Readable LLM responses while streaming/generating

[fernandaspets]

What specific problem does this solve?

The problem is when the LLM starts streaming it's response I can't follow along and read it. When I scrolled up it keeps going right back to the bottom and the box in which the streaming text is in is not big enough to have time to ready almost anything. It would be very nice if we could make it so ites easy to scrolll back and forth and the place you want to read stays there and doesn't hop back to the bottom of the stream right away before you get a chance to read.

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• I've searched existing Issues and Discussions for duplicates
• This describes a specific problem with clear impact and context

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• Yes, I'd like to help implement this feature

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[hannesrudolph]

Hey @fernandaspets, thank you for the report!

This is a UX issue where during LLM response streaming, the chat interface automatically scrolls to the bottom, making it difficult to follow along with the streaming text. When scrolling up to read earlier parts of the response, the interface immediately jumps back to the bottom before there's time to read anything.

The root cause lies in the auto-scroll behavior implemented in https://github.com/RooCodeInc/Roo-Code/blob/main/webview-ui/src/components/chat/ChatView.tsx. The current implementation has several mechanisms that aggressively force scrolling to bottom during streaming:

1. Height-based auto-scroll: When https://github.com/RooCodeInc/Roo-Code/blob/main/webview-ui/src/components/chat/ChatRow.tsx#L71-82 detects height changes in the last message (which happens continuously during streaming as text content grows), it calls onHeightChange which triggers handleRowHeightChange in ChatView, automatically scrolling to bottom.

2. Message count auto-scroll: The useEffect that watches groupedMessages.length triggers auto-scroll whenever new messages are added.

3. Insufficient scroll lock mechanism: While there is a disableAutoScrollRef that should prevent auto-scrolling when users manually scroll up (set to true on wheel up events at https://github.com/RooCodeInc/Roo-Code/blob/main/webview-ui/src/components/chat/ChatView.tsx#L1144), it gets reset to false too aggressively - specifically when reaching the bottom again via the atBottomStateChange callback at https://github.com/RooCodeInc/Roo-Code/blob/main/webview-ui/src/components/chat/ChatView.tsx#L1447-1453.

The problem is that during active streaming, even brief moments where scrolling to the bottom (perhaps accidentally or due to momentum) immediately re-enables auto-scrolling, making it nearly impossible to maintain a stable reading position while the content is actively growing. The height change detection continues to trigger scrolls even when there's explicit indication of wanting to read earlier content by scrolling up.

A solution would need to implement a more sophisticated scroll lock mechanism that persists user intent to read earlier content during streaming, possibly with a timeout or explicit user action to re-enable auto-scrolling, rather than the current immediate re-enabling when briefly touching the bottom.

[nikhil-swamix]

Also when applied a diff, its jumping to top of file? any idea why it happens? scroll position not saved.
started happening recently... @KJ7LNW @mrubens

[KJ7LNW]

Are you talking about the entire chat view, or some portion of it? (like when it displays code blocks? I am aware of the code block problem jumping to the bottom after I scroll up: it did not used to do that so a regression was introduced at some point.)

However, if you are talking about the entire chat view then I am not sure about that, as I have not experienced it (but I am also on an older 3.16.5 version at the moment)