Split code into three Dart files

This follows recommendations [1] from the flutter documentation.

[1]: https://docs.flutter.dev/app-architecture/concepts

1 files changed, 83 insertions, 0 deletions

diff --git a/lib/ui.dart b/lib/ui.dart
new file mode 100644
index 0000000..5397044
--- /dev/null
+++ b/lib/ui.dart
@@ -0,0 +1,83 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+
+import 'data.dart';
+
+class UI extends StatelessWidget {
+  const UI({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const MaterialApp(
+      home: ContactList(),
+    );
+  }
+}
+
+class ContactList extends StatefulWidget {
+  const ContactList({super.key});
+
+  @override
+  State<ContactList> createState() => _ContactListState();
+}
+
+class _ContactListState extends State<ContactList> {
+  late final List<Contact> contacts;
+  Timer? _timer;
+
+  @override
+  void initState() {
+    super.initState();
+
+    contacts = <Contact>[
+      Contact(address: "Living Room Window", isOpen: false),
+      Contact(address: "Front Door", isOpen: true),
+      Contact(address: "Back Door", isOpen: false),
+      Contact(address: "Garage Window", isOpen: true),
+    ];
+
+    _timer = Timer.periodic(const Duration(seconds: 1), (_) {
+      setState(() {
+        contacts[0].isOpen = !contacts[0].isOpen;
+      });
+    });
+  }
+
+  @override
+  void dispose() {
+    _timer?.cancel();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text("Contacts")),
+      body: ListView.builder(
+        itemCount: contacts.length,
+        itemBuilder: (BuildContext context, int index) {
+          final Contact contact = contacts[index];
+          return ContactTile(contact: contact);
+        },
+      ),
+    );
+  }
+}
+
+class ContactTile extends StatelessWidget {
+  final Contact contact;
+
+  const ContactTile({super.key, required this.contact});
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      leading: Icon(
+        contact.isOpen ? Icons.meeting_room : Icons.door_front_door,
+        color: contact.isOpen ? Colors.red : Colors.green,
+      ),
+      title: Text(contact.address),
+    );
+  }
+}