From beda5096d18bc13e56da4fd91355298244307f80 Mon Sep 17 00:00:00 2001
From: schroda <50052685+schroda@users.noreply.github.com>
Date: Sat, 26 Apr 2025 23:19:01 +0200
Subject: [PATCH] Add option to disable "infinite chapter scroll"

---
 public/locales/en.json                        |  4 +++
 src/modules/metadata/Metadata.constants.ts    |  1 +
 .../behaviour/ReaderBehaviourSettings.tsx     | 12 ++++++++
 .../components/viewer/ReaderChapterViewer.tsx |  9 +++++-
 .../ReaderInfiniteScrollUpdateChapter.tsx     | 30 ++++++++++---------
 .../reader/components/viewer/ReaderViewer.tsx |  4 +++
 .../constants/ReaderSettings.constants.tsx    |  2 ++
 .../useReaderInfiniteScrollUpdateChapter.ts   |  8 ++++-
 src/modules/reader/services/ReaderControls.ts | 16 +++++++---
 src/modules/reader/types/Reader.types.ts      |  1 +
 10 files changed, 67 insertions(+), 20 deletions(-)

diff --git a/public/locales/en.json b/public/locales/en.json
index 69761542..3eb013c6 100644
--- a/public/locales/en.json
+++ b/public/locales/en.json
@@ -946,6 +946,10 @@
         "stretch_image": "Toggle stretch image"
       },
       "image_preload_amount": "Preload images",
+      "infinite_scroll": {
+        "description": "Keep previous and upcoming chapters visible while reading in continuous reading modes, allowing seamless scrolling between chapters.",
+        "title": "Continuous chapter display"
+      },
       "label": {
         "behaviour": "Behaviour",
         "fit_page_to_window": "Fit page to window",
diff --git a/src/modules/metadata/Metadata.constants.ts b/src/modules/metadata/Metadata.constants.ts
index 44025a08..d70097e2 100644
--- a/src/modules/metadata/Metadata.constants.ts
+++ b/src/modules/metadata/Metadata.constants.ts
@@ -87,6 +87,7 @@ const APP_METADATA_OBJECT: Record<AppMetadataKeys, undefined> = {
     showChapterNumber: undefined,
     extensionLanguages: undefined,
     showNsfw: undefined,
+    shouldUseInfiniteScroll: undefined,
 };
 
