createTicker method

@override Ticker createTicker(TickerCallback onTick)

Creates a ticker with the given callback.

The kind of ticker provided depends on the kind of ticker provider.

Implementation

@override
Ticker createTicker(TickerCallback onTick) {
  assert(
    () {
      if (_ticker == null) {
        return true;
      }
      throw FlutterError.fromParts(<DiagnosticsNode>[
        ErrorSummary(
          "$runtimeType is a GetSingleTickerProviderStateMixin but multiple tickers were created.",
        ),
        ErrorDescription(
          "A GetSingleTickerProviderStateMixin can only be used as a TickerProvider once.",
        ),
        ErrorHint(
          "If a State is used for multiple AnimationController objects, or if it is passed to other "
          "objects and those objects might use it more than one time in total, then instead of "
          "mixing in a GetSingleTickerProviderStateMixin, use a regular GetTickerProviderStateMixin.",
        ),
      ]);
    }(),
    "",
  );
  _ticker =
      Ticker(onTick, debugLabel: kDebugMode ? "created by $this" : null);
  // We assume that this is called from initState, build, or some sort of
  // event handler, and that thus TickerMode.of(context) would return true. We
  // can't actually check that here because if we're in initState then we're
  // not allowed to do inheritance checks yet.
  return _ticker!;
}