absoluteToRelativeIndex method
Tuple2<T, int>
absoluteToRelativeIndex(
{ - required int absoluteIndex,
})
Implementation
Tuple2<T, int> absoluteToRelativeIndex({required int absoluteIndex}) {
var currSectionBeginIndex = 0;
for (var i = 0; i < arr.length; ++i) {
if (currSectionBeginIndex <= absoluteIndex &&
currSectionBeginIndex + getCount(arr[i]) > absoluteIndex) {
return Tuple2(arr[i], absoluteIndex - currSectionBeginIndex);
}
currSectionBeginIndex += getCount(arr[i]);
}
throw Exception(
'indexCountedList see invalid index=$absoluteIndex (itemCount=${length()})');
}