The expand cross-faded two unrelated grids, so a day's cell jumped from a
46dp row near the top of the screen to a full-height one halfway down and
the dots simply vanished where bars appeared. It read as a swap, not as the
month opening up.
Tag the pieces that mean the same thing on both sides and let Compose carry
them: each cell pill grows, its number rides along, and every dot travels
out to the bar it stood for — which only works because the dots are now
seated by lane, so each one has exactly one bar to become.
The tags travel as a composition local with a null default, so the paged,
continuous, and dense styles — which share these same row and cell
composables — provide nothing and pay nothing. Reduced motion provides
nothing either, leaving the plain cross-fade underneath.
A multi-day bar is anchored on the day it starts in its row; the dots on
the days it merely covers are left unmatched and fade where they stand
while the bar sweeps out over them. Only one of them could become the bar
without the others teleporting into it.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Jean-Luc Makiola
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