fix(toc): not reacting to attribute changes in CKEditor

apps/client/src/widgets/sidebar/TableOfContents.tsx

@@ -1,6 +1,6 @@
 import "./TableOfContents.css";
 
-import { CKTextEditor, ModelElement } from "@triliumnext/ckeditor5";
+import { attributeChangeAffectsHeading, CKTextEditor, ModelElement } from "@triliumnext/ckeditor5";
 import clsx from "clsx";
 import { useCallback, useEffect, useRef, useState } from "preact/hooks";
 
@@ -170,7 +170,8 @@ function EditableTextTableOfContents() {
 
             const affectsHeadings = changes.some( change => {
                 return (
-                    change.type === 'insert' || change.type === 'remove' || (change.type === 'attribute' && change.attributeKey === 'headingLevel')
+                    change.type === 'insert' || change.type === 'remove' ||
+                    (change.type === 'attribute' && attributeChangeAffectsHeading(change, textEditor))
                 );
             });
             if (affectsHeadings) {

packages/ckeditor5/src/index.ts

@@ -11,6 +11,7 @@ export type { EditorConfig, MentionFeed, MentionFeedObjectItem, ModelNode, Model
 export type { TemplateDefinition } from "ckeditor5-premium-features";
 export { default as buildExtraCommands } from "./extra_slash_commands.js";
 export { default as getCkLocale } from "./i18n.js";
+export * from "./utils.js";
 
 // Import with sideffects to ensure that type augmentations are present.
 import "@triliumnext/ckeditor5-math";

packages/ckeditor5/src/utils.ts

@@ -0,0 +1,37 @@
+import { DifferItemAttribute, ModelDocumentFragment, ModelElement, ModelNode } from "ckeditor5";
+import { CKTextEditor } from "src";
+
+function isHeadingElement(node: ModelElement | ModelNode | ModelDocumentFragment | null): node is ModelElement {
+    return !!node
+        && typeof (node as any).is === "function"
+        && (node as any).is("element")
+        && typeof (node as any).name === "string"
+        && (node as any).name.startsWith("heading");
+}
+
+function hasHeadingAncestor(node: ModelElement | ModelNode | ModelDocumentFragment | null): boolean {
+    let current: ModelElement | ModelNode | ModelDocumentFragment | null = node;
+    while (current) {
+        if (isHeadingElement(current)) return true;
+        current = current.parent;
+    }
+    return false;
+}
+
+export function attributeChangeAffectsHeading(change: DifferItemAttribute, editor: CKTextEditor): boolean {
+    if (change.type !== "attribute") return false;
+
+    // Fast checks on range boundaries
+    if (hasHeadingAncestor(change.range.start.parent) || hasHeadingAncestor(change.range.end.parent)) {
+        return true;
+    }
+
+    // Robust check across the whole changed range
+    const range = editor.model.createRange(change.range.start, change.range.end);
+    for (const item of range.getItems()) {
+        const baseNode = item.is("$textProxy") ? item.parent : item;
+        if (hasHeadingAncestor(baseNode)) return true;
+    }
+
+    return false;
+}