Initial commit

lib/app.dart

@@ -0,0 +1,78 @@
+import 'package:flutter/material.dart';
+
+import 'backend.dart';
+import 'screens/home.dart';
+import 'widgets/player_bar.dart';
+
+class App extends StatefulWidget {
+  @override
+  _AppState createState() => _AppState();
+}
+
+class _AppState extends State<App> with SingleTickerProviderStateMixin {
+  final nestedNavigator = GlobalKey<NavigatorState>();
+
+  AnimationController playerBarAnimation;
+  Backend backend;
+
+  @override
+  void initState() {
+    super.initState();
+
+    playerBarAnimation = AnimationController(
+      vsync: this,
+      duration: Duration(milliseconds: 300),
+    );
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+
+    backend = Backend.of(context);
+    backend.playerActive.listen((active) =>
+        active ? playerBarAnimation.forward() : playerBarAnimation.reverse());
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Musicus',
+      theme: ThemeData(
+        brightness: Brightness.dark,
+        accentColor: Colors.amber,
+        textSelectionColor: Colors.grey[600],
+        cursorColor: Colors.amber,
+        textSelectionHandleColor: Colors.amber,
+        toggleableActiveColor: Colors.amber,
+        fontFamily: 'Libertinus Sans',
+      ),
+      // The nested Navigator is for every screen from which the player bar at
+      // the bottom should be accessible. The WillPopScope widget intercepts
+      // taps on the system back button and redirects them to the nested
+      // navigator.
+      home: WillPopScope(
+        onWillPop: () async => !(await nestedNavigator.currentState.maybePop()),
+        child: Scaffold(
+          body: Navigator(
+            key: nestedNavigator,
+            onGenerateRoute: (settings) => settings.name == '/'
+                ? MaterialPageRoute(
+                    builder: (context) => HomeScreen(),
+                  )
+                : null,
+            initialRoute: '/',
+          ),
+          bottomNavigationBar: SizeTransition(
+            sizeFactor: CurvedAnimation(
+              curve: Curves.easeOut,
+              parent: playerBarAnimation,
+            ),
+            axisAlignment: -1.0,
+            child: PlayerBar(),
+          ),
+        ),
+      ),
+    );
+  }
+}