createTicker method
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) {
if (_tickerModeNotifier == null) {
// Setup TickerMode notifier before we vend the first ticker.
_updateTickerModeNotifier();
}
assert(_tickerModeNotifier != null, 'TickerModeNotifier is null');
_tickers ??= <_WidgetTicker>{};
final result = _WidgetTicker(onTick, this, debugLabel: kDebugMode ? 'created by ${describeIdentity(this)}' : null)..muted = !_tickerModeNotifier!.value;
_tickers!.add(result);
return result;
}