Desktop: Resolves #520: Save and restore the cursor position when switching between notes (#13447)

.eslintignore

@@ -281,6 +281,7 @@ packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/shouldPasteResources.
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/shouldPasteResources.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/types.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useContextMenu.js
+packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useCursorPositioning.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useEditDialog.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useEditDialogEventListeners.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useKeyboardRefocusHandler.js
@@ -322,6 +323,7 @@ packages/app-desktop/gui/NoteEditor/utils/useEffectiveNoteId.js
 packages/app-desktop/gui/NoteEditor/utils/useFolder.js
 packages/app-desktop/gui/NoteEditor/utils/useFormNote.test.js
 packages/app-desktop/gui/NoteEditor/utils/useFormNote.js
+packages/app-desktop/gui/NoteEditor/utils/useInitialCursorLocation.js
 packages/app-desktop/gui/NoteEditor/utils/useMessageHandler.js
 packages/app-desktop/gui/NoteEditor/utils/useNoteSearchBar.js
 packages/app-desktop/gui/NoteEditor/utils/usePluginEditorView.test.js

.gitignore

@@ -254,6 +254,7 @@ packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/shouldPasteResources.
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/shouldPasteResources.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/types.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useContextMenu.js
+packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useCursorPositioning.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useEditDialog.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useEditDialogEventListeners.js
 packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useKeyboardRefocusHandler.js
@@ -295,6 +296,7 @@ packages/app-desktop/gui/NoteEditor/utils/useEffectiveNoteId.js
 packages/app-desktop/gui/NoteEditor/utils/useFolder.js
 packages/app-desktop/gui/NoteEditor/utils/useFormNote.test.js
 packages/app-desktop/gui/NoteEditor/utils/useFormNote.js
+packages/app-desktop/gui/NoteEditor/utils/useInitialCursorLocation.js
 packages/app-desktop/gui/NoteEditor/utils/useMessageHandler.js
 packages/app-desktop/gui/NoteEditor/utils/useNoteSearchBar.js
 packages/app-desktop/gui/NoteEditor/utils/usePluginEditorView.test.js

packages/app-desktop/app.reducer.test.ts

@@ -52,7 +52,7 @@ describe('app.reducer', () => {
 			...createAppDefaultState({}),
 			backgroundWindows: {
 				testWindow: {
-					...createAppDefaultWindowState(),
+					...createAppDefaultWindowState(null),
 					windowId: 'testWindow',
 
 					visibleDialogs: {

packages/app-desktop/app.reducer.ts

@@ -26,10 +26,21 @@ export interface AppStateDialog {
 	props: Record<string, any>;
 }
 
-export interface EditorScrollPercents {
+export interface NoteIdToScrollPercent {
 	[noteId: string]: number;
 }
 
+type RichTextEditorSelectionBookmark = unknown;
+
+export interface EditorCursorLocations {
+	readonly richText?: RichTextEditorSelectionBookmark;
+	readonly markdown?: number;
+}
+
+export interface NoteIdToEditorCursorLocations {
+	[noteId: string]: EditorCursorLocations;
+}
+
 export interface VisibleDialogs {
 	[dialogKey: string]: boolean;
 }
@@ -42,6 +53,9 @@ export interface AppWindowState extends WindowState {
 	devToolsVisible: boolean;
 	// eslint-disable-next-line @typescript-eslint/no-explicit-any -- Old code before rule was applied
 	watchedResources: any;
+
+	lastEditorScrollPercents: NoteIdToScrollPercent;
+	lastEditorCursorLocations: NoteIdToEditorCursorLocations;
 }
 
 interface BackgroundWindowStates {
@@ -55,7 +69,6 @@ export interface AppState extends State, AppWindowState {
 	// eslint-disable-next-line @typescript-eslint/no-explicit-any -- Old code before rule was applied
 	navHistory: any[];
 	watchedNoteFiles: string[];
-	lastEditorScrollPercents: EditorScrollPercents;
 	focusedField: string;
 	layoutMoveMode: boolean;
 	startupPluginsLoaded: boolean;
@@ -66,7 +79,7 @@ export interface AppState extends State, AppWindowState {
 	isResettingLayout: boolean;
 }
 
