next method
void
next()
Implementation
void next() {
if (_focusOrder.isEmpty) return;
final start = _focusedNode != null
? (_indexOf(_focusedNode!) + 1) % _focusOrder.length
: 0;
var i = start;
do {
if (_focusOrder[i].canFocus) {
focus(_focusOrder[i]);
return;
}
i = (i + 1) % _focusOrder.length;
} while (i != start);
}