keypadKeyboard property
How tall the digit pad is — what a phone or number field gets —
or null where this device does not shrink for one.
Null is the conservative answer and it means no shrink: the letters height stands. It covers three different situations on purpose, because they all want the same behaviour — a device that genuinely does not shrink (every iPad, and Gboard, which swaps the layout without moving the height), a device with no keyboard at all, and a cell nobody has measured yet. A keyboard that is too tall is the failure this whole distinction exists to remove, so an unmeasured cell must never guess downwards.
Implementation
final double? keypadKeyboard;