eleven / messenger Public

web: the WYSIWYG composer — ProseMirror backend, format-as-you-type (#531) (#888)

The rich backend behind the PR #885 facade: composer-pm.js mounts a
ProseMirror EditorView wearing the textarea's exact skin (auto-grow is
pure CSS — no JS measuring to go stale). Format-as-you-type input rules
(**bold**, *i*, `code`, ~s~, lists, quotes, fences) with Backspace-undo;
⌘B/⌘I/⌘E/⌘⇧X/⌘⇧7/8/9 shortcuts; desktop Enter sends everywhere except
inside a code fence; Shift+Enter (and touch Enter) stay structural —
the keyboard never splits paragraphs, so wire bytes never drift. Huge
pastes skip coercion past 100KB and refuse past 1MB.

chat.js: primed dynamic import (never in native webviews; plain
fallback if it fails), commands read plaintext while the wire carries
serialized markdown, edit loads parse markdown and ↓-undo compares a
captured baseline. Theme sheet gains 'Format as you type' (default on,
live reconfigure) and 'Classic plain-text composer' (the escape hatch).

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Paul Campbell 3 months ago 9548c6a86e5441cc4cf047558fc40c9dfdbc83dc parent 69f06f8

6 files changed, +457 −20

changelog/2026-07-14-rich-composer.md +7 −0
web/static/apps/chat.js +45 −15
web/static/composer-pm.js +271 −0
web/static/composer.js +38 −1
web/static/shell.js +33 −1
web/static/style.css +63 −3

diff --git a/changelog/2026-07-14-rich-composer.md b/changelog/2026-07-14-rich-composer.md

new file mode 100644

index 0000000..32c1c19

--- /dev/null

+++ b/changelog/2026-07-14-rich-composer.md

@@ -0,0 +1,7 @@

+🤖 The message box now formats as you type. Type `**bold**` and it turns bold

+the moment you close the stars — same for *italics*, `code`, ~strikethrough~,

+"- " lists, "> " quotes and ``` code blocks — or use the shortcuts you already

+know: ⌘B, ⌘I, and friends. Backspace right after undoes the formatting, and

+what you send is exactly what everyone sees, on every device. Prefer typing

+the markers and seeing them stay put? Turn off "Format as you type" in the

+Theme sheet — or switch back to the classic plain-text box entirely.

diff --git a/web/static/apps/chat.js b/web/static/apps/chat.js

index 562c9ac..06e2b0f 100644

--- a/web/static/apps/chat.js

+++ b/web/static/apps/chat.js

@@ -25,7 +25,18 @@

import { defineApp, keyedList, runCommand, runAppMention, messageActionsFor, renderSurfaces, commandCatalog, buildLocalNotice, renderApp, deliverAnswer, parseMeCommand, defaultCommandFor, appChatReadOnly, setCommandPanelHost, notifyCommandPanel, motionOK } from "../apps.js";

import { replySnippet, formatBytes, emojiOnlyCount, firstLink, youtubeId, typingSummary } from "../format.js";

import { parseMessage, renderTree } from "../markdown.js";

-import { createComposer } from "../composer.js";

+import { createComposer, adoptComposer, classicComposerPref, formatAsYouTypePref } from "../composer.js";

+// The rich (ProseMirror) composer backend loads via a primed dynamic import —

+// fetching starts at module load, mounts long after — and never in the native

+// shells' webviews (they draw their own composer; the hidden one stays the

+// cheap textarea). If the import fails, the factory quietly falls back to the

+// plain backend: chat always works.

+let pmModule = null;

+// (typeof guard: the event-vector tests import this module under Node.)

+if (typeof document !== "undefined" && !document.documentElement.classList.contains("native")) {

+ import("../composer-pm.js").then((m) => (pmModule = m)).catch(() => null);

import { renderCard, CARD_CSS } from "../cards.js";

import { emojify } from "../emoji.js";

import { fileIcon, shouldSend, composerToken, ownMessage, sameSender } from "../ui.js";

@@ -2660,8 +2671,10 @@ function buildSkeleton(el, ctx) {

// can slot in behind the same handle. The handler bodies are function

// declarations further down (hoisted; they run long after the skeleton is

// fully built, so the consts they close over are all live by then).

