up method
Change position up position by n
cells.
Default value of n
is 1.
Return true on success.
up();
up(2);
...
Implementation
bool up([int n = 1, bool alternate = true]) {
if (n <= 0) {
return false;
}
final int newRow = _row - n;
if (validatePosition(newRow, _column)) {
_row = newRow;
return true;
}
return copyMode && _alternativePosition(newRow, true) && alternate;
}