cover art color scheme extraction (in background)

refactor text styles to use theme
port over part of album screen

lib/app/ui/cover_art_theme.dart

@@ -0,0 +1,56 @@
+import 'package:cached_network_image/cached_network_image.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_hooks/flutter_hooks.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+
+import '../state/source.dart';
+import '../util/color_scheme.dart';
+import 'theme.dart';
+
+class CoverArtTheme extends HookConsumerWidget {
+  const CoverArtTheme({
+    super.key,
+    required this.coverArt,
+    required this.child,
+  });
+
+  final String? coverArt;
+  final Widget child;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final source = ref.watch(sourceProvider);
+    final sourceId = ref.watch(sourceIdProvider);
+
+    final getColorScheme = useMemoized(
+      () async {
+        try {
+          return await colorSchemefromImageProvider(
+            brightness: Brightness.dark,
+            provider: CachedNetworkImageProvider(
+              coverArt != null
+                  ? source.coverArtUri(coverArt!, thumbnail: true).toString()
+                  : 'https://placehold.net/400x400.png',
+              cacheKey: coverArt != null
+                  ? '$sourceId$coverArt${true}'
+                  : 'https://placehold.net/400x400.png',
+            ),
+          );
+        } catch (err) {
+          print(err);
+          return null;
+        }
+      },
+      [source, sourceId, coverArt],
+    );
+
+    final colorScheme = useFuture(getColorScheme).data;
+
+    return colorScheme != null
+        ? Theme(
+            data: subtracksTheme(colorScheme),
+            child: child,
+          )
+        : child;
+  }
+}