 export const VALID_APP_METADATA_KEYS = Object.keys(APP_METADATA_OBJECT);
diff --git a/src/modules/reader/components/settings/behaviour/ReaderBehaviourSettings.tsx b/src/modules/reader/components/settings/behaviour/ReaderBehaviourSettings.tsx
index 360f8198..7b9b5803 100644
--- a/src/modules/reader/components/settings/behaviour/ReaderBehaviourSettings.tsx
+++ b/src/modules/reader/components/settings/behaviour/ReaderBehaviourSettings.tsx
@@ -54,6 +54,18 @@ export const ReaderBehaviourSettings = ({
                     onChange={(_, checked) => updateSetting('shouldOffsetDoubleSpreads', checked)}
                 />
             )}
+            <CheckboxInput
+                label={
+                    <Box>
+                        <Typography>{t('reader.settings.infinite_scroll.title')}</Typography>
+                        <Typography variant="body2" color="textDisabled">
+                            {t('reader.settings.infinite_scroll.description')}
+                        </Typography>
+                    </Box>
+                }
+                checked={settings.shouldUseInfiniteScroll}
+                onChange={(_, checked) => updateSetting('shouldUseInfiniteScroll', checked)}
+            />
             <CheckboxInput
                 label={
                     <Box>
diff --git a/src/modules/reader/components/viewer/ReaderChapterViewer.tsx b/src/modules/reader/components/viewer/ReaderChapterViewer.tsx
index 052ad8bf..e7d9287c 100644
--- a/src/modules/reader/components/viewer/ReaderChapterViewer.tsx
+++ b/src/modules/reader/components/viewer/ReaderChapterViewer.tsx
@@ -64,6 +64,7 @@ const BaseReaderChapterViewer = ({
     pageScaleMode,
     shouldOffsetDoubleSpreads,
     readingDirection,
+    shouldUseInfiniteScroll,
     imagePreLoadAmount,
     pageGap,
     chapterId,
@@ -107,7 +108,12 @@ const BaseReaderChapterViewer = ({
     Omit<ReaderPagerProps, 'pages' | 'totalPages' | 'pageLoadStates' | 'handleAsInitialRender' | 'resumeMode'> &
     Pick<
         IReaderSettings,
-        'readingMode' | 'shouldOffsetDoubleSpreads' | 'readingDirection' | 'readerWidth' | 'pageScaleMode'
+        | 'readingMode'
+        | 'shouldOffsetDoubleSpreads'
+        | 'readingDirection'
+        | 'readerWidth'
+        | 'pageScaleMode'
+        | 'shouldUseInfiniteScroll'
     > &
     Pick<ReaderStateChapters, 'setReaderStateChapters'> & {
         updateCurrentPageIndex: ReturnType<typeof ReaderControls.useUpdateCurrentPageIndex>;
@@ -412,6 +418,7 @@ const BaseReaderChapterViewer = ({
                 <ReaderInfiniteScrollUpdateChapter
                     readingMode={readingMode}
                     readingDirection={readingDirection}
+                    shouldUseInfiniteScroll={shouldUseInfiniteScroll}
                     chapterId={chapterId}
                     previousChapterId={previousChapterId}
                     nextChapterId={nextChapterId}
diff --git a/src/modules/reader/components/viewer/ReaderInfiniteScrollUpdateChapter.tsx b/src/modules/reader/components/viewer/ReaderInfiniteScrollUpdateChapter.tsx
index f738b828..0cc998fa 100644
--- a/src/modules/reader/components/viewer/ReaderInfiniteScrollUpdateChapter.tsx
+++ b/src/modules/reader/components/viewer/ReaderInfiniteScrollUpdateChapter.tsx
@@ -9,13 +9,14 @@
 import { memo } from 'react';
 import { withPropsFrom } from '@/modules/core/hoc/withPropsFrom.tsx';
 import { useReaderInfiniteScrollUpdateChapter } from '@/modules/reader/hooks/useReaderInfiniteScrollUpdateChapter.ts';
-import { ReadingDirection, ReadingMode, TReaderScrollbarContext } from '@/modules/reader/types/Reader.types.ts';
+import { IReaderSettings, TReaderScrollbarContext } from '@/modules/reader/types/Reader.types.ts';
 import { ReaderControls } from '@/modules/reader/services/ReaderControls.ts';
 import { ChapterIdInfo } from '@/modules/chapter/services/Chapters.ts';
 
