feat(editor): improve latex editing support (#14924)

## Summary
- support converting selected text into inline LaTeX equations
- support turning text blocks into LaTeX equation blocks
- add equation entries to editor toolbars while keeping inline equation
with text formatting actions

## Tests
- yarn tsc -b blocksuite/affine/inlines/latex/tsconfig.json
blocksuite/affine/blocks/note/tsconfig.json
blocksuite/affine/blocks/root/tsconfig.json
blocksuite/affine/rich-text/tsconfig.json
blocksuite/affine/widgets/keyboard-toolbar/tsconfig.json --pretty false
- git diff --check origin/canary...HEAD

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
  * Equation block support with conversion from existing blocks.
  * Inline LaTeX insertion added to the inline formatting toolbar.
* Equation action added to the keyboard toolbar; Equation blocks
searchable via math/equation/latex aliases.

* **Improvements**
* Inline LaTeX editor opens and syncs more reliably; selection/convert
flow preserves distinct LaTeX values when converting in reverse order.

* **Tests**
  * New e2e tests for inline LaTeX conversions and value preservation.

<!-- review_stack_entry_start -->

[![Review Change
Stack](https://storage.googleapis.com/coderabbit_public_assets/review-stack-in-coderabbit-ui.svg)](https://app.coderabbit.ai/change-stack/toeverything/AFFiNE/pull/14924)

<!-- review_stack_entry_end -->
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/blocks/note/src/commands/block-type.ts

@@ -121,6 +121,38 @@ export const updateBlockType: Command<
     }
     return next({ updatedBlocks: [newModel] });
   };
+  const transformToLatex: Command<{}, { updatedBlocks: BlockModel[] }> = (
+    _,
+    next
+  ) => {
+    if (flavour !== 'affine:latex') return;
+
+    const newModels: BlockModel[] = [];
+    blockModels.forEach(model => {
+      if (
+        !matchModels(model, [
+          ParagraphBlockModel,
+          ListBlockModel,
+          CodeBlockModel,
+        ])
+      ) {
+        return;
+      }
+
+      const latex = model.text?.toString() ?? '';
+      const newId = transformModel(model, 'affine:latex', { latex });
+      if (!newId) {
+        return;
+      }
+      const newModel = doc.getModelById(newId);
+      if (newModel) {
+        newModels.push(newModel);
+      }
+    });
+
+    if (newModels.length === 0) return;
+    return next({ updatedBlocks: newModels });
+  };
 
   const focusText: Command<{ updatedBlocks: BlockModel[] }> = (ctx, next) => {
     const { updatedBlocks } = ctx;
@@ -185,6 +217,27 @@ export const updateBlockType: Command<
     });
     return next();
   };
+  const selectBlocks: Command<{ updatedBlocks: BlockModel[] }> = (
+    ctx,
+    next
+  ) => {
+    const { updatedBlocks } = ctx;
+    if (!updatedBlocks || updatedBlocks.length === 0) {
+      return false;
+    }
+
+    requestAnimationFrame(() => {
+      host.selection.setGroup(
+        'note',
+        updatedBlocks.map(model =>
+          host.selection.create(BlockSelection, {
+            blockId: model.id,
+          })
+        )
+      );
+    });
+    return next();
+  };
 
   const [result, resultCtx] = std.command
     .chain()
@@ -196,6 +249,7 @@ export const updateBlockType: Command<
     .try<{ updatedBlocks: BlockModel[] }>(chain => [
       chain.pipe(mergeToCode),
       chain.pipe(appendDivider),
+      chain.pipe(transformToLatex),
       chain.pipe((_, next) => {
         const newModels: BlockModel[] = [];
         blockModels.forEach(model => {
@@ -227,6 +281,14 @@ export const updateBlockType: Command<
     ])
     // focus
     .try(chain => [
+      chain
+        .pipe((_, next) => {
+          if (flavour === 'affine:latex') {
+            return next();
+          }
+          return false;
+        })
+        .pipe(selectBlocks),
       chain.pipe((_, next) => {
         if (['affine:code', 'affine:divider'].includes(flavour)) {
           return next();

blocksuite/affine/blocks/root/package.json

@@ -30,6 +30,7 @@
     "@blocksuite/affine-gfx-pointer": "workspace:*",
     "@blocksuite/affine-gfx-shape": "workspace:*",
     "@blocksuite/affine-gfx-text": "workspace:*",
+    "@blocksuite/affine-inline-latex": "workspace:*",
     "@blocksuite/affine-inline-preset": "workspace:*",
     "@blocksuite/affine-model": "workspace:*",
     "@blocksuite/affine-rich-text": "workspace:*",

