Merge pull request 'perf(editor): срезать работу на каждый keystroke — латентность печати (#343)' (#357) from perf/343-typing-latency into develop

Reviewed-on: #357

apps/client/src/features/editor/components/audio/audio-menu.tsx

@@ -46,6 +46,13 @@ export function AudioMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip getAttributes unless an audio node is active. The menu
+      // only shows for an active audio node (shouldShow), so the null state while
+      // inactive is never rendered — behavior unchanged.
+      if (!ctx.editor.isActive("audio")) {
+        return null;
+      }
+
       const audioAttrs = ctx.editor.getAttributes("audio");
 
       return {

apps/client/src/features/editor/components/callout/callout-menu.tsx

@@ -43,8 +43,15 @@ export function CalloutMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip the per-type isActive() probes unless a callout is
+      // active. The menu only shows for an active callout (shouldShow), so the
+      // null state while inactive is never rendered — behavior unchanged.
+      if (!ctx.editor.isActive("callout")) {
+        return null;
+      }
+
       return {
-        isCallout: ctx.editor.isActive("callout"),
+        isCallout: true,
         isInfo: ctx.editor.isActive("callout", { type: "info" }),
         isNote: ctx.editor.isActive("callout", { type: "note" }),
         isSuccess: ctx.editor.isActive("callout", { type: "success" }),

apps/client/src/features/editor/components/code-block/code-block-view.tsx

@@ -22,6 +22,12 @@ export default function CodeBlockView(props: NodeViewProps) {
   const [isSelected, setIsSelected] = useState(false);
 
   useEffect(() => {
+    // #343 PART 6: `isSelected` only drives the mermaid source's visibility (the
+    // `hidden` prop below). For every non-mermaid code block it is never read,
+    // so skip the per-block `selectionUpdate` listener entirely — otherwise N
+    // code blocks each add a global listener + a setState on every caret move.
+    if (language !== "mermaid") return;
+
     const updateSelection = () => {
       const { state } = editor;
       const { from, to } = state.selection;
@@ -32,11 +38,14 @@ export default function CodeBlockView(props: NodeViewProps) {
       setIsSelected(isNodeSelected);
     };
 
+    // Initialize on attach so switching a block's language to "mermaid" reflects
+    // the current selection immediately (the listener was not running before).
+    updateSelection();
     editor.on("selectionUpdate", updateSelection);
     return () => {
       editor.off("selectionUpdate", updateSelection);
     };
-  }, [editor, getPos(), node.nodeSize]);
+  }, [editor, getPos(), node.nodeSize, language]);
 
   function changeLanguage(language: string) {
     setLanguageValue(language);

apps/client/src/features/editor/components/fixed-toolbar/use-toolbar-state.ts

@@ -1,5 +1,7 @@
 import type { Editor } from "@tiptap/react";
 import { useEditorState } from "@tiptap/react";
+import { undoDepth, redoDepth } from "@tiptap/pm/history";
+import { yUndoPluginKey } from "@tiptap/y-tiptap";
 
 export interface ToolbarState {
   isBold: boolean;
@@ -16,14 +18,45 @@ export interface ToolbarState {
   canRedo: boolean;
 }
 
-// Undo/redo come from either StarterKit's history or the Yjs collaboration
-// history extension. During the brief moment a page is rendered with the
-// static editor (mainExtensions only, undoRedo disabled), neither is loaded
-// and editor.can().undo/redo is undefined.
-function safeCan(editor: Editor, command: "undo" | "redo"): boolean {
-  const can = editor.can() as Record<string, unknown>;
-  const fn = can[command];
-  return typeof fn === "function" ? (fn as () => boolean)() : false;
+// Undo/redo availability, computed WITHOUT `editor.can().undo()/.redo()`.
+//
+// `editor.can()` runs the command as a dry-run (building a throwaway state +
+// transaction) — the most expensive work in this selector, and it ran on every
+// keystroke (and every REMOTE keystroke under collaboration). Instead we read
+// the history stack depth directly, which is a cheap plugin-state lookup and
+// mirrors exactly what the undo/redo commands themselves check:
+//
+//  - Collaboration (Yjs): the yjs UndoManager's undo/redo stack lengths — the
+//    same `undoStack.length === 0` / `redoStack.length === 0` guard the
+//    Collaboration extension's undo/redo commands use.
+//  - Plain history (templates / non-collab): prosemirror-history's undoDepth /
+//    redoDepth, which back the UndoRedo extension.
+//
+// When neither history backend is installed (the pre-sync static editor —
+// mainExtensions only, undoRedo disabled), both fall through to 0 -> false,
+// matching the previous `safeCan` behavior.
+function historyAvailability(editor: Editor): {
+  canUndo: boolean;
+  canRedo: boolean;
+} {
+  const state = editor.state;
+
+  // Collaboration history (Yjs) takes precedence when present.
+  const yState = yUndoPluginKey.getState(state) as
+    | { undoManager?: { undoStack: unknown[]; redoStack: unknown[] } }
+    | undefined;
+  if (yState?.undoManager) {
+    return {
+      canUndo: yState.undoManager.undoStack.length > 0,
+      canRedo: yState.undoManager.redoStack.length > 0,
+    };
+  }
+
+  // Plain prosemirror-history (returns 0 when the history plugin is absent).
+  return {
+    canUndo: undoDepth(state) > 0,
+    canRedo: redoDepth(state) > 0,
+  };
 }
 