 const BaseReaderInfiniteScrollUpdateChapter = ({
     readingMode,
     readingDirection,
+    shouldUseInfiniteScroll,
     chapterId,
     previousChapterId,
     nextChapterId,
@@ -27,19 +28,18 @@ const BaseReaderInfiniteScrollUpdateChapter = ({
     scrollbarXSize,
     scrollbarYSize,
     scrollElement,
-}: Pick<TReaderScrollbarContext, 'scrollbarXSize' | 'scrollbarYSize'> & {
-    readingMode: ReadingMode;
-    readingDirection: ReadingDirection;
-    chapterId: ChapterIdInfo['id'];
-    previousChapterId?: ChapterIdInfo['id'];
-    nextChapterId?: ChapterIdInfo['id'];
-    isPreviousChapterVisible: boolean;
-    isCurrentChapter: boolean;
-    isNextChapterVisible: boolean;
-    imageWrapper: HTMLElement | null;
-    openChapter: ReturnType<typeof ReaderControls.useOpenChapter>;
-    scrollElement: HTMLElement | null;
-}) => {
+}: Pick<TReaderScrollbarContext, 'scrollbarXSize' | 'scrollbarYSize'> &
+    Pick<IReaderSettings, 'readingMode' | 'readingDirection' | 'shouldUseInfiniteScroll'> & {
+        chapterId: ChapterIdInfo['id'];
+        previousChapterId?: ChapterIdInfo['id'];
+        nextChapterId?: ChapterIdInfo['id'];
+        isPreviousChapterVisible: boolean;
+        isCurrentChapter: boolean;
+        isNextChapterVisible: boolean;
+        imageWrapper: HTMLElement | null;
+        openChapter: ReturnType<typeof ReaderControls.useOpenChapter>;
+        scrollElement: HTMLElement | null;
+    }) => {
     useReaderInfiniteScrollUpdateChapter(
         'first',
         chapterId,
@@ -48,6 +48,7 @@ const BaseReaderInfiniteScrollUpdateChapter = ({
         isPreviousChapterVisible,
         readingMode,
         readingDirection,
+        shouldUseInfiniteScroll,
         openChapter,
         imageWrapper,
         scrollbarXSize,
@@ -62,6 +63,7 @@ const BaseReaderInfiniteScrollUpdateChapter = ({
         isNextChapterVisible,
         readingMode,
         readingDirection,
+        shouldUseInfiniteScroll,
         openChapter,
         imageWrapper,
         scrollbarXSize,
diff --git a/src/modules/reader/components/viewer/ReaderViewer.tsx b/src/modules/reader/components/viewer/ReaderViewer.tsx
index bdb091b5..8f636fb2 100644
--- a/src/modules/reader/components/viewer/ReaderViewer.tsx
+++ b/src/modules/reader/components/viewer/ReaderViewer.tsx
@@ -94,6 +94,7 @@ const BaseReaderViewer = forwardRef(
             setTransitionPageMode,
             readingMode,
             readingDirection,
+            shouldUseInfiniteScroll,
             readerWidth,
             pageScaleMode,
             shouldOffsetDoubleSpreads,
@@ -134,6 +135,7 @@ const BaseReaderViewer = forwardRef(
                 IReaderSettings,
                 | 'readingMode'
                 | 'readingDirection'
+                | 'shouldUseInfiniteScroll'
                 | 'readerWidth'
                 | 'pageScaleMode'
                 | 'shouldOffsetDoubleSpreads'
@@ -408,6 +410,7 @@ const BaseReaderViewer = forwardRef(
                             pageScaleMode={pageScaleMode}
                             shouldOffsetDoubleSpreads={shouldOffsetDoubleSpreads}
                             readingDirection={readingDirection}
+                            shouldUseInfiniteScroll={shouldUseInfiniteScroll}
                             updateCurrentPageIndex={isCurrentChapter ? updateCurrentPageIndex : noOp}
                             scrollIntoView={isCurrentChapter && visibleChapters.scrollIntoView}
                             resumeMode={getReaderChapterViewResumeMode(
@@ -465,6 +468,7 @@ export const ReaderViewer = withPropsFrom(
         'setTransitionPageMode',
         'readingMode',
         'readingDirection',
+        'shouldUseInfiniteScroll',
         'readerWidth',
         'pageScaleMode',
         'shouldOffsetDoubleSpreads',
diff --git a/src/modules/reader/constants/ReaderSettings.constants.tsx b/src/modules/reader/constants/ReaderSettings.constants.tsx
index 0d7de605..6db9d723 100644
--- a/src/modules/reader/constants/ReaderSettings.constants.tsx
+++ b/src/modules/reader/constants/ReaderSettings.constants.tsx
@@ -71,6 +71,7 @@ const GLOBAL_READER_SETTING_OBJECT: Record<keyof IReaderSettingsGlobal, undefine
     shouldInformAboutMissingChapter: undefined,
     shouldInformAboutScanlatorChange: undefined,
     scrollAmount: undefined,
+    shouldUseInfiniteScroll: undefined,
 };
 
 export const GLOBAL_READER_SETTING_KEYS = Object.keys(GLOBAL_READER_SETTING_OBJECT);
@@ -155,6 +156,7 @@ export const DEFAULT_READER_SETTINGS: IReaderSettings = {
     shouldInformAboutMissingChapter: true,
     shouldInformAboutScanlatorChange: true,
     scrollAmount: ReaderScrollAmount.LARGE,
+    shouldUseInfiniteScroll: true,
 };
 
