Enhance incognito mode (#4073)

* When in Incognito Mode don't set lastUsedSource

* When in Incognito Mode don't save chapter progress

Still allows tracking and mark as read when reaching last page

* When in Incognito Mode don't mark as read (overwritten if hasTrackers)

app/src/main/java/eu/kanade/tachiyomi/ui/browse/source/SourceController.kt

@@ -194,7 +194,9 @@ class SourceController :
      * Opens a catalogue with the given controller.
      */
     private fun openSource(source: CatalogueSource, controller: BrowseSourceController) {
+        if (!preferences.incognitoMode().get()) {
             preferences.lastUsedSource().set(source.id)
+        }
         parentController!!.router.pushController(controller.withFadeTransaction())
     }
 

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

@@ -133,6 +133,13 @@ class ReaderPresenter(
         }.map(::ReaderChapter)
     }
 
+    private var hasTrackers: Boolean = false
+    private val checkTrackers: (Manga) -> Unit = { manga ->
+        val tracks = db.getTracks(manga).executeAsBlocking()
+
+        hasTrackers = tracks.size > 0
+    }
+
     /**
      * Called when the presenter is created. It retrieves the saved active chapter if the process
      * was restored.
@@ -224,6 +231,8 @@ class ReaderPresenter(
         this.manga = manga
         if (chapterId == -1L) chapterId = initialChapterId
 
+        checkTrackers(manga)
+
         val context = Injekt.get<Application>()
         val source = sourceManager.getOrStub(manga.source)
         loader = ChapterLoader(context, downloadManager, manga, source)
@@ -357,7 +366,8 @@ class ReaderPresenter(
 
         // Save last page read and mark as read if needed
         selectedChapter.chapter.last_page_read = page.index
-        if (selectedChapter.pages?.lastIndex == page.index) {
+        val shouldTrack = !preferences.incognitoMode().get() || hasTrackers
+        if (selectedChapter.pages?.lastIndex == page.index && shouldTrack) {
             selectedChapter.chapter.read = true
             updateTrackChapterRead(selectedChapter)
             deleteChapterIfNeeded(selectedChapter)
@@ -408,16 +418,19 @@ class ReaderPresenter(
 
     /**
      * Saves this [chapter] progress (last read page and whether it's read).
+     * If incognito mode isn't on or has at least 1 tracker
      */
     private fun saveChapterProgress(chapter: ReaderChapter) {
+        if (!preferences.incognitoMode().get() || hasTrackers) {
             db.updateChapterProgress(chapter.chapter).asRxCompletable()
                 .onErrorComplete()
                 .subscribeOn(Schedulers.io())
                 .subscribe()
         }
+    }
 
     /**
-     * Saves this [chapter] last read history.
+     * Saves this [chapter] last read history if incognito mode isn't on.
      */
     private fun saveChapterHistory(chapter: ReaderChapter) {
         if (!preferences.incognitoMode().get()) {