-export const createAppDefaultWindowState = (): AppWindowState => {
+export const createAppDefaultWindowState = (globalState: AppState|null): AppWindowState => {
 	return {
 		...defaultWindowState,
 		visibleDialogs: {},
@@ -75,6 +88,12 @@ export const createAppDefaultWindowState = (): AppWindowState => {
 		editorCodeView: true,
 		devToolsVisible: false,
 		watchedResources: {},
+
+		// Maintain the scroll and cursor location for secondary windows separate from the
+		// main window. This prevents scrolling in a secondary window from changing/resetting
+		// the default scroll position in the main window:
+		lastEditorCursorLocations: globalState?.lastEditorCursorLocations ?? {},
+		lastEditorScrollPercents: globalState?.lastEditorScrollPercents ?? {},
 	};
 };
 
@@ -82,7 +101,7 @@ export const createAppDefaultWindowState = (): AppWindowState => {
 export function createAppDefaultState(resourceEditWatcherDefaultState: any): AppState {
 	return {
 		...defaultState,
-		...createAppDefaultWindowState(),
+		...createAppDefaultWindowState(null),
 		route: {
 			type: 'NAV_GO',
 			routeName: 'Main',
@@ -90,7 +109,6 @@ export function createAppDefaultState(resourceEditWatcherDefaultState: any): App
 		},
 		navHistory: [],
 		watchedNoteFiles: [],
-		lastEditorScrollPercents: {},
 		visibleDialogs: {}, // empty object if no dialog is visible. Otherwise contains the list of visible dialogs.
 		focusedField: null,
 		layoutMoveMode: false,
@@ -299,6 +317,18 @@ export default function(state: AppState, action: any) {
 			}
 			break;
 
+		case 'EDITOR_CURSOR_POSITION_SET':
+			{
+				newState = { ...state };
+				const newCursorLocations = { ...newState.lastEditorCursorLocations };
+				newCursorLocations[action.noteId] = {
+					...(newCursorLocations[action.noteId] ?? {}),
+					...action.location,
+				};
+				newState.lastEditorCursorLocations = newCursorLocations;
+			}
+			break;
+
 		case 'NOTE_DEVTOOLS_TOGGLE':
 			newState = { ...state };
 			newState.devToolsVisible = !newState.devToolsVisible;

packages/app-desktop/commands/openNoteInNewWindow.ts

@@ -2,7 +2,7 @@ import { CommandRuntime, CommandDeclaration, CommandContext } from '@joplin/lib/
 import { _ } from '@joplin/lib/locale';
 import { stateUtils } from '@joplin/lib/reducer';
 import Note from '@joplin/lib/models/Note';
-import { createAppDefaultWindowState } from '../app.reducer';
+import { AppState, createAppDefaultWindowState } from '../app.reducer';
 import Setting from '@joplin/lib/models/Setting';
 
 export const declaration: CommandDeclaration = {
@@ -25,7 +25,7 @@ export const runtime = (): CommandRuntime => {
 				folderId: note.parent_id,
 				windowId: `window-${noteId}-${idCounter++}`,
 				defaultAppWindowState: {
-					...createAppDefaultWindowState(),
+					...createAppDefaultWindowState(context.state as AppState),
 					noteVisiblePanes: Setting.value('noteVisiblePanes'),
 					editorCodeView: Setting.value('editor.codeView'),
 				},

