Shrinking the grid to fit meant a configured tile-width was quietly
ignored the moment enough windows were open — a setting that silently
does not apply is a bug, not a policy. Tiles are now the size the config
asks for and the extra rows scroll.
The layout became a viewport: it reports how many rows fit, elem/tile/
label take a scroll offset and return nothing for tiles above or below
the fold, and hit-testing follows the offset so a click lands on what is
under the cursor rather than what used to be there. Any keyboard move
goes through select(), which scrolls the least that keeps the selection
visible; PgUp/PgDn jump a screen. A scrollbar appears in the right margin
only when there is something to scroll, so it reads as a hint rather than
furniture.
Tiles scrolled out of sight get a null buffer, which unmaps their
subsurface, and the live clock skips them — a long list no longer spends
readback bandwidth on pixels nobody can see. Re-placing the subsurfaces
happens once per dispatch in the event loop rather than inside the key
handler, so holding an arrow key coalesces.
Shrinking survives for one case only: a tile too large for even a single
row or column, where otherwise nothing could be drawn. The old
shrink-to-fit test was rewritten around that, since its premise (twenty
tiles at full size cannot fit) is now answered by scrolling instead.
Verified against the session: 16 tiles at tile-width = 40ppt gives a 2x8
grid with 2 rows visible; three Downs scroll to row 2 and Enter returns
index 6, matching its own list; 82% of the viewport changes across the
scroll; and the scrollbar thumb measures 634px tall at y=24 unscrolled
and y=658 at scroll 2, both what the geometry predicts.
Milad Alizadeh
30c478872a