A row was one TextEdit holding the whole message, so every delta
re-shaped every paragraph of a long reply through parley -- the one phase
where iris trails Compose on the phone (p50 18.2ms vs 13.4ms, bench v2).
- client-core/src/markdown_blocks.rs: split a message into its top-level
blocks with their source, through the same pulldown-cmark the renderer
parses with so the two cannot disagree about where a block starts, plus
common_prefix. Appending markdown can rewrite an earlier block (a
trailing --- turns the paragraph above into a heading), so the fast
path compares the prefix it keeps rather than assuming it -- with the
test that says so.
- transcript-ui: a row is a Span of one TextEdit per block;
RowBlocks::apply_delta replaces the block a delta lands in;
TranscriptScreen keeps the tail row's blocks, seeded in build_tree as
well as push_row (a screen opened onto a streaming reply took the
rebuild path for its first delta otherwise, with nothing to say so).
- A block is the selection unit: Selection is keyed by (RowKey, u32),
which is reading order at both levels, and the pointer-captured half of
a drag resolves the block under the finger from its drawn box
(Selection::locate) instead of from the row's extent.
Pass condition: a_delta_into_a_long_reply_redraws_the_same_widgets_as_a_short_one
drives a real UiRenderState and asserts the draw count for a delta into a
100-paragraph (3,000+ char) reply equals the count for a one-paragraph
one. 30 either way; it read 630 against 30 twice on the way there.
Emulator stream phase, same AVD before and after: p50 61.5 -> 54.5ms,
p90 211.7 -> 113.1ms, p99 342.6 -> 137.4ms, worst 403.6 -> 143.0ms, 202
-> 293 frames in the same 21 seconds. Selection across blocks verified
with a real long-press drag.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
irisandClaude Fable 5.1
e1030d69f6