Flutter - Dismiss all dismisables

I am implementing a notification list and have each item dismissable by swipe.

I would like to add a "Clear All" button that will remove all the notifications one by one in an animation similar to the swipe motion.

Is there a way you can access a dismissable widget to dismiss it programmatically? I could just empty the list and setState, however that wouldn't give me an animation.

My list:

ListView.builder(
    itemCount: notifications.length,
    itemBuilder: (context, i) {
       return Dismissible(
           key: Key(notifications[i].hashCode.toString()),
           onDismissed: (DismissDirection direction){
              onDismissed(notifications[i]);
           },
        child: Card(
           child: ListTile(
              leading: Text(DateTime
                 .now()
                 .difference(notifications[i].happendAt)
                 .inMinutes
                 .toString() +
                    "m ago"),
              subtitle: Text(notifications[i].action),
              title: Text(notifications[i].title)),
      ));
})