packages/app-desktop/gui/NoteEditor/NoteBody/CodeMirror/v6/CodeMirror.tsx

@@ -342,6 +342,7 @@ const CodeMirror = (props: NoteBodyEditorProps, ref: ForwardedRef<NoteBodyEditor
 		} else if (event.kind === EditorEventType.Change) {
 			codeMirror_change(event.value);
 		} else if (event.kind === EditorEventType.SelectionRangeChange) {
+			props.onCursorMotion({ markdown: event.from });
 			setSelectionRange({ from: event.from, to: event.to });
 		} else if (event.kind === EditorEventType.UpdateSearchDialog) {
 			if (lastSearchState.current?.searchText !== event.searchState.searchText) {
@@ -355,7 +356,7 @@ const CodeMirror = (props: NoteBodyEditorProps, ref: ForwardedRef<NoteBodyEditor
 		} else if (event.kind === EditorEventType.FollowLink) {
 			void CommandService.instance().execute('openItem', event.link);
 		}
-	}, [editor_scroll, codeMirror_change, props.setLocalSearch, props.setShowLocalSearch]);
+	}, [editor_scroll, codeMirror_change, props.setLocalSearch, props.setShowLocalSearch, props.onCursorMotion]);
 
 	const onSelectPastBeginning = useCallback(() => {
 		void CommandService.instance().execute('focusElement', 'noteTitle');
@@ -400,12 +401,16 @@ const CodeMirror = (props: NoteBodyEditorProps, ref: ForwardedRef<NoteBodyEditor
 		props.tabMovesFocus,
 	]);
 
+	const initialCursorLocationRef = useRef(0);
+	initialCursorLocationRef.current = props.initialCursorLocation.markdown ?? 0;
+
 	useSyncEditorValue({
 		content: props.content,
 		visiblePanes: props.visiblePanes,
 		onMessage: props.onMessage,
 		editorRef,
 		noteId: props.noteId,
+		initialCursorLocationRef,
 	});
 
 	const renderEditor = () => {
@@ -414,6 +419,7 @@ const CodeMirror = (props: NoteBodyEditorProps, ref: ForwardedRef<NoteBodyEditor
 				<Editor
 					style={styles.editor}
 					initialText={props.content}
+					initialSelectionRef={initialCursorLocationRef}
 					initialNoteId={props.noteId}
 					ref={editorRef}
 					settings={editorSettings}

packages/app-desktop/gui/NoteEditor/NoteBody/CodeMirror/v6/Editor.tsx

@@ -1,5 +1,5 @@
 import * as React from 'react';
-import { ForwardedRef } from 'react';
+import { ForwardedRef, RefObject } from 'react';
 import { useEffect, useState, useRef, forwardRef, useImperativeHandle } from 'react';
 import { EditorProps, LogMessageCallback, OnEventCallback, ContentScriptData } from '@joplin/editor/types';
 import createEditor from '@joplin/editor/CodeMirror/createEditor';
@@ -23,6 +23,7 @@ import getResourceBaseUrl from '../../../utils/getResourceBaseUrl';
 interface Props extends EditorProps {
 	style: React.CSSProperties;
 	pluginStates: PluginStates;
+	initialSelectionRef: RefObject<number>;
 
 	onEditorPaste: (event: Event)=> void;
 	externalSearch: SearchMarkers;
@@ -127,6 +128,9 @@ const Editor = (props: Props, ref: ForwardedRef<CodeMirrorControl>) => {
 				direction: 'unset',
 			},
 		});
+		const cursor = props.initialSelectionRef.current;
+		editor.select(cursor, cursor);
+
 		setEditor(editor);
 
 		return () => {

packages/app-desktop/gui/NoteEditor/NoteBody/CodeMirror/v6/utils/useSyncEditorValue.ts

@@ -9,15 +9,18 @@ interface Props {
 	onMessage: OnMessage;
 	editorRef: RefObject<CodeMirrorControl>;
 	noteId: string;
+	initialCursorLocationRef: RefObject<number>;
 }
 
