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fix(mobile): build channel section rows lazily - #9401
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Mount Solo and Team rows as lazy slivers while preserving section controls, sorting, and clipped collapse transitions. Co-authored-by: Karl <9e8471f7b792e46c9c100840959dc71c660786c79c2a3165dbcaf58f52c4266e@buzz.block.builderlab.xyz> Signed-off-by: Michael Fransen <[email protected]>
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🤖 The pre-review recommends landing this with one small fix, #9416 (sliver semantics clip): without it, while a section opens, rows not yet revealed are reachable screen-reader nodes for the duration of the animation, which the old section body excluded. Please merge the fix into your branch (it needs no approval there, since the review rules cover only main and the release branches); this PR is then approved and merged on Tom's go-ahead. Report: buzz://message?channel=e71f9a2a-ac46-473d-a24e-5e16fd8cb7b1&id=689a3f16b435c66e0a9bc59d2541fe25233730e9af5eb6f050686e02ff901c27
…9416) Fix for a regression found in review of [#9401 lazy section rows](#9401). This PR targets that PR's branch. While a channel section opens, `CollapsibleSliverBody` clips painting to the revealed extent, but its render object didn't report that clip to the semantics compiler (`RenderProxySliver` inherits `describeApproximatePaintClip => null`). Every mounted row under the clip, including rows drawn beneath the following section, stayed a reachable screen-reader node until the 220 ms animation finished. The old `ClipRect`-based body reported its clip, so those rows were excluded. The fix reports the same rect that `paint` clips to while the section is animating, and nothing once it's fully open. **Pareto:** accessibility returns to the pre-#9401 behavior during the expand animation; painting, layout and hit testing are unchanged, and the fully open and collapsed states produce the same semantics tree as before. ### Validation - Added tests: `collapsible_sliver_body_test.dart` opens a 10-row section and, one frame in, checks that screen readers reach exactly the rows above the painted extent (rows 0 to 3), then that all ten are reachable once open. It fails without the override (Row 4 reachable while drawn below the clip). - Full mobile suite and `just mobile-check` pass locally. - No visible change, so no screenshots or app run; the change only affects the semantics tree during the expand animation. Signed-off-by: Tom Brow <[email protected]> Co-authored-by: Tom Brow <[email protected]> Co-authored-by: studio <dc2fc481343672df31a689840c09299972e704dac592e0da6f18486646a7ee3e@buzz.block.builderlab.xyz>
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## Summary Improve scrolling performance in the Messages channel list by avoiding unnecessary inventory rebuilds as the header moves. Keep scroll-driven header state in a notifier and retain the inventory while the header animates. Provider and parent updates still rebuild the inventory with current channel data. This complements the lazy-row optimization in #9401. In manual iPhone runs with 500 channels, adding lazy rows on top of header isolation reduced maximum observed Flutter UI work from **65.5 ms to 4.2 ms**. That measurement reflects the added lazy-row change; no standalone performance gain was established for header isolation. This is an independent production-only change. Test fixtures and diagnostic instrumentation are excluded; regression checks were run locally and are not included in this PR. ### Related issue Related: #5911 addresses scrolling behavior inside conversations. This change addresses header-triggered rebuilds in the Messages channel inventory. No matching open PR or issue was identified in the focused duplicate search. ### Testing Exercised Messages on a physical iPhone with 500 channels against an isolated local relay. Header collapse and channel updates worked. This change alone did not remove the large scroll stalls; lazy section rows are a separate change. The device run preceded the refresh onto current main. Local-only regression checks passed 10 tests on this independent branch. They verify stable inventory identity during header movement and visible channel updates. These checks are excluded from the commit. Remaining visible jumps are under investigation; this PR does not claim to resolve them. Generated with Codex Signed-off-by: Michael Fransen <[email protected]> Co-authored-by: Karl <9e8471f7b792e46c9c100840959dc71c660786c79c2a3165dbcaf58f52c4266e@buzz.block.builderlab.xyz>
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…small * origin/main: fix(mobile): build channel section rows lazily (#9401) fix(cli): treat a retried sidebar write the relay already stored as success (#9202) Signed-off-by: Ravneet Arora <[email protected]>
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Summary
Improve scrolling performance in the Messages channel list by building Solo and Team rows only as needed. Sections currently mount all their rows as one scroll item, which causes long UI stalls with large channel lists.
In manual iPhone runs with 500 channels, maximum observed Flutter UI work fell from 65.5 ms to 4.2 ms after adding lazy rows to a build with header isolation (#9400). The tester reported much smoother scrolling. This was an exploratory comparison with different gestures, not a controlled benchmark of this independent branch.
Use stable channel keys and retain section controls, sorting, and collapse animations. Clip the sliver extent during collapse so the animation does not mount the entire section. The shared transition supports downward vertical lists.
This is an independent production-only change. Test fixtures and diagnostic instrumentation are excluded; regression checks were run locally and are not included in this PR.
Related issue
Related: #5911 addresses scrolling behavior inside conversations. This change addresses eager row mounting in the Messages channel inventory. No matching open PR or issue was identified in the focused duplicate search.
Testing
On a physical iPhone with 500 channels against an isolated local relay, maximum Flutter UI work fell from 65.5 ms to 4.2 ms after adding lazy rows to a build that already isolated header rebuilds. The tester reported much smoother scrolling. Gestures differed between runs, so this is not a controlled benchmark or an isolated measurement of this branch on its own. The device run preceded the refresh onto current main.
Local-only regression journeys passed 12 tests on this independent branch. They cover page laziness and updates, variable-height rows, large text, the last row, collapse reversal, reduced motion, and semantics. These checks are excluded from the commit.
Smaller visible jumps remain under investigation; this PR does not claim to resolve them.
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