Two things were wrong with the hold, and each hid the other.
It held a *share* of the row's height: the point the finger was on stayed, in
proportion, which is the same miss in miniature as holding an edge. Tap away
from the middle of a long card and the heading landed most of a card's height
from the finger, and off it. A shut card is a heading, and the only place it
belongs is centred under the hand that shut it, wherever down the card the tap
was.
And the correction was worked out from the change in height, which needs the
list to behave the way the arithmetic assumed. It does not: which item it holds
still across a resize depends on what it has composed -- a row taller than the
screen is anchored on itself -- and a scroll it cannot honour in full is
honoured in part with nothing said. Measured rather than predicted now: each
measure pass asks for the error it can see, and the pass that answers is where
the rest becomes askable. Three passes is the worst seen, including the one
where a card that reached past the bottom of the screen has shut, left the
viewport entirely, and has to be asked back to the bottom edge before there is
anything to measure at all.
The pass has to be the *measure* one. A scroll asked for during placement is
never picked up by another measure and does nothing whatever -- which is what
the first version of this did, and why a close moved nothing -- so the list
took an `afterMeasure` hook and the correction lives there.
Checked with ktfmtFormat, compileDebugKotlin, lintDebug and testDebugUnitTest,
and on the emulator against the sandbox, against a 2,785px card in a
conversation with room on both sides: closed at 1450 it lands 1387..1513, at
1700 it lands 1637..1763, at 1950 it lands 1887..2013 -- centred on the tap to
the pixel each time. Opening by the heading still holds the heading still, and
a group closed from its footer bar lands on the bar. Where the conversation
runs out -- a card at the very start with nothing above it to scroll -- it
lands as close as the list can put it, which is what it could always do.
iris-ai
1b38579b97