 export function useToolbarState(editor: Editor | null): ToolbarState | null {
@@ -31,6 +64,7 @@ export function useToolbarState(editor: Editor | null): ToolbarState | null {
     editor,
     selector: (ctx) => {
       if (!ctx.editor) return null;
+      const { canUndo, canRedo } = historyAvailability(ctx.editor);
       return {
         isBold: ctx.editor.isActive("bold"),
         isItalic: ctx.editor.isActive("italic"),
@@ -42,8 +76,8 @@ export function useToolbarState(editor: Editor | null): ToolbarState | null {
         isBulletList: ctx.editor.isActive("bulletList"),
         isOrderedList: ctx.editor.isActive("orderedList"),
         isTaskList: ctx.editor.isActive("taskList"),
-        canUndo: safeCan(ctx.editor, "undo"),
-        canRedo: safeCan(ctx.editor, "redo"),
+        canUndo,
+        canRedo,
       };
     },
   });

apps/client/src/features/editor/components/image/image-menu.tsx

@@ -38,6 +38,14 @@ export function ImageMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip the expensive per-keystroke work (getAttributes + the
+      // alignment isActive() probes) unless an image is actually active. The
+      // menu is only shown when an image is active (see shouldShow), so a null
+      // state while inactive is never rendered — behavior is unchanged.
+      if (!ctx.editor.isActive("image")) {
+        return null;
+      }
+
       const imageAttrs = ctx.editor.getAttributes("image");
 
       return {

apps/client/src/features/editor/components/pdf/pdf-menu.tsx

@@ -25,6 +25,13 @@ export function PdfMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip getAttributes unless a pdf node is active. The menu
+      // only shows for an active pdf node (shouldShow), so the null state while
+      // inactive is never rendered — behavior unchanged.
+      if (!ctx.editor.isActive("pdf")) {
+        return null;
+      }
+
       const pdfAttrs = ctx.editor.getAttributes("pdf");
 
       return {

apps/client/src/features/editor/components/subpages/subpages-menu.tsx

@@ -70,7 +70,14 @@ export const SubpagesMenu = React.memo(
     // toggle without re-rendering on every keystroke.
     const isRecursive = useEditorState({
       editor,
-      selector: (ctx) => ctx.editor?.getAttributes("subpages")?.recursive ?? false,
+      // #343 PART 1: skip getAttributes unless a subpages node is active. The
+      // menu only shows for an active subpages node (shouldShow), so the value
+      // is only read then; getAttributes on an inactive node returns the default
+      // (recursive === false) anyway, so this is behavior-preserving.
+      selector: (ctx) =>
+        ctx.editor?.isActive("subpages")
+          ? (ctx.editor.getAttributes("subpages")?.recursive ?? false)
+          : false,
     });
 
     return (

apps/client/src/features/editor/components/table-of-contents/table-of-contents.tsx

@@ -4,6 +4,7 @@ import React, { FC, useEffect, useRef, useState } from "react";
 import classes from "./table-of-contents.module.css";
 import clsx from "clsx";
 import { Box, Text, Title } from "@mantine/core";
+import { useDebouncedCallback } from "@mantine/hooks";
 import { useTranslation } from "react-i18next";
 
 type TableOfContentsProps = {
@@ -79,13 +80,21 @@ export const TableOfContents: FC<TableOfContentsProps> = (props) => {
     setHeadingDOMNodes(result.nodes);
   };
 
+  // Debounce the update-driven rescan: `$nodes("heading")` scans every heading
+  // in the document, and it previously ran on EVERY keystroke while the TOC
+  // panel was open. The panel is derived UI, so recomputing ~300ms after typing
+  // settles keeps it correct without doing an all-headings scan per keystroke
+  // (#343, PART 7). `useDebouncedCallback` returns a stable reference and always
+  // invokes the latest `handleUpdate`.
+  const debouncedHandleUpdate = useDebouncedCallback(handleUpdate, 300);
+
   useEffect(() => {
-    props.editor?.on("update", handleUpdate);
+    props.editor?.on("update", debouncedHandleUpdate);
 
     return () => {
-      props.editor?.off("update", handleUpdate);
+      props.editor?.off("update", debouncedHandleUpdate);
     };
-  }, [props.editor]);
+  }, [props.editor, debouncedHandleUpdate]);
 
   useEffect(
     () => {

apps/client/src/features/editor/components/video/video-menu.tsx

@@ -31,6 +31,13 @@ export function VideoMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip getAttributes + alignment isActive() probes unless a
+      // video is active. The menu only shows for an active video (shouldShow),
+      // so the null state while inactive is never rendered — behavior unchanged.
+      if (!ctx.editor.isActive("video")) {
+        return null;
+      }
+
       const videoAttrs = ctx.editor.getAttributes("video");
 
       return {