show chapter toolbar when changing chapters with buffer page off

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

@@ -492,7 +492,7 @@ class ReaderActivity : BaseRxActivity<ReaderPresenter>(),
      */
     @SuppressLint("SetTextI18n")
     fun onPageSelected(page: ReaderPage) {
-        presenter.onPageSelected(page)
+        val newChapter = presenter.onPageSelected(page)
         val pages = page.chapter.pages ?: return
 
         // Set bottom page number
@@ -507,6 +507,10 @@ class ReaderActivity : BaseRxActivity<ReaderPresenter>(),
             left_page_text.text = "${pages.size}"
         }
 
+        if (newChapter && config?.showNewChapter == false) {
+            systemUi?.show()
+        }
+
         // Set seekbar progress
         page_seekbar.max = pages.lastIndex
         page_seekbar.progress = page.index
@@ -679,6 +683,8 @@ class ReaderActivity : BaseRxActivity<ReaderPresenter>(),
          */
         private var customFilterColorSubscription: Subscription? = null
 
+        var showNewChapter = false
+
         /**
          * Initializes the reader subscriptions.
          */
@@ -715,6 +721,9 @@ class ReaderActivity : BaseRxActivity<ReaderPresenter>(),
 
             subscriptions += preferences.colorFilterMode().asObservable()
                 .subscribe { setColorFilter(preferences.colorFilter().getOrDefault()) }
+
+            subscriptions += preferences.alwaysShowChapterTransition().asObservable()
+                .subscribe { showNewChapter = it }
         }
 
         /**

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

@@ -24,9 +24,6 @@ import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.model.ViewerChapters
 import eu.kanade.tachiyomi.util.storage.DiskUtil
 import eu.kanade.tachiyomi.util.system.ImageUtil
-import java.io.File
-import java.util.Date
-import java.util.concurrent.TimeUnit
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
@@ -39,6 +36,9 @@ import rx.schedulers.Schedulers
 import timber.log.Timber
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
+import java.io.File
+import java.util.Date
+import java.util.concurrent.TimeUnit
 
 /**
  * Presenter used by the activity to perform background operations.
@@ -318,8 +318,8 @@ class ReaderPresenter(
      * read, update tracking services, enqueue downloaded chapter deletion, and updating the active chapter if this
      * [page]'s chapter is different from the currently active.
      */
-    fun onPageSelected(page: ReaderPage) {
-        val currentChapters = viewerChaptersRelay.value ?: return
+    fun onPageSelected(page: ReaderPage): Boolean {
+        val currentChapters = viewerChaptersRelay.value ?: return false
 
         val selectedChapter = page.chapter
 
@@ -337,7 +337,9 @@ class ReaderPresenter(
             Timber.d("Setting ${selectedChapter.chapter.url} as active")
             onChapterChanged(currentChapters.currChapter, selectedChapter)
             loadNewChapter(selectedChapter)
+            return true
         }
+        return false
     }
 
     /**

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

@@ -187,7 +187,8 @@ abstract class PagerViewer(val activity: ReaderActivity) : BaseViewer {
      */
     private fun setChaptersInternal(chapters: ViewerChapters) {
         Timber.d("setChaptersInternal")
-        var forceTransition = config.alwaysShowChapterTransition || adapter.items.getOrNull(pager.currentItem) is ChapterTransition
+        val forceTransition = config.alwaysShowChapterTransition || adapter.items.getOrNull(pager
+            .currentItem) is ChapterTransition
         adapter.setChapters(chapters, forceTransition)
 
         // Layout the pager once a chapter is being set

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

@@ -174,7 +174,7 @@ class WebtoonViewer(val activity: ReaderActivity) : BaseViewer {
      */
     override fun setChapters(chapters: ViewerChapters) {
         Timber.d("setChapters")
-        var forceTransition = config.alwaysShowChapterTransition || currentPage is ChapterTransition
+        val forceTransition = config.alwaysShowChapterTransition || currentPage is ChapterTransition
         adapter.setChapters(chapters, forceTransition)
 
         if (recycler.visibility == View.GONE) {