From 77a491965625bc30ee084dc95f8c2f287abb8950 Mon Sep 17 00:00:00 2001
From: perokhe <81130286+perokhe@users.noreply.github.com>
Date: Thu, 27 Mar 2025 08:25:25 -0600
Subject: [PATCH] Fix next chapter button occasionally jumping to the last page
 of the current chapter (#1920)

(cherry picked from commit 941dde341eb11703eadae543f351c9284617541c)

# Conflicts:
#	CHANGELOG.md
#	app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt
---
 .../ui/reader/viewer/pager/PagerViewer.kt         | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt
index 0d95f4c17..94628f64b 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt
@@ -105,11 +105,7 @@ abstract class PagerViewer(val activity: ReaderActivity) : Viewer {
         pager.offscreenPageLimit = 1
         pager.id = R.id.reader_pager
         pager.adapter = adapter
-        pager.addOnPageChangeListener(
-            // SY -->
-            pagerListener,
-            // SY <--
-        )
+        pager.addOnPageChangeListener(pagerListener)
         pager.tapListener = { event ->
             val viewPosition = IntArray(2)
             pager.getLocationOnScreen(viewPosition)
@@ -291,6 +287,9 @@ abstract class PagerViewer(val activity: ReaderActivity) : Viewer {
      * Sets the active [chapters] on this pager.
      */
     private fun setChaptersInternal(chapters: ViewerChapters) {
+        // Remove listener so the change in item doesn't trigger it
+        pager.removeOnPageChangeListener(pagerListener)
+
         val forceTransition =
             config.alwaysShowChapterTransition ||
                 adapter.joinedItems.getOrNull(pager.currentItem)?.first is ChapterTransition
@@ -303,6 +302,8 @@ abstract class PagerViewer(val activity: ReaderActivity) : Viewer {
             moveToPage(pages[min(chapters.currChapter.requestedPage, pages.lastIndex)])
             pager.isVisible = true
         }
+
+        pager.addOnPageChangeListener(pagerListener)
     }
 
     /**
@@ -475,9 +476,9 @@ abstract class PagerViewer(val activity: ReaderActivity) : Viewer {
     fun setChaptersDoubleShift(chapters: ViewerChapters) {
         // Remove Listener since we're about to change the size of the items
         // If we don't the size change could put us on a new chapter
-        pager.removeOnPageChangeListener(pagerListener)
+        // pager.removeOnPageChangeListener(pagerListener)
         setChaptersInternal(chapters)
-        pager.addOnPageChangeListener(pagerListener)
+        // pager.addOnPageChangeListener(pagerListener)
         // Since we removed the listener while shifting, call page change to update the ui
         onPageChange(pager.currentItem)
     }