Initial commit

lib/providers/playback_active_provider.dart

@@ -0,0 +1,35 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_riverpod/legacy.dart';
+
+
+final playbackActiveProvider = StateProvider<bool>((ref) => false);
+
+
+class DetailPageActivity extends Notifier<int> {
+  var _disposed = false;
+
+  @override
+  int build() {
+    ref.onDispose(() => _disposed = true);
+    return 0;
+  }
+
+  void enter() {
+    if (_disposed) return;
+    state = state + 1;
+  }
+
+  void leave() {
+    if (_disposed || state <= 0) return;
+    state = state - 1;
+  }
+}
+
+final detailPageActivityProvider = NotifierProvider<DetailPageActivity, int>(
+  DetailPageActivity.new,
+);
+
+
+final detailPageActiveProvider = Provider<bool>(
+  (ref) => ref.watch(detailPageActivityProvider) > 0,
+);