pub const PROVISIONAL_ROWS: u16 = 8;Expand description
How tall a block is, in display rows, before its file has been measured.
A provisional reservation, replaced once the header read lands. It is not zero and not one: zero would make the block invisible while still holding a matrix slot, and one would make every image visibly jump from a single line to its real height as the reads complete — the reflow the whole design is arranged to avoid. Eight rows is roughly a small figure, so the common case settles with little or no movement.