- const composer = createComposer({

+ const inEmbed = !!(host && host.embed);

+ const composerOpts = {

placeholder: composerHints.get(ctx.threadId) || basePlaceholder(),

+ formatAsYouType: formatAsYouTypePref(),

onInput: () => onComposerInput(),

onKeydown: (e) => onComposerKeydown(e),

// Caret moves (click / arrows) can enter or leave a token too — re-check.

@@ -2677,7 +2690,15 @@ function buildSkeleton(el, ctx) {

setTimeout(closeTypeahead, 100);

onPaste: (e) => onComposerPaste(e),

- });

+ // Rich-backend file routes (ProseMirror owns paste/drop on its element).

+ onPasteFiles: (files) => stageFiles(files),

+ onDropFiles: (files) => stageFiles(files),

+ onOversizePaste: () => stageError("That's too long for a message — attach it as a file instead."),

+ };

+ const composer =

+ pmModule && !inEmbed && !appChatReadOnly(ctx.threadId) && !classicComposerPref()

+ ? adoptComposer(pmModule.createRichComposer(composerOpts))

+ : createComposer(composerOpts);

const applyFieldLabel = () => {

const label = composerLabels.get(ctx.threadId) || "";

fieldLabel.textContent = label;

@@ -2753,6 +2774,7 @@ function buildSkeleton(el, ctx) {

// ---- composer state (per mount; a fresh open rebuilds it clean) ----

let replyTo = null; // { id, name, snippet } — the original payload shape

let editing = null; // the item being edited

+ let editBaseline = ""; // getMarkdown() right after edit-load (the ↓-undo comparator)

let pending = []; // staged attachments: { att | null (uploading), name, isImage }

let sendQueued = false; // Enter landed mid-upload — auto-send once the uploads finish

let staging = 0; // stageFiles batches in flight — a queued send waits for the whole batch

@@ -2804,7 +2826,6 @@ function buildSkeleton(el, ctx) {

replyBanner.classList.remove("hidden");

}

};

- const inEmbed = !!(host && host.embed);

if (inEmbed) root.classList.add("embed"); // the native shell draws the composer

// The owning app declared its chat a read-only stream — no composer to draw.

if (appChatReadOnly(ctx.threadId)) root.classList.add("readonly");

@@ -2943,7 +2964,8 @@ function buildSkeleton(el, ctx) {

startEdit(m) {

replyTo = null;

editing = m;

- composer.setText(m.text, { notify: true }); // resize + reveal send

+ composer.setMarkdown(m.text, { notify: true }); // resize + reveal send

+ editBaseline = composer.getMarkdown(); // ↓-undo compares against this, not raw bytes

refreshBanners();

if (inEmbed) host.native({ editing: { text: m.text } });

if (!inEmbed) composer.focus();

@@ -3201,7 +3223,7 @@ function buildSkeleton(el, ctx) {

// Blockquote continuation: pasting multi-line text onto a bare "> " line

// prefixes every line after the first with "> " so the whole quote stays a

// quote — matches the original composer's paste behaviour.

- if (!files.length) {

+ if (!files.length && composer.kind === "plain") {

const textItem = [...(e.clipboardData?.items || [])].find((i) => i.type === "text/plain");

if (textItem) {

const start = composer.getCaret();

@@ -3435,8 +3457,12 @@ function buildSkeleton(el, ctx) {

if (e.key === "Enter" || e.key === "Tab") return e.preventDefault(), acceptTypeahead();

if (e.key === "Escape") return e.preventDefault(), closeTypeahead();

}

- // Desktop Enter sends (Shift+Enter newlines); touch Enter newlines.

- if (shouldSend(e, coarse)) {

+ // Desktop Enter sends (Shift+Enter newlines); touch Enter newlines. A

+ // code fence is the one context that explicitly means "multi-line

+ // content", so Enter newlines there too. The isComposing guard stops a

+ // Japanese/Korean composition-confirm from sending early (a pre-existing

+ // textarea quirk, fixed while we're here).