blocksuite/affine/blocks/root/src/configs/toolbar.ts

@@ -15,6 +15,7 @@ import {
 import type { HighlightType } from '@blocksuite/affine-components/highlight-dropdown-menu';
 import { toast } from '@blocksuite/affine-components/toast';
 import { EditorChevronDown } from '@blocksuite/affine-components/toolbar';
+import { insertInlineLatex } from '@blocksuite/affine-inline-latex';
 import {
   deleteTextCommand,
   formatBlockCommand,
@@ -61,6 +62,7 @@ import {
   DeleteIcon,
   DuplicateIcon,
   LinkedPageIcon,
+  TeXIcon,
 } from '@blocksuite/icons/lit';
 import {
   type BlockComponent,
@@ -199,9 +201,9 @@ const alignActionGroup = {
 const inlineTextActionGroup = {
   id: 'b.inline-text',
   when: ({ chain }) => isFormatSupported(chain).run()[0],
-  actions: textFormatConfigs.map(
+  actions: textFormatConfigs.flatMap(
     ({ id, name, action, activeWhen, icon }, score) => {
-      return {
+      const textAction: ToolbarAction = {
         id,
         icon,
         score,
@@ -209,6 +211,28 @@ const inlineTextActionGroup = {
         run: ({ host }) => action(host),
         active: ({ host }) => activeWhen(host),
       };
+
+      if (id !== 'underline') {
+        return [textAction];
+      }
+
+      return [
+        textAction,
+        {
+          id: 'inline-latex',
+          icon: TeXIcon(),
+          score: score + 0.5,
+          tooltip: 'Inline Equation',
+          run: ({ host }) => {
+            host.std.command
+              .chain()
+              .pipe(getTextSelectionCommand)
+              .pipe(insertInlineLatex)
+              .run();
+          },
+          active: () => false,
+        },
+      ];
     }
   ),
 } as const satisfies ToolbarActionGroup;

blocksuite/affine/blocks/root/tsconfig.json

@@ -27,6 +27,7 @@
     { "path": "../../gfx/pointer" },
     { "path": "../../gfx/shape" },
     { "path": "../../gfx/text" },
+    { "path": "../../inlines/latex" },
     { "path": "../../inlines/preset" },
     { "path": "../../model" },
     { "path": "../../rich-text" },

blocksuite/affine/inlines/latex/src/command.ts

@@ -2,14 +2,48 @@ import {
   DocModeProvider,
   TelemetryProvider,
 } from '@blocksuite/affine-shared/services';
+import type { AffineInlineEditor } from '@blocksuite/affine-shared/types';
 import type { Command, TextSelection } from '@blocksuite/std';
+import type { InlineRange } from '@blocksuite/std/inline';
+
+function openInlineLatexEditor(
+  inlineEditor: AffineInlineEditor,
+  index: number
+) {
+  inlineEditor
+    .waitForUpdate()
+    .then(async () => {
+      await inlineEditor.waitForUpdate();
+
+      const textPoint = inlineEditor.getTextPoint(index);
+      if (!textPoint) return;
+      const [text] = textPoint;
+      const latexNode = text.parentElement?.closest('affine-latex-node');
+      if (!latexNode) return;
+      latexNode.toggleEditor();
+    })
+    .catch(console.error);
+}
+
+function getSingleBlockInlineRange(
+  textSelection: TextSelection
+): InlineRange | null {
+  if (textSelection.to) {
+    return null;
+  }
+
+  return {
+    index: textSelection.from.index,
+    length: textSelection.from.length,
+  };
+}
 
 export const insertInlineLatex: Command<{
   currentTextSelection?: TextSelection;
   textSelection?: TextSelection;
 }> = (ctx, next) => {
   const textSelection = ctx.textSelection ?? ctx.currentTextSelection;
-  if (!textSelection || !textSelection.isCollapsed()) return;
+  if (!textSelection) return;
 
   const blockComponent = ctx.std.view.getBlock(textSelection.from.blockId);
   if (!blockComponent) return;
@@ -20,24 +54,19 @@ export const insertInlineLatex: Command<{
   const inlineEditor = richText.inlineEditor;
   if (!inlineEditor) return;
 