 export const READER_PROGRESS_BAR_POSITION_TO_PLACEMENT: Record<ProgressBarPosition, TooltipProps['placement']> = {
diff --git a/src/modules/reader/hooks/useReaderInfiniteScrollUpdateChapter.ts b/src/modules/reader/hooks/useReaderInfiniteScrollUpdateChapter.ts
index bca9588e..cc869b75 100644
--- a/src/modules/reader/hooks/useReaderInfiniteScrollUpdateChapter.ts
+++ b/src/modules/reader/hooks/useReaderInfiniteScrollUpdateChapter.ts
@@ -240,6 +240,7 @@ export const useReaderInfiniteScrollUpdateChapter = (
     isChapterToOpenVisible: boolean,
     readingMode: ReadingMode,
     readingDirection: ReadingDirection,
+    shouldUseInfiniteScroll: boolean,
     openChapter: ReturnType<typeof ReaderControls.useOpenChapter>,
     image: HTMLElement | null,
     scrollbarXSize: number,
@@ -250,7 +251,11 @@ export const useReaderInfiniteScrollUpdateChapter = (
         image,
         useCallback(
             (entries) => {
-                if (!isContinuousReadingMode(readingMode) || chapterToOpenId === undefined) {
+                if (
+                    !shouldUseInfiniteScroll ||
+                    !isContinuousReadingMode(readingMode) ||
+                    chapterToOpenId === undefined
+                ) {
                     return;
                 }
 
@@ -297,6 +302,7 @@ export const useReaderInfiniteScrollUpdateChapter = (
                 isChapterToOpenVisible,
                 readingMode,
                 readingDirection,
+                shouldUseInfiniteScroll,
                 openChapter,
                 scrollbarXSize,
                 scrollbarYSize,
diff --git a/src/modules/reader/services/ReaderControls.ts b/src/modules/reader/services/ReaderControls.ts
index 17f37bc9..47db755f 100644
--- a/src/modules/reader/services/ReaderControls.ts
+++ b/src/modules/reader/services/ReaderControls.ts
@@ -175,8 +175,12 @@ export class ReaderControls {
         scrollIntoView?: boolean,
     ) => void {
         const { t } = useTranslation();
-        const { readingMode, shouldInformAboutMissingChapter, shouldInformAboutScanlatorChange } =
-            ReaderService.useSettings();
+        const {
+            readingMode,
+            shouldInformAboutMissingChapter,
+            shouldInformAboutScanlatorChange,
+            shouldUseInfiniteScroll,
+        } = ReaderService.useSettings();
         const {
             currentChapter,
             previousChapter,
@@ -239,7 +243,7 @@ export class ReaderControls {
                         const isAlreadyLoaded =
                             lastLeadingChapterSourceOrder <= chapterToOpen.sourceOrder &&
                             lastTrailingChapterSourceOrder >= chapterToOpen.sourceOrder;
-                        const keepRenderedChapters = !scrollIntoView || isAlreadyLoaded;
+                        const keepRenderedChapters = shouldUseInfiniteScroll && (!scrollIntoView || isAlreadyLoaded);
 
                         if (keepRenderedChapters) {
                             setReaderStateChapters((prevState) =>
@@ -255,7 +259,10 @@ export class ReaderControls {
                         }
 
                         openChapter(chapterToOpen, {
-                            resumeMode: getReaderOpenChapterResumeMode(isSpecificChapterMode, isPreviousChapter),
+                            resumeMode: getReaderOpenChapterResumeMode(
+                                isSpecificChapterMode || !keepRenderedChapters,
+                                isPreviousChapter,
+                            ),
                             updateInitialChapter: !keepRenderedChapters,
                         });
                     } catch (error) {
@@ -274,6 +281,7 @@ export class ReaderControls {
                 shouldInformAboutScanlatorChange,
                 lastLeadingChapterSourceOrder,
                 lastTrailingChapterSourceOrder,
+                shouldUseInfiniteScroll,
             ],
         );
     }
diff --git a/src/modules/reader/types/Reader.types.ts b/src/modules/reader/types/Reader.types.ts
index 6fe7227e..6ffd281a 100644
--- a/src/modules/reader/types/Reader.types.ts
+++ b/src/modules/reader/types/Reader.types.ts
@@ -160,6 +160,7 @@ export interface IReaderSettingsGlobal {
     shouldInformAboutMissingChapter: boolean;
     shouldInformAboutScanlatorChange: boolean;
     scrollAmount: ReaderScrollAmount;
+    shouldUseInfiniteScroll: boolean;
 }
 
 export interface IReaderSettingsManga {