+ if (shouldSend(e, coarse) && !composer.inCodeBlock() && !e.isComposing) {

e.preventDefault();

compose.requestSubmit();

return;

@@ -3482,7 +3508,7 @@ function buildSkeleton(el, ctx) {

// below the cursor to navigate to (the original rule).

if (e.key === "ArrowDown" && editing) {

const afterCursor = composer.getText().slice(composer.getSelectionEnd());

- if (composer.getText() === editing.text && !afterCursor.includes("\n")) {

+ if (composer.getMarkdown() === editBaseline && !afterCursor.includes("\n")) {

e.preventDefault();

composer.setText("");

cancelEdit();

@@ -3497,7 +3523,11 @@ function buildSkeleton(el, ctx) {

setSendQueued(true); // still uploading — send as soon as it lands

return;

}

- const text = emojify(composer.getText().trim()); // :tada: → 🎉, like the original composer

+ // Two readings of the composer: commands parse the PLAIN text (a command

+ // is not prose), the wire carries the serialized markdown. On the plain

+ // backend the two are identical bytes, exactly as before.

+ const plain = emojify(composer.getText().trim());

+ const text = emojify(composer.getMarkdown().trim()); // :tada: → 🎉, like the original composer

const resetInput = () => {

composer.clear();

refreshSend();

@@ -3508,7 +3538,7 @@ function buildSkeleton(el, ctx) {

// line ("Alice waves"), not a bubble — instead of answering privately, so

// it's handled here rather than through runCommand (see parseMeCommand).

if (!editing) {

- const action = parseMeCommand(text);

+ const action = parseMeCommand(plain);

if (action !== null) {

if (!action) return resetInput(); // bare "/me" — nothing to say

ctx.emit({ text: `${ctx.meName || "Someone"} ${action}`, action: true }).then((sent) => {

@@ -3523,7 +3553,7 @@ function buildSkeleton(el, ctx) {

// instead of sending — it answers in place with a private "only visible to you"

// reply that stacks in the feed and persists (addLocalNotice). Skipped while

// editing, like the original composer.

- if (!editing && runCommand(text, ctx.threadId, (r) => addLocalNotice(ctx, r))) {

+ if (!editing && runCommand(plain, ctx.threadId, (r) => addLocalNotice(ctx, r))) {

resetInput();

return;

}

@@ -3531,7 +3561,7 @@ function buildSkeleton(el, ctx) {

// app, the text runs its default command — an EVENT into this thread (shown

// as an action line), not a message. Leading-@ only; a mention mid-text is

// ordinary conversation. See runAppMention.

- if (!editing && !replyTo && !pending.length && text && text[0] === "@" && runAppMention(text, ctx.threadId, (r) => addLocalNotice(ctx, r))) {

+ if (!editing && !replyTo && !pending.length && plain && plain[0] === "@" && runAppMention(plain, ctx.threadId, (r) => addLocalNotice(ctx, r))) {

resetInput();

return;

}

@@ -3539,10 +3569,10 @@ function buildSkeleton(el, ctx) {

// instead of sending a message nobody reads — typing "buy milk" into To-do

// just adds it (defaultCommandFor gates this to app-threads with no bot;

// slash text never falls through here, a "/" always means command).

- if (!editing && !replyTo && text && text[0] !== "/" && !pending.length) {

+ if (!editing && !replyTo && plain && plain[0] !== "/" && !pending.length) {

const dc = defaultCmd();

if (dc) {

- const typed = text;

+ const typed = plain;

runCommand(dc.name + " " + typed, ctx.threadId, (r) => {

addLocalNotice(ctx, r);

// A reply with no `short` is the command PUSHING BACK ("when should

diff --git a/web/static/composer-pm.js b/web/static/composer-pm.js

new file mode 100644

index 0000000..f049576

--- /dev/null

+++ b/web/static/composer-pm.js

@@ -0,0 +1,271 @@

+// 🤖 The rich composer backend (#531): a ProseMirror EditorView behind the

+// same facade contract as composer.js's plain textarea. chat.js cannot tell

+// the two apart — the handle speaks plain-string+caret for the typeahead,

+// markdown for the wire (composer-md.js owns both mappings). This module is

+// loaded via a primed dynamic import (never in embed mode), so the native

+// shells' webviews and the classic-composer escape hatch never pay for it.

