Moving through a browsed share felt laggy for the same reason the
results did: the popup re-flattened the whole expanded tree on every
frame, cloning every row's name and path, then built a table row for
each, and every keypress flattened it twice more. A heavy sharer's
tree runs to tens of thousands of rows once a few folders are open.
The flattened rows now live on the browse state and are rebuilt only
when a folder opens or closes, and the popup draws the visible page
alone. In the harness a 30,000-row tree went from 11ms to 0.35ms a
frame and a keypress from 2.7ms to under a microsecond.
The downloads pane had the same shape (every transfer became a row
each frame, and a select-all can queue ten thousand), so it takes the
same page window, which now lives beside page_of for every pane to
share.
Michel de Graaf
0931bb01b4