revamp new trip flow

frontend/lib/modules/new_trip_options_button.dart

@@ -0,0 +1,41 @@
+import 'package:anyway/pages/new_trip_preferences.dart';
+import 'package:anyway/structs/trip.dart';
+import 'package:auto_size_text/auto_size_text.dart';
+import 'package:flutter/material.dart';
+
+
+class NewTripOptionsButton extends StatefulWidget {
+  final Trip trip;
+
+  const NewTripOptionsButton({required this.trip});
+
+  @override
+  State<NewTripOptionsButton> createState() => _NewTripOptionsButtonState();
+}
+
+class _NewTripOptionsButtonState extends State<NewTripOptionsButton> {
+
+  @override
+  Widget build(BuildContext context) {
+    return ListenableBuilder(
+      listenable: widget.trip,
+      builder: (BuildContext context, Widget? child) {
+        if (widget.trip.landmarks.isEmpty){
+          return Container();
+        }
+        return FloatingActionButton.extended(
+          onPressed: () async {
+            Navigator.of(context).push(
+              MaterialPageRoute(
+                builder: (context) => NewTripPreferencesPage(trip: widget.trip)
+              )
+            );
+          },
+          icon: const Icon(Icons.add),
+          label: const AutoSizeText('Set preferences')
+        ); 
+      }
+    );
+  }
+}
+