Three attempts at "draw the widget, then move its drawing to where its
alignment says" failed, and the notes are worth more than the attempts: the
move is a change of coordinate frame, and no split of the stored state
carries it. Moving a widget's region with its drawing has a later local
redraw ask a differently rounded question, which crosses the one boundary
`Span` needs exact. Leaving the region alone lets the placed box accumulate,
because `try_reuse` returns a clean subtree's size without walking into it.
Both are measured.
Also recorded: that a container reporting a child's size while handing it a
bigger box places that content twice, which is what the align override is
for; that a widget must not report more than it occupies, which is why
`Scroll` now fills both axes; and Bryan's decision that alignment is one
fraction per axis rather than four directions, with the middle as the
default because the edges assume a direction.
The alignment work is in the working tree at `8220a78` and not committed.
Its one red case, and the four things queued behind it, are listed.
iris-ai
085fc97334