-  inlineEditor.insertText(
-    {
-      index: textSelection.from.index,
-      length: 0,
-    },
-    ' '
-  );
-  inlineEditor.formatText(
-    {
-      index: textSelection.from.index,
-      length: 1,
-    },
-    {
-      latex: '',
-    }
-  );
+  const inlineRange = getSingleBlockInlineRange(textSelection);
+  if (!inlineRange) return;
+
+  const latex = textSelection.isCollapsed()
+    ? ''
+    : inlineEditor.yTextString.slice(
+        inlineRange.index,
+        inlineRange.index + inlineRange.length
+      );
+
+  inlineEditor.insertText(inlineRange, ' ', { latex });
   inlineEditor.setInlineRange({
-    index: textSelection.from.index,
+    index: inlineRange.index,
     length: 1,
   });
 
@@ -56,19 +85,9 @@ export const insertInlineLatex: Command<{
     control: 'create inline equation',
   });
 
-  inlineEditor
-    .waitForUpdate()
-    .then(async () => {
-      await inlineEditor.waitForUpdate();
-
-      const textPoint = inlineEditor.getTextPoint(textSelection.from.index + 1);
-      if (!textPoint) return;
-      const [text] = textPoint;
-      const latexNode = text.parentElement?.closest('affine-latex-node');
-      if (!latexNode) return;
-      latexNode.toggleEditor();
-    })
-    .catch(console.error);
+  if (textSelection.isCollapsed()) {
+    openInlineLatexEditor(inlineEditor, inlineRange.index + 1);
+  }
 
   next();
 };

blocksuite/affine/inlines/latex/src/latex-node/latex-node.ts

@@ -15,7 +15,7 @@ import {
 import type { DeltaInsert } from '@blocksuite/store';
 import { signal } from '@preact/signals-core';
 import katex from 'katex';
-import { css, html, render } from 'lit';
+import { css, html, type PropertyValues, render } from 'lit';
 import { property } from 'lit/decorators.js';
 
 export class AffineLatexNode extends SignalWatcher(
@@ -85,6 +85,8 @@ export class AffineLatexNode extends SignalWatcher(
 
   private _editorAbortController: AbortController | null = null;
 
+  private _isEditorOpen = false;
+
   readonly latex$ = signal('');
 
   readonly latexEditorSignal = signal('');
@@ -174,6 +176,22 @@ export class AffineLatexNode extends SignalWatcher(
     return result;
   }
 
+  protected override updated(changedProperties: PropertyValues<this>) {
+    super.updated(changedProperties);
+
+    if (!changedProperties.has('delta') || this._isEditorOpen) {
+      return;
+    }
+
+    const latex = this.deltaLatex;
+    if (this.latex$.peek() !== latex) {
+      this.latex$.value = latex;
+    }
+    if (this.latexEditorSignal.peek() !== latex) {
+      this.latexEditorSignal.value = latex;
+    }
+  }
+
   override render() {
     return html`<span class="affine-latex" data-selected=${this.selected}
       ><div class="latex-container"></div>
@@ -212,9 +230,11 @@ export class AffineLatexNode extends SignalWatcher(
       },
     });
 
+    this._isEditorOpen = true;
     this._editorAbortController.signal.addEventListener(
       'abort',
       () => {
+        this._isEditorOpen = false;
         portal.remove();
         const latex = this.latexEditorSignal.peek();
         this.latex$.value = latex;

blocksuite/affine/rich-text/src/conversion.ts

@@ -13,6 +13,7 @@ import {
   QuoteIcon,
   TextIcon,
 } from '@blocksuite/affine-components/icons';
+import { TeXIcon } from '@blocksuite/icons/lit';
 import type { TemplateResult } from 'lit';
 
 /**
@@ -119,6 +120,15 @@ export const textConversionConfigs: TextConversionConfig[] = [
     hotkey: [`Mod-Alt-c`],
     icon: CodeBlockIcon,
   },
+  {
+    flavour: 'affine:latex',
+    type: undefined,
+    name: 'Equation',
+    description: 'Formula block with LaTeX rendering.',
+    hotkey: null,
+    icon: TeXIcon(),
+    searchAlias: ['mathBlock', 'equationBlock', 'latexBlock'],
+  },
   {
     flavour: 'affine:paragraph',
     type: 'quote',

blocksuite/affine/widgets/keyboard-toolbar/src/config.ts

@@ -222,6 +222,17 @@ const textToolActionItems: KeyboardToolbarActionItem[] = [
       });
     },
   },
+  {
+    name: 'Equation',
+    showWhen: ({ std }) =>
+      std.store.schema.flavourSchemaMap.has('affine:latex'),
+    icon: TeXIcon(),
+    action: ({ std }) => {
+      std.command.exec(updateBlockType, {
+        flavour: 'affine:latex',
+      });
+    },
+  },
   {
     name: 'Quote',
     showWhen: ({ std }) =>

tests/blocksuite/e2e/latex/inline.spec.ts

@@ -1,5 +1,12 @@
 import { expect } from '@playwright/test';
 
