters.lastIndex - currentChapterIndex + includeCurrentChapter.toInt())
+    }
+
+    /**
+     * Downloads the given list of chapters with the manager.
+     * @param chapters the list of chapters to download.
+     */
+    private fun downloadChapters(chapters: List<ChapterItem>) {
+        downloadManager.downloadChapters(manga!!, chapters.filter { !it.isDownloaded })
+    }
+
     /**
      * Determines if deleting option is enabled and nth to last chapter actually exists.
      * If both conditions are satisfied enqueues chapter for delete

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

@@ -1,16 +1,22 @@
 package eu.kanade.tachiyomi.ui.reader.viewer
 
 import android.content.Context
+import android.graphics.drawable.Drawable
 import android.util.AttributeSet
 import android.view.LayoutInflater
 import android.widget.LinearLayout
+import android.widget.TextView
 import androidx.annotation.ColorInt
 import androidx.core.text.bold
 import androidx.core.text.buildSpannedString
 import androidx.core.view.isVisible
 import eu.kanade.tachiyomi.R
+import eu.kanade.tachiyomi.data.database.models.Manga
+import eu.kanade.tachiyomi.data.download.DownloadManager
 import eu.kanade.tachiyomi.databinding.ReaderTransitionViewBinding
 import eu.kanade.tachiyomi.ui.reader.model.ChapterTransition
+import eu.kanade.tachiyomi.util.system.contextCompatDrawable
+import eu.kanade.tachiyomi.util.system.dpToPx
 
 class ReaderTransitionView @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null) :
     LinearLayout(context, attrs) {
@@ -22,10 +28,11 @@ class ReaderTransitionView @JvmOverloads constructor(context: Context, attrs: At
         layoutParams = LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)
     }
 
-    fun bind(transition: ChapterTransition) {
+    fun bind(transition: ChapterTransition, downloadManager: DownloadManager, manga: Manga?) {
+        manga ?: return
         when (transition) {
-            is ChapterTransition.Prev -> bindPrevChapterTransition(transition)
-            is ChapterTransition.Next -> bindNextChapterTransition(transition)
+            is ChapterTransition.Prev -> bindPrevChapterTransition(transition, downloadManager, manga)
+            is ChapterTransition.Next -> bindNextChapterTransition(transition, downloadManager, manga)
         }
 
         missingChapterWarning(transition)
@@ -34,21 +41,34 @@ class ReaderTransitionView @JvmOverloads constructor(context: Context, attrs: At
     /**
      * Binds a previous chapter transition on this view and subscribes to the page load status.
      */
-    private fun bindPrevChapterTransition(transition: ChapterTransition) {
+    private fun bindPrevChapterTransition(
+        transition: ChapterTransition,
+        downloadManager: DownloadManager,
+        manga: Manga,
+    ) {
         val prevChapter = transition.to
 
         val hasPrevChapter = prevChapter != null
         binding.lowerText.isVisible = hasPrevChapter
         if (hasPrevChapter) {
             binding.upperText.textAlignment = TEXT_ALIGNMENT_TEXT_START
+            val isPrevDownloaded = downloadManager.isChapterDownloaded(prevChapter!!.chapter, manga)
+            val isCurrentDownloaded = downloadManager.isChapterDownloaded(transition.from.chapter, manga)
+
+            val downloadIcon = context.contextCompatDrawable(R.drawable.ic_file_download_24dp)?.mutate()
+            val cloudIcon = context.contextCompatDrawable(R.drawable.ic_cloud_24dp)?.mutate()
             binding.upperText.text = buildSpannedString {
                 bold { append(context.getString(R.string.previous_title)) }
-                append("\n${prevChapter!!.chapter.name}")
+                append("\n${prevChapter.chapter.name}")
             }
             binding.lowerText.text = buildSpannedString {
                 bold { append(context.getString(R.string.current_chapter)) }
                 append("\n${transition.from.chapter.name}")
             }
+
+            binding.lowerText.setDrawable(null)
+            if (isPrevDownloaded && !isCurrentDownloaded) binding.upperText.setDrawable(downloadIcon)
+            else if (!isPrevDownloaded && isCurrentDownloaded) binding.upperText.setDrawable(cloudIcon)
         } else {
             binding.upperText.textAlignment = TEXT_ALIGNMENT_CENTER
             binding.upperText.text = context.getString(R.string.theres_no_previous_chapter)
@@ -58,27 +78,46 @@ class ReaderTransitionView @JvmOverloads constructor(context: Context, attrs: At
     /**
      * Binds a next chapter transition on this view and subscribes to the load status.
      */
-    private fun bindNextChapterTransition(transition: ChapterTransition) {
+    private fun bindNextChapterTransition(
+        transition: ChapterTransition,
+        downloadManager: DownloadManager,
+        manga: Manga,
+    ) {
         val nextChapter = transition.to
 