 // Updates the editor's value as necessary
-const useSyncEditorValue = ({ content, visiblePanes, onMessage, editorRef, noteId }: Props) => {
+const useSyncEditorValue = ({ content, visiblePanes, onMessage, editorRef, noteId, initialCursorLocationRef }: Props) => {
 	const visiblePanesRef = useRef(visiblePanes);
 	visiblePanesRef.current = visiblePanes;
 	const onMessageRef = useRef(onMessage);
 	onMessageRef.current = onMessage;
 
+	const lastNoteIdRef = useRef(noteId);
+
 	useEffect(() => {
 		// Include the noteId in the update props to give plugins access
 		// to the current note ID.
@@ -25,13 +28,23 @@ const useSyncEditorValue = ({ content, visiblePanes, onMessage, editorRef, noteI
 		if (editorRef.current?.updateBody(content, updateProps)) {
 			editorRef.current?.clearHistory();
 
+			// Only reset the cursor location when switching notes. If, for example,
+			// the note is updated from a secondary window, the cursor location shouldn't
+			// reset.
+			const noteChanged = lastNoteIdRef.current !== noteId;
+			if (noteChanged) {
+				const cursorLocation = initialCursorLocationRef.current;
+				editorRef.current?.select(cursorLocation, cursorLocation);
+			}
+			lastNoteIdRef.current = noteId;
+
 			// If the viewer isn't visible, the content should be considered rendered
 			// after the editor has finished updating:
 			if (!visiblePanesRef.current.includes('viewer')) {
 				onMessageRef.current({ channel: 'noteRenderComplete' });
 			}
 		}
-	}, [content, noteId, editorRef]);
+	}, [content, noteId, editorRef, initialCursorLocationRef]);
 };
 
 export default useSyncEditorValue;

packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/TinyMCE.tsx

@@ -23,7 +23,7 @@ import { themeStyle } from '@joplin/lib/theme';
 import { loadScript } from '../../../utils/loadScript';
 import bridge from '../../../../services/bridge';
 import { TinyMceEditorEvents } from './utils/types';
-import type { Editor, EditorEvent } from 'tinymce';
+import type { Bookmark, Editor, EditorEvent } from 'tinymce';
 import { joplinCommandToTinyMceCommands, TinyMceCommand } from './utils/joplinCommandToTinyMceCommands';
 import shouldPasteResources from './utils/shouldPasteResources';
 import lightTheme from '@joplin/lib/themes/light';
@@ -47,6 +47,7 @@ import Setting from '@joplin/lib/models/Setting';
 import useTextPatternsLookup, { TextPatternContext } from './utils/useTextPatternsLookup';
 import { toFileProtocolPath } from '@joplin/utils/path';
 import { RenderResultPluginAsset } from '@joplin/renderer/types';
+import useCursorPositioning from './utils/useCursorPositioning';
 
 const logger = Logger.create('TinyMCE');
 
@@ -1046,6 +1047,12 @@ const TinyMCE = (props: NoteBodyEditorProps, ref: Ref<NoteBodyEditorRef>) => {
 		return true;
 	}
 
+	const { onInitialContentSet } = useCursorPositioning({
+		initialCursorLocation: props.initialCursorLocation.richText as Bookmark,
+		onCursorUpdate: props.onCursorMotion,
+		editor,
+	});
+
 	const lastNoteIdRef = useRef(props.noteId);
 	useEffect(() => {
 		if (!editor) return () => {};
@@ -1136,6 +1143,7 @@ const TinyMCE = (props: NoteBodyEditorProps, ref: Ref<NoteBodyEditorRef>) => {
 			await loadDocumentAssets(props.themeId, editor, allAssets);
 
 			dispatchDidUpdate(editor);
+			onInitialContentSet();
 		};
 
 		void loadContent();

packages/app-desktop/gui/NoteEditor/NoteBody/TinyMCE/utils/useCursorPositioning.ts

