Structure "reader" in sub-features

src/features/reader/viewer/hooks/useReaderScrollToStartOnPageChange.ts

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import { MutableRefObject, useLayoutEffect } from 'react';
+import { Direction } from '@mui/material/styles';
+import { ReadingDirection } from '@/features/reader/Reader.types.ts';
+import { getScrollToXForReadingDirection } from '@/features/reader/viewer/pager/ReaderPager.utils.tsx';
+import { ReaderStatePages } from '@/features/reader/overlay/progress-bar/ReaderProgressBar.types.ts';
+
+export const useReaderScrollToStartOnPageChange = (
+    currentPageIndex: ReaderStatePages['currentPageIndex'],
+    isContinuousReadingModeActive: boolean,
+    themeDirection: Direction,
+    readingDirection: ReadingDirection,
+    scrollElementRef: MutableRefObject<HTMLDivElement | null>,
+): void => {
+    useLayoutEffect(() => {
+        if (!isContinuousReadingModeActive) {
+            scrollElementRef.current?.scrollTo(
+                getScrollToXForReadingDirection(scrollElementRef.current, themeDirection, readingDirection),
+                0,
+            );
+        }
+    }, [currentPageIndex]);
+};