fix(web): smart auto-scroll for chat #2775

agent/protocol/agent_stream.py

@@ -191,8 +191,8 @@ class AgentStreamExecutor:
         # Log user message with model info
         
         thinking_enabled = self._is_thinking_enabled()
-        thinking_label = "💭 thinking" if thinking_enabled else "⚡ fast"
-        logger.info(f"🤖 {self.model.model} | {thinking_label} | 👤 {user_message}")        
+        thinking_label = " | 💭 thinking" if thinking_enabled else ""
+        logger.info(f"🤖 {self.model.model}{thinking_label} | 👤 {user_message}")        
         
         # Add user message (Claude format - use content blocks for consistency)
         self.messages.append({

channel/web/chat.html

@@ -288,7 +288,7 @@
                 <!-- ====================================================== -->
                 <!-- VIEW: Chat                                              -->
                 <!-- ====================================================== -->
-                <div id="view-chat" class="view active">
+                <div id="view-chat" class="view active relative">
                     <!-- Messages -->
                     <div id="chat-messages" class="flex-1 overflow-y-auto">
                         <!-- Welcome Screen -->
@@ -364,6 +364,18 @@
                         </div>
                     </div>
 
+                    <!-- Scroll-to-bottom FAB -->
+                    <button id="scroll-to-bottom-btn"
+                            class="hidden absolute right-5 bottom-[80px] z-10
+                                   w-9 h-9 rounded-full shadow-lg
+                                   bg-white dark:bg-[#2A2A2A] border border-slate-200 dark:border-white/15
+                                   text-slate-500 dark:text-slate-400 hover:text-primary-500 dark:hover:text-primary-400
+                                   flex items-center justify-center cursor-pointer transition-all duration-200
+                                   hover:shadow-xl hover:scale-105"
+                            onclick="_autoScrollEnabled = true; scrollChatToBottom(true);">
+                        <i class="fas fa-chevron-down text-sm"></i>
+                    </button>
+
                     <!-- Chat Input -->
                     <div class="flex-shrink-0 border-t border-slate-200 dark:border-white/10 bg-white dark:bg-[#1A1A1A] px-4 py-3">
                         <div class="max-w-3xl mx-auto">

channel/web/static/js/console.js

@@ -462,6 +462,16 @@ const sendBtn = document.getElementById('send-btn');
 const messagesDiv = document.getElementById('chat-messages');
 const fileInput = document.getElementById('file-input');
 
+// Smart auto-scroll: pause when user scrolls up, resume when near bottom
+let _autoScrollEnabled = true;
+const _SCROLL_THRESHOLD = 80; // px from bottom to re-enable auto-scroll
+
+messagesDiv.addEventListener('scroll', () => {
+    const distFromBottom = messagesDiv.scrollHeight - messagesDiv.scrollTop - messagesDiv.clientHeight;
+    _autoScrollEnabled = distFromBottom <= _SCROLL_THRESHOLD;
+    _updateScrollToBottomBtn();
+});
+
 // Intercept internal navigation links in chat messages
 messagesDiv.addEventListener('click', (e) => {
     const copyBtn = e.target.closest('.copy-msg-btn');
@@ -1438,7 +1448,8 @@ function createBotMessageEl(content, timestamp, requestId, msg) {
 function addUserMessage(content, timestamp, attachments) {
     const el = createUserMessageEl(content, timestamp, attachments);
     messagesDiv.appendChild(el);
-    scrollChatToBottom();
+    _autoScrollEnabled = true;
+    scrollChatToBottom(true);
 }
 
 function addBotMessage(content, timestamp, requestId) {
@@ -1531,7 +1542,7 @@ function loadHistory(page) {
             if (isFirstLoad) {
                 // Use requestAnimationFrame to ensure the DOM has fully rendered
                 // before scrolling, otherwise scrollHeight may not reflect new content.
-                requestAnimationFrame(() => scrollChatToBottom());
+                requestAnimationFrame(() => scrollChatToBottom(true));
             } else {
                 // Restore scroll position so loading older messages doesn't jump the view
                 messagesDiv.scrollTop = messagesDiv.scrollHeight - prevScrollHeight;
@@ -2049,8 +2060,17 @@ function formatToolArgs(args) {
     }
 }
 
-function scrollChatToBottom() {
-    messagesDiv.scrollTop = messagesDiv.scrollHeight;
+function scrollChatToBottom(force) {
+    if (force || _autoScrollEnabled) {
+        messagesDiv.scrollTop = messagesDiv.scrollHeight;
+    }
+}
+
+function _updateScrollToBottomBtn() {
+    const btn = document.getElementById('scroll-to-bottom-btn');
+    if (!btn) return;
+    const distFromBottom = messagesDiv.scrollHeight - messagesDiv.scrollTop - messagesDiv.clientHeight;
+    btn.classList.toggle('hidden', distFromBottom <= _SCROLL_THRESHOLD);
 }
 
 function applyHighlighting(container) {