needsHighlight method
Checks if the given index is set to be highlighted.
@param index @return
Implementation
bool needsHighlight(int index) {
// no highlight
if (!valuesToHighlight()) return false;
for (int i = 0; i < indicesToHighlight!.length; i++) {
if (indicesToHighlight![i].x!.toInt() == index) return true;
}
return false;
}