Agent chat: the bottom stack is a no-scroll zone

Merged
TE
15d ago
+52-47

Summary

In the agent chat, the bottom stack is a no-scroll zone, as in the Claude desktop app. The stack is the notices (limit reached, errors), a question, the pull request dock, the queued prompts, the composer and its footer row. Leo, 2026-10-20: "all of these areas are essentially a no-scroll zone."

  • wheelPassThrough.ts: only Jump to latest passes the wheel to the transcript. The wheel over the stack or the composer's card scrolls nothing. The empty gutters beside and under the card still scroll the transcript (Leo, 2026-10-20: "if it's not in the composer it should just scroll").
  • bottomStack.css: the stack's own scrollers (the queue, the pull request dock, a question) contain their overscroll, so reaching a part's end scrolls nothing else. A long draft already keeps the wheel at its ends.
  • The stack still floats over the transcript's foot. An in-flow stack (the transcript ending above it) broke the tuned queue, fade and layout-shift behaviour, so it was backed out of this PR; it and the newline scroll jump follow in their own PRs.

Takes back #22341: the wheel over the composer and the stack no longer scrolls the transcript (Leo, 2026-10-20, above). Jump to latest keeps it.

Adopted from the composer-scroll lane (its session ended); its commits carry its work.

Changelog

Changed: In agent chat, scrolling over the notices, queued messages, the composer and its footer no longer scrolls the transcript.

Testing

Browser test webviews/test/agent-pane-wheel-pass-through.test.ts (real Chromium and WebKit wheel events, CMUX_BROWSER_TESTS=1): new case: the wheel over the composer's card scrolls nothing either way, and the wheel in the gutter beside it scrolls the transcript either way; the long-draft ↓ case now checks that the last line is visible.

Observed / Not run

  • Not run locally: browser tests (builds and tests are off on this Mac; on huge-blue the file's Playwright setup timed out under bun 1.3.14). CI's browser lane is the check.

Agent session: cosmic-gray

🤖 Generated with Claude Code