tui2: stop baking streaming wraps; reflow agent markdown #8761
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Background Streaming assistant prose in tui2 was being rendered with viewport-width wrapping during streaming, then stored in history cells as already split `Line`s. Those width-derived breaks became indistinguishable from hard newlines, so the transcript could not "un-split" on resize. This also degraded copy/paste, since soft wraps looked like hard breaks. What changed - Introduce width-agnostic `MarkdownLogicalLine` output in `tui2/src/markdown_render.rs`, preserving markdown wrap semantics: initial/subsequent indents, per-line style, and a preformatted flag. - Update the streaming collector (`tui2/src/markdown_stream.rs`) to emit logical lines (newline-gated) and remove any captured viewport width. - Update streaming orchestration (`tui2/src/streaming/*`) to queue and emit logical lines, producing `AgentMessageCell::new_logical(...)`. - Make `AgentMessageCell` store logical lines and wrap at render time in `HistoryCell::transcript_lines_with_joiners(width)`, emitting joiners so copy/paste can join soft-wrap continuations correctly. Overlay deferral When an overlay is active, defer *cells* (not rendered `Vec<Line>`) and render them at overlay close time. This avoids baking width-derived wraps based on a stale width. Tests + docs - Add resize/reflow regression tests + snapshots for streamed agent output. - Expand module/API docs for the new logical-line streaming pipeline and clarify joiner semantics. - Align scrollback-related docs/comments with current tui2 behavior (main draw loop does not flush queued "history lines" to the terminal). More details See `codex-rs/tui2/docs/streaming_wrapping_design.md` for the full problem statement and solution approach, and `codex-rs/tui2/docs/tui_viewport_and_history.md` for viewport vs printed output behavior.
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Screen.Recording.2026-01-05.at.2.10.48.PM.mov |
easong-openai
approved these changes
Jan 6, 2026
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Background
Streaming assistant prose in tui2 was being rendered with viewport-width wrapping during streaming, then stored in history cells as already split
Lines. Those width-derived breaks became indistinguishable from hard newlines, so the transcript could not "un-split" on resize. This also degraded copy/paste, since soft wraps looked like hard breaks.What changed
MarkdownLogicalLineoutput intui2/src/markdown_render.rs, preserving markdown wrap semantics: initial/subsequent indents, per-line style, and a preformatted flag.tui2/src/markdown_stream.rs) to emit logical lines (newline-gated) and remove any captured viewport width.tui2/src/streaming/*) to queue and emit logical lines, producingAgentMessageCell::new_logical(...).AgentMessageCellstore logical lines and wrap at render time inHistoryCell::transcript_lines_with_joiners(width), emitting joiners so copy/paste can join soft-wrap continuations correctly.Overlay deferral
When an overlay is active, defer cells (not rendered
Vec<Line>) and render them at overlay close time. This avoids baking width-derived wraps based on a stale width.Tests + docs
More details
See
codex-rs/tui2/docs/streaming_wrapping_design.mdfor the full problem statement and solution approach, andcodex-rs/tui2/docs/tui_viewport_and_history.mdfor viewport vs printed output behavior.