         val hasNextChapter = nextChapter != null
         binding.lowerText.isVisible = hasNextChapter
         if (hasNextChapter) {
             binding.upperText.textAlignment = TEXT_ALIGNMENT_TEXT_START
+            val isCurrentDownloaded = downloadManager.isChapterDownloaded(transition.from.chapter, manga)
+            val isNextDownloaded = downloadManager.isChapterDownloaded(nextChapter!!.chapter, manga)
             binding.upperText.text = buildSpannedString {
                 bold { append(context.getString(R.string.finished_chapter)) }
                 append("\n${transition.from.chapter.name}")
             }
             binding.lowerText.text = buildSpannedString {
                 bold { append(context.getString(R.string.next_title)) }
-                append("\n${nextChapter!!.chapter.name}")
+                append("\n${nextChapter.chapter.name}")
             }
+
+            val downloadIcon = context.contextCompatDrawable(R.drawable.ic_file_download_24dp)?.mutate()
+            val cloudIcon = context.contextCompatDrawable(R.drawable.ic_cloud_24dp)?.mutate()
+
+            binding.upperText.setDrawable(null)
+            if (!isCurrentDownloaded && isNextDownloaded) binding.lowerText.setDrawable(downloadIcon)
+            else if (isCurrentDownloaded && !isNextDownloaded) binding.lowerText.setDrawable(cloudIcon)
         } else {
             binding.upperText.textAlignment = TEXT_ALIGNMENT_CENTER
             binding.upperText.text = context.getString(R.string.theres_no_next_chapter)
         }
     }
 
+    private fun TextView.setDrawable(drawable: Drawable?) {
+        drawable?.setTint(binding.lowerText.currentTextColor)
+        setCompoundDrawablesRelativeWithIntrinsicBounds(null, null, drawable, null)
+        compoundDrawablePadding = 8.dpToPx
+    }
+
     fun setTextColors(@ColorInt color: Int) {
         binding.upperText.setTextColor(color)
         binding.warningText.setTextColor(color)

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerTransitionHolder.kt

@@ -57,7 +57,7 @@ class PagerTransitionHolder(
         addView(transitionView)
         addView(pagesContainer)
 
-        transitionView.bind(transition)
+        transitionView.bind(transition, viewer.downloadManager, viewer.activity.presenter.manga)
         transition.to?.let { observeStatus(it) }
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt

@@ -10,6 +10,7 @@ import androidx.core.view.children
 import androidx.core.view.isVisible
 import androidx.viewpager.widget.ViewPager
 import eu.kanade.tachiyomi.R
+import eu.kanade.tachiyomi.data.download.DownloadManager
 import eu.kanade.tachiyomi.ui.reader.ReaderActivity
 import eu.kanade.tachiyomi.ui.reader.model.ChapterTransition
 import eu.kanade.tachiyomi.ui.reader.model.InsertPage
@@ -21,6 +22,7 @@ import eu.kanade.tachiyomi.ui.reader.viewer.ViewerNavigation
 import kotlinx.coroutines.MainScope
 import kotlinx.coroutines.cancel
 import timber.log.Timber
+import uy.kohesive.injekt.injectLazy
 
 /**
  * Implementation of a [BaseViewer] to display pages with a [ViewPager].
@@ -28,6 +30,8 @@ import timber.log.Timber
 @Suppress("LeakingThis")
 abstract class PagerViewer(val activity: ReaderActivity) : BaseViewer {
 
+    val downloadManager: DownloadManager by injectLazy()
+
     val scope = MainScope()
 
     /**

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonTransitionHolder.kt

@@ -64,7 +64,7 @@ class WebtoonTransitionHolder(
      * Binds the given [transition] with this view holder, subscribing to its state.
      */
     fun bind(transition: ChapterTransition) {
-        transitionView.bind(transition)
+        transitionView.bind(transition, viewer.downloadManager, viewer.activity.presenter.manga)
         transition.to?.let { observeStatus(it, transition) }
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonViewer.kt

