findCalloutPoints function

List<FluentCustomizedCalloutDataPoint>? findCalloutPoints(List<FluentCustomizedCalloutData> data, Object? x, { required bool isXAxisDate, })

The callout rows at x, or null when there are none.

Ports findCalloutPoints (utilities.ts:2560-2577), including the null guard at :2564. Upstream returns { x, values }, but its x is the argument the caller already holds, so the port returns the rows alone. Recorded divergence.

isXAxisDate is a port addition. Upstream's scale inverts to a Date, so its x instanceof Date test is enough; a Flutter time scale inverts to a double, so a caller on a date axis may hold epoch milliseconds. When isXAxisDate is true a numeric x is read as milliseconds since epoch and finds the same entry a DateTime would.

Implementation

List<FluentCustomizedCalloutDataPoint>? findCalloutPoints(
  List<FluentCustomizedCalloutData> data,
  Object? x, {
  required bool isXAxisDate,
}) {
  if (x == null) {
    return null;
  }
  // utilities.ts:2568.
  final key = switch (x) {
    final DateTime value => value.millisecondsSinceEpoch,
    final num value when isXAxisDate => value.toInt(),
    _ => x,
  };
  for (final entry in data) {
    final entryX = entry.x;
    final entryKey = entryX is DateTime
        ? entryX.millisecondsSinceEpoch
        : entryX;
    if (entryKey == key) {
      return entry.values;
    }
  }
  // utilities.ts:2569-2571.
  return null;
}