@@ -0,0 +1,55 @@
+import { useCallback, useEffect, useRef } from 'react';
+import { Bookmark, Editor } from 'tinymce';
+import { OnCursorMotion } from '../../../utils/types';
+
+interface Props {
+	initialCursorLocation: Bookmark;
+	editor: Editor;
+	onCursorUpdate: OnCursorMotion;
+}
+
+const useCursorPositioning = ({ initialCursorLocation, editor, onCursorUpdate }: Props) => {
+	const initialCursorLocationRef = useRef(initialCursorLocation);
+	initialCursorLocationRef.current = initialCursorLocation;
+
+	const appliedInitialCursorLocationRef = useRef(false);
+	const onInitialContentSet = useCallback(() => {
+		if (editor) {
+			if (initialCursorLocationRef.current) {
+				editor.selection.moveToBookmark(initialCursorLocationRef.current);
+			}
+
+			appliedInitialCursorLocationRef.current = true;
+		}
+	}, [editor]);
+
+	useEffect(() => {
+		if (!editor) return () => {};
+
+		editor.on('ContentSet', onInitialContentSet);
+
+		const onSelectionChange = () => {
+			// Wait until the initial cursor position has been set. This avoids resetting
+			// the initial cursor position to zero when the editor first loads.
+			if (!appliedInitialCursorLocationRef.current) return;
+
+			// Use an offset bookmark -- the default bookmark type is not preserved after unloading
+			// and reloading the editor.
+			const offsetBookmarkId = 2;
+			onCursorUpdate({
+				richText: editor.selection.getBookmark(offsetBookmarkId, true),
+			});
+		};
+
+		editor.on('SelectionChange', onSelectionChange);
+
+		return () => {
+			editor.off('ContentSet', onInitialContentSet);
+			editor.off('SelectionChange', onSelectionChange);
+		};
+	}, [editor, onCursorUpdate, onInitialContentSet]);
+
+	return { onInitialContentSet };
+};
+
+export default useCursorPositioning;

packages/app-desktop/gui/NoteEditor/NoteEditor.tsx

@@ -18,7 +18,7 @@ import { NoteEditorProps, FormNote, OnChangeEvent, AllAssetsOptions, NoteBodyEdi
 import CommandService from '@joplin/lib/services/CommandService';
 import Button, { ButtonLevel } from '../Button/Button';
 import eventManager, { EventName } from '@joplin/lib/eventManager';
-import { AppState } from '../../app.reducer';
+import { AppState, EditorCursorLocations } from '../../app.reducer';
 import ToolbarButtonUtils, { ToolbarButtonInfo } from '@joplin/lib/services/commands/ToolbarButtonUtils';
 import { _, _n } from '@joplin/lib/locale';
 import NoteTitleBar from './NoteTitle/NoteTitleBar';
@@ -57,6 +57,7 @@ import StatusBar from './StatusBar';
 import useVisiblePluginEditorViewIds from '@joplin/lib/hooks/plugins/useVisiblePluginEditorViewIds';
 import useConnectToEditorPlugin from './utils/useConnectToEditorPlugin';
 import getResourceBaseUrl from './utils/getResourceBaseUrl';
+import useInitialCursorLocation from './utils/useInitialCursorLocation';
 
 const debounce = require('debounce');
 
@@ -409,6 +410,14 @@ function NoteEditorContent(props: NoteEditorProps) {
 		});
 	}, [props.dispatch]);
 