@@ -11,6 +11,7 @@ import androidx.core.view.isGone
 import androidx.core.view.isVisible
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.WebtoonLayoutManager
+import eu.kanade.tachiyomi.data.download.DownloadManager
 import eu.kanade.tachiyomi.ui.reader.ReaderActivity
 import eu.kanade.tachiyomi.ui.reader.model.ChapterTransition
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
@@ -21,6 +22,7 @@ import kotlinx.coroutines.MainScope
 import kotlinx.coroutines.cancel
 import rx.subscriptions.CompositeSubscription
 import timber.log.Timber
+import uy.kohesive.injekt.injectLazy
 import kotlin.math.max
 import kotlin.math.min
 
@@ -29,6 +31,8 @@ import kotlin.math.min
  */
 class WebtoonViewer(val activity: ReaderActivity, val hasMargins: Boolean = false) : BaseViewer {
 
+    val downloadManager: DownloadManager by injectLazy()
+
     private val scope = MainScope()
 
     /**

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

@@ -82,9 +82,8 @@ class SettingsDownloadController : SettingsController() {
             titleRes = R.string.download_new_chapters
 
             switchPreference {
-                key = Keys.downloadNew
+                bindTo(preferences.downloadNewChapters())
                 titleRes = R.string.download_new_chapters
-                defaultValue = false
             }
             triStateListPreference(activity) {
                 key = Keys.downloadNewCategories
@@ -96,21 +95,39 @@ class SettingsDownloadController : SettingsController() {
 
                 preferences.downloadNewChapters().asImmediateFlowIn(viewScope) { isVisible = it }
             }
-            preferenceCategory {
-                titleRes = R.string.automatic_removal
+        }
 
-                intListPreference(activity) {
-                    key = Keys.deleteRemovedChapters
-                    titleRes = R.string.delete_removed_chapters
-                    summary = activity?.getString(R.string.delete_downloaded_if_removed_online)
-                    entriesRes = arrayOf(
-                        R.string.ask_on_chapters_page,
-                        R.string.always_keep,
-                        R.string.always_delete
-                    )
-                    entryRange = 0..2
-                    defaultValue = 0
-                }
+        preferenceCategory {
+            titleRes = R.string.download_ahead
+
+            intListPreference(activity) {
+                bindTo(preferences.autoDownloadAfterReading())
+                titleRes = R.string.auto_download_after_reading
+                entriesRes = arrayOf(
+                    R.string.never,
+                    R.string.next_unread_chapter,
+                    R.string.next_2_unread,
+                    R.string.next_3_unread,
+                    R.string.next_5_unread,
+                )
+                entryValues = listOf(0, 1, 2, 3, 5)
+            }
+            infoPreference(R.string.download_ahead_info)
+        }
+
+        preferenceCategory {
+            titleRes = R.string.automatic_removal
+
+            intListPreference(activity) {
+                bindTo(preferences.deleteRemovedChapters())
+                titleRes = R.string.delete_removed_chapters
+                summary = activity?.getString(R.string.delete_downloaded_if_removed_online)
+                entriesRes = arrayOf(
+                    R.string.ask_on_chapters_page,
+                    R.string.always_keep,
+                    R.string.always_delete
+                )
+                entryRange = 0..2
             }
         }
     }

app/src/main/res/drawable/ic_cloud_24dp.xml

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?actionBarTintColor">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M19.35,10.04C18.67,6.59 15.64,4 12,4 9.11,4 6.6,5.64 5.35,8.04 2.34,8.36 0,10.91 0,14c0,3.31 2.69,6 6,6h13c2.76,0 5,-2.24 5,-5 0,-2.64 -2.05,-4.78 -4.65,-4.96z"/>
+</vector>

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

@@ -525,6 +525,8 @@
     <string name="select_ending_chapter">Select ending chapter</string>
     <string name="search_chapters">Search chapters</string>
     <string name="next_unread_chapter">Next unread chapter</string>
+    <string name="next_2_unread">Next 2 unread</string>
+    <string name="next_3_unread">Next 3 unread</string>
     <string name="next_5_unread">Next 5 unread</string>
     <string name="custom_range">Custom range</string>
     <string name="all_chapters">All chapters</string>
@@ -932,6 +934,9 @@
     <string name="third_to_last">Third to last chapter</string>
     <string name="fourth_to_last">Fourth to last chapter</string>
     <string name="fifth_to_last">Fifth to last chapter</string>
+    <string name="download_ahead">Download ahead</string>
+    <string name="auto_download_after_reading">Download next unread chapters after reading</string>
+    <string name="download_ahead_info">Download ahead only applies to entries in library and if the last chapter read was downloaded</string>
     <string name="download_new_chapters">Download new chapters</string>
     <string name="categories_to_include_in_download">Categories to include in download</string>
     <string name="delete_removed_chapters">Delete removed chapters</string>