default activity selector

lib/widgets/activities/activity_card.dart

@@ -33,7 +33,7 @@ class ActivityCardState extends State<ActivityCard> {
           if (snapshot.hasData) {
             List<MediaItem> mediaItems = snapshot.data!;
 
-            return Card(
+            return Card.outlined(
               color: atm.activity?.id == widget.activity.id
                   ? Theme.of(context).colorScheme.primaryContainer
                   : Theme.of(context).colorScheme.surfaceContainerLow,

lib/widgets/sessions/session_card_full.dart

@@ -52,7 +52,7 @@ class _SessionCardFullState extends State<SessionCardFull> {
     final MediaItem? sessionImage = mediaItems
         .firstWhereOrNull((mediaItem) => mediaItem.type == MediaType.location);
 
-    return Card(
+    return Card.outlined(
       color: (session.status == SessionStatus.started)
           ? Theme.of(context).colorScheme.primaryContainer
           : Theme.of(context).colorScheme.surfaceContainerLow,

lib/widgets/sessions/session_view_activities.dart

@@ -23,6 +23,7 @@ class _SessionViewActivitiesState extends State<SessionViewActivities> {
         builder: (context, snapshot) {
           if (snapshot.hasData) {
             final activities = snapshot.data!;
+            if (activities.isNotEmpty) {
               return Expanded(
                   child: ListView.builder(
                 // shrinkWrap: true,
@@ -32,6 +33,22 @@ class _SessionViewActivitiesState extends State<SessionViewActivities> {
                   return ActivityCard(activity: activities[index]);
                 },
               ));
+            } else {
+              return Expanded(
+                  child: ListView(
+                      padding: const EdgeInsets.fromLTRB(10, 0, 10, 0),
+                      children: [
+                    Card.outlined(
+                        child: ListTile(
+                      onTap: () {},
+                      autofocus: true,
+                      leading: Icon(Icons.add_box_rounded),
+                      title: Text('Add an Activity!'),
+                      subtitle: Text(
+                          'Here you can associate one or more activities that you can follow during your session.'),
+                    ))
+                  ]));
+            }
           } else {
             return GenericProgressIndicator();
           }