wip

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

frontend/src/components/editor-page/editor-pane/codemirror-extensions/use-sync-to-redux-extension.ts

@@ -0,0 +1,27 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { useMemo } from 'react'
+import { EditorView } from '@codemirror/view'
+import { setNoteContent } from '../../../../redux/note-details/methods'
+
+/**
+ * Syncs the CodeMirror content to the redux store.
+ *
+ * @return the codemirror extension that updates the redux state
+ */
+export const useSyncToReduxExtension = () => {
+  return useMemo(
+    () =>
+      EditorView.updateListener.of((update) => {
+        if (!update.docChanged) {
+          return
+        }
+        setNoteContent(update.state.sliceDoc())
+      }),
+    []
+  )
+}

frontend/src/components/editor-page/editor-pane/editor-pane.tsx

@@ -24,7 +24,6 @@ import { useApplyScrollState } from './hooks/use-apply-scroll-state'
 import { useCursorActivityCallback } from './hooks/use-cursor-activity-callback'
 import { useDisconnectOnUserLoginStatusChange } from './hooks/use-disconnect-on-user-login-status-change'
 import { useUpdateCodeMirrorReference } from './hooks/use-update-code-mirror-reference'
-import { useBindYTextToRedux } from './hooks/yjs/use-bind-y-text-to-redux'
 import { useCodeMirrorYjsExtension } from './hooks/yjs/use-code-mirror-yjs-extension'
 import { useOnMetadataUpdated } from './hooks/yjs/use-on-metadata-updated'
 import { useOnNoteDeleted } from './hooks/yjs/use-on-note-deleted'
@@ -43,6 +42,7 @@ import { lintGutter } from '@codemirror/lint'
 import { oneDark } from '@codemirror/theme-one-dark'
 import ReactCodeMirror from '@uiw/react-codemirror'
 import React, { useEffect, useMemo } from 'react'
+import { useSyncToReduxExtension } from './codemirror-extensions/use-sync-to-redux-extension'
 
 export type EditorPaneProps = ScrollProps
 
@@ -83,12 +83,14 @@ export const EditorPane: React.FC<EditorPaneProps> = ({ scrollState, onScroll, o
   useOnMetadataUpdated(messageTransporter)
   useOnNoteDeleted(messageTransporter)
 
-  useBindYTextToRedux(realtimeDoc)
   useReceiveRealtimeUsers(messageTransporter)
   useSendRealtimeActivity(messageTransporter)
 
+  const syncToReduxExtension = useSyncToReduxExtension()
+
   const extensions = useMemo(
     () => [
+      syncToReduxExtension,
       linterExtension,
       lintGutter(),
       markdown({
@@ -107,17 +109,18 @@ export const EditorPane: React.FC<EditorPaneProps> = ({ scrollState, onScroll, o
       spellCheckExtension
     ],
     [
+      syncToReduxExtension,
       linterExtension,
       remoteCursorsExtension,
-      autoCompletionExtension,
+      lineWrappingExtension,
       editorScrollExtension,
       tablePasteExtensions,
       fileInsertExtension,
+      autoCompletionExtension,
       cursorActivityExtension,
       updateViewContextExtension,
       yjsExtension,
-      spellCheckExtension,
-      lineWrappingExtension
+      spellCheckExtension
     ]
   )
 

frontend/src/components/editor-page/editor-pane/hooks/yjs/use-bind-y-text-to-redux.ts

@@ -1,22 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-import { setNoteContent } from '../../../../../redux/note-details/methods'
-import type { RealtimeDoc } from '@hedgedoc/commons'
-import { useEffect } from 'react'
-
-/**
- * One-Way-synchronizes the text of the markdown content channel from the given {@link RealtimeDoc realtime doc} into the global application state.
- *
- * @param realtimeDoc The {@link RealtimeDoc realtime doc} that contains the markdown content
- */
-export const useBindYTextToRedux = (realtimeDoc: RealtimeDoc): void => {
-  useEffect(() => {
-    const yText = realtimeDoc.getMarkdownContentChannel()
-    const yTextCallback = () => setNoteContent(yText.toString())
-    yText.observe(yTextCallback)
-    return () => yText.unobserve(yTextCallback)
-  }, [realtimeDoc])
-}

frontend/src/hooks/common/use-deferred-state.ts

@@ -0,0 +1,39 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { useCallback, useEffect, useRef, useState } from 'react'
+import { useInterval } from 'react-use'
+
+/**
+ * Takes a value that changes often and outputs the last value that hasn't been changed in the last interval.
+ *
+ * @param value The value to defer
+ * @param initialValue The initial value that is used until the first update
+ * @param checkInterval The interval in ms that is used to check for updates. Default is 200ms.
+ * @return The slowed down value
+ */
+export const useDeferredState = <T>(value: T, initialValue: T, checkInterval = 200): T => {
+  const valueRef = useRef<T>(initialValue)
+  const lastTimestamp = useRef<number>(0)
+  const [deferredValue, setDeferredValue] = useState<T>(initialValue)
+
+  useEffect(() => {
+    valueRef.current = value
+    lastTimestamp.current = new Date().getTime()
+  }, [value])
+
+  useInterval(
+    useCallback(() => {
+      const currentTimeStamp = new Date().getTime()
+      if (currentTimeStamp - lastTimestamp.current >= checkInterval) {
+        setDeferredValue(valueRef.current)
+      }
+    }, [checkInterval]),
+    checkInterval
+  )
+
+  return deferredValue
+}

frontend/src/hooks/common/use-trimmed-note-markdown-content-without-frontmatter.ts

@@ -6,6 +6,7 @@
 import { useFrontendConfig } from '../../components/common/frontend-config-context/use-frontend-config'
 import { useApplicationState } from './use-application-state'
 import { useMemo } from 'react'
+import { useDeferredState } from './use-deferred-state'
 
 /**
  * Returns the markdown content from the global application state trimmed to the maximal note length and without the frontmatter lines.
@@ -28,7 +29,8 @@ export const useTrimmedNoteMarkdownContentWithoutFrontmatter = (): string[] => {
     }
   }, [markdownContent, maxLength])
 
-  return useMemo(() => {
-    return trimmedLines.slice(lineOffset)
-  }, [lineOffset, trimmedLines])
+  return useDeferredState(
+    useMemo(() => trimmedLines.slice(lineOffset), [lineOffset, trimmedLines]),
+    []
+  )
 }