fix: Remember cursor position when autofocus on load

Signed-off-by: Julius Härtl <jus@bitgrid.net>

src/components/Editor.vue

@@ -83,6 +83,7 @@ import { loadState } from '@nextcloud/initial-state'
 import { emit, subscribe, unsubscribe } from '@nextcloud/event-bus'
 import { Collaboration } from '@tiptap/extension-collaboration'
 import { CollaborationCursor } from '@tiptap/extension-collaboration-cursor'
+import Autofocus from '../extensions/Autofocus.js'
 import { Doc } from 'yjs'
 
 import {
@@ -493,6 +494,9 @@ export default {
 								})
 							},
 							extensions: [
+								Autofocus.configure({
+									fileId: this.fileId,
+								}),
 								Collaboration.configure({
 									document: this.$ydoc,
 								}),
@@ -587,7 +591,7 @@ export default {
 				this.contentLoaded = true
 				if (this.autofocus && !this.readOnly) {
 					this.$nextTick(() => {
-						this.$editor.commands.focus()
+						this.$editor.commands.autofocus()
 					})
 				}
 				this.emit('ready')

src/extensions/Autofocus.js

@@ -0,0 +1,61 @@
+/*
+ * @copyright Copyright (c) 2023 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import { Extension } from '@tiptap/core'
+
+export default Extension.create({
+	addOptions() {
+		return {
+			fileId: null,
+		}
+	},
+	addStorage() {
+		return {
+			started: false,
+		}
+	},
+	onCreate() {
+		if (this.options.fileId === null) {
+			throw new Error('fileId needs to be provided')
+		}
+		this.storage.started = true
+	},
+	onSelectionUpdate({ editor }) {
+		if (!this.storage.started) {
+			return
+		}
+
+		const pos = editor.state.selection.$anchor.pos
+		sessionStorage.setItem('text-lastPos-' + this.options.fileId, pos)
+	},
+	addCommands() {
+		return {
+			autofocus: () => ({ commands, editor }) => {
+				const pos = sessionStorage.getItem('text-lastPos-' + this.options.fileId)
+				if (pos) {
+					return commands.focus(pos)
+				}
+
+				return commands.focus('start')
+			},
+		}
+	},
+})