+import {
+  dragBetweenIndices,
+  enterPlaygroundRoom,
+  focusRichText,
+  initEmptyParagraphState,
+  waitNextFrame,
+} from '../utils/actions/index.js';
 import {
   cutByKeyboard,
   pasteByKeyboard,
@@ -15,17 +22,13 @@ import {
   type,
   undoByKeyboard,
 } from '../utils/actions/keyboard.js';
-import {
-  enterPlaygroundRoom,
-  focusRichText,
-  initEmptyParagraphState,
-} from '../utils/actions/misc.js';
 import {
   assertRichTextInlineDeltas,
   assertRichTextInlineRange,
 } from '../utils/asserts.js';
 import { ZERO_WIDTH_FOR_EMPTY_LINE } from '../utils/inline-editor.js';
 import { test } from '../utils/playwright.js';
+import { getFormatBar } from '../utils/query.js';
 
 test('add inline latex at the start of line', async ({ page }, testInfo) => {
   await enterPlaygroundRoom(page);
@@ -240,6 +243,63 @@ test('add inline latex using slash menu', async ({ page }, testInfo) => {
   expect(await latexElement.locator('.katex').innerHTML()).toBe(innerHTML);
 });
 
+test('should preserve distinct latex values when converting selections in reverse order', async ({
+  page,
+}) => {
+  await enterPlaygroundRoom(page);
+  await initEmptyParagraphState(page);
+  await focusRichText(page);
+
+  await type(page, 'a+b test a^2 test');
+
+  await dragBetweenIndices(page, [0, 9], [0, 12]);
+  const { formatBar } = getFormatBar(page);
+  await expect(formatBar).toBeVisible();
+  await formatBar.getByRole('button', { name: 'Inline equation' }).click();
+  await waitNextFrame(page);
+
+  await assertRichTextInlineDeltas(page, [
+    {
+      insert: 'a+b test ',
+    },
+    {
+      insert: ' ',
+      attributes: {
+        latex: 'a^2',
+      },
+    },
+    {
+      insert: ' test',
+    },
+  ]);
+
+  await dragBetweenIndices(page, [0, 0], [0, 3]);
+  await expect(formatBar).toBeVisible();
+  await formatBar.getByRole('button', { name: 'Inline equation' }).click();
+  await waitNextFrame(page);
+
+  await assertRichTextInlineDeltas(page, [
+    {
+      insert: ' ',
+      attributes: {
+        latex: 'a+b',
+      },
+    },
+    {
+      insert: ' test ',
+    },
+    {
+      insert: ' ',
+      attributes: {
+        latex: 'a^2',
+      },
+    },
+    {
+      insert: ' test',
+    },
+  ]);
+});
+
 test('add inline latex using markdown shortcut', async ({ page }) => {
   await enterPlaygroundRoom(page);
   await initEmptyParagraphState(page);

tools/utils/src/workspace.gen.ts

@@ -365,6 +365,7 @@ export const PackageList = [
       'blocksuite/affine/gfx/pointer',
       'blocksuite/affine/gfx/shape',
       'blocksuite/affine/gfx/text',
+      'blocksuite/affine/inlines/latex',
       'blocksuite/affine/inlines/preset',
       'blocksuite/affine/model',
       'blocksuite/affine/rich-text',

yarn.lock

@@ -2241,6 +2241,7 @@ __metadata:
     "@blocksuite/affine-gfx-pointer": "workspace:*"
     "@blocksuite/affine-gfx-shape": "workspace:*"
     "@blocksuite/affine-gfx-text": "workspace:*"
+    "@blocksuite/affine-inline-latex": "workspace:*"
     "@blocksuite/affine-inline-preset": "workspace:*"
     "@blocksuite/affine-model": "workspace:*"
     "@blocksuite/affine-rich-text": "workspace:*"