+	const onCursorMotion = useCallback((location: EditorCursorLocations) => {
+		props.dispatch({
+			type: 'EDITOR_CURSOR_POSITION_SET',
+			noteId: formNoteRef.current.id,
+			location,
+		});
+	}, [props.dispatch]);
+
 	function renderNoNotes(rootStyle: React.CSSProperties) {
 		const emptyDivStyle = {
 			backgroundColor: 'black',
@@ -419,6 +428,9 @@ function NoteEditorContent(props: NoteEditorProps) {
 	}
 
 	const searchMarkers = useSearchMarkers(showLocalSearch, localSearchMarkerOptions, props.searches, props.selectedSearchId, props.highlightedWords);
+	const initialCursorLocation = useInitialCursorLocation({
+		lastEditorCursorLocations: props.lastEditorCursorLocations, noteId: props.noteId,
+	});
 
 	const markupLanguage = formNote.markup_language;
 	const editorProps: NoteBodyEditorPropsAndRef = {
@@ -432,6 +444,7 @@ function NoteEditorContent(props: NoteEditorProps) {
 		content: formNote.body,
 		contentMarkupLanguage: markupLanguage,
 		contentOriginalCss: formNote.originalCss,
+		initialCursorLocation,
 		resourceInfos: resourceInfos,
 		resourceDirectory: Setting.value('resourceDir'),
 		htmlToMarkdown: htmlToMarkdown,
@@ -442,6 +455,7 @@ function NoteEditorContent(props: NoteEditorProps) {
 		dispatch: props.dispatch,
 		noteToolbar: null,
 		onScroll: onScroll,
+		onCursorMotion,
 		setLocalSearchResultCount: setLocalSearchResultCount,
 		setLocalSearch: localSearch_change,
 		setShowLocalSearch,
@@ -729,6 +743,7 @@ const mapStateToProps = (state: AppState, ownProps: ConnectProps) => {
 		notesParentType: windowState.notesParentType,
 		selectedNoteTags: windowState.selectedNoteTags,
 		lastEditorScrollPercents: state.lastEditorScrollPercents,
+		lastEditorCursorLocations: state.lastEditorCursorLocations,
 		selectedNoteHash: windowState.selectedNoteHash,
 		searches: state.searches,
 		selectedSearchId: windowState.selectedSearchId,

packages/app-desktop/gui/NoteEditor/utils/types.ts

@@ -14,6 +14,7 @@ import { ScrollbarSize } from '@joplin/lib/models/settings/builtInMetadata';
 import { RefObject, SetStateAction } from 'react';
 import * as React from 'react';
 import { ResourceEntity, ResourceLocalStateEntity } from '@joplin/lib/services/database/types';
+import { EditorCursorLocations, NoteIdToEditorCursorLocations, NoteIdToScrollPercent } from '../../../app.reducer';
 
 export interface AllAssetsOptions {
 	contentMaxWidthTarget?: string;
@@ -40,8 +41,8 @@ export interface NoteEditorProps {
 	notesParentType: string;
 	// eslint-disable-next-line @typescript-eslint/no-explicit-any -- Old code before rule was applied
 	selectedNoteTags: any[];
-	// eslint-disable-next-line @typescript-eslint/no-explicit-any -- Old code before rule was applied
-	lastEditorScrollPercents: any;
+	lastEditorScrollPercents: NoteIdToScrollPercent;
+	lastEditorCursorLocations: NoteIdToEditorCursorLocations;
 	selectedNoteHash: string;
 	// eslint-disable-next-line @typescript-eslint/no-explicit-any -- Old code before rule was applied
 	searches: any[];
@@ -83,6 +84,7 @@ export interface NoteBodyEditorRef {
 export { MarkupToHtmlOptions };
 export type MarkupToHtmlHandler = (markupLanguage: MarkupLanguage, markup: string, options: MarkupToHtmlOptions)=> Promise<RenderResult>;
 export type HtmlToMarkdownHandler = (markupLanguage: number, html: string, originalCss: string, parseOptions?: ParseOptions)=> Promise<string>;
+export type OnCursorMotion = (event: EditorCursorLocations)=> void;
 
