previous method

void previous()

Completes current active showcase and starts previous one otherwise will finish the entire showcase view

Implementation

void previous() {
  if (ids != null && ((activeWidgetId ?? 0) - 1) >= 0 && mounted) {
    setState(() {
      _onComplete();
      activeWidgetId = activeWidgetId! - 1;
      _onStart();
      if (activeWidgetId! >= ids!.length) {
        _cleanupAfterSteps();
        widget.onFinish?.call();
      }
    });
  }
}