+//

+// Behaviour rules carried over from the design:

+// - Desktop Enter sends EVERYWHERE except inside a code fence (the one

+// context that explicitly means "multi-line content"); Shift+Enter — and

+// touch Enter — are structural: newline in a fence, next item in a list,

+// hard_break in a paragraph. The keyboard NEVER splits paragraphs (wire

+// bytes: hard_break is "\n"; "\n\n" only ever comes from edit-loads).

+// - "Format as you type" (input rules) is a default-ON setting; OFF still

+// leaves ⌘B/⌘I working and literal markdown rendering in the feed. The

+// toggle reconfigures plugins live — history and doc survive.

+// - Backspace runs undoInputRule first: typing *x* then Backspace restores

+// the literal text instead of leaving surprise styling.

+import {

+ EditorState, EditorView, TextSelection,

+ history, undo, redo, keymap, baseKeymap,

+ inputRules, InputRule, wrappingInputRule, textblockTypeInputRule, undoInputRule,

+ chainCommands, toggleMark, newlineInCode, wrapIn, lift,

+ wrapInList, splitListItem, liftListItem,

+} from "./vendor/prosemirror.js";

+import {

+ composerSchema as schema,

+ parseToDoc, serializeDoc, docText, textOffsetFromPos, posFromTextOffset,

+} from "./composer-md.js";

+// Paste guards (the reverted-native-attempt lesson): a giant paste must never

+// wedge the input. Past 100KB we skip schema/HTML coercion and insert plain

+// text in one transaction; past 1MB we refuse and point at attachments.

+const PASTE_PLAIN_BYTES = 100_000;

+const PASTE_MAX_BYTES = 1_000_000;

+// --- input rules ("format as you type") ---------------------------------------

+// ProseMirror has no built-in mark input rule — the standard shape: fire on

+// the closing marker, swap the matched text for a marked run, and clear the

+// stored mark so the next keystroke types unstyled (Slack behaviour).

+function markInputRule(regexp, markType) {

+ return new InputRule(regexp, (state, match, start, end) => {

+ const content = match[1];

+ if (!content) return null;

+ const $start = state.doc.resolve(start);

+ if ($start.parent.type.spec.code) return null; // never inside a fence

+ if (state.doc.rangeHasMark(start, end, schema.marks.code)) return null;

+ return state.tr

+ .replaceWith(start, end, schema.text(content, [markType.create()]))

+ .removeStoredMark(markType);

+ });

+function buildInputRules() {

+ return inputRules({

+ rules: [

+ // strong before em, so the ** closer never half-fires the * rule

+ markInputRule(/\*\*([^*\s](?:[^*]*[^*\s])?)\*\*$/, schema.marks.strong),

+ markInputRule(/(?<!\*)\*([^*\s](?:[^*]*[^*\s])?)\*$/, schema.marks.em),

+ markInputRule(/`([^`\s](?:[^`]*[^`\s])?)`$/, schema.marks.code),

+ markInputRule(/(?<!~)~([^~\s](?:[^~]*[^~\s])?)~$/, schema.marks.strike),

+ wrappingInputRule(/^\s*([-*])\s$/, schema.nodes.bullet_list),

+ wrappingInputRule(

+ /^(\d+)\.\s$/,

+ schema.nodes.ordered_list,

+ (match) => ({ order: +match[1] }),

+ (match, node) => node.childCount + node.attrs.order === +match[1],

+ ),

+ wrappingInputRule(/^\s*>\s$/, schema.nodes.blockquote),

+ textblockTypeInputRule(/^```$/, schema.nodes.code_block),

+ ],

+ });

+// --- the backend ----------------------------------------------------------------

+export function createRichComposer(opts = {}) {

+ const insertHardBreak = (state, dispatch) => {

+ if (dispatch) dispatch(state.tr.replaceSelectionWith(schema.nodes.hard_break.create()).scrollIntoView());

+ return true;

+ };

+ // Structural Enter: newline in a fence, next item in a list (an empty item

+ // lifts out), hard_break everywhere else — splitBlock is unreachable, so

+ // the keyboard can never mint a "\n\n".

