Opening a conversation with several unread messages showed them all
expanded, each with its unread bar. The moment the auto-mark-read timer
fired, every one of them collapsed except the last, and the bars
vanished -- so the messages you had just been given were taken away
again, and the only record of which ones they were went with them (#69).
Both came from the same place: expansion and the bar were derived from
`$seen`, live. Marking read on the server changed what the view thought
it was looking at.
Marking read is not the problem. Opening a thread is the signal that you
are reading it, and mbunkus was explicit that turning the setting off is
not the answer he wants. What was wrong was letting a change *this view
caused* alter its own shape underneath the reader.
The thread now remembers which messages were unread when it was opened,
and uses that for expansion and for the bar. The set only grows while a
thread is open -- a message arriving unread joins it -- and is discarded
on the way to another thread. The server still gets marked read on the
timer, exactly as before, and the message list still updates.
It is accumulated during render rather than in an effect. It is derived
purely from the messages already in hand and adding an id twice does
nothing, while an effect would repaint a frame later -- which is the
flicker this exists to remove.
Verified against the mock with markReadDelay at 0, the harshest setting,
where the timer fires immediately: six seconds after opening a
three-message thread, the server reports all three seen while the view
still shows all three expanded with their bars. Before, two of the three
would have collapsed in the first instant.
jcoffey-dev
d4b39c06d6