moveInLetterGrid method
Move by the given amount
in the letter grid.
Implementation
void moveInLetterGrid(final int amount) {
_currentPosition += amount;
if (_currentPosition < 0) {
_currentPosition = 0;
} else if (_currentPosition >= controllerAlphabet.length) {
_currentPosition = controllerAlphabet.length - 1;
}
outputText(convertChar(currentLetter));
}