+ const structuralEnter = chainCommands(newlineInCode, splitListItem(schema.nodes.list_item), insertHardBreak);

+ const chatKeymap = keymap({

+ Enter: structuralEnter, // desktop send was already taken upstream (handleKeyDown)

+ "Shift-Enter": structuralEnter,

+ "Mod-b": toggleMark(schema.marks.strong),

+ "Mod-i": toggleMark(schema.marks.em),

+ "Mod-e": toggleMark(schema.marks.code),

+ "Mod-Shift-x": toggleMark(schema.marks.strike),

+ "Mod-Shift-7": wrapInList(schema.nodes.ordered_list),

+ "Mod-Shift-8": wrapInList(schema.nodes.bullet_list),

+ "Mod-Shift-9": chainCommands(wrapIn(schema.nodes.blockquote), lift),

+ "Mod-z": undo,

+ "Mod-Shift-z": redo,

+ "Mod-y": redo,

+ Backspace: chainCommands(undoInputRule, baseKeymap["Backspace"]),

+ });

+ let rulesOn = opts.formatAsYouType !== false;

+ const rulesPlugin = buildInputRules();

+ // Plugin instances are created ONCE and shared by both configurations, so

+ // the format-as-you-type toggle's reconfigure preserves history state.

+ const basePlugins = [history(), chatKeymap, keymap(baseKeymap)];

+ const pluginsFor = (on) => (on ? [rulesPlugin, ...basePlugins] : basePlugins);

+ const freshState = (doc) =>

+ EditorState.create({

+ schema,

+ doc: doc || undefined,

+ plugins: pluginsFor(rulesOn),

+ selection: doc ? TextSelection.atEnd(doc) : undefined,

+ });

+ const view = new EditorView(null, {

+ state: freshState(),

+ dispatchTransaction(tr) {

+ view.updateState(view.state.apply(tr));

+ refreshEmpty();

+ if (tr.docChanged && opts.onInput) opts.onInput();

+ },

+ // DIRECT view props run before every plugin: chat.js's keydown layer

+ // (typeahead nav, shouldSend → submit, Escape layering, ↑/↓ edit) sees

+ // keys first; anything it preventDefaulted is consumed, everything else

+ // falls through to the keymaps above.

+ handleKeyDown: (view, e) => {

+ if (opts.onKeydown) opts.onKeydown(e);

+ return e.defaultPrevented;

+ },

+ handlePaste: (view, e) => {

+ const files = [...((e.clipboardData && e.clipboardData.files) || [])];

+ if (files.length) {

+ if (opts.onPasteFiles) opts.onPasteFiles(files);

+ return true;

+ }

+ const text = e.clipboardData && e.clipboardData.getData("text/plain");

+ if (text && text.length > PASTE_MAX_BYTES) {

+ if (opts.onOversizePaste) opts.onOversizePaste();

+ return true;

+ }

+ if (text && text.length > PASTE_PLAIN_BYTES) {

+ // One plain-text transaction — no HTML parse, no schema coercion.

+ view.dispatch(view.state.tr.insertText(text).scrollIntoView());

+ return true;

+ }

+ return false; // ProseMirror's paste (rich HTML degrades through the schema)

+ },

+ handleDrop: (view, e) => {

+ const files = [...((e.dataTransfer && e.dataTransfer.files) || [])];

+ if (files.length) {

+ if (opts.onDropFiles) opts.onDropFiles(files);

+ return true;

+ }

+ return false;

+ },

+ attributes: {

+ class: "composer-input",

+ role: "textbox",

+ "aria-multiline": "true",

+ },

+ });

+ // Caret moves (click / arrows) can enter or leave a typeahead token —

+ // ProseMirror leaves these DOM events alone, so plain listeners match the

+ // textarea backend's wiring exactly.

