keyStyle method
The style for keys with role.
Implementation
KeyStyle keyStyle(KeyRole role) => switch (role) {
KeyRole.digit || KeyRole.decimal || KeyRole.sign => digitKey,
KeyRole.operator => operatorKey,
KeyRole.equals => equalsKey,
KeyRole.function ||
KeyRole.constant ||
KeyRole.paren ||
KeyRole.clear ||
KeyRole.backspace ||
KeyRole.percent ||
KeyRole.memory ||
KeyRole.mode => functionKey,
};