 export interface MessageEvent {
 	channel: string;
@@ -109,11 +111,13 @@ export interface NoteBodyEditorProps {
 	contentKey: string;
 	contentMarkupLanguage: number;
 	contentOriginalCss: string;
+	initialCursorLocation: EditorCursorLocations;
 	onChange(event: OnChangeEvent): void;
 	// eslint-disable-next-line @typescript-eslint/no-explicit-any -- Old code before rule was applied
 	onWillChange(event: any): void;
 	onMessage: OnMessage;
 	onScroll(event: { percent: number }): void;
+	onCursorMotion: OnCursorMotion;
 	markupToHtml: MarkupToHtmlHandler;
 	htmlToMarkdown: HtmlToMarkdownHandler;
 	allAssets: (markupLanguage: MarkupLanguage, options: AllAssetsOptions)=> Promise<RenderResultPluginAsset[]>;

packages/app-desktop/gui/NoteEditor/utils/useInitialCursorLocation.ts

@@ -0,0 +1,17 @@
+import { useMemo } from 'react';
+import { EditorCursorLocations, NoteIdToEditorCursorLocations } from '../../../app.reducer';
+
+interface Props {
+	lastEditorCursorLocations: NoteIdToEditorCursorLocations;
+	noteId: string;
+}
+
+const useInitialCursorLocation = ({ noteId, lastEditorCursorLocations }: Props) => {
+	const lastCursorLocation = lastEditorCursorLocations[noteId];
+
+	return useMemo((): EditorCursorLocations => {
+		return lastCursorLocation ?? { };
+	}, [lastCursorLocation]);
+};
+
+export default useInitialCursorLocation;

packages/app-desktop/gui/NoteEditor/utils/useScrollWhenReadyOptions.ts

@@ -1,13 +1,13 @@
 import { RefObject, useCallback, useRef } from 'react';
 import { NoteBodyEditorRef, ScrollOptions, ScrollOptionTypes } from './types';
 import usePrevious from '@joplin/lib/hooks/usePrevious';
-import type { EditorScrollPercents } from '../../../app.reducer';
+import type { NoteIdToScrollPercent } from '../../../app.reducer';
 import useNowEffect from '@joplin/lib/hooks/useNowEffect';
 
 interface Props {
 	noteId: string;
 	selectedNoteHash: string;
-	lastEditorScrollPercents: EditorScrollPercents;
+	lastEditorScrollPercents: NoteIdToScrollPercent;
 	editorRef: RefObject<NoteBodyEditorRef>;
 }
 
@@ -15,7 +15,7 @@ const useScrollWhenReadyOptions = ({ noteId, selectedNoteHash, lastEditorScrollP
 	const scrollWhenReadyRef = useRef<ScrollOptions|null>(null);
 
 	const previousNoteId = usePrevious(noteId);
-	const lastScrollPercentsRef = useRef<EditorScrollPercents>(null);
+	const lastScrollPercentsRef = useRef<NoteIdToScrollPercent>(null);
 	lastScrollPercentsRef.current = lastEditorScrollPercents;
 
 	// This needs to be a nowEffect to prevent race conditions

packages/app-desktop/gui/utils/NoteListUtils.test.ts

@@ -38,7 +38,7 @@ describe('NoteListUtils', () => {
 		const mockStore = {
 			getState: () => {
 				return {
-					...createAppDefaultWindowState(),
+					...createAppDefaultWindowState(null),
 					settings: {},
 				};
 			},

packages/editor/CodeMirror/CodeMirrorControl.ts

@@ -89,8 +89,14 @@ export default class CodeMirrorControl extends CodeMirror5Emulation implements E
 	}
 
 	public select(anchor: number, head: number) {
+		const maximumPosition = this.editor.state.doc.length;
 		this.editor.dispatch(this.editor.state.update({
-			selection: { anchor, head },
+			selection: {
+				// Ensure that (anchor, head) are in range.
+				// (CodeMirror throws when (anchor, head) are out-of-range.)
+				anchor: Math.min(anchor, maximumPosition),
+				head: Math.min(head, maximumPosition),
+			},
 			scrollIntoView: true,
 		}));
 	}