+ if (opts.onKeyup) view.dom.addEventListener("keyup", opts.onKeyup);

+ if (opts.onClick) view.dom.addEventListener("click", opts.onClick);

+ view.dom.addEventListener("focus", () => opts.onFocus && opts.onFocus());

+ view.dom.addEventListener("blur", () => opts.onBlur && opts.onBlur());

+ const isEmptyDoc = () => docText(view.state.doc).trim() === "";

+ const refreshEmpty = () => view.dom.classList.toggle("pm-empty", isEmptyDoc());

+ if (opts.placeholder) view.dom.setAttribute("data-placeholder", opts.placeholder);

+ refreshEmpty();

+ // Silent state swaps (no dispatchTransaction → no onInput) for programmatic

+ // writes; { notify: true } fires the same change pipeline typing does.

+ const swapDoc = (doc, o = {}) => {

+ view.updateState(freshState(doc));

+ refreshEmpty();

+ if (o.notify && opts.onInput) opts.onInput();

+ };

+ // Plain text in (native pushback etc.): literal paragraph + hard_breaks —

+ // NOT markdown-parsed, so predictable for text that came from getText().

+ const plainDoc = (text) => {

+ const parts = String(text || "").split("\n");

+ const children = [];

+ parts.forEach((line, i) => {

+ if (i > 0) children.push(schema.nodes.hard_break.create());

+ if (line) children.push(schema.text(line));

+ });

+ return schema.node("doc", null, [schema.node("paragraph", null, children)]);

+ };

+ return {

+ kind: "rich",

+ el: view.dom,

+ view, // exposed for the live settings toggle (composer.js registry)

+ focus() {

+ view.focus();

+ },

+ hasFocus() {

+ return view.hasFocus();

+ },

+ isEmpty() {

+ return isEmptyDoc();

+ },

+ getText() {

+ return docText(view.state.doc);

+ },

+ getCaret() {

+ return textOffsetFromPos(view.state.doc, view.state.selection.from);

+ },

+ getSelectionEnd() {

+ return textOffsetFromPos(view.state.doc, view.state.selection.to);

+ },

+ setText(v, o = {}) {

+ swapDoc(plainDoc(v), o);

+ },

+ replaceRange(start, end, insert) {

+ const doc = view.state.doc;

+ const from = posFromTextOffset(doc, start);

+ const to = posFromTextOffset(doc, end);

+ let tr = view.state.tr.insertText(insert, from, to);

+ tr = tr.setSelection(TextSelection.create(tr.doc, from + insert.length));

+ view.dispatch(tr.scrollIntoView());

+ view.focus();

+ },

+ insertAtCaret(text) {

+ view.dispatch(view.state.tr.insertText(text).scrollIntoView());

+ view.focus();

+ },

+ getMarkdown() {

+ return serializeDoc(view.state.doc);

+ },

+ setMarkdown(v, o = {}) {

+ swapDoc(parseToDoc(v), o);

+ },

+ clear() {

+ swapDoc(null); // fresh state, fresh history — ⌘Z can't resurrect a sent message

+ },

+ setPlaceholder(s) {

+ view.dom.setAttribute("data-placeholder", s || "");

+ },

+ setAriaLabel(s) {

+ view.dom.setAttribute("aria-label", s || "");

+ },

+ setIndent(px) {

+ view.dom.style.paddingLeft = px ? `${px}px` : "";

+ },

+ inCodeBlock() {

+ return view.state.selection.$from.parent.type.name === "code_block";

+ },

+ setFormatAsYouType(on) {

+ if (on === rulesOn) return;

+ rulesOn = on;

+ // reconfigure keeps state for plugins present on both sides — the doc

+ // and undo history survive the toggle.

+ view.updateState(view.state.reconfigure({ plugins: pluginsFor(on) }));

+ },

+ destroy() {

+ view.destroy();

+ },

+ };

diff --git a/web/static/composer.js b/web/static/composer.js

index 64e9b78..44d9189 100644

--- a/web/static/composer.js

+++ b/web/static/composer.js

@@ -39,11 +39,48 @@ export function anyComposerHasText() {

}

export function createComposer(opts = {}) {

- const handle = createPlainComposer(opts);

+ return adoptComposer(createPlainComposer(opts));

+// The rich backend (composer-pm.js) is dynamically imported by chat.js — it

+// registers its handles here so the draft guard and live settings see every

+// composer regardless of backend.

+export function adoptComposer(handle) {

live.add(new WeakRef(handle));

return handle;

}

+// --- composer preferences (localStorage, like the theme prefs in shell.js) ---

+const FMT_KEY = "lchat_fmt_as_you_type";

+const CLASSIC_KEY = "lchat_classic_composer";

+// Default ON: absent means enabled.

+export function formatAsYouTypePref() {

+ return localStorage.getItem(FMT_KEY) !== "0";

+export function setFormatAsYouType(on) {

+ localStorage.setItem(FMT_KEY, on ? "1" : "0");

+ // Live-reconfigure every mounted composer — no remount, history survives.

+ for (const ref of live) {

+ const c = ref.deref();

+ if (!c) {

+ live.delete(ref);

+ continue;

+ }

+ c.setFormatAsYouType(on);

+ }

+// The escape hatch: force the plain textarea backend (picked up on the next

+// composer mount — shell.js reopens the pane when toggled).

+export function classicComposerPref() {

+ return localStorage.getItem(CLASSIC_KEY) === "1";

+export function setClassicComposer(on) {

+ localStorage.setItem(CLASSIC_KEY, on ? "1" : "0");

// The plain backend — today's <textarea>, behaviour preserved to the letter

// (auto-grow to 140px, input/keydown wiring, splice-based typeahead inserts).

function createPlainComposer(opts) {

diff --git a/web/static/shell.js b/web/static/shell.js

index 4927f8e..f4f20bf 100644

--- a/web/static/shell.js

+++ b/web/static/shell.js

@@ -175,7 +175,7 @@ import {

getBackfillMark as storeBackfillMark,

runBackfill as storeRunBackfill,

} from "/static/store.js";

-import { anyComposerHasText } from "/static/composer.js";

+import { anyComposerHasText, formatAsYouTypePref, setFormatAsYouType, classicComposerPref, setClassicComposer } from "/static/composer.js";

const SESSION_KEY = "lchat_session";

const ACTIVE_KEY = "lchat_active"; // last-open thread id, so a refresh lands back in it

@@ -539,6 +539,38 @@ function showThemePicker() {

card.appendChild(row);

}

+ // Composer preferences (#531): "Format as you type" applies live to every

+ // mounted composer; "Classic composer" (the plain-textarea escape hatch)

+ // takes effect on the next thread open — reopening the current one here so

+ // the choice is visible immediately.

+ const composerLabel = document.createElement("label");

+ composerLabel.className = "field-label";

+ composerLabel.textContent = "Composer";

+ composerLabel.style.marginTop = "14px";

+ card.appendChild(composerLabel);

+ const toggleRow = (labelText, checked, onchange) => {

+ const row = document.createElement("label");

+ row.className = "composer-pref-row";

+ const box = document.createElement("input");

+ box.type = "checkbox";

+ box.checked = checked;

+ box.onchange = () => onchange(box.checked);

+ const txt = document.createElement("span");

+ txt.textContent = labelText;

+ row.append(box, txt);

+ card.appendChild(row);

+ return row;

+ };

+ toggleRow("Format as you type (**bold** becomes bold)", formatAsYouTypePref(), (on) => setFormatAsYouType(on));

+ toggleRow("Classic plain-text composer", classicComposerPref(), (on) => {

+ setClassicComposer(on);

+ // Remount the open thread's pane so the switch is immediate. Parked panes

+ // rebuild on their next open (appPaneCache entries are dropped).

+ for (const k of Object.keys(appPaneCache)) delete appPaneCache[k];

+ const active = localStorage.getItem(ACTIVE_KEY);

+ if (active && typeof openThreadById === "function") openThreadById(active);

+ });

const foot = document.createElement("div");

foot.className = "sheet-foot";

const done = document.createElement("button");

diff --git a/web/static/style.css b/web/static/style.css

index 632a438..0e3bc3f 100644

--- a/web/static/style.css

+++ b/web/static/style.css

@@ -340,7 +340,7 @@ input, textarea {

input:focus, textarea:focus { outline: 2px solid var(--accent); border-color: transparent; }

/* the message box doesn't get the bright focus ring (chat-app convention) — the

coloured caret is the cue. */

-.composer textarea:focus { outline: none; border-color: var(--border); }

+.composer .composer-input:focus { outline: none; border-color: var(--border); }

/* ---- centered card layout (join / fallback) ---- */

.center {

@@ -1551,7 +1551,7 @@ input:focus, textarea:focus { outline: 2px solid var(--accent); border-color: tr

variable from the base rule; the two declarations after it restore what

the shorthand resets. Higher-specificity sizes (.jumbo-emoji) still win. */

.msg .bubble { font: -apple-system-body; font-family: inherit; line-height: 1.35; }

- .composer textarea { font-size: 17px; }

+ .composer .composer-input { font-size: 17px; }

.thread-row-name { font-size: 17px; }

.thread-row-preview { font-size: 14px; }

}

@@ -1590,7 +1590,7 @@ input:focus, textarea:focus { outline: 2px solid var(--accent); border-color: tr

@media (prefers-reduced-motion: reduce) {

.composer-label { transition: none; }

}

-.composer textarea {

+.composer .composer-input {

flex: 1;

resize: none;

max-height: 140px;

@@ -1612,6 +1612,66 @@ input:focus, textarea:focus { outline: 2px solid var(--accent); border-color: tr

/* The shared lifted-panel input fill (see --input-bg / .eleven-input). */

background: var(--input-bg);

}

+/* The rich composer (composer-pm.js): a ProseMirror contenteditable wearing

+ the same skin. Auto-grow is pure CSS here — min/max-height + overflow — so

+ there is no JS measuring to go stale (the lesson from the reverted native

+ attempt). The textarea's implicit border comes back explicitly. */

+.composer .composer-input[contenteditable] {

+ position: relative;

+ border: 1px solid var(--border);

+ white-space: pre-wrap;

+ overflow-wrap: break-word;

+ color: var(--ink);

+ caret-color: var(--accent);

+.composer .composer-input[contenteditable] p { margin: 0; }

+/* In-composer blocks: the bubble treatments at composer scale. */

+.composer .composer-input[contenteditable] ul,

+.composer .composer-input[contenteditable] ol { margin: 2px 0; padding-left: 22px; }

+.composer .composer-input[contenteditable] blockquote {

+ margin: 2px 0;

+ padding: 1px 0 1px 10px;

+ border-left: 3px solid color-mix(in srgb, var(--ink) 30%, transparent);

+ color: color-mix(in srgb, var(--ink) 72%, transparent);

+.composer .composer-input[contenteditable] pre {

+ margin: 2px 0;

+ padding: 6px 8px;

+ border-radius: 8px;

+ background: color-mix(in srgb, var(--ink) 8%, transparent);

+ font-family: ui-monospace, SFMono-Regular, Menlo, monospace;

+ font-size: 0.92em;

+ overflow-x: auto;

+ white-space: pre;

+.composer .composer-input[contenteditable] code {

+ font-family: ui-monospace, SFMono-Regular, Menlo, monospace;

+ font-size: 0.92em;

+ background: color-mix(in srgb, var(--ink) 8%, transparent);

+ padding: 1px 5px;

+ border-radius: 5px;

+.composer .composer-input[contenteditable] pre code { background: none; padding: 0; font-size: 1em; }

+/* Placeholder: contenteditable has no native one — the pm-empty class is

+ maintained by the backend; float keeps the caret on the first line. */

+/* Theme-sheet composer preference rows (#531) */

+.composer-pref-row {

+ display: flex;

+ align-items: center;

+ gap: 10px;

+ margin: 8px 0;

+ font-size: 14px;

+ color: var(--ink);

+ cursor: pointer;

+.composer-pref-row input[type="checkbox"] { accent-color: var(--accent); width: 18px; height: 18px; margin: 0; }

+.composer .composer-input.pm-empty::before {

+ content: attr(data-placeholder);

+ color: var(--muted);

+ float: left;

+ height: 0;

+ pointer-events: none;

/* eleven-input — the reusable text-input surface: the same lifted-panel fill the

chat composer uses, so inputs across the app and its mini-apps read as one.