fix: тема доски синхронизируется между учителем и учениками в реальном времени

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/controllers/classroomController.js

@@ -22,6 +22,7 @@ const GUEST_EVENTS = new Set([
   'classroom_stroke_updated', 'classroom_page_added', 'classroom_page_changed',
   'classroom_template_changed', 'classroom_page_cleared', 'classroom_page_renamed',
   'classroom_page_duplicated', 'classroom_page_deleted', 'classroom_ended',
+  'classroom_board_theme',
 ]);
 
 /* ── Helper: broadcast to all session participants ─────────────────────── */
@@ -490,6 +491,21 @@ function updatePageTemplate(req, res) {
   res.json({ ok: true, template });
 }
 
+/* PATCH /api/classroom/:id/board-theme — change board theme and broadcast to all */
+function updateBoardTheme(req, res) {
+  const sessionId = Number(req.params.id);
+  const VALID_THEMES = new Set(['chalkboard', 'blackboard', 'whiteboard', 'dark', 'grid', 'dots']);
+  const { theme } = req.body;
+  if (!theme || !VALID_THEMES.has(theme)) return res.status(400).json({ error: 'invalid theme' });
+  const session = db.prepare(`SELECT * FROM classroom_sessions WHERE id=? AND status='active'`).get(sessionId);
+  if (!session) return res.status(404).json({ error: 'Сессия не активна' });
+  if (session.teacher_id !== req.user.id && req.user.role !== 'admin')
+    return res.status(403).json({ error: 'Нет доступа' });
+  db.prepare('UPDATE classroom_sessions SET board_theme=? WHERE id=?').run(theme, sessionId);
+  emitToSession(sessionId, { type: 'classroom_board_theme', sessionId, theme });
+  res.json({ ok: true, theme });
+}
+
 /* POST /api/classroom/:id/hand — raise hand */
 function raiseHand(req, res) {
   const sessionId = Number(req.params.id);
@@ -1521,6 +1537,7 @@ module.exports = {
   addPage,
   changePage,
   updatePageTemplate,
+  updateBoardTheme,
   getPages,
   renamePage,
   duplicatePage,

backend/src/db/migrate.js

@@ -2858,6 +2858,8 @@ db.exec(`
 
 // Guest token for classroom sessions (public read-only whiteboard access)
 try { db.exec("ALTER TABLE classroom_sessions ADD COLUMN guest_token TEXT UNIQUE"); } catch {}
+// Board theme per session (synced to all participants)
+try { db.exec("ALTER TABLE classroom_sessions ADD COLUMN board_theme TEXT NOT NULL DEFAULT 'chalkboard'"); } catch {}
 
 // Persistent draw permissions (survives server restart)
 db.exec(`

backend/src/routes/classroom.js

@@ -76,6 +76,7 @@ router.get('/:id/pages',                          ...auth,    c.getPages);
 router.post('/:id/pages',                         ...teacher, c.addPage);
 router.put('/:id/page',                           ...teacher, c.changePage);
 router.patch('/:id/page-template',                ...teacher, c.updatePageTemplate);
+router.patch('/:id/board-theme',                  ...teacher, c.updateBoardTheme);
 router.patch('/:id/pages/:pageNum/name',          ...teacher, c.renamePage);
 router.post('/:id/pages/:pageNum/duplicate',      ...teacher, c.duplicatePage);
 router.delete('/:id/pages/:pageNum',              ...teacher, c.deletePage);

frontend/classroom.html

@@ -3160,6 +3160,7 @@
   let _me = null;
   let _session = null;
   let _sessionId = null;
+  let _sessionBoardTheme = null; // pending theme from session data, applied in initWhiteboard
   let _sseHandle = null;
   let _participants = {};   // userId -> {name, micMuted}
   let _raisedHands  = {};   // userId -> userName
@@ -3554,6 +3555,12 @@
         if (sel) sel.value = data.template;
         wbUpdateThumbnail(_wbCurrentPage);
       }
+    } else if (data.type === 'classroom_board_theme') {
+      if (_sessionId == data.sessionId && _wb) {
+        _wb.setBoardTheme(data.theme);
+        const sel = document.getElementById('wb-theme-select');
+        if (sel) sel.value = data.theme;
+      }
     } else if (data.type === 'classroom_hand_raised') {
       if (_sessionId == data.sessionId) onHandRaised(data.userId, data.userName);
     } else if (data.type === 'classroom_hand_lowered') {
@@ -3981,6 +3988,8 @@
     // page state
     _wbCurrentPage = session.current_page || 1;
     _totalPages    = session.pageCount    || 1;
+    // Remember board theme from session — will be applied in initWhiteboard
+    if (session.board_theme) _sessionBoardTheme = session.board_theme;
     _raisedHands   = {};
     _handRaised    = false;
     _followTeacher = true;
@@ -4069,8 +4078,12 @@
       stylusMultiplier: _prefs.stylusMultiplier,
     });
 
-    // Sync board theme selector to whiteboard default
-    { const sel = document.getElementById('wb-theme-select'); if (sel) sel.value = 'chalkboard'; }
+    // Apply session board theme (set by teacher, synced for all participants)
+    if (_sessionBoardTheme && _sessionBoardTheme !== 'chalkboard') {
+      _wb.setBoardTheme(_sessionBoardTheme);
+    }
+    { const sel = document.getElementById('wb-theme-select'); if (sel) sel.value = _sessionBoardTheme || 'chalkboard'; }
+    _sessionBoardTheme = null; // consumed
 
     // Apply saved whiteboard defaults from user preferences
     if (canEdit && LS.prefs) {
@@ -5508,10 +5521,13 @@
   function wbSetBoardTheme(theme) {
     if (!_wb) return;
     _wb.setBoardTheme(theme);
-    // Update selector if called programmatically
     const sel = document.getElementById('wb-theme-select');
     if (sel) sel.value = theme;
     if (LS.prefs) LS.prefs.set('wb.theme', theme);
+    // Broadcast to students if in active session
+    if (_sessionId) {
+      LS.patch(`/api/classroom/${_sessionId}/board-theme`, { theme }).catch(() => {});
+    }
   }
